A flexible one-component epoxy encapsulating adhesive

Abstract

The present invention belongs to the technical field of adhesives, and relates to a flexible one-component epoxy encapsulation adhesive, wherein the encapsulation adhesive comprises 20 to 50 parts of silicone-modified epoxy resin, 30 to 60 parts of polyurethane-modified epoxy resin, 5 to 10 parts of reactive diluent, 1 to 3 parts of silane coupling agent, 2 to 4 parts of curing agent, and 2 to 4 parts of accelerator according to weight parts; the silicone-modified epoxy resin is prepared by isocyanate ethyl acrylate, hydrogen-containing polydimethylsiloxane and bisphenol A epoxy resin. The present invention adds silicone / acrylate oligomers with repeated rotatable Si-O bonds as the main chain, so that the adhesive has very low adhesion on its surface after curing, and improves oil resistance; in addition, it also has good flexibility, low temperature resistance and excellent moisture resistance; it has excellent adhesion to PI materials, and has advantages in high temperature aging resistance and insulation performance, and is widely used in the bonding, potting and protection of new energy battery pack components.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a flexible single-component epoxy encapsulating adhesive. Background Art

[0002] In recent years, new energy vehicles have been welcomed by the public due to their characteristics of no exhaust emissions and low vehicle cost. The rapid growth of China's automobile market has led to a surge in the scale of automotive electronic products. The future development trend of automotive electronics is to use on-board computers as carriers to integrate communications, navigation, audio-visual entertainment, network control, etc. into an integrated multimedia information system. The use of functions such as automatic driving, active and passive safety systems has led to a continuous increase in the proportion of electrified equipment in new energy vehicles. In the next few years, China will become the country with the fastest growth rate in the global automotive electronics market, providing a broader development space for the automotive electronics market. The rapid development of the automotive electronics industry will quickly open up the market demand for downstream automotive accessories and components.

[0003] FPC stands for Flexible Printed Circuit, which is mainly used in dashboards, heat sinks, engines, door locks, wipers, CDs and monitors. Due to the rapid popularity of smart phones and tablets around the world, the growth rate will slow down, and wearable devices have not yet started to increase in volume. Therefore, the consumer electronics market has gradually matured, and the automotive market is expected to become the next growth area due to the increasing intelligence and electronicization of automobiles.

[0004] At present, there has been a lack of breakthroughs in the field of automotive power battery weight control, and more accurate information collection is required inside automotive power batteries. Flexible FPC can reduce the weight of battery packs and reduce assembly processes. The working environment of flexible electronic circuits is narrow, tortuous, and even folded in space, which puts higher requirements on the connection between FPC and other connectors; and the working environment of automobiles has higher safety requirements than ordinary electronic products, and the circuit operation of general automobiles has the characteristics of large current, which requires the reliability of printed circuit boards (PCBs) to be higher and more environmentally adaptable. This requires the current and future encapsulation glue to have good flexibility, high cohesion, and resistance to bending; at the same time, it puts higher requirements on its high and low temperature resistance and long-term resistance to temperature and humidity aging, salt spray and other environmental resistance requirements; in addition, the electrical performance requirements of the encapsulation glue are also becoming increasingly stringent.

[0005] The encapsulation and protection of the connection between the vehicle-mounted FPC cable and the connector, the solutions currently used in the market are mainly UV-curing adhesive and one-component epoxy adhesive. UV-curing adhesives have some remarkable characteristics such as good compatibility, fast curing speed, high strength, and environmental protection, so they are widely used in the fields of optics, electronic appliances, digital optical disks, etc. However, most of the UV-curing adhesives on the market are based on polyurethane-modified acrylates, which have great limitations in heat resistance, water resistance, and environmental resistance, which greatly limits the application of UV-curing adhesives in the field of new energy vehicles. Epoxy curing adhesives often have defects such as large internal stress, poor toughness, and poor impact resistance, and toughening agents need to be added. Therefore, it is necessary to further improve the encapsulation adhesive used for vehicle-mounted FPC cables to improve its flexibility, bending resistance and other properties. Summary of the invention

[0006] The present invention aims at solving the above-mentioned deficiencies in the prior art and provides a flexible one-component epoxy encapsulating adhesive.

[0007] The specific technical solutions of the present invention are as follows:

[0008] A flexible one-component epoxy encapsulating adhesive, comprising the following components in parts by weight:

[0009] 20-50 parts of silicone modified epoxy resin, 30-60 parts of polyurethane modified epoxy resin, 5-10 parts of reactive diluent, 1-3 parts of silane coupling agent, 2-4 parts of curing agent, 2-4 parts of accelerator;

[0010] The organosilicon-modified epoxy resin is prepared from ethyl isocyanate acrylate, hydrogen-containing polydimethylsiloxane and bisphenol A epoxy resin.

[0011] The organosilicon-modified epoxy resin of the present invention has a relatively high content of isocyanate groups and acrylates on the side chains of the repeating units, and can form a colloidal structure with a higher cross-linking density, retain a relatively high cohesive force and adhesive force, reduce the internal stress of the epoxy, and increase the toughness and high temperature resistance of the resin, so that the colloid has the advantages of good thermal stability, low surface energy, low temperature flexibility, weather resistance, hydrophobicity, flame retardancy, oxidation resistance, high dielectric strength, etc., and can be effectively used in the bonding, sealing, and protection of new energy battery components, giving full play to the great role of epoxy adhesive.

[0012] Furthermore, the preparation method of the organosilicon-modified epoxy resin comprises the following steps:

[0013] (1) synthesizing prepolymer A from isocyanate ethyl acrylate and hydrogen-containing polydimethylsiloxane under the action of platinum;

[0014] (2) Prepolymer A and bisphenol A epoxy resin are reacted with a catalyst and a stabilizer, triphenyl phosphate, to synthesize the organosilicon-modified epoxy resin.

[0015] Furthermore, the reaction formula of step (1) is as follows:

[0016]

[0017] Wherein, the molecular weight of hydrogen-containing polydimethylsiloxane is 2000-20000; the degree of polymerization n=1-5; m=5-20;

[0018] Ethyl isocyanate acrylate and hydrogen-containing polydimethylsiloxane are added to a reaction kettle in a molar ratio of 2:1, and toluene solvent is added. The mixture is stirred at a speed of 500-800 r / min for 30 min, and the temperature is slowly raised to 65-80° C., and chloroplatinic acid isopropanol solution is added. Under the protection of N2, the mixture is stirred at a speed of 500-800 r / min for 3-5 h, and the infrared spectrum is tested every half an hour. When the C=C double bond completely disappears, the stirring is stopped to obtain prepolymer A.

[0019] The added amounts of the toluene solvent and the chloroplatinic acid isopropanol solution are 50-100% and 0.008-0.015‰ of the total mass of the isocyanate ethyl acrylate and the hydrogen-containing polydimethylsiloxane respectively; the mass fraction of chloroplatinic acid in the chloroplatinic acid isopropanol solution is 2%.

[0020] Furthermore, the reaction formula of step (2) is as follows:

[0021]

[0022] Wherein, the degree of polymerization n=1-5; m=5-20; p=1-1.8;

[0023] On the basis of step (1), triphenyl phosphate as a stabilizer, a catalyst, and bisphenol A epoxy resin are added in sequence, the temperature is raised to 90° C., and the reaction is carried out at a rotation speed of 500 to 800 r / min for 2 to 4 hours; sampling is performed every 30 minutes to determine the NCO value until the measured value is zero, and the material is discharged for standby use to obtain an organosilicon-modified epoxy resin;

[0024] The added amounts of the stabilizer and catalyst are 0.02-0.1‰ and 0.5-1‰ of the total mass of ethyl isocyanate acrylate and hydrogen-containing polydimethylsiloxane respectively; the molar ratio of the bisphenol A epoxy resin to the prepolymer A is 2:1.

[0025] Furthermore, the catalyst is a compound of one or more of toluenesulfonic acid, zinc acetate, antimony trioxide, titanate and organotin, preferably antimony oxalate and phosphoric acid.

[0026] Furthermore, the polyurethane modified epoxy resin is Lepmod special PU modified epoxy resin EPU-133 series, including one or two of EPU-300A, EPU-105, EPU-253, EPU-301, and EPU-302.

[0027] Furthermore, the active diluent is one or two of propylene oxide o-cresyl ether, o-cresyl glycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, ethylene glycol diglycidyl ether and butanediol diglycidyl ether.

[0028] Furthermore, the silane coupling agent is one or two of γ-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH560), γ-(methacryloyloxy)propyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane (Z-6020).

[0029] Furthermore, the curing agent is a compound of a latent curing agent dicyandiamide produced by Changzhou Calla Lily Resin Company and a high temperature resistant modified amine accelerator Fujicure 1141 produced by Fuji Chemical Industry Co., Ltd. of Japan.

[0030] Furthermore, the mass ratio of the latent curing agent dicyandiamide to the high temperature resistant modified amine accelerator Fuji Chemical Industry Co., Ltd. Fuji 1141 is 8:1-5.

[0031] Furthermore, the thixotropic agent is fumed silica, and one or two or more of TS-720, EH-5 of Cabot Corporation, R202 of Evonik Corporation, and A200 of Evonik Corporation are selected.

[0032] Furthermore, the preparation method of the flexible one-component epoxy encapsulating adhesive is as follows: organic silicon modified epoxy resin, polyurethane modified epoxy resin, active diluent, and silane coupling agent are added to a double planetary power mixing kettle in sequence, the temperature is controlled at 25 to 35°C, evacuated to a vacuum degree of -0.08 to -0.05MPa, and stirred at 500-1000 rpm for 0.5 to 2 hours; then a curing agent and an accelerator are added in sequence, the temperature is controlled at 25 to 35°C, evacuated to a vacuum degree of -0.08 to -0.05MPa, stirred at 800-1200 rpm for 0.5 to 2 hours, and then a thixotropic agent is added, the temperature is controlled at 25 to 35°C, evacuated to a vacuum degree of -0.08 to -0.05MPa, stirred at 800 to 1200 rpm for 20 to 40 minutes, until the mixture is evenly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0033] The beneficial effects of the present invention are:

[0034] The flexible one-component epoxy encapsulating adhesive of the present invention has excellent adhesion to PI materials, and has good moisture and heat resistance and insulation properties. It has more advantages than UV-curing adhesives and conventional tough epoxy adhesives, and is widely used in the bonding, potting and protection of new energy battery pack components.

[0035] The flexible one-component epoxy encapsulating adhesive of the present invention adds a silicone / acrylate oligomer with a repetitive rotatable Si-O bond as the main chain, so that the adhesive has a very low adhesion on the surface after curing, thereby being resistant to oil pollution. In addition, the flexible one-component epoxy encapsulating adhesive of the present invention has good flexibility, low temperature resistance, and moisture resistance. The raw material hydrogenated silicone oil is low in cost and easy to obtain, and the acrylate is introduced into the end by two end-cappings. The preparation method is simple to operate and has a high conversion rate. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0037] Preparation of silicone modified epoxy resin:

[0038] Add 1000 g of ethyl isocyanate acrylate and hydrogenated polydimethylsiloxane in a molar ratio of 2:1 to a reactor, add 1000 g of toluene solvent, and stir for 30 min to completely dissolve ethyl isocyanate acrylate and hydrogenated polydimethylsiloxane; then, slowly heat to 80°C, add 0.15 g of chloroplatinic acid isopropanol solution, and stir for 4 h under N2 protection, wherein the mass fraction of chloroplatinic acid in the chloroplatinic acid isopropanol solution is 2%; The infrared spectrum was tested for half an hour, and the reaction was stopped when the C=C double bond disappeared completely to obtain prepolymer A; then 0.1g of stabilizer triphenyl phosphate, 0.5g of catalyst antimony oxalate, 0.5g of catalyst phosphoric acid and 300g of bisphenol A epoxy resin 128 were added in sequence, fully stirred under vacuum conditions at 90°C, and the reaction was continued for 3 hours; then, samples were taken every half an hour to determine the NCO value until the measured value was zero, and the material was discharged for use to obtain silicone-modified epoxy resin. The conversion rate of this reaction was 93%.

[0039] The prepared organosilicon-modified epoxy resin is used in the following examples or comparative examples, and multiple batches are prepared as needed.

[0040] Embodiment 1:

[0041] Preparation of a flexible one-component epoxy encapsulation adhesive:

[0042] According to the weight parts, 30 parts of organosilicon-modified epoxy resin, 40 parts of polyurethane-modified epoxy resin, 8 parts of reactive diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is uniformly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0043] The polyurethane modified epoxy resin is EPU-300A in the Lepmod special PU modified epoxy resin EPU-133 series; the active diluent is o-cresyl glycidyl ether; the coupling agent is γ-aminopropyltriethoxysilane (KH550); the curing agent is a compound of 3.2 parts of the latent curing agent dicyandiamide produced by Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 of Cabot Corporation.

[0044] Embodiment 2:

[0045] Preparation of a flexible one-component epoxy encapsulation adhesive:

[0046] According to the weight parts, 35 parts of organosilicon-modified epoxy resin, 40 parts of polyurethane-modified epoxy resin, 8 parts of reactive diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is evenly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0047] The polyurethane modified epoxy resin is EPU-105 in the Lepmod special PU modified epoxy resin EPU-133 series; the active diluent is hexanediol diglycidyl ether; the coupling agent is γ-aminopropyltriethoxysilane (KH550); the curing agent is a compound of 3.2 parts of the latent curing agent dicyandiamide produced by Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 of Cabot Corporation.

[0048] Embodiment 3:

[0049] Preparation of a flexible one-component epoxy encapsulation adhesive:

[0050] According to the weight parts, 40 parts of organosilicon-modified epoxy resin, 40 parts of polyurethane-modified epoxy resin, 8 parts of reactive diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is evenly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0051] The polyurethane modified epoxy resin is Lepmod special PU modified epoxy resin EPU-133 series, including EPU-300A; the active diluent is o-cresyl glycidyl ether; the coupling agent is N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane (KH550); the curing agent is a compound of 3.2 parts of latent curing agent dicyandiamide from Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 from Cabot Corporation.

[0052] Embodiment 4:

[0053] Preparation of a flexible one-component epoxy encapsulation adhesive:

[0054] According to the weight parts, 45 parts of organosilicon-modified epoxy resin, 40 parts of polyurethane-modified epoxy resin, 8 parts of reactive diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is uniformly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0055] The polyurethane modified epoxy resin is EPU-105 in the Lepmod special PU modified epoxy resin EPU-133 series; the active diluent is hexanediol diglycidyl ether; the coupling agent is γ-aminopropyltriethoxysilane (KH550); the curing agent is a compound of 3.2 parts of the latent curing agent dicyandiamide produced by Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 of Cabot Corporation.

[0056] Embodiment 5:

[0057] Preparation of a flexible one-component epoxy encapsulation adhesive:

[0058] According to the weight parts, 50 parts of organosilicon-modified epoxy resin, 40 parts of polyurethane-modified epoxy resin, 8 parts of reactive diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is uniformly stirred, and the flexible one-component epoxy encapsulating adhesive is obtained by sealing and packaging.

[0059] The polyurethane modified epoxy resin is EPU-105 in the Lepmod special PU modified epoxy resin EPU-133 series; the active diluent is o-cresyl glycidyl ether; the coupling agent is N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; the curing agent is a compound of 3.2 parts of the latent curing agent dicyandiamide produced by Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 of Cabot Corporation.

[0060] Comparative Example 1:

[0061] Preparation of a one-component epoxy encapsulation adhesive:

[0062] According to the weight parts, 42 parts of bisphenol A epoxy resin, 40 parts of polyurethane modified epoxy resin, 8 parts of active diluent and 2 parts of silane coupling agent are added to the double planetary power mixing kettle in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, and stirred at 800 rpm for 1 hour; then 4 parts of curing agent and 3 parts of accelerator are added in sequence, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 1 hour, 1 part of thixotropic agent is added, the temperature is controlled at 25-35°C, evacuated to a vacuum degree of -0.08-0.05MPa, stirred at 1000 rpm for 0.5 hour, until the mixture is uniformly stirred, and sealed and packaged to obtain the single-component epoxy encapsulating adhesive.

[0063] The bisphenol A epoxy resin is Miki 128, the polyurethane modified epoxy resin is EPU-300A in the Lepmod special PU modified epoxy resin EPU-133 series; the active diluent is o-cresyl glycidyl ether; the coupling agent is N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; the curing agent is a compound of 3.2 parts of the latent curing agent dicyandiamide produced by Changzhou Calla Resin Company and 0.8 parts of Fuji Chemical Industry Co., Ltd. Fuji 1141 high temperature resistant modified amine accelerator; the thixotropic agent is TS-720 of Cabot Corporation.

[0064] The beneficial effects of the present invention are further illustrated below in conjunction with experimental data:

[0065] Experimental testing:

[0066] Tensile shear strength: According to GB / T 7124-2008 standard, the tensile shear strength of PI is tested, and the curing condition is 120℃ / 30min;

[0067] Elastic modulus test instrument: DMA;

[0068] Glass transition temperature: DSC;

[0069] Salt spray test: refer to GB / T 2423.17-2008;

[0070] Drop 0.02 ml of glue on the FPC soft board, cure it at 120℃ / 30min, put it into the salt spray cabinet, age it for 100h, take it out and restore it to room temperature, then bend it 90° to check the interface cracking.

[0071] Low temperature resistance test: drop 0.02ml of glue on the FPC soft board, solidify it at 120℃ / 30min, put it in the freezing condition of -40℃ for 16h, age it for 500h, take it out and restore it to room temperature, then bend it 90° to check the interface cracking;

[0072] Double 85 cracking test after aging: drop 0.02ml glue on the FPC soft board, cure it at 120℃ / 30min, put it in 85℃, 85% humidity, age it for 1000h, take it out and restore it to room temperature, then bend it 90° to check the interface cracking;

[0073] Electrically immersed test: The cured sample is immersed in water at a temperature of 25°C for 1000 hours. During the test, a constant voltage of 5V is continuously applied to each NTC in the FPC sample through the connector; the duration is 1000 hours. After the sample is taken out and restored to room temperature, the appearance of the glue and the change rate of the insulation withstand voltage performance of the NTC are inspected.

[0074] The test results are shown in the following table:

[0075]

[0076] Results and Analysis:

[0077] It can be seen from the data in the above table that compared with comparative example 1, the epoxy encapsulation adhesive of the present invention has excellent adhesion to PI in Examples 1 to 5 of the present invention, which is incomparable to ultraviolet light and ordinary epoxy adhesives. Compared with comparative example 1, Examples 1 to 5 have excellent salt spray resistance, low temperature resistance, and moisture and heat resistance, and the cracking after aging has also been greatly improved. Its electrical properties also have outstanding performance. In summary, Example 4 has better comprehensive performance. While retaining a higher Tg, the modulus and shear force have greater advantages. The present invention can be widely used in the bonding, sealing, and protection of new energy battery components.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible one-component epoxy encapsulating adhesive, characterized in that: According to weight parts, it includes the following components: 20-50 parts of silicone modified epoxy resin, 30-60 parts of polyurethane modified epoxy resin, 5-10 parts of reactive diluent, 1-3 parts of silane coupling agent, 2-4 parts of curing agent, 2-4 parts of accelerator; The organosilicon-modified epoxy resin is prepared from ethyl isocyanate acrylate, hydrogen-containing polydimethylsiloxane and bisphenol A epoxy resin.

2. The flexible one-component epoxy encapsulating adhesive according to claim 1, characterized in that: The preparation method of the organosilicon-modified epoxy resin comprises the following steps: (1) Ethyl isocyanate acrylate and hydrogen-containing polydimethylsiloxane are used to synthesize prepolymer A under the action of platinum; (2) Prepolymer A and bisphenol A epoxy resin are reacted with a catalyst and a stabilizer, triphenyl phosphate, to synthesize the organosilicon-modified epoxy resin.

3. The flexible one-component epoxy encapsulating adhesive according to claim 2, characterized in that: The molar ratio of the isocyanate ethyl acrylate to the hydrogen-containing polydimethylsiloxane is 2:1; the molar ratio of the bisphenol A epoxy resin to the prepolymer A is 2:

1.

4. The flexible one-component epoxy encapsulating adhesive according to claim 3, characterized in that: The amounts of the stabilizer and the catalyst added are 0.02-0.1‰ and 0.5-1‰ of the total mass of ethyl isocyanate acrylate and hydrogen-containing polydimethylsiloxane, respectively.

5. The flexible one-component epoxy encapsulating adhesive according to claim 4, characterized in that: The catalyst is one or a combination of toluenesulfonic acid, zinc acetate, antimony trioxide, titanate and organic tin.

6. The flexible one-component epoxy encapsulating adhesive according to claim 1, characterized in that: The active diluent is one or two of propylene oxide o-cresyl ether, o-cresyl glycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, ethylene glycol diglycidyl ether and butanediol diglycidyl ether.

7. The flexible one-component epoxy encapsulating adhesive according to claim 1, characterized in that: The silane coupling agent is one or two of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane.

8. The flexible one-component epoxy encapsulating adhesive according to claim 1, characterized in that: The curing agent is a latent curing agent dicyandiamide and a Fujicure 1141 high temperature resistant modified amine accelerator compounded in a mass ratio of 8:1-5.

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