Cationic epoxy adhesive for electronic three-proofing and preparation method thereof

Abstract

The invention provides a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof, and belongs to the technical field of adhesives. According to the invention, alicyclic epoxy resin is fluorinated and modified with silane, so that moisture resistance, corrosion resistance and mechanical properties are enhanced; 3-mercaptopropyltrimethoxysilane is grafted to polydimethylsiloxane through ultraviolet, so that the compatibility of the polydimethylsiloxane is improved, and the toughness of the polydimethylsiloxane is improved; hyperbranched polyester reacts with trimethyl phosphate to endow the material with flame retardance and metal adhesion; the microencapsulated slow-release curing agent solves the problem of insufficient ultraviolet curing deep layer, and realizes uniform curing of the surface layer and the deep layer; according to the invention, ultraviolet and natural curing are combined, rapid shaping and deep curing are considered, the processing efficiency, mechanical properties and chemical stability of the material are obviously optimized, and various requirements of electronic three-proofing and high-performance materials are met.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives and relates to a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. Background Art

[0002] In the manufacture and application of modern electronic equipment, protection against mildew, moisture, and salt spray is crucial, especially when the equipment is exposed to long-term harsh environments. These measures are directly related to the reliability and service life of the equipment. With the continuous advancement of technology, the application scenarios of electronic equipment are becoming increasingly diverse, with applications such as outdoor equipment, industrial automation, and military equipment placing higher demands on their protective performance. Therefore, selecting the right adhesive for the packaging and protection of electronic components has become a key issue.

[0003] Traditional epoxy adhesives, due to their excellent bond strength, heat resistance, and good mechanical properties, are widely used in the packaging and protection of electronic components, becoming the mainstream material in this field. However, despite their excellent performance in many aspects, epoxy adhesives still have some significant shortcomings in electronic three-proof applications. First, the performance of many epoxy resins tends to deteriorate significantly in high humidity environments, resulting in weakened bond strength and even failure. This phenomenon is particularly pronounced in humid or rainy environments, which can cause electronic component failure and thus affect the normal operation of the entire equipment.

[0004] Secondly, the chemical resistance of traditional epoxy adhesives is insufficient, making them ineffective against a wide range of chemical media. In certain industrial environments or outdoor applications, electronic devices may be exposed to various chemicals, such as corrosive gases, oils, and other chemical solvents. The intrusion of these chemicals can damage epoxy adhesives, affecting their bonding performance and durability. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. In the present invention, the alicyclic epoxy resin is modified with perfluorobutanol and KH-560, and hydrophobic fluorocarbon chains and silicon-oxygen-silicon bonds are introduced to form an organic-inorganic hybrid structure, which enhances moisture resistance, corrosion resistance, thermal stability and mechanical properties; 3-mercaptopropyltrimethoxysilane is grafted onto polydimethylsiloxane through an ultraviolet light-initiated reaction, which improves the compatibility with the epoxy resin, and enhances the toughness and impact resistance through the flexible chain segment. The functionalized polymer prepared by the ester exchange reaction of hyperbranched polyester and trimethyl phosphate gives the material excellent flame retardancy, chemical stability and metal adhesion; in addition, the slow-release BF3-MEA curing agent is prepared by microencapsulation technology, which solves the problem of insufficient deep layer of ultraviolet curing and realizes comprehensive curing of the surface and deep layers. The present invention combines UV curing and natural curing strategies, taking into account both rapid shaping and deep curing, significantly optimizing the processing efficiency, mechanical properties and chemical stability of the material, and meeting the various needs of electronic three-proof and high-performance materials.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a cationic epoxy adhesive for electronic three-proofing, the method for preparing the cationic epoxy adhesive for electronic three-proofing comprising:

[0008] S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol, reacting to obtain reaction solution B; adding KH-560 to an ethanol / water mixture for pre-hydrolysis to obtain a silicon grafting solution, adding the solution to reaction solution B, adjusting the pH, reacting, and treating to obtain a fluorine-silicon modified epoxy resin;

[0009] S2: vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane are mixed, and the mixture is irradiated with ultraviolet light to obtain a reaction mixture, which is mixed with n-hexane and treated to obtain modified polydimethylsiloxane; the mixture is mixed with bisphenol F epoxy resin, reacted, and treated to obtain a crude product; the crude product is dispersed in benzyl alcohol, and rotary evaporated to obtain a toughened prepolymer;

[0010] S3: mixing a hyperbranched polyester with trimethyl phosphate, reacting under nitrogen protection to obtain a first reaction solution, adjusting the pH, hydrolyzing and acidifying to obtain a third reaction solution, cooling the reaction solution, pouring it into an ethanol / water mixed solution for precipitation, and treating it to obtain a phosphate polymer;

[0011] S4: adding gelatin, gum arabic, and nano-silica to deionized water to obtain a primary wall material solution, and adjusting the pH to obtain a wall material solution; mixing the BF3-MEA complex with an ethanol / glycerol mixed solution, and adjusting the pH to obtain a core material solution; mixing the core material solution with the wall material solution to obtain a reaction solution G, emulsifying and complexing, and adding isophorone diisocyanate and ethylenediamine to obtain a reaction solution H, reacting, and treating to obtain microencapsulated BF3-MEA;

[0012] S5: After premixing fluorosilicone-modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430, a primary product was obtained. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing.

[0013] Specifically, S1: mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol, adding tetrabutylammonium bromide to obtain reaction solution A, heating and stirring under nitrogen protection to obtain reaction solution B; adding KH-560 to an ethanol / water mixture to pre-hydrolyze to obtain a silicon grafting solution, adding the pre-hydrolyzed solution to the reaction solution B to obtain a mixed solution, adjusting the pH thereof to obtain reaction solution C, continuing the reaction at a constant temperature, filtering, washing, and vacuum drying to obtain a fluorosilicone-modified epoxy resin;

[0014] S2: vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane are mixed, and a photoinitiator Irgacure 651 is added to obtain a reaction solution D. The reaction mixture is irradiated with ultraviolet light to obtain a reaction solution D, which is mixed with n-hexane and filtered to obtain a primary product. The primary product is washed, rotary evaporated, and dried to obtain a modified polydimethylsiloxane. The primary product is mixed with bisphenol F epoxy resin EPON 862 in toluene, and tetraphenylphosphine bromide is added to obtain a reaction solution E. The reaction is carried out at a constant temperature, and the crude product is acid-washed and rotary evaporated to obtain a crude product. The crude product is dispersed in benzyl alcohol and rotary evaporated to obtain a toughened prepolymer.

[0015] S3: Mixing a hyperbranched polyester Boltorn H30 with trimethyl phosphate, adding potassium carbonate to obtain a reaction solution F, reacting under nitrogen to obtain a first reaction solution, adjusting the pH with hydrochloric acid to obtain a second reaction solution, hydrolyzing and acidifying to obtain a third reaction solution, cooling the third reaction solution, pouring the third reaction solution into an ethanol / water mixed solution for precipitation and purification, and drying to obtain a phosphate polymer;

[0016] S4: gelatin and gum arabic are mixed and added to deionized water, nano-silica is added to obtain a primary wall material solution, and the pH is adjusted to obtain a wall material solution; a BF3-MEA complex is mixed with an ethanol / glycerol mixed solution, and the pH is adjusted to obtain a core material solution; the solution is added to the wall material solution to obtain a reaction solution G, emulsified to obtain an emulsion, cooled and coagulated, and then isophorone diisocyanate and ethylenediamine are added to obtain a reaction solution H, cross-linked, centrifuged, washed, and dried to obtain microencapsulated BF3-MEA;

[0017] S5: After premixing fluorosilicone-modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430, a primary product was obtained. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing.

[0018] As a preferred technical solution of the present invention, in step S1, the molar ratio of the alicyclic epoxy resin to perfluorobutanol is 1:0.25-0.35, for example, it can be 1:0.25, 1:0.26, 1:0.27, 1:0.28, 1:0.29, 1:0.30, 1:0.31, 1:0.32, 1:0.33, 1:0.34 or 1:0.35, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0019] In some optional embodiments, the feeding amount of the tetrabutylammonium bromide is 0.3-0.5% of the total mass of the alicyclic epoxy resin and perfluorobutanol, for example, it can be 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.40%, 0.42%, 0.44%, 0.46%, 0.48% or 0.50%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0020] In some optional embodiments, the reaction solution A is heated to 50-60°C and stirred for reaction, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0021] In some optional embodiments, the reaction liquid A is stirred for 2-3 hours, for example, it can be 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours or 3 hours, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0022] In some optional embodiments, the mass ratio of KH-560 to the ethanol / water mixture is 1:2-3, for example, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9 or 1:3, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0023] The volume ratio of ethanol to water in the ethanol / water mixture is 9:1;

[0024] In some optional embodiments, the temperature for pre-hydrolysis of KH-560 in an ethanol / water mixture is 50-60°C, for example, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but values ​​other than these and values ​​not referenced within this numerical range are also applicable.

[0025] In some optional embodiments, the KH-560 is added to the ethanol / water mixture for pre-hydrolysis for 60-70 min, for example, 60 min, 61 min, 62 min, 63 min, 64 min, 65 min, 66 min, 67 min, 68 min, 69 min or 70 min, but is not limited to such values, and values ​​not included in this numerical range are also applicable.

[0026] In some optional embodiments, the feeding amount of KH-560 is 10-15% of the total mass of the alicyclic epoxy resin and perfluorobutanol, for example, it can be 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5% or 15%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0027] In some optional embodiments, the pH of the mixed solution is adjusted to 5.5-6, for example, it can be 5.5, 5.55, 5.6, 5.65, 5.7, 5.75, 5.8, 5.85, 5.9, 5.95 or 6, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0028] In some optional embodiments, the temperature of the constant temperature reaction of the reaction liquid C is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0029] In some optional embodiments, the constant temperature reaction time of the reaction liquid C is 1-1.5h, for example, it can be 1h, 1.05h, 1.1h, 1.15h, 1.2h, 1.25h, 1.3h, 1.35h, 1.4h, 1.45h or 1.5h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0030] As a preferred technical solution of the present invention, in step S2, the molar ratio of the vinyl-terminated polydimethylsiloxane to 3-mercaptopropyltrimethoxysilane is 1:0.9-1.1, for example, it can be 1:0.9, 1:0.92, 1:0.94, 1:0.96, 1:0.98, 1:1, 1:1.02, 1:1.04, 1:1.06, 1:1.08 or 1:1.1, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0031] In some optional embodiments, the mass fraction of the photoinitiator in the reaction liquid D is 0.5-0.8wt.%, for example, it can be 0.5wt.%, 0.53wt.%, 0.56wt.%, 0.59wt.%, 0.62wt.%, 0.65wt.%, 0.68wt.%, 0.71wt.%, 0.74wt.%, 0.77wt.% or 0.8wt.%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0032] In some optional embodiments, the irradiation intensity of the ultraviolet irradiation of the reaction solution is 20-25 mW / cm 2 , for example, it can be 20mW / cm 2 , 20.5mW / cm 2 , 21mW / cm 2 , 21.5mW / cm 2 , 22mW / cm 2 , 22.5mW / cm 2 , 23mW / cm 2 , 23.5mW / cm 2 , 24mW / cm 2 , 24.5mW / cm 2 or 25mW / cm 2 , but are not limited to such numerical values, and numerical values ​​not mentioned in this numerical range are also applicable.

[0033] In some optional embodiments, the time of ultraviolet irradiation of the reaction liquid D is 3-5 minutes, for example, it can be 3 minutes, 3.2 minutes, 3.4 minutes, 3.6 minutes, 3.8 minutes, 4 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes or 5 minutes, but it is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0034] In some optional embodiments, the volume ratio of the reaction mixture to n-hexane is 1:3-5, for example, it can be 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8 or 1:5, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0035] In some optional embodiments, the mass ratio of the modified polydimethylsiloxane to the bisphenol F epoxy resin is 1:0.7-0.9, for example, it can be 1:0.7, 1:0.72, 1:0.74, 1:0.76, 1:0.78, 1:0.8, 1:0.82, 1:0.84, 1:0.86, 1:0.88 or 1:0.9, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0036] In some optional embodiments, the total mass fraction of the modified polydimethylsiloxane and bisphenol F epoxy resin in toluene is 15-20 wt.%, for example, it can be 15 wt.%, 15.5 wt.%, 16 wt.%, 16.5 wt.%, 17 wt.%, 17.5 wt.%, 18 wt.%, 18.5 wt.%, 19 wt.%, 19.5 wt.% or 20 wt.%, but is not limited to such values, and values ​​not mentioned in this numerical range are equally applicable.

[0037] In some optional embodiments, the feeding amount of the tetraphenylphosphine bromide is 0.05-0.1% of the total mass of the modified polydimethylsiloxane and the bisphenol F epoxy resin, for example, it can be 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095% or 0.1%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0038] In some optional embodiments, the temperature of the constant temperature reaction of the reaction liquid E is 120-125°C, for example, it can be 120°C, 120.5°C, 121°C, 121.5°C, 122°C, 122.5°C, 123°C, 123.5°C, 124°C, 124.5°C or 125°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0039] In some optional embodiments, the constant temperature reaction time of the reaction liquid E is 2-2.5h, for example, it can be 2h, 2.05h, 2.1h, 2.15h, 2.2h, 2.25h, 2.3h, 2.35h, 2.4h, 2.45h or 2.5h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0040] The acid washing uses hydrochloric acid with a concentration of 0.1M.

[0041] In some optional embodiments, the amount of benzyl alcohol added is 30-40% by mass of the crude product, for example, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0042] As a preferred technical solution of the present invention, in step S3, the molar ratio of the hyperbranched polyester to trimethyl phosphate is 1:1.1-1.3, for example, it can be 1:1.1, 1:1.2, 1:1.14, 1:1.16, 1:1.18, 1:1.2, 1:1.22, 1:1.24, 1:1.26, 1:1.28 or 1:1.3, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0043] In some optional embodiments, the feeding amount of potassium carbonate is 1.5-2.5% of the total mass of the hyperbranched polyester and trimethyl phosphate, for example, it can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0044] In some optional embodiments, the reaction temperature of the reaction liquid F under nitrogen protection is 120-130°C, for example, it can be 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0045] In some optional embodiments, the reaction time of the reaction liquid F under nitrogen protection is 7-8h, for example, it can be 7h, 7.1h, 7.2h, 7.3h, 7.4h, 7.5h, 7.6h, 7.7h, 7.8h, 7.9h or 8h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0046] In some optional embodiments, the concentration of the hydrochloric acid is 0.1-0.2M, for example, it can be 0.1M, 0.11M, 0.12M, 0.13M, 0.14M, 0.15M, 0.16M, 0.17M, 0.18M, ​​0.19M or 0.2M, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0047] In some optional embodiments, the pH of the first reaction solution is adjusted to 2.8-3 using hydrochloric acid, for example, it can be 2.8, 2.82, 2.84, 2.86, 2.88, 2.9, 2.92, 2.94, 2.96, 2.98 or 3, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0048] In some optional embodiments, the temperature for hydrolysis and acidification of the second reaction liquid is 60-65°C, for example, it can be 60°C, 60.5°C, 61°C, 61.5°C, 62°C, 62.5°C, 63°C, 63.5°C, 64°C, 64.5°C or 65°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0049] In some optional embodiments, the hydrolysis and acidification time of the second reaction liquid is 2-3h, for example, it can be 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0050] In some optional embodiments, the volume ratio of the third reaction liquid to the ethanol / water mixed solution is 1:5-6, for example, it can be 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, 1:5.5, 1:5.6, 1:5.7, 1:5.8, 1:5.9 or 1:6, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0051] The volume ratio of ethanol to water in the ethanol / water mixed solution is 7:3.

[0052] As a preferred technical solution of the present invention, in step S4, the mass ratio of gelatin to gum arabic is 1:1.

[0053] In some optional embodiments, the total mass fraction of the gelatin and gum arabic in deionized water is 5-10 wt.%, for example, it can be 5 wt.%, 5.5 wt.%, 6 wt.%, 6.5 wt.%, 7 wt.%, 7.5 wt.%, 8 wt.%, 8.5 wt.%, 9 wt.%, 9.5 wt.% or 10 wt.%, but is not limited to such values, and values ​​not mentioned in this numerical range are equally applicable.

[0054] In some optional embodiments, the mass fraction of the nano-silica in the primary wall material solution is 1-2wt.%, for example, it can be 1wt.%, 1.1wt.%, 1.2wt.%, 1.3wt.%, 1.4wt.%, 1.5wt.%, 1.6wt.%, 1.7wt.%, 1.8wt.%, 1.9wt.% or 2wt.%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0055] In some optional embodiments, the pH of the primary wall material solution is adjusted to 4.3-4.7, for example, it can be 4.3, 4.34, 4.38, 4.42, 4.46, 4.5, 4.54, 4.58, 4.62, 4.66 or 4.7, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0056] The volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:2;

[0057] In some optional embodiments, the mass ratio of the BF3-MEA complex to the ethanol / glycerol mixed solution is 1:2-2.5, for example, it can be 1:2, 1:2.05, 1:2.1, 1:2.15, 1:2.2, 1:2.25, 1:2.3, 1:2.35, 1:2.4, 1:2.45 or 1:2.5, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0058] In some optional embodiments, the pH of the BF3-MEA complex is adjusted to 2.8-3.2 after mixing with the ethanol / glycerol mixed solution, for example, it can be 2.8, 2.84, 2.88, 2.92, 2.96, 3.0, 3.04, 3.08, 3.12, 3.16 or 3.2, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0059] In some optional embodiments, the mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:1.8-2.2, for example, it can be 1:1.8, 1:1.84, 1:1.88, 1:1.92, 1:1.96, 1:2.0, 1:2.04, 1:2.08, 1:2.12, 1:2.16 or 1:2.2, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0060] In some optional embodiments, the emulsification temperature of the reaction liquid G is 45-50°C, for example, it can be 45°C, 45.5°C, 46°C, 46.5°C, 47°C, 47.5°C, 48°C, 48.5°C, 49°C, 49.5°C or 50°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0061] In some optional embodiments, the emulsification time of the reaction liquid G is 5-8 min, for example, it can be 5 min, 5.3 min, 5.6 min, 5.9 min, 6.2 min, 6.5 min, 6.8 min, 7.1 min, 7.4 min, 7.7 min or 8 min, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0062] In some optional embodiments, the emulsion is cooled to 8-12°C for complex coagulation, for example, it can be 8°C, 8.4°C, 8.8°C, 9.2°C, 9.6°C, 10°C, 10.4°C, 10.8°C, 11.2°C, 11.6°C or 12°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0063] In some optional embodiments, the emulsion re-coagulation time is 1.5-2h, for example, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0064] In some optional embodiments, the feeding amount of the isophorone diisocyanate is 4-6% of the mass of the BF3-MEA complex, for example, it can be 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.6%, 5.8% or 6%, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0065] In some optional embodiments, the molar ratio of ethylenediamine to isophorone diisocyanate is 1.1-1.2:1, for example, 1.1:1, 1.11:1, 1.12:1, 1.13:1, 1.14:1, 1.15:1, 1.16:1, 1.17:1, 1.18:1, 1.19:1 or 1.2:1, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0066] In some optional embodiments, the temperature of the cross-linking reaction of the reaction liquid H is 45-50°C, for example, it can be 45°C, 45.5°C, 46°C, 46.5°C, 47°C, 47.5°C, 48°C, 48.5°C, 49°C, 49.5°C or 50°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0067] In some optional embodiments, the cross-linking reaction time of the reaction liquid H is 3-4h, for example, it can be 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h or 4h, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0068] As a preferred technical solution of the present invention, in step S5, the premixing temperature of the fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether is 40-45°C, for example, it can be 40°C, 40.5°C, 41°C, 41.5°C, 42°C, 42.5°C, 43°C, 43.5°C, 44°C, 44.5°C or 45°C, but is not limited to such values, and values ​​not mentioned in this numerical range are also applicable.

[0069] The mass ratio of the fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA and leveling agent FC-4430 is (28-32): (18-22): (15-20): (6-8): (7-9): (3.5-4.5): (0.5-1): (3-4): (0.3-0.4).

[0070] In a second aspect, the present invention provides a cationic epoxy adhesive for electronic triple protection prepared by the above-mentioned preparation method.

[0071] The present invention selects a cycloaliphatic epoxy resin as the base resin primarily due to its excellent performance characteristics and structural advantages. Cycloaliphatic epoxy resins have a rigid cyclic backbone, which imparts a high glass transition temperature and excellent mechanical properties to the material. Their molecular structure also provides excellent chemical resistance, low hygroscopicity, and thermal stability. Furthermore, the epoxy groups on the cycloaliphatic epoxy resins are active sites for cationic polymerization reactions. During the curing process, cationic ring-opening polymerization can form a dense cross-linked network, significantly enhancing the material's strength and stability.

[0072] In order to further improve the functional performance of alicyclic epoxy resin, perfluorobutanol is introduced in the present invention to modify it. Perfluorobutanol molecules contain hydroxyl groups and highly hydrophobic fluorocarbon chains, and their hydroxyl groups can undergo ring-opening reactions with the epoxy groups of alicyclic epoxy resins. Under the catalysis of tetrabutylammonium bromide, the hydroxyl groups of perfluorobutanol attack the epoxy groups through nucleophilic attacks to generate ether bonds, while stably introducing the fluorocarbon chains into the resin molecular structure. The introduction of fluorine-containing groups reduces the surface energy of the modified resin, thereby enhancing the moisture-proof and corrosion-resistant properties of the material, meeting the requirements of electronic three-proof. In addition, by optimizing the reaction conditions, the excessive ring-opening reaction of the epoxy group is effectively avoided, ensuring that a sufficiently high cross-linking density and excellent mechanical properties can be formed in the subsequent curing process.

[0073] After fluorination, the present invention further introduces KH-560 to silane-modify the alicyclic epoxy resin to optimize its overall performance. KH-560 undergoes partial hydrolysis in an ethanol / water system, converting the trimethoxysilyl groups into silanols. The silanols then undergo a condensation reaction to form silicon-oxygen-silicon bonds. Simultaneously, the silanols undergo a ring-opening reaction with the alicyclic epoxy resin, forming silicon-oxygen-carbon bonds. This coupling reaction creates an organic-inorganic hybrid structure at the molecular level.

[0074] The introduction of silicon grafting significantly improves the performance of modified epoxy resins in many aspects: the silicon-oxygen-silicon bond has a high bond energy, and its introduction significantly improves the thermal stability of the modified resin, enabling it to adapt to long-term use in higher temperature environments; secondly, KH-560, as a silane coupling agent, has a molecular structure that combines inorganic silicon-oxygen bonds and organic epoxy groups, which can enhance the interfacial bonding between the modified resin and the substrate through chemical bonding; in addition, the siloxane chain segment has high flexibility, which can significantly alleviate the internal stress generated by the high cross-linking density during the curing process, thereby reducing interfacial cracks and warping, and improving the mechanical properties and durability of the material.

[0075] The present invention achieves efficient grafting of vinyl-terminated polydimethylsiloxane with 3-mercaptopropyltrimethoxysilane through a chemical reaction triggered by ultraviolet light. Specifically, under the action of an ultraviolet light initiator, the vinyl groups of the vinyl-terminated polydimethylsiloxane are excited by ultraviolet light to generate active free radicals. These free radicals can quickly trigger an addition reaction between the mercapto group and the vinyl group of 3-mercaptopropyltrimethoxysilane to form a carbon-sulfur bond, thereby achieving the grafting of 3-mercaptopropyltrimethoxysilane onto the polydimethylsiloxane chain and generating a polydimethylsiloxane-silane copolymer. Through this reaction, the polydimethylsiloxane segment not only introduces a flexible silicon-oxygen-silicon structure, but also introduces active siloxy groups through 3-mercaptopropyltrimethoxysilane, providing active sites for subsequent chemical bonding with the epoxy resin.

[0076] The introduction of flexible polydimethylsiloxane segments plays a key role in the toughness and impact resistance of the adhesive. The main chain of polydimethylsiloxane is composed of silicon-oxygen-silicon bonds, which makes polydimethylsiloxane exhibit high flexibility and low modulus. The flexible segments can effectively relieve the concentration of external stress in the material and absorb impact loads, thereby significantly improving the impact resistance and elongation at break of the adhesive. In addition, due to its high hydrophobicity, unmodified polydimethylsiloxane has significant interfacial incompatibility with epoxy resins with higher polarity, and is prone to phase separation during the curing process, resulting in a decrease in material performance. Therefore, chemical modification is used to introduce siloxy groups, allowing polydimethylsiloxane to react chemically with epoxy resins to solve the compatibility problem.

[0077] Under the catalysis of tetraphenylphosphine bromide, the modified polydimethylsiloxane can react with the epoxy groups of bisphenol F epoxy resin through its siloxy groups. Under the action of the catalyst, the epoxy groups undergo a ring-opening reaction, forming silicon-oxygen-carbon bonds with the siloxy groups, thereby achieving chemical bonding between the two molecules. This chemical bonding embeds the flexible polydimethylsiloxane segments into the cross-linked network of the epoxy resin at the molecular level, forming a covalently linked organic-inorganic hybrid structure. The low viscosity of bisphenol F epoxy resin facilitates the uniform dispersion of the modified polydimethylsiloxane, avoiding localized unevenness during mixing. Its high crosslinking density, combined with the flexible polydimethylsiloxane segments, can form a uniform and dense network structure within the material, which not only improves the material's strength and heat resistance, but also effectively alleviates the internal stress caused by the high crosslinking density through the dispersion of the flexible segments.

[0078] The present invention successfully prepared a functionalized polymer containing a high density of phosphate bonds and phosphonic acid groups by designing an ester exchange reaction between a hyperbranched polyester and trimethyl phosphate. Under the catalytic action of potassium carbonate, the hydroxyl groups in the hyperbranched polyester and the ester groups in the trimethyl phosphate undergo an ester exchange reaction to form phosphate bonds. This process ensures that the phosphate groups are evenly distributed throughout the molecular structure of the hyperbranched polyester while retaining the multi-branched structure of the hyperbranched molecule. Subsequently, through acidic hydrolysis treatment, some of the phosphate bonds are hydrolyzed, releasing the phosphonic acid groups, further endowing the material with specific functional properties.

[0079] The introduction of a hyperbranched structure is a key design feature of the present invention. Hyperbranched polyesters possess a highly branched three-dimensional structure, with a large number of reactive groups distributed within and on the surface of the molecule, enabling them to provide an extremely high functional group density. This high density of phosphate bonds imparts excellent flame retardancy to the material. Furthermore, the phosphate bonds and phosphonic acid groups possess excellent chemical stability, significantly enhancing the material's corrosion resistance, particularly in high humidity or corrosive environments, where the material exhibits excellent durability.

[0080] Furthermore, the introduction of phosphonic acid groups further enhances the material's adhesion to metal surfaces. Phosphonic acid groups have a strong ability to form chemical bonds with metal surfaces, creating a stable interfacial bond through chemical adsorption or coordination with the metal oxide layer. This bond not only securely connects the adhesive to the metal surface but also effectively improves peel strength, ensuring the material's reliability in complex environments.

[0081] The present invention prepares a slow-release BF3-MEA curing agent through microencapsulation technology, effectively controls the release process of the catalyst, and optimizes the curing performance of the epoxy system. Specifically, gelatin and gum arabic are used as wall materials, and a stable wall material structure is initially formed through the electrostatic interaction between the two. Gelatin has cationic groups, while gum arabic has anionic groups. Under appropriate pH conditions, the two can form a uniform initial wall material solution through electrostatic attraction. On this basis, a low-temperature complex coagulation process is used to further aggregate and precipitate the wall material in the aqueous solution, coating the core material BF3-MEA complex to form a microcapsule structure with preliminary mechanical strength. Nano-silica enhances the density of the microcapsule wall and reduces water permeability through physical filling and interaction with surface hydroxyl groups.

[0082] To further enhance the microcapsules' mechanical properties and environmental stability, the present invention incorporates a crosslinking reaction. Through an addition reaction between isophorone diisocyanate and the amino groups and ethylenediamine in the wall material, a three-dimensional crosslinked polyurea network is generated. This improves the microcapsule's strength and durability while maintaining its sustained-release capacity. This crosslinked polyurea network forms a dense protective layer on the microcapsule surface, effectively preventing premature release of the core material's BF3-MEA complex during storage or processing, ensuring its latent properties.

[0083] Microencapsulated BF3-MEA plays a key role in the UV post-curing stage of epoxy systems. During the initial curing phase, UV-induced cationic polymerization primarily targets surface epoxy groups, forming a preliminary cured structure. However, due to the limited penetration depth of UV curing, the curing of deeper epoxy groups is often incomplete. At this point, the microencapsulated BF3-MEA gradually releases the BF3-MEA complex under heating. As a strong cationic catalyst, BF3 effectively promotes the ring-opening polymerization of epoxy groups, further enhancing the degree of deep-layer curing and crosslinking density. This slow-release mechanism ensures uniform curing of the epoxy system from the surface to the deeper layers, improving the overall physical properties and chemical stability of the material.

[0084] In this application, comprehensive crosslinking of surface and deep-layer epoxy groups is achieved through UV curing and natural curing. UV curing is responsible for rapid shaping and surface curing, while natural curing completes the deep-layer curing reaction through a slow-release catalyst. The two complement each other in time and space, improving processing efficiency while ensuring the material's mechanical properties, chemical stability, and deep-layer curing effect.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] This invention uses a cycloaliphatic epoxy resin as the matrix, whose epoxy groups form a dense cross-linked network through cationic polymerization, improving strength and chemical stability. Through perfluorobutanol modification, hydrophobic fluorocarbon chains are introduced into the resin molecules, reducing surface energy and significantly enhancing moisture and corrosion resistance. Further silanization modification using KH-560 silane coupling agent introduces silicon-oxygen-silicon bonds to form an organic-inorganic hybrid structure, improving thermal stability, interfacial bonding, and flexibility, thereby reducing internal stress and optimizing mechanical properties and durability, meeting the high-performance requirements of electronic three-proof.

[0087] The present invention grafts 3-mercaptopropyltrimethoxysilane onto vinyl-terminated polydimethylsiloxane through an ultraviolet light-induced reaction to generate a copolymer containing active siloxy groups, thereby resolving its compatibility problem with epoxy resin. After modification, the polydimethylsiloxane chemically bonds to the bisphenol F epoxy resin via the siloxy groups, forming an organic-inorganic hybrid network. The flexible silicon-oxygen-silicon chain segments significantly enhance toughness and impact resistance while mitigating internal stress. The high cross-linking density network structure further enhances the strength and heat resistance of the material, achieving a combination of high toughness and high strength.

[0088] The present invention prepares a functionalized polymer containing a high density of phosphate bonds and phosphonic acid groups through an ester exchange reaction between a hyperbranched polyester and trimethyl phosphate. The hyperbranched structure provides a high functional group density, endowing the material with excellent flame retardancy and chemical stability, while the phosphate bonds synergistically flame retardant through the condensed phase and gas phase, effectively inhibiting flame propagation. Simultaneously, the phosphonic acid groups enhance the material's adhesion to metal surfaces, forming stable chemical bonds with the metal oxide layer, improving interfacial bonding and peel strength, and significantly enhancing the material's durability and reliability in high humidity and corrosive environments.

[0089] This invention uses microencapsulation technology to prepare a sustained-release BF3-MEA curing agent. Gelatin and gum arabic form a stable wall material, and polyurea crosslinking enhances the strength and sustained-release properties of the microcapsules. The microencapsulated BF3-MEA is gradually released during the post-UV curing stage, addressing the problem of insufficient UV curing depth. It evenly promotes the ring-opening polymerization of epoxy groups, achieving complete curing from the surface layer to the deep layer, significantly improving the material's mechanical properties and chemical stability.

[0090] In this application, comprehensive crosslinking of surface and deep-layer epoxy groups is achieved through UV curing and natural curing. UV curing is responsible for rapid shaping and surface curing, while natural curing completes the deep-layer curing reaction through a slow-release catalyst. The two complement each other in time and space, improving processing efficiency while ensuring the material's mechanical properties, chemical stability, and deep-layer curing effect. DETAILED DESCRIPTION

[0091] The technical solutions of the present invention are described in detail below with reference to specific embodiments. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications made to the embodiments described herein.

[0092] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products without further purification or treatment.

[0093] Example 1

[0094] This embodiment provides a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. The preparation method of the cationic epoxy adhesive for electronic three-proofing specifically includes the following steps:

[0095] S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol in a molar ratio of 1:0.3, adding tetrabutylammonium bromide to obtain reaction solution A, wherein the amount of tetrabutylammonium bromide added is 0.4% of the total mass of the alicyclic epoxy resin and perfluorobutanol, heating to 50°C under nitrogen protection and stirring for reaction for 2.5 hours to obtain reaction solution B; adding KH-560 to an ethanol / water mixture and pre-hydrolyzing at 50°C for 65 minutes to obtain a silicon grafting solution, wherein the volume ratio of ethanol to water in the ethanol / water mixture is 9:1, and the mass ratio of KH-560 to anhydrous ethanol is 1:2.5, and adding it to reaction solution B to obtain a mixed solution, wherein the amount of KH-560 added is 12% of the total mass of the alicyclic epoxy resin and perfluorobutanol, adjusting its pH to 5.8 to obtain reaction solution C, continuing the reaction at a constant temperature of 50°C for 1.2 hours, filtering, washing, and vacuum drying to obtain a fluorosilicone-modified epoxy resin;

[0096] S2: Vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane were mixed in a molar ratio of 1:1, and a photoinitiator, Irgacure 651, was added to obtain a reaction solution D, wherein the mass fraction of the photoinitiator in the reaction solution D was 0.65 wt.%, and the reaction mixture was irradiated with ultraviolet light for 4 minutes to obtain a reaction mixture, wherein the irradiation intensity of the ultraviolet light irradiation of the reaction solution D was 24 mW / cm 2 , mixing it with n-hexane in a volume ratio of 1:3, filtering to obtain a primary product, washing, rotary evaporation, and drying to obtain modified polydimethylsiloxane; mixing it with bisphenol F epoxy resin EPON862 in toluene in a mass ratio of 1:0.8, wherein the total mass fraction of modified polydimethylsiloxane and bisphenol F epoxy resin in toluene is 18wt.%, adding tetraphenylphosphine bromide to obtain reaction solution E, wherein the feeding amount of tetraphenylphosphine bromide is 0.08% of the total mass of modified polydimethylsiloxane and bisphenol F epoxy resin, reacting at a constant temperature of 120°C for 2.4h, using 0.1M hydrochloric acid for acid washing, rotary evaporation to obtain a crude product, which is dispersed in benzyl alcohol, wherein the amount of benzyl alcohol added is 30% of the mass of the crude product, and continuing rotary evaporation to obtain a toughened prepolymer;

[0097] S3: Hyperbranched polyester Boltorn H30 and trimethyl phosphate are mixed in a molar ratio of 1:1.2, potassium carbonate is added to obtain a reaction solution F, wherein the amount of potassium carbonate added is 2% of the total mass of the hyperbranched polyester and trimethyl phosphate, and the reaction is carried out at 125° C. for 7 h under nitrogen protection to obtain a first reaction solution, which is adjusted to pH 2.9 with 0.15 M hydrochloric acid to obtain a second reaction solution, and hydrolyzed and acidified at 60° C. for 2 h to obtain a third reaction solution, which is cooled and poured into an ethanol / water mixed solution for precipitation and purification, wherein the volume ratio of ethanol to water in the ethanol / water mixed solution is 7:3, and the volume ratio of the third reaction solution to the ethanol / water mixed solution is 1:5.5, and dried to obtain a phosphate polymer;

[0098] S4: gelatin and gum arabic are mixed in a mass ratio of 1:1 and added to deionized water, wherein the total mass fraction of gelatin and gum arabic in deionized water is 8wt.%, nano-silica is added to obtain a primary wall material solution, wherein the mass fraction of nano-silica in the primary wall material solution is 1.5wt.%, and the pH is adjusted to 4.3 to obtain a wall material solution; BF3-MEA complex is mixed with ethanol / glycerol mixed solution in a mass ratio of 1:2.3, wherein the volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:2, and the pH is adjusted to 3 to obtain a core material solution; and added Add the BF3-MEA complex to the wall material solution to obtain a reaction solution G, wherein the mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:2, emulsify at 45°C for 5 minutes to obtain an emulsion, cool it to 10°C and perform complex coagulation for 1.5 hours, then add isophorone diisocyanate and ethylenediamine to obtain a reaction solution H, wherein the amount of isophorone diisocyanate is 5% of the mass of the BF3-MEA complex, the molar ratio of ethylenediamine to isophorone diisocyanate is 1.15:1, and cross-link at 45°C for 3.5 hours. Centrifuge, wash, and dry to obtain microencapsulated BF3-MEA;

[0099] S5: Fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether were premixed at 44°C, and then toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 were added in sequence to obtain a primary product. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing, wherein the mass ratio of fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 was 30:20:17:7:8:4:0.8:3.5:0.37.

[0100] Example 2

[0101] This embodiment provides a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. The preparation method of the cationic epoxy adhesive for electronic three-proofing specifically includes the following steps:

[0102] S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol in a molar ratio of 1:0.32, adding tetrabutylammonium bromide to obtain reaction solution A, wherein the amount of tetrabutylammonium bromide added is 0.3% of the total mass of the alicyclic epoxy resin and perfluorobutanol, heating to 55°C under nitrogen protection and stirring for 2 hours to obtain reaction solution B; adding KH-560 to an ethanol / water mixture and pre-hydrolyzing at 60°C for 60 minutes to obtain a silicon grafting solution, wherein the volume ratio of ethanol to water in the ethanol / water mixture is 9:1, and the mass ratio of KH-560 to anhydrous ethanol is 1:2, and adding the solution to reaction solution B to obtain a mixed solution, wherein the amount of KH-560 added is 15% of the total mass of the alicyclic epoxy resin and perfluorobutanol, adjusting its pH to 5.7 to obtain reaction solution C, continuing the reaction at a constant temperature of 60°C for 1.4 hours, filtering, washing, and vacuum drying to obtain a fluorosilicone-modified epoxy resin;

[0103] S2: Vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane were mixed at a molar ratio of 1:1.05, and a photoinitiator, Irgacure 651, was added to obtain a reaction solution D, wherein the mass fraction of the photoinitiator in the reaction solution D was 0.7 wt.%. The reaction mixture was irradiated with ultraviolet light for 3 minutes to obtain a reaction mixture, wherein the irradiation intensity of the ultraviolet light irradiation of the reaction solution D was 20 mW / cm 2 , mixing it with n-hexane in a volume ratio of 1:4, filtering to obtain a primary product, washing, rotary evaporation, and drying to obtain modified polydimethylsiloxane; mixing it with bisphenol F epoxy resin EPON862 in toluene in a mass ratio of 1:0.84, wherein the total mass fraction of modified polydimethylsiloxane and bisphenol F epoxy resin in toluene is 17wt.%, adding tetraphenylphosphine bromide to obtain reaction solution E, wherein the feeding amount of tetraphenylphosphine bromide is 0.07% of the total mass of modified polydimethylsiloxane and bisphenol F epoxy resin, reacting at a constant temperature of 122°C for 2.3h, using 0.1M hydrochloric acid for acid washing, rotary evaporation to obtain a crude product, which is dispersed in benzyl alcohol, wherein the amount of benzyl alcohol added is 35% of the mass of the crude product, and continuing rotary evaporation to obtain a toughened prepolymer;

[0104] S3: Hyperbranched polyester Boltorn H30 and trimethyl phosphate were mixed in a molar ratio of 1:1.25, potassium carbonate was added to obtain a reaction solution F, wherein the amount of potassium carbonate added was 2.2% of the total mass of the hyperbranched polyester and trimethyl phosphate, and the mixture was reacted at 128° C. for 7.6 h under nitrogen protection to obtain a first reaction solution, which was adjusted to pH 2.85 with 0.18 M hydrochloric acid to obtain a second reaction solution, and hydrolyzed and acidified at 62° C. for 2.5 h to obtain a third reaction solution, which was cooled and poured into an ethanol / water mixed solution for precipitation and purification, wherein the volume ratio of ethanol to water in the ethanol / water mixed solution was 7:3, and the volume ratio of the third reaction solution to the ethanol / water mixed solution was 1:5, and dried to obtain a phosphate polymer;

[0105] S4: gelatin and gum arabic are mixed in a mass ratio of 1:1 and added to deionized water, wherein the total mass fraction of gelatin and gum arabic in deionized water is 7wt.%, nano-silica is added to obtain a primary wall material solution, wherein the mass fraction of nano-silica in the primary wall material solution is 1.8wt.%, and the pH is adjusted to 4.5 to obtain a wall material solution; BF3-MEA complex is mixed with ethanol / glycerol mixed solution in a mass ratio of 1:2.2, wherein the volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:2, and the pH is adjusted to 3.1 to obtain a core material solution; and added Add the BF3-MEA complex to the wall material solution to obtain a reaction solution G, wherein the mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:2.1, emulsify at 47°C for 7 minutes to obtain an emulsion, cool it to 11°C and perform complex coagulation for 1.6 hours, then add isophorone diisocyanate and ethylenediamine to obtain a reaction solution H, wherein the amount of isophorone diisocyanate is 5.5% of the mass of the BF3-MEA complex, and the molar ratio of ethylenediamine to isophorone diisocyanate is 1.18:1, and cross-link at 48°C for 4 hours. Centrifuge, wash, and dry to obtain microencapsulated BF3-MEA;

[0106] S5: Fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether were premixed at 43°C, and then toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 were added in sequence to obtain a primary product. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing, wherein the mass ratio of fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 was 29:21:18:6:8.5:3.5:0.5:3.8:0.3.

[0107] Example 3

[0108] This embodiment provides a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. The preparation method of the cationic epoxy adhesive for electronic three-proofing specifically includes the following steps:

[0109] S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol in a molar ratio of 1:0.25, adding tetrabutylammonium bromide to obtain reaction solution A, wherein the amount of tetrabutylammonium bromide added is 0.42% of the total mass of the alicyclic epoxy resin and perfluorobutanol, heating to 58°C under nitrogen protection and stirring for reaction for 3 hours to obtain reaction solution B; adding KH-560 to an ethanol / water mixture and pre-hydrolyzing at 55°C for 68 minutes to obtain a silicon grafting solution, wherein the volume ratio of ethanol to water in the ethanol / water mixture is 9:1, and the mass ratio of KH-560 to anhydrous ethanol is 1:3, and adding it to reaction solution B to obtain a mixed solution, wherein the amount of KH-560 added is 10% of the total mass of the alicyclic epoxy resin and perfluorobutanol, adjusting its pH to 5.5 to obtain reaction solution C, continuing the reaction at a constant temperature of 58°C for 1 hour, filtering, washing, and vacuum drying to obtain a fluorosilicone modified epoxy resin;

[0110] S2: Vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane were mixed at a molar ratio of 1:0.9, and a photoinitiator, Irgacure 651, was added to obtain a reaction solution D, wherein the mass fraction of the photoinitiator in the reaction solution D was 0.5 wt.%, and ultraviolet light was used to irradiate the reaction solution D for 4.2 minutes to obtain a reaction mixture, wherein the irradiation intensity of the ultraviolet light was 22 mW / cm 2 , mixing it with n-hexane in a volume ratio of 1:4.2, filtering to obtain a primary product, washing, rotary evaporation, and drying to obtain modified polydimethylsiloxane; mixing it with bisphenol F epoxy resin EPON862 in toluene in a mass ratio of 1:0.7, wherein the total mass fraction of modified polydimethylsiloxane and bisphenol F epoxy resin in toluene is 15wt.%, adding tetraphenylphosphine bromide to obtain reaction solution E, wherein the feeding amount of tetraphenylphosphine bromide is 0.05% of the total mass of modified polydimethylsiloxane and bisphenol F epoxy resin, reacting at a constant temperature of 124°C for 2h, using 0.1M hydrochloric acid for acid washing, rotary evaporation to obtain a crude product, which is dispersed in benzyl alcohol, wherein the amount of benzyl alcohol added is 40% of the mass of the crude product, and continuing rotary evaporation to obtain a toughened prepolymer;

[0111] S3: Hyperbranched polyester Boltorn H30 and trimethyl phosphate were mixed in a molar ratio of 1:1.1, potassium carbonate was added to obtain a reaction solution F, wherein the amount of potassium carbonate added was 1.5% of the total mass of the hyperbranched polyester and trimethyl phosphate, and the reaction was carried out at 120° C. for 7.7 h under nitrogen protection to obtain a first reaction solution, which was adjusted to pH 2.8 with 0.1 M hydrochloric acid to obtain a second reaction solution, and hydrolyzed and acidified at 64° C. for 2.8 h to obtain a third reaction solution, which was cooled and poured into an ethanol / water mixed solution for precipitation and purification, wherein the volume ratio of ethanol to water in the ethanol / water mixed solution was 7:3, and the volume ratio of the third reaction solution to the ethanol / water mixed solution was 1:6, and dried to obtain a phosphate polymer;

[0112] S4: gelatin and gum arabic are mixed in a mass ratio of 1:1 and added to deionized water, wherein the total mass fraction of gelatin and gum arabic in deionized water is 5wt.%, nano-silica is added to obtain a primary wall material solution, wherein the mass fraction of nano-silica in the primary wall material solution is 1wt.%, and the pH is adjusted to 4.6 to obtain a wall material solution; BF3-MEA complex is mixed with ethanol / glycerol mixed solution in a mass ratio of 1:2, wherein the volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:2, and the pH is adjusted to 2.8 to obtain a core material solution; and added to Add the BF3-MEA complex to the wall material solution to obtain a reaction solution G, wherein the mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:1.8, emulsify at 48°C for 6 minutes to obtain an emulsion, cool it to 8°C and perform complex coagulation for 1.8 hours, then add isophorone diisocyanate and ethylenediamine to obtain a reaction solution H, wherein the amount of isophorone diisocyanate is 4% of the mass of the BF3-MEA complex, and the molar ratio of ethylenediamine to isophorone diisocyanate is 1.1:1, and cross-link at 47°C for 3 hours. Centrifuge, wash, and dry to obtain microencapsulated BF3-MEA;

[0113] S5: Fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether were premixed at 40°C, and then toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 were added in sequence to obtain a primary product. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing, wherein the mass ratio of fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 was 28:18:15:7.4:7:4.5:0.7:3:0.36.

[0114] Example 4

[0115] This embodiment provides a cationic epoxy adhesive for electronic three-proofing and a preparation method thereof. The preparation method of the cationic epoxy adhesive for electronic three-proofing specifically includes the following steps:

[0116] S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol in a molar ratio of 1:0.35, adding tetrabutylammonium bromide to obtain reaction solution A, wherein the amount of tetrabutylammonium bromide added is 0.5% of the total mass of the alicyclic epoxy resin and perfluorobutanol, heating to 60°C under nitrogen protection and stirring for reaction for 2.8 hours to obtain reaction solution B; adding KH-560 to an ethanol / water mixture and pre-hydrolyzing at 57°C for 70 minutes to obtain a silicon grafting solution, wherein the volume ratio of ethanol to water in the ethanol / water mixture is 9:1, and the mass ratio of KH-560 to anhydrous ethanol is 1:2.8, and adding it to reaction solution B to obtain a mixed solution, wherein the amount of KH-560 added is 13% of the total mass of the alicyclic epoxy resin and perfluorobutanol, adjusting its pH to 6.0 to obtain reaction solution C, continuing the reaction at a constant temperature of 55°C for 1.5 hours, filtering, washing, and vacuum drying to obtain a fluorosilicone modified epoxy resin;

[0117] S2: Vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane were mixed at a molar ratio of 1:1.1, and a photoinitiator, Irgacure 651, was added to obtain a reaction solution D, wherein the mass fraction of the photoinitiator in the reaction solution D was 0.8 wt.%, and the reaction mixture was irradiated with ultraviolet light for 5 minutes to obtain a reaction mixture, wherein the irradiation intensity of the ultraviolet light irradiation of the reaction solution D was 25 mW / cm 2 , mixing it with n-hexane in a volume ratio of 1:5, filtering to obtain a primary product, washing, rotary evaporation, and drying to obtain modified polydimethylsiloxane; mixing it with bisphenol F epoxy resin EPON862 in toluene in a mass ratio of 1:0.9, wherein the total mass fraction of modified polydimethylsiloxane and bisphenol F epoxy resin in toluene is 20wt.%, adding tetraphenylphosphine bromide to obtain reaction solution E, wherein the feeding amount of tetraphenylphosphine bromide is 0.1% of the total mass of modified polydimethylsiloxane and bisphenol F epoxy resin, reacting at a constant temperature of 125°C for 2.5h, using 0.1M hydrochloric acid for acid washing, rotary evaporation to obtain a crude product, which is dispersed in benzyl alcohol, wherein the amount of benzyl alcohol added is 38% of the mass of the crude product, and continuing rotary evaporation to obtain a toughened prepolymer;

[0118] S3: Hyperbranched polyester Boltorn H30 and trimethyl phosphate are mixed in a molar ratio of 1:1.3, potassium carbonate is added to obtain a reaction solution F, wherein the amount of potassium carbonate added is 2.5% of the total mass of the hyperbranched polyester and trimethyl phosphate, and the reaction is carried out at 130° C. for 8 h under nitrogen protection to obtain a first reaction solution, which is adjusted to pH 3 with 0.2 M hydrochloric acid to obtain a second reaction solution, and hydrolyzed and acidified at 65° C. for 3 h to obtain a third reaction solution, which is cooled and poured into an ethanol / water mixed solution for precipitation and purification, wherein the volume ratio of ethanol to water in the ethanol / water mixed solution is 7:3, and the volume ratio of the third reaction solution to the ethanol / water mixed solution is 1:5.8, and dried to obtain a phosphate polymer;

[0119] S4: gelatin and gum arabic are mixed in a mass ratio of 1:1 and added to deionized water, wherein the total mass fraction of gelatin and gum arabic in deionized water is 10wt.%, nano-silica is added to obtain a primary wall material solution, wherein the mass fraction of nano-silica in the primary wall material solution is 2wt.%, and the pH is adjusted to 4.7 to obtain a wall material solution; BF3-MEA complex is mixed with ethanol / glycerol mixed solution in a mass ratio of 1:2.5, wherein the volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:2, and the pH is adjusted to 3.2 to obtain a core material solution; add it into the wall material solution to obtain a reaction solution G, wherein the mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:2.2, emulsified at 50°C for 8 minutes to obtain an emulsion, which is cooled to 12°C for complex coagulation for 2 hours, and then isophorone diisocyanate and ethylenediamine are added to obtain a reaction solution H, wherein the amount of isophorone diisocyanate is 6% of the mass of the BF3-MEA complex, the molar ratio of ethylenediamine to isophorone diisocyanate is 1.2:1, and the cross-linking reaction is carried out at 50°C for 3.7 hours. The mixture is centrifuged, washed, and dried to obtain microencapsulated BF3-MEA;

[0120] S5: Fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether were premixed at 45°C, and then toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 were added in sequence to obtain a primary product. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing, wherein the mass ratio of fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430 was 32:22:20:8:9:4.2:1:4:0.4.

[0121] Comparative Example 1

[0122] This comparative example provides a cationic epoxy adhesive for electronic triple-proofing. The difference from Example 1 is that in S1, the step of reacting the alicyclic epoxy resin with perfluorobutanol is omitted, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0123] Comparative Example 2

[0124] This comparative example provides a cationic epoxy adhesive for electronic triple-proofing. The difference from Example 1 is that in S1, unmodified alicyclic epoxy resin is directly used without modification. The other operating steps and process parameters are exactly the same as those in Example 1.

[0125] Comparative Example 3

[0126] This comparative example provides a cationic epoxy adhesive for electronic triple protection. The difference from Example 1 is that in S5, no microencapsulated BF3-MEA is added, and only UV curing is used. The other operating steps and process parameters are exactly the same as those in Example 1.

[0127] The performance test of the cationic epoxy adhesives for electronic triple protection of Examples 1-4 and Comparative Examples 1-3 was carried out, and the specific process is as follows:

[0128] The viscosity of the sample was tested according to GB / T 2794-2013;

[0129] High temperature and high humidity aging test: The sample is coated on the surface of tinplate, cured with a high pressure mercury lamp and then naturally cured, and finally subjected to a high temperature and high humidity aging test;

[0130] The UV curing conditions include: UV curing using a high-pressure mercury lamp;

[0131] Natural curing conditions: Place it in a gradient constant temperature environment (40℃ / 2h, 70-80℃ / 3h, room temperature / 24h) under light-proof conditions;

[0132] The test results are shown in Table 1.

[0133] Table 1: Performance test results of cationic epoxy adhesives for electronic three-proofing in Examples 1-4 and Comparative Examples 1-3

[0134]

[0135]

[0136] The test results of Example 1 and Comparative Example 1 show that when the step of reacting the alicyclic epoxy resin with perfluorobutanol is omitted in S1, the viscosity of the adhesive increases. This is because the intermolecular interaction between the polar groups in the alicyclic epoxy resin without the introduction of fluorocarbon chains is enhanced, and the molecular chain fluidity is significantly reduced, resulting in increased viscosity. At the same time, due to the lack of the hydrophobic properties of the fluorocarbon chains, the hygroscopicity of the material is increased, and the polar epoxy groups and hydroxyl groups are more likely to react with water molecules in a hot and humid environment and degrade, and corrosive ions are more likely to penetrate and destroy the matrix structure.

[0137] From the test results of Example 1 and Comparative Example 2, it can be seen that when the unmodified alicyclic epoxy resin is used directly, the bulk viscosity of the unmodified alicyclic epoxy resin is low, but due to the strong hydrogen bonds and dipole-dipole interactions between its intermolecular polar groups, local aggregation is easily formed, resulting in a slight increase in the viscosity of the system; since the unmodified alicyclic epoxy resin lacks the hydrophobicity of the fluorocarbon chain and the flexible structure introduced by the silicone segment, the polar epoxy groups and hydroxyl groups are highly hygroscopic in a humid and hot environment, resulting in material degradation; and the unmodified alicyclic epoxy resin lacks the synergistic protection of fluorine and silicon, corrosive ions directly attack the interface, and the corrosion resistance is significantly reduced.

[0138] From the test results of Example 1 and Comparative Example 3, it can be seen that when only UV curing is used without adding microencapsulated BF3-MEA, the viscosity of the adhesive is slightly reduced. This is because after omitting the microencapsulated curing agent, the solid particles in the system are reduced and the fluidity of the system is slightly improved; due to insufficient UV curing depth, the internal curing of the material is incomplete, the cross-linking density is low, the hygroscopicity is increased, and it is easy to deteriorate in a humid and hot environment; due to the presence of a large number of curing defects inside the material due to only UV curing, the penetration of corrosive ions at the defects is accelerated, and the corrosion resistance is seriously reduced.

[0139] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a cationic epoxy adhesive for electronic three-proofing, characterized in that: The preparation method comprises: S1: Mixing alicyclic epoxy resin ERL-4221 and perfluorobutanol, reacting to obtain reaction solution B; adding KH-560 to an ethanol / water mixture for pre-hydrolysis to obtain a silicon grafting solution, adding the solution to reaction solution B, adjusting the pH, reacting, and treating to obtain a fluorine-silicon modified epoxy resin; S2: vinyl-terminated polydimethylsiloxane and 3-mercaptopropyltrimethoxysilane are mixed, and the mixture is irradiated with ultraviolet light to obtain a reaction mixture, which is mixed with n-hexane and treated to obtain modified polydimethylsiloxane; the mixture is mixed with bisphenol F epoxy resin, reacted, and treated to obtain a crude product; the crude product is dispersed in benzyl alcohol, and rotary evaporated to obtain a toughened prepolymer; S3: mixing a hyperbranched polyester with trimethyl phosphate, reacting under nitrogen protection to obtain a first reaction solution, adjusting the pH, hydrolyzing and acidifying to obtain a third reaction solution, cooling the reaction solution, pouring it into an ethanol / water mixed solution for precipitation, and treating it to obtain a phosphate polymer; S4: adding gelatin, gum arabic, and nano-silica to deionized water to obtain a primary wall material solution, and adjusting the pH to obtain a wall material solution; mixing the BF3-MEA complex with an ethanol / glycerol mixed solution, and adjusting the pH to obtain a core material solution; mixing the core material solution with the wall material solution to obtain a reaction solution G, emulsifying and complexing, and adding isophorone diisocyanate and ethylenediamine to obtain a reaction solution H, reacting, and treating to obtain microencapsulated BF3-MEA; S5: After premixing fluorosilicone-modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA, and leveling agent FC-4430, a primary product was obtained. After shear dispersion and vacuum degassing, the product was allowed to stand to obtain a cationic epoxy adhesive for electronic triple-proofing.

2. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S1, the molar ratio of the alicyclic epoxy resin to perfluorobutanol is 1:0.25-0.

35.

3. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S1: The mass ratio of KH-560 to ethanol / water mixture is 1:2-3; The volume ratio of ethanol to water in the ethanol / water mixture is 9:1; The feeding amount of KH-560 is 10-15% of the total mass of the alicyclic epoxy resin and perfluorobutanol; The pH of the mixed solution is adjusted to 5.5-6.

4. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S2: The molar ratio of the vinyl terminated polydimethylsiloxane to 3-mercaptopropyltrimethoxysilane is 1:0.9-1.1; The volume ratio of the reaction mixture to n-hexane is 1:3-5; The mass ratio of the modified polydimethylsiloxane to the bisphenol F epoxy resin is 1:0.7-0.9; The added amount of the benzyl alcohol is 30-40% of the mass of the crude product.

5. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S3: The molar ratio of the hyperbranched polyester to trimethyl phosphate is 1:1.1-1.3; The pH of the first reaction solution is adjusted to 2.8-3 using hydrochloric acid; The volume ratio of the third reaction liquid to the ethanol / water mixed solution is 1:5-6; The volume ratio of ethanol to water in the ethanol / water mixed solution is 7:

3.

6. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S4: The mass ratio of gelatin to gum arabic is 1:1; The pH of the initial wall material solution is adjusted to 4.3-4.7 to obtain a wall material solution; The volume ratio of ethanol to glycerol in the ethanol / glycerol mixed solution is 8:

2.

7. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S4: The BF3-MEA complex is mixed with the ethanol / glycerol mixed solution and the pH is adjusted to 2.8-3.2; The mass ratio of the BF3-MEA complex to the total mass of gelatin and gum arabic is 1:1.8-2.

2.

8. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S4: The amount of isophorone diisocyanate added is 4-6% of the mass of the BF3-MEA complex; The molar ratio of the ethylenediamine to isophorone diisocyanate is 1.1-1.2:

1.

9. The method for preparing a cationic epoxy adhesive for electronic triple protection according to claim 1, characterized in that: In S5: The temperature of premixing the fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, and 1,4-cyclohexanedimethanol diglycidyl ether is 40-45° C. The mass ratio of the fluorosilicone modified epoxy resin, bisphenol F epoxy resin EPON862, 1,4-cyclohexanedimethanol diglycidyl ether, toughening prepolymer, phosphate polymer, photoinitiator CPI-210S, EsacureTZT, microencapsulated BF3-MEA and leveling agent FC-4430 is (28-32): (18-22): (15-20): (6-8): (7-9): (3.5-4.5): (0.5-1): (3-4): (0.3-0.4).

10. A cationic epoxy adhesive for electronic triple-proofing prepared by the preparation method according to any one of claims 1 to 9.

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