High-toughness low-thermal-expansion-coefficient photo-thermal dual-curing epoxy glue as well as preparation method and application thereof

Abstract

The invention discloses a high-toughness low-thermal-expansion-coefficient photo-thermal dual-curing epoxy adhesive and a preparation method and application thereof, and belongs to the technical field of photo-thermal dual-curing epoxy adhesives. The photo-thermal dual-curing epoxy adhesive is prepared from the following raw materials in parts by weight: 10 to 18 parts of organic silicon modified epoxy spiro resin, 6 to 10 parts of photo-thermal dual-curing resin, 1 to 5 parts of novolac epoxy resin, 1 to 3 parts of epoxy diluent, 3 to 8 parts of rubber toughened epoxy resin, 0.5 to 1.5 parts of epoxy thermal initiator, 0.3 to 0.8 part of photoinitiator and 0.3 to 0.8 part of silane coupling agent. 70-80 parts of amphiphilic spherical silicon dioxide and 0.3-0.8 part of a stabilizer. The photo-thermal dual-curing epoxy glue has the advantages of low viscosity, high bonding strength, high elongation at break, low thermal expansion coefficient, low elastic modulus, high tensile strength and glass transition temperature, and good construction performance and construction effect when being used for electronic product packaging.

Description

Technical Field

[0001] This invention belongs to the field of photothermal dual-solid epoxy adhesive technology, specifically relating to a high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive, its preparation method, and its application. Background Technology

[0002] With the popularization of 5G and the upgrading of new energy and various 3C electronic products, the demand for chips is increasing, and the requirements for chip specifications are also becoming more stringent. Traditional photothermal dual-solid epoxy adhesives used in electronic packaging have good stability, strong adhesion, high bulk strength, and good resistance to damp heat aging, which can effectively protect wafers and various crystal circuits. However, due to the use of traditional epoxy resins, the content of halogens such as chloride ions cannot be controlled. In order to maintain high heat resistance and stability, a high proportion of phenolic epoxy resin is generally introduced, which results in high brittleness, high rigidity, high elastic modulus, and stress concentration. In addition, the fillers used are basically imported, which are expensive, have long feeding time, unstable output, and high coefficient of thermal expansion.

[0003] Therefore, there is a need to provide a high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive and its preparation method. This invention involves the re-spirocyclic treatment of conventional epoxy resin modified with silicone to obtain a silicone-modified epoxy spirocyclic resin, and then preparing amphiphilic spherical silica. This provides a photothermal dual-solid epoxy adhesive based on the silicone-modified epoxy spirocyclic resin and amphiphilic spherical silica, exhibiting low viscosity, high adhesive strength, high toughness, low thermal expansion coefficient, and low elastic modulus.

[0005] The technical solution adopted by this invention to solve its technical problem is: This invention provides a high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive, comprising the following raw materials by weight: The composition includes: 10-18 parts of silicone-modified epoxy spirocyclic resin, 6-10 parts of photothermal dual-curing resin, 1-5 parts of phenolic epoxy resin, 1-3 parts of epoxy diluent, 3-8 parts of rubber toughening epoxy resin, 0.5-1.5 parts of epoxy thermal initiator, 0.3-0.8 parts of photoinitiator, 0.3-0.8 parts of silane coupling agent, 70-80 parts of amphiphilic spherical silica, and 0.3-0.8 parts of stabilizer. The preparation method of organosilicon-modified epoxy spirocyclic resin includes the following steps: (1) Mix bisphenol A epoxy resin with 3-isocyanate-propyltrimethoxysilane, add phosphoric acid, stir evenly, heat to 60-90℃ and react for 2-4 hours to obtain organosilicon modified epoxy resin. (2) Mix organosilicon-modified epoxy resin with 6-caprolactone, then add dichloromethane for dilution, stir evenly, heat to 60-90℃, then add boron trifluoride ether, react at 60-90℃ for 3-5 hours, and then wash with alkali and dry to obtain organosilicon-modified epoxy spirocyclic resin. The preparation method of amphiphilic spherical silica includes the following steps: A silane is added to an aqueous solution of a high molecular weight organic acid to carry out a reaction, and then centrifuged to obtain the amphiphilic silica microspheres; the high molecular weight organic acid is polystyrene sulfonic acid (PSS) or a perfluorosulfonic acid-based polymer (Nafion); the silane is one or more of aminosilane, hydroxysilane and mercaptosilane.

[0006] In some embodiments, the high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive comprises the following raw materials by weight: The composition includes 10-15 parts of silicone-modified epoxy spirocyclic resin, 8 parts of photothermal dual-curing resin, 1-3 parts of phenolic epoxy resin, 1-2 parts of epoxy diluent, 3-5 parts of rubber toughening epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of photoinitiator, 0.5 parts of silane coupling agent, 70-78 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0007] In some embodiments, the synthetic route of the organosilicon-modified epoxy spirocyclic resin is as follows:

[0008] The preparation method of organosilicon-modified epoxy spirocyclic resin includes the following steps: (1) Epoxy resin organosilicon modification Bisphenol A epoxy resin and 3-isocyanate-propyltrimethoxysilane were added to a reaction vessel, then phosphoric acid was added, the mixture was stirred evenly, and the temperature was raised to 60-90℃ and reacted for 2-4 hours. The modified organosilicon-modified epoxy resin was obtained by polycondensation reaction. (2) Spirocyclization of organosilicon-modified epoxy resin The obtained organosilicon-modified epoxy resin and 6-caprolactone were added to a reaction vessel, and then dichloromethane was added for dilution. The mixture was stirred evenly, heated to 60-90℃, and boron trifluoride ether was added as a catalyst to carry out a polycondensation reaction. After 3-5 hours, a spirocyclic organosilicon-modified epoxy resin was obtained. Finally, an alkaline washing treatment was performed to remove excess chloride ions, and the product organosilicon-modified epoxy spirocyclic resin was obtained after drying.

[0009] In some embodiments, the preparation method of amphiphilic spherical silica includes the following steps: Add silane solution dropwise to an aqueous solution of a high molecular weight organic acid over 50-60 minutes. After the addition is complete, continue the reaction for 12-16 hours. Centrifuge and dry at 50-60℃ for 12-16 hours to obtain amphiphilic silica microspheres. The aqueous solution of the high molecular weight organic acid is a polystyrene sulfonic acid aqueous solution (PSS solution) or a perfluorosulfonic acid polymer aqueous solution (Nafion solution). The silane solution is an aminosilane (aminopropyltrimethyl / ethoxysilane), a hydroxysilane (hydroxypropyltrimethyl / ethoxysilane), or a mercaptosilane (mercaptopropyltrimethyl / ethoxysilane).

[0010] In some embodiments, the mass ratio of the polymeric organic acid to the silane is 10:(1-20).

[0011] In some embodiments, the photothermal dual-curing resin is an alicyclic epoxy resin, preferably the alicyclic epoxy resin 2021P from Daicel Japan, which is highly active and can be used for both cationic photocuring and epoxy ring-opening for further thermocuring. It can be used for both photocuring and thermocuring polymerization reactions initiated by photoinitiators and thermocuring polymerization reactions initiated by thermal initiators. The dual curing method provides convenience for the manufacturing process.

[0012] In some embodiments, the phenolic epoxy resin is one or two of Dow Chemical's DEN-431 and DEN-438, and Huntsman's EPALLOY 8250 and EPALLOY 1180; this can improve heat resistance and chemical resistance.

[0013] In some embodiments, the epoxy diluent is an oxa-diluting monomer, such as one or two of oxacyclohexane, dioxacyclohexane, oxacyclobutane, and 3,3'-[oxybis(methylene)]bis[3-ethyl]oxacyclobutane; this can increase the photocuring reaction rate and dilute the epoxy resin to improve wettability.

[0014] In some embodiments, the rubber-toughened epoxy resin is obtained by graft polymerization modification of rubber masterbatch and epoxy resin. This resin can provide excellent toughness, reduce internal stress, and enhance the adhesion of plastics. The rubber-toughened epoxy resin is preferably EPP-175 rubber-modified epoxy resin from Complex High-Tech Materials Co., Ltd.

[0015] In some embodiments, the epoxy thermal initiator is one or more of peroxides, organic acid anhydrides, and amine compounds. Epoxy thermal initiators are substances capable of initiating polymerization reactions at certain temperatures. These initiators achieve curing by initiating the reaction of active groups in the epoxy resin to form a three-dimensional network structure. Preferably, the epoxy thermal initiator is one of the ammonium-blocked Lewis salts Vicbase TC3632 and Vicbase TC1612 produced by Shenzhen Kaiji.

[0016] In some embodiments, the photoinitiator includes one or more of benzoin and its derivatives, benzoyl groups, alkyl phenyl ketones, acyl phosphorus oxides, benzophenones, and cationic photoinitiators. Photoinitiators are primarily used in photocuring reactions to generate free radicals or ions by absorbing light energy, thereby initiating polymerization or crosslinking reactions.

[0017] In some embodiments, the photoinitiator includes one or more of benzophenone-1-hydroxycyclohexylbenzophenone, phenylbis(2,4,6-trimethylbenzoyl)phosphine, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-isopropylthioxanthrone, diaryliodomonium salt, and triarylthiomonium salt.

[0018] In some embodiments, the silane coupling agent is one or more selected from epoxy silanes, vinyl silanes, amino silanes, and methacryloxy silanes. The preferred silane coupling agent is γ-glycidoxypropyltrimethoxysilane. Silane coupling agents are organosilicon compounds with functional groups such as epoxy, hydroxyl, and amino groups in their chemical structure, thus exhibiting good thermal stability and weather resistance, as well as excellent electrical and mechanical properties.

[0019] In some implementations, the stabilizer is barbituric acid; the stabilizer is mainly used to improve the stability and long-term storage performance of the product; the corresponding stabilizer is added mainly according to the reaction type of the adhesive curing agent.

[0020] This invention provides a method for preparing the above-mentioned high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive, comprising the following steps: The silicone-modified epoxy spirocyclic resin, photothermal dual-curing resin, phenolic epoxy resin, epoxy diluent, and rubber toughening epoxy resin are mixed, heated to 70-80℃ and stirred evenly, cooled to 40-50℃, epoxy thermal initiator, photoinitiator, and stabilizer are added, stirred evenly, cooled to room temperature, silane coupling agent and amphiphilic spherical silica are added, stirred, and dispersed evenly to obtain a high-toughness, low thermal expansion coefficient photothermal dual-curing epoxy adhesive.

[0021] This invention provides an application of the above-mentioned high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive in electronic product packaging.

[0022] The beneficial effects of this invention are: The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive of the present invention is based on silicone-modified epoxy spirocyclic resin and amphiphilic spherical silica. It has low viscosity, high adhesive strength, high elongation at break, low thermal expansion coefficient, and low elastic modulus. At the same time, it has high tensile strength and glass transition temperature, and has good construction performance and construction effect when used for electronic product packaging. Attached Figure Description

[0023] Figure 1The figures show the performance test results of the photothermal dual-solid epoxy adhesives in the embodiments and comparative examples of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments.

[0025] The following will clearly and completely describe the concept, specific solutions, and technical effects of the present invention in conjunction with embodiments, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. The various technical features in the present invention can be combined interactively without contradicting each other.

[0026] The preparation methods of the organosilicon-modified epoxy spirocyclic resins used in the examples and comparative examples are as follows.

[0027] The raw materials for preparing organosilicon-modified epoxy spirocyclic resin include, by weight, the following: 0.5 parts dichloromethane 0.3 parts boron trifluoride diethyl ether 15 parts of isocyanate-propyltrimethoxysilane 35 parts of bisphenol A epoxy resin (E42, Shanghai Maclean Biochemical Technology Co., Ltd.) 30 parts caprolactone 15 parts of phosphoric acid (H3PO4).

[0028] The synthetic route for organosilicon-modified epoxy spirocyclic resin is as follows:

[0029] The preparation method includes the following steps: (1) Epoxy resin organosilicon modification Bisphenol A epoxy resin and 3-isocyanate-propyltrimethoxysilane were added to a reaction vessel, then phosphoric acid was added, the mixture was stirred evenly, and the temperature was raised to 75°C; the reaction was carried out for 3 hours; the modified organosilicon-modified epoxy resin was obtained by polycondensation reaction. (2) Spirocyclization of organosilicon-modified epoxy resin The obtained organosilicon-modified epoxy resin and 6-caprolactone were added to a reaction vessel, and then dichloromethane was added for dilution and stirring until homogeneous. The temperature was raised to 75°C, and boron trifluoride ether was added as a catalyst to carry out a polycondensation reaction. After 4 hours, a spirocyclic organosilicon-modified epoxy resin was obtained. Finally, an alkaline washing treatment was performed to remove excess chloride ions, and after drying, the finished organosilicon-modified epoxy spirocyclic resin was obtained.

[0030] The preparation methods of the amphiphilic spherical silica used in the examples and comparative examples are as follows: A polystyrene sulfonic acid aqueous solution (PSS solution) was prepared by adding 15g PSS and 150g deionized water to a round-bottom flask and stirring thoroughly at 40℃. Then, 15g of silane solution (hydroxypropyltriethoxysilane solution) was slowly added dropwise over 60 minutes. The solution underwent a self-assembly and hydrolysis reaction, gradually changing from clear to off-white. After the addition was complete, the reaction was continued for 12 hours. After centrifugation, the solution was dried at 60℃ for 12 hours to obtain amphiphilic silica microspheres.

[0031] The alicyclic epoxy resin (photothermal dual-curing resin) used in the examples and comparative examples was Daicel's alicyclic epoxy resin 2021P, the phenolic epoxy resin was Dow Chemical's DEN 431, the oxa diluent monomer (epoxy diluent) was Donghua New Materials' DE101 (3-ethyl-3-epoxypropane methanol), the rubber toughening epoxy resin was Rubber Modified Epoxy Resin EPP-175 from Complex High-Tech Materials Co., Ltd., the epoxy thermal initiator was Shenzhen Kaiji Vicbase TC3632, the cationic photoinitiator (photoinitiator) was SAN-APRO CPI-210S (triarylsulfonium salt), the silane coupling agent was KH-560, and the stabilizer was barbituric acid.

[0032] The preparation methods of the photothermal dual-cured epoxy adhesives in the examples and comparative examples are as follows: Organosilicon-modified epoxy spirocyclic resin (or bisphenol A epoxy resin E42), alicyclic epoxy resin, phenolic epoxy resin, oxa diluent monomer, and rubber toughening epoxy resin are added in proportion and mixed and stirred evenly at 80°C (1 h). Then, the temperature is lowered to 50°C, and epoxy thermal initiator, cationic photoinitiator, and stabilizer are added. The mixture is stirred and dissolved for 2 h. After the curing agent and initiator particles are completely dissolved, the mixture is cooled to room temperature, and silane coupling agent is added. Finally, amphiphilic spherical silica (or spherical silica Yaduma E8) is added and stirred for 2 h. The powder is then dispersed evenly using a centrifugal disperser (0.5 h) to obtain the photothermal dual-curing epoxy adhesive.

[0033] Example 1: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 10 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 3 parts of phenolic epoxy resin, 2 parts of oxo-dilutable monomer, 5 parts of rubber-toughened epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 70 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0034] Example 2: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 15 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 3 parts of phenolic epoxy resin, 2 parts of oxo-dilutable monomer, 5 parts of rubber-toughened epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 70 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0035] Example 3: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 10 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 3 parts of phenolic epoxy resin, 2 parts of oxo-dilutable monomer, 5 parts of rubber-toughened epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 75 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0036] Example 4: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 15 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 1 part of phenolic epoxy resin, 1 part of oxa diluent monomer, 3 parts of rubber toughening epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 78 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0037] Example 5: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 12.5 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 1 part of phenolic epoxy resin, 1 part of oxo-dilutable monomer, 3 parts of rubber-toughened epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 75 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

[0038] Comparative Example 1: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: 10 parts bisphenol A epoxy resin, 8 parts alicyclic epoxy resin, 3 parts phenolic epoxy resin, 2 parts oxo-diluting monomer, 5 parts rubber toughening epoxy resin, 1 part epoxy thermal initiator, 0.5 parts cationic photoinitiator, 0.5 parts silane coupling agent, 70 parts spherical silica, and 0.5 parts stabilizer.

[0039] Comparative Example 2: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: 15 parts bisphenol A epoxy resin, 8 parts alicyclic epoxy resin, 3 parts phenolic epoxy resin, 2 parts oxo-diluting monomer, 5 parts rubber toughening epoxy resin, 1 part epoxy thermal initiator, 0.5 parts cationic photoinitiator, 0.5 parts silane coupling agent, 75 parts spherical silica, and 0.5 parts stabilizer.

[0040] Comparative Example 3: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: 10 parts bisphenol A epoxy resin, 5 parts organosilicon modified epoxy spirocyclic resin, 8 parts alicyclic epoxy resin, 1 part phenolic epoxy resin, 1 part oxa diluent monomer, 3 parts rubber toughening epoxy resin, 1 part epoxy thermal initiator, 0.5 parts cationic photoinitiator, 0.5 parts silane coupling agent, 78 parts spherical silica, and 0.5 parts stabilizer.

[0041] Comparative Example 4: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: The composition includes 10 parts of organosilicon-modified spirocyclic epoxy resin, 8 parts of alicyclic epoxy resin, 3 parts of phenolic epoxy resin, 2 parts of oxo-dilutable monomer, 5 parts of rubber-toughened epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of cationic photoinitiator, 0.5 parts of silane coupling agent, 70 parts of spherical silica, and 0.5 parts of stabilizer.

[0042] Comparative Example 5: The photothermal dual-curing epoxy adhesive comprises the following raw materials by weight: 10 parts bisphenol A epoxy resin, 8 parts alicyclic epoxy resin, 3 parts phenolic epoxy resin, 2 parts oxo-diluting monomer, 5 parts rubber toughening epoxy resin, 1 part epoxy thermal initiator, 0.5 parts cationic photoinitiator, 0.5 parts silane coupling agent, 70 parts amphiphilic spherical silica, and 0.5 parts stabilizer.

[0043] Performance testing: To compare the performance differences between traditional bisphenol A epoxy resin and silicone-modified spirocyclic epoxy resin, as well as between traditional spherical silica and modified amphiphilic spherical silica, these materials were applied to the same adhesive formulation. Data were compared by using different proportions of spirocyclic resin to replace traditional bisphenol A epoxy resin, and by using different powders in the same proportion within the same formulation. The performance differences were verified by comparing parameters such as adhesive viscosity, bond strength, tensile strength, elastic modulus, elongation at break, coefficient of thermal expansion, and glass transition temperature (TG).

[0044] The curing conditions are: UV 10000mj (mercury lamp source) + 120℃ for 2 hours.

[0045] The viscosity, bond strength, tensile strength, elongation at break, glass transition temperature, coefficient of thermal expansion, and modulus of elasticity were tested. The test results are as follows: Figure 1 .

[0046] Test method: Viscosity: Cone-plate viscometer, #4, 10 RPM; ASTM D4287.

[0047] Bond strength: universal tensile testing machine, GB / T 7124-2008, substrate: stainless steel-stainless steel.

[0048] Tensile strength / elongation at break: Universal tensile testing machine, GB / T 1040.1-2018.

[0049] Coefficient of thermal expansion / glass transition temperature: Static thermomechanical analyzer (TMA 450, TA Instruments, USA), GB / T4339-2008.

[0050] Elastic modulus: Dynamic thermomechanical analyzer (DMA), GB / T 40396-2021.

[0051] Results analysis: By comparing Example 1 with Comparative Example 1 and Example 4 with Comparative Example 3, it was found that the organosilicon-modified epoxy spirocyclic resin and amphiphilic spherical silica can effectively reduce viscosity, improve adhesion, increase elongation at break, reduce coefficient of thermal expansion, and reduce elastic modulus compared with traditional bisphenol A epoxy resin and spherical silica. Moreover, while toughening, it can also maintain high tensile strength and glass transition temperature. This indicates that using this resin can improve toughness while maintaining strong bulk properties and good temperature resistance and aging resistance.

[0052] By comparing Comparative Example 1 with Comparative Example 4 and Comparative Example 1 with Comparative Example 5, it can be concluded that although both silicone-modified spirocyclic resin and amphiphilic spherical silica enhance the performance of the adhesive individually—for example, in Comparative Example 4, the introduction of silicone-modified spirocyclic epoxy resin significantly improved the elongation at break of the adhesive; and in Comparative Example 5, the introduction of amphiphilic spherical silica greatly reduced the coefficient of thermal expansion—the improvement in adhesive strength and the reduction in elastic modulus are relatively small. In Example 1, however, the two not only exerted their unique properties but also complemented each other in terms of improving adhesive strength and reducing elastic modulus, exhibiting a synergistic effect and achieving significant results.

[0053] in conclusion: Compared to traditional epoxy resins and spherical silica, silicone-modified epoxy spirocyclic resins and amphiphilic spherical silica can significantly improve the performance of photothermal dual-solid epoxy adhesives. Specifically, they can increase elongation at break, reduce the coefficient of thermal expansion, improve workability, and have a lower elastic modulus, making them more suitable for current mainstream chip packaging technology and optical component positioning and fixing technology.

[0054] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive, characterized in that, By weight, it includes the following ingredients: The composition includes: 10-18 parts of silicone-modified epoxy spirocyclic resin, 6-10 parts of photothermal dual-curing resin, 1-5 parts of phenolic epoxy resin, 1-3 parts of epoxy diluent, 3-8 parts of rubber toughening epoxy resin, 0.5-1.5 parts of epoxy thermal initiator, 0.3-0.8 parts of photoinitiator, 0.3-0.8 parts of silane coupling agent, 70-80 parts of amphiphilic spherical silica, and 0.3-0.8 parts of stabilizer. The preparation method of organosilicon-modified epoxy spirocyclic resin includes the following steps: (1) Mix bisphenol A epoxy resin with 3-isocyanate-propyltrimethoxysilane, add phosphoric acid, stir evenly, heat to 60-90℃ and react for 2-4 hours to obtain organosilicon modified epoxy resin. (2) Mix organosilicon-modified epoxy resin with 6-caprolactone, then add dichloromethane for dilution, stir evenly, heat to 60-90℃, then add boron trifluoride ether, react at 60-90℃ for 3-5 hours, and then wash with alkali and dry to obtain organosilicon-modified epoxy spirocyclic resin. The preparation method of amphiphilic spherical silica includes the following steps: Silane is added to an aqueous solution of a high molecular weight organic acid to carry out a reaction, and then centrifuged to obtain the amphiphilic silica microspheres; the high molecular weight organic acid is polystyrene sulfonic acid or a perfluorosulfonic acid-based polymer; the silane is one or more of aminosilane, hydroxysilane and mercaptosilane.

2. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 1, characterized in that, By weight, it includes the following ingredients: The composition includes 10-15 parts of silicone-modified epoxy spirocyclic resin, 8 parts of photothermal dual-curing resin, 1-3 parts of phenolic epoxy resin, 1-2 parts of epoxy diluent, 3-5 parts of rubber toughening epoxy resin, 1 part of epoxy thermal initiator, 0.5 parts of photoinitiator, 0.5 parts of silane coupling agent, 70-78 parts of amphiphilic spherical silica, and 0.5 parts of stabilizer.

3. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 1 or 2, characterized in that, The preparation method of amphiphilic spherical silica includes the following steps: Add silane solution dropwise to an aqueous solution of a high molecular weight organic acid over 50-60 minutes. After the addition is complete, continue the reaction for 12-16 hours. Centrifuge and dry at 50-60°C for 12-16 hours to obtain amphiphilic silica microspheres. The aqueous solution of the high molecular weight organic acid is an aqueous solution of polystyrene sulfonic acid or a perfluorosulfonic acid-based polymer, and the silane solution is an aminosilane, hydroxysilane, or mercaptosilane.

4. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 1 or 2, characterized in that, The photothermal dual-curing resin is an alicyclic epoxy resin; The phenolic epoxy resin is one or two of Dow Chemical's DEN-431 and DEN-438, and Huntsman's EPALLOY 8250 and EPALLOY 1180. The epoxy diluent is an oxygen-based diluent monomer.

5. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 4, characterized in that, The alicyclic epoxy resin is Daicel's 2021P alicyclic epoxy resin from Japan. The oxadiluent monomer is one or two of oxacyclohexane, dioxacyclohexane, oxacyclobutane, and 3,3'-[oxybis(methylene)]bis[3-ethyl]oxacyclobutane.

6. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 1 or 2, characterized in that, The rubber-toughened epoxy resin is obtained by graft polymerization modification of rubber masterbatch and epoxy resin; The epoxy thermal initiator is one or more of peroxides, organic acid anhydrides, and amine compounds; Photoinitiators include one or more of benzoin and its derivatives, benzoyl groups, alkyl phenyl ketones, acyl phosphorus oxides, benzophenones, and cationic photoinitiators; The silane coupling agent is one or more of epoxy silane, vinyl silane, amino silane, and methacryloxy silane.

7. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 6, characterized in that, The rubber-toughened epoxy resin is EPP-175, a rubber-modified epoxy resin from Complex High-Tech Materials Co., Ltd. The epoxy thermal initiator is one of the ammonium-blocked Lewis salts Vicbase TC3632 and Vicbase TC1612 produced by Shenzhen Kaiji. Photoinitiators include one or more of benzophenone-1-hydroxycyclohexylbenzophenone, phenylbis(2,4,6-trimethylbenzoyl)phosphine, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-isopropylthioxanthrone, and diaryliodomonium salts; The silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

8. The high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to claim 1 or 2, characterized in that, The stabilizer is barbituric acid.

9. A method for preparing the high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to any one of claims 1-8, comprising the following steps: The silicone-modified epoxy spirocyclic resin, photothermal dual-curing resin, phenolic epoxy resin, epoxy diluent, and rubber toughening epoxy resin are mixed, heated to 70-80℃ and stirred evenly, cooled to 40-50℃, epoxy thermal initiator, photoinitiator, and stabilizer are added, stirred evenly, cooled to room temperature, silane coupling agent and amphiphilic spherical silica are added, stirred, and dispersed evenly to obtain a high-toughness, low thermal expansion coefficient photothermal dual-curing epoxy adhesive.

10. The application of the high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive according to any one of claims 1-8 or the high-toughness, low-thermal-expansion-coefficient photothermal dual-solid epoxy adhesive prepared by the preparation method according to claim 9 in electronic product packaging.

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