Preparation method of epoxy resin plastic encapsulating material

Abstract

The present application relates to the technical field of plastic encapsulation materials, and particularly relates to a preparation method of an epoxy resin plastic encapsulation material.The method comprises the following steps: compounding epoxy resin, phenolic resin, fillers and loaded flame retardant mesoporous silica, and then melt mixing to obtain high-performance plastic encapsulation materials; the loaded flame retardant mesoporous silica is prepared by the following steps: first, preparing DOPA by oxidizing DOPO; then, compounding the DOPA with mesoporous silica; and finally, preparing the loaded flame retardant mesoporous silica by a guanine modified dopamine hydrochloride polymerization coating reaction.The present application constructs a gradient release function flame retardant system, controls the release behavior of the flame retardant by modifying the dopamine coating layer, realizes the synergistic effect of the nitrogen and phosphorus flame retardant components, and solves the problem of unclear marking caused by the addition of traditional flame retardants.The material is particularly suitable for the field of high-density electronic packaging and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic encapsulation materials, and particularly relates to a preparation method of an epoxy resin plastic encapsulation material. BACKGROUND

[0002] With the development of electronic packaging technology towards high density and high integration, the performance requirements of epoxy resin plastic encapsulation materials are increasingly stringent. Traditional epoxy plastic encapsulation materials have many technical bottlenecks in terms of flame retardant performance and laser marking effect. In terms of flame retardant performance, conventional flame retardants (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)) often have the problems of large addition amount and affecting the mechanical properties of the material; in terms of laser marking, the existing materials often cause uneven carbonization on the surface, resulting in insufficient marking contrast. These problems seriously restrict the application of epoxy plastic encapsulation materials in high-reliability packaging fields.

[0003] In the current technology, it is difficult to achieve balanced performance by simply physically mixing flame retardants. For example, nitrogen-based flame retardants are prone to produce micro-bubbles at high temperatures, resulting in rough material surface; excessive phosphorus-based flame retardants are prone to form a dense carbon layer, hindering the exposure of inorganic fillers for laser marking. In addition, poor compatibility between the flame retardant and the resin matrix can cause phase separation, poor dispersion of the flame retardant, and poor laser printing. Although some research has attempted to use mesoporous materials to load flame retardants, the traditional loading method cannot achieve controlled release of the flame retardant components, resulting in low flame retardant efficiency or deterioration of processing performance.

[0004] Therefore, it is urgent to develop a new type of epoxy resin plastic encapsulation material to achieve comprehensive optimization of flame retardant performance and laser marking effect. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a preparation method of an epoxy resin plastic encapsulation material to solve the problem of poor laser marking effect caused by the addition of traditional flame retardants.

[0006] Based on the above purpose, the present application provides a preparation method of an epoxy resin plastic encapsulation material, comprising the following steps:

[0007] The epoxy resin, phenolic resin, inorganic filler, colorant, release agent, coupling agent, curing accelerator, reactive stress modifier, and flame retardant-loaded mesoporous silica are uniformly mixed and melt-mixed on an open mill at 90-105℃, and then cooled to obtain the epoxy resin plastic encapsulation material.

[0008] The weight ratio of the epoxy resin, phenolic resin, inorganic filler, colorant, release agent, coupling agent, curing accelerator, reactive stress modifier, flame retardant loaded mesoporous silica is 4-10 parts: 2-10 parts: 70-90 parts: 0.1-0.5 parts: 0.2-0.6 parts: 0.1-0.4 parts: 0.03-0.07 parts: 0.1-0.5 parts: 0.2-0.6;

[0009] The preparation steps of the flame retardant loaded mesoporous silica are as follows:

[0010] S1: Dissolve DOPO in ethanol, heat to 85℃, add hydrogen peroxide solution dropwise and react for 12h, purify to obtain DOPA;

[0011] S2: Mix DOPA with mesoporous silica uniformly and react at 130℃ for 30 min to obtain DOPA-mesoporous silica, namely SiO2@DOPA;

[0012] S3: Ultrasonically disperse DOPA-mesoporous silica in deionized water, add dopamine hydrochloride and guanine and disperse for 10 min, then add Tris buffer solution, adjust the pH value to 8.5, and react at 40℃ for 12h, purify to obtain PDA-coated DOPA-mesoporous silica, namely G-PDA@SiO2@DOPA;

[0013] Preferably, the amount of DOPO, ethanol, and hydrogen peroxide solution in step S1 is 3-5g: 100mL: 20mL.

[0014] Preferably, the concentration of the hydrogen peroxide solution in step S1 is 30%.

[0015] Preferably, the purification in step S1 is filtration, washing, and drying.

[0016] Preferably, the amount of DOPA and mesoporous silica in step S2 is 3-4g: 6-8g.

[0017] Preferably, the mesoporous silica in step S2 has an outer diameter of 450-550nm and a pore size of 2-4nm.

[0018] Preferably, the amount of DOPA-mesoporous silica, dopamine hydrochloride, guanine, and deionized water in step S3 is 6-8g: 6-8g: 1.51g: 1000mL.

[0019] Preferably, the purification in step S3 is centrifugal filtration, and the obtained precipitate is repeatedly resuspended and centrifuged.

[0020] Preferably, the epoxy resin is any one of an o-cresol novolac epoxy resin, a dicyclopentadiene epoxy resin, a polyaromatic epoxy resin, a multifunctional epoxy resin, a biphenyl epoxy resin, a naphthol novolac epoxy resin, a sulfide epoxy resin.

[0021] Preferably, the phenolic resin is any one of a phenol novolac resin, an o-methyl phenol novolac resin, a biphenyl novolac resin, a polyaromatic novolac resin, and a phenol aralkyl novolac resin.

[0022] Preferably, the inorganic filler is any one of silicon dioxide, aluminum oxide, boron nitride, boron carbide, and silicon carbide. More preferably, the inorganic filler is silicon dioxide.

[0023] Preferably, the colorant is carbon black.

[0024] Preferably, the release agent is a wax-based compound, and more preferably, the release agent is any one of a palm wax, a montanic acid ester wax, a polyethylene wax, an oxidized polyethylene wax, and a polyamide wax.

[0025] Preferably, the coupling agent is any one of a mercapto-type silane coupling agent, an amino-type silane coupling agent, and an epoxy-type silane coupling agent.

[0026] Preferably, the curing accelerator is any one of an imidazole compound, a tertiary amine compound, and an organic phosphine compound.

[0027] Preferably, the reactive stress modifier is any one of a carboxyl silicone oil, an amino silicone oil, and an epoxy silicone oil.

[0028] Advantages of the present application:

[0029] The present application effectively enhances the compatibility of inorganic flame retardants with a resin matrix by constructing a mesoporous silica carrier system coated with dopamine, constructs a stable three-dimensional network, improves the dispersibility of the flame retardant, and realizes the time sequence effect of nitrogen and phosphorus flame retardant components through the gradient release mechanism of the flame retardant system, avoiding the defects of single flame retardants and enhancing the flame retardant efficiency through synergistic effect. At the same time, the gradient decomposition characteristics realize the controllable release of the flame retardant components, avoiding the easy generation of micro-bubbles by nitrogen-based flame retardants at high temperatures, resulting in rough material surface. Excessive phosphorus-based flame retardants easily form a dense carbon layer, hindering the exposure of inorganic fillers under laser marking and causing poor printing effect, ensuring uniform carbonization and filler exposure under laser action, and avoiding the problem of blurred marking caused by excessive carbonization.

[0030] The carrier design of the flame retardant components of the present application effectively reduces the interference of the flame retardant on the curing process, maintains excellent fluidity and formability of the material. The construction of the interface transition layer alleviates the difference in the thermal expansion coefficient between the inorganic flame retardant and the matrix, reduces the curing stress, and improves the packaging reliability. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with specific examples.

[0032] The properties or sources of the raw materials used in the examples and comparative examples of the present application are as follows:

[0033] Mesoporous silica: Aladdin S433694, outer diameter 450-550 nm, pore size 2-4 nm; 9,10 dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO): Shanghai Maikelin Biochemical Technology Co., Ltd.; hydrogen peroxide: Chengdu Kelong Chemical Co., Ltd.; guanine: Shanghai Maikelin Biochemical Technology Co., Ltd.; dopamine hydrochloride: Shanghai Maikelin Biochemical Technology Co., Ltd.; tris(hydroxymethyl)aminomethane (Tris): Tianjin Damao Chemical Reagent Factory; inorganic filler 1: spherical silica, purchased from Jiangsu Lianrui New Material Co., Ltd., model DQ1150; inorganic filler 2: angular silica, Jiangsu Lianrui New Material Co., Ltd., model DC1330; epoxy resin: o-cresol formaldehyde epoxy resin, purchased from Nanya Electronic Materials (Kunshan) Co., Ltd., model DF1200B; curing agent: linear phenolic resin, purchased from Shandong Shengquan New Material Co., Ltd., model PF-8011; accelerator: 2-methylimidazole, purchased from Nanjing Musen Chemical Co., Ltd.; stress reliever: epoxy and polyether dual-functional modified silicone oil, purchased from Ruiningna Electronic Materials (Shanghai) Co., Ltd., model BES5-2130; coupling agent 1: epoxytrimethoxysilane, purchased from Shandong Sikexin Material Co., Ltd.; coupling agent 2: mercaptotrimethoxysilane, purchased from Shandong Sikexin Material Co., Ltd.; release agent: palm wax, purchased from East Asia Chemical Co., Ltd.

[0034] Example 1: An epoxy resin plastic encapsulating material, the specific preparation steps are as follows:

[0035] (1) 3g of DOPO was dissolved in 1000mL of ethanol, heated to 85℃, 20mL of hydrogen peroxide solution was slowly added and reacted for 12h, filtered and washed, and dried to obtain DOPA;

[0036] (2) Under nitrogen protection, 3g of DOPA was uniformly mixed with 6g of mesoporous silica, and reacted at 130℃ for 30min to obtain DOPA-mesoporous silica, namely SiO2@DOPA;

[0037] (3) 6 g of DOPA-mesoporous silica powder was ultrasonically dispersed in 1000 mL of deionized water, ultrasonic dispersion for 30 min, 6 g of dopamine hydrochloride and 1.51 g of guanine were added respectively and stirred for 10 min, then Tris buffer was added, the pH value was adjusted to 8.5, and the reaction was carried out at 40℃ for 12 h, purification, centrifugal washing with distilled water for three times, and soaking in distilled water under gentle stirring for three days to remove unbound polydopamine, the obtained black precipitate was washed with distilled water again, and dried in an oven at 60℃ to obtain PDA-coated DOPA-mesoporous silica, namely G-PDA@SiO2@DOPA;

[0038] (4) 10 g of o-cresol formaldehyde type epoxy resin, 4 g of linear phenolic resin, 40 g of spherical silica, 40 g of angular silica, 0.2 g of epoxy group trimethoxysilane, 0.2 g of mercapto trimethoxysilane, 0.4 g of carbon black, 0.5 g of palm wax, 0.05 g of 2-methyl imidazole, 0.1 g of epoxy and polyether bifunctional modified silicone oil, and 0.4 g of flame retardant G-PDA@SiO2@DOPA were sequentially added to a high-speed mixer, mixed uniformly, and melt mixed on an open type rubber mixing machine at 90℃. The uniformly mixed material was taken out of the open type rubber mixing machine, cooled and crushed to obtain a powdery material, and finally preformed into a cake to obtain an epoxy resin plastic packaging material.

[0039] Example 2: An epoxy resin plastic packaging material, the specific preparation steps are as follows:

[0040] (1) 4 g of DOPO was dissolved in 1000 mL of ethanol, heated to 85℃, and 20 mL of hydrogen peroxide solution was slowly added and reacted for 12 h, filtered and washed, and dried to obtain DOPA;

[0041] (2) Under nitrogen protection, 4 g of DOPA was uniformly mixed with 8 g of mesoporous silica, and reacted at 130℃ for 30 min to obtain DOPA-mesoporous silica, namely SiO2@DOPA;

[0042] (3) 6 g of DOPA-mesoporous silica powder was ultrasonically dispersed in 1000 mL of deionized water, ultrasonic dispersion for 30 min, 6 g of dopamine hydrochloride and 1.51 g of guanine were added respectively and stirred for 10 min, then Tris buffer was added, the pH value was adjusted to 8.5, and the reaction was carried out at 40℃ for 12 h, purification, centrifugal washing with distilled water for three times, and soaking in distilled water under gentle stirring for three days to remove unbound polydopamine, the obtained black precipitate was washed with distilled water again, and dried in an oven at 60℃ to obtain PDA-coated DOPA-mesoporous silica, namely G-PDA@SiO2@DOPA;

[0043] (4) o-cresol novolac type epoxy resin 10 g, linear phenolic resin 4 g, spherical silica 30 g, angular silica 50 g, epoxy group trimethoxysilane 0.2 g, mercapto trimethoxysilane 0.2 g, carbon black 0.4 g, palm wax 0.5 g, 2-methyl imidazole 0.05 g, epoxy and polyether dual functional group modified silicone oil 0.1 g, flame retardant G-PDA@SiO2@DOPA 0.5 g are sequentially added into a high-speed mixer, mixed uniformly, melt mixed on an open type rubber mixing mill at 95℃, the uniformly mixed material is taken out from the open type rubber mixing mill, cooled and crushed to obtain a powdery material, and finally preformed into a cake to obtain an epoxy resin plastic packaging material.

[0044] Example 3: An epoxy resin plastic packaging material, the specific preparation steps are as follows:

[0045] (1) 5 g of DOPO is dissolved in 1000 mL of ethanol, heated to 85℃, 20 mL of hydrogen peroxide solution is slowly added dropwise and reacted for 12 h, filtered, washed and dried to obtain DOPA;

[0046] (2) Under nitrogen protection, 4 g of DOPA is uniformly mixed with 8 g of mesoporous silica, and reacted at 130℃ for 30 min to obtain DOPA-mesoporous silica, namely SiO2@DOPA;

[0047] (3) 8 g of DOPA-mesoporous silica powder is ultrasonically dispersed in 1000 mL of deionized water for 30 min, 8 g of dopamine hydrochloride and 1.51 g of guanine are added and stirred for 10 min, then Tris buffer solution is added, the PH value is adjusted to 8.5, and the reaction is carried out at 40℃ for 12 h, then purified, centrifuged with distilled water for three times, and immersed in distilled water under gentle stirring for three days to remove unbound polydopamine, the obtained black precipitate is washed with distilled water again and dried in an oven at 60℃ to obtain PDA-coated DOPA-mesoporous silica, namely G-PDA@SiO2@DOPA;

[0048] (4) o-cresol novolac type epoxy resin 10 g, linear phenolic resin 4 g, spherical silica 50 g, angular silica 30 g, epoxy group trimethoxysilane 0.2 g, mercapto trimethoxysilane 0.2 g, carbon black 0.4 g, palm wax 0.5 g, 2-methyl imidazole 0.05 g, epoxy and polyether dual functional group modified silicone oil 0.1 g, flame retardant G-PDA@SiO2@DOPA 0.6 g are sequentially added into a high-speed mixer, mixed uniformly, melt mixed on an open type rubber mixing mill at 105℃, the uniformly mixed material is taken out from the open type rubber mixing mill, cooled and crushed to obtain a powdery material, and finally preformed into a cake to obtain an epoxy resin plastic packaging material.

[0049] Comparative Example 1: The difference from Example 1 is that G-PDA@SiO2@DOPA is replaced by SiO2@DOPA, and the remaining steps are the same as Example 2.

[0050] Comparative Example 2: The difference from Example 1 is that DOPA and guanine reaction is added to the raw materials, and the specific steps are as follows:

[0051] (1) 21.7g of DOPA was dissolved in 200mL of anhydrous ethanol, and stirred uniformly; 15.1g of guanine was dissolved in 200mL of deionized water, and stirred uniformly, the two solutions were mixed together, and stirred at 70°C for 4h to obtain the flame retardant DOPA-G;

[0052] The o-cresol formaldehyde type epoxy resin 10g, the linear phenolic resin 4g, the spherical silica 40g, the angular silica 40g, the epoxy-based trimethoxysilane 0.2g, the mercapto trimethoxysilane 0.2g, the carbon black 0.4g, the palm wax 0.5g, the 2-methyl imidazole 0.05g, the epoxy and polyether bifunctional modified silicone oil 0.1g, and the flame retardant DOPA-G 0.4g were sequentially added into a high-speed mixer, mixed uniformly, and melt mixed on an open type rubber mixing machine at 90°C. The uniformly mixed material was taken out from the open type rubber mixing machine, cooled and crushed to obtain a powdery material, and finally preformed into a cake to obtain an epoxy resin plastic sealing material.

[0053] Comparative Example 3: The difference from Example 1 is that guanine, DOPO and mesoporous silica are mixed and added, and the specific steps are as follows:

[0054] The guanine, DOPO and mesoporous silica were physically mixed in a mass ratio of 1:1:1 for 10min to obtain a mixture A.

[0055] The o-cresol formaldehyde type epoxy resin 10g, the linear phenolic resin 4g, the spherical silica 40g, the angular silica 40g, the epoxy-based trimethoxysilane 0.2g, the mercapto trimethoxysilane 0.2g, the carbon black 0.4g, the palm wax 0.5g, the 2-methyl imidazole 0.05g, the epoxy and polyether bifunctional modified silicone oil 0.1g, and the mixture A 0.4g were sequentially added into a high-speed mixer, mixed uniformly, and melt mixed on an open type rubber mixing machine at 90°C. The uniformly mixed material was taken out from the open type rubber mixing machine, cooled and crushed to obtain a powdery material, and finally preformed into a cake to obtain an epoxy resin plastic sealing material.

[0056] Comparative Example 4: The difference from Example 1 is that no flame retardant is added, and the specific steps are as follows:

[0057] Into a high-speed mixer, 10 g of o-cresol novolac epoxy resin, 4 g of linear phenol formaldehyde resin, 40 g of spherical silica, 40 g of angular silica, 0.2 g of epoxy group trimethoxysilane, 0.2 g of mercapto trimethoxysilane, 0.4 g of carbon black, 0.5 g of palm wax, 0.05 g of 2-methyl imidazole, and 0.1 g of epoxy and polyether bifunctional modified silicone oil were sequentially added, mixed uniformly, and melt-mixed on an open mill at 90°C. The uniformly mixed material was taken out of the open mill, cooled, and crushed to obtain a powdered material. Finally, the powdered material was pre-formed into a cake to obtain an epoxy resin plastic packaging material.

[0058] Performance test

[0059] According to the GB / T 40564-2021 “Epoxy Plastic Packaging Material for Electronic Packaging” standard, the spiral flow length, gelation time, and bending strength of the epoxy resin compositions prepared in the examples and comparative examples were determined.

[0060] Spiral flow length (SF): a spiral mold was used to measure the spiral flow length. The length of the spiral flow was measured under the conditions of a mold press temperature of 175°C, an injection clamping pressure of 6.9 MPa, and a hardening time of 120 s.

[0061] Gelation time (GT): the epoxy molding powder was poured onto the center of an electric heating plate at 175±2°C, and immediately flattened with a tongue depressor. The flattened area was controlled to be 5 cm 2 . The time was counted from the start of the powder melting, and the melt was pushed with the tongue depressor at a frequency of 1 / s. When the melt changed from a fluid to a gel state, the end point was determined, and the time used was read.

[0062] Bending strength and modulus: a sample bar was pressed by a mold press (the sample bar size was 80 mm long, 10 mm wide, and 4 mm high), and the molding conditions were as follows: a metal mold temperature of 175±2°C, an injection pressure of 70±2 kg / cm 2 , and a curing time of 120 s. The bending strength and modulus of the molded sample bar were determined by a three-point bending test method on a universal tensile testing machine.

[0063] Flash length: the flash length was determined on a mold press with a flash metal mold, the mold temperature was 175±2°C, the transfer pressure was 70 kg±2 kg / cm 2 , 20±2 g of sample powder was poured into the plastic packaging machine cavity for molding, and the flash mold measured the length of the overflow from different grooves after the mold was moved to the operation table after molding for 120 s.

[0064] Flame retardant performance test: according to GB / T 2408-2021, the sample was cut into a long strip of 130 mm x 13 mm x 3 mm, and a vertical burning tester was used for the experiment.

[0065] Laser marking experiment: Raycus fiber laser with wavelength 1064 nm was used, and marking was performed under a lens with a focal length of 160 mm. The specific steps were as follows:

[0066] After the samples obtained in the examples and comparative examples were molded, they were polished with 2000 mesh sandpaper and cleaned by ultrasonic ethanol to ensure the surface was clean. The marking parameters were set as follows: power 20 W, scanning speed 1000 mm / s, frequency 20 kHz, filling interval 0.05 mm, and spot diameter about 40 µm. The marking pattern was a 10 mm x 10 mm square. Then, contrast measurement was performed. The color difference ΔE between the laser area and the unmarked area was used to represent the clarity of the printing. The KonicaMinolta CR-400 colorimeter was used for testing, using D65 light source and 10° observation angle. The L*, a*, and b* values were measured at the center and four corners of the laser marking area, and compared with the unmarked area to calculate ΔL, Δa, and Δb. Then, the average value ΔE was calculated according to the CIE 1976 standard formula. Wherein, ΔE≥25 indicates that the printing contrast is significant and the identification is clear, 15≤ΔE<25 is medium readable, and ΔE<15 is low contrast. The performance test results are shown in Table 1.

[0067] Table 1 Performance test results

[0068] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Spiral flow length (cm) 83 79 89 82 86 84 82 Gelation time (s) 23 22 22 24 23 21 22 175 °C flexural strength (Kgf / cm 2 )]> 373.4 309.0 428.1 315.0 323.1 353.2 345.7 175 °C flexural modulus (Kgf / mm 2 )]> 440.2 396.5 512.7 338.3 442.6 343.5 416.0 Flash 5um / 10um (mm) 0.8 / 1.0 0.8 / 0.8 0.8 / 0.8 1.4 / 1.6 1.0 / 1.2 1.4 / 1.6 0.8 / 1.0 Flame retardant rating (UL-94) V-0 V-0 V-0 V-1 V-0 V-1 V-2 Contrast (ΔΕ) 31 30 31 18 21 23 11

[0069] As can be seen from the data of Examples 1-3 in Table 1, the epoxy resin plastic packaging material prepared by the present application exhibits significant comprehensive performance advantages. The PDA coating layer formed by the self-polymerization of dopamine on the surface of mesoporous silica provides a uniform interface transition, greatly improving the compatibility between the flame retardant and the matrix, and improving the dispersibility of the flame retardant in the matrix. The introduction of guanine molecules not only provides nitrogen-based flame retardants, but also may cross-link with the resin through its nitrogen-containing heterocyclic structure. This multi-level interface interaction jointly constructs a stable three-dimensional network structure, reducing the risk of small molecule overflow of the epoxy plastic packaging material. At the same time, through the self-polymerization coating of dopamine on the surface of mesoporous silica, a hierarchical composite material system is formed, realizing the controlled release of functional components. Under high temperature conditions, the gradient decomposition characteristics of the PDA coating layer enable the flame retardant components to function in stages, thereby achieving more efficient flame retardant protection, neutralizing the advantages of nitrogen and phosphorus flame retardants, and avoiding the shortcomings of unclear printing and poor effect during laser marking. The present application provides a new solution for electronic packaging materials.

[0070] From the data comparison of Example 1 and Comparative Examples 1-3 in Table 1, it can be seen that the present application realizes the significant improvement of the flame retardant performance, printing effect, mechanical property of the material and the significant reduction of overflow by constructing the dopamine-coated mesoporous silica carrier system. The performance improvement may be due to the gradient release mechanism and interface enhancement effect formed by the dopamine coating layer in the material system:

[0071] Firstly, the PDA coating layer can form a stable interface transition zone with the resin matrix, enhance the compatibility between the flame retardant and the matrix, reduce the risk of small molecule overflow, and at the same time, P, N, Si synergistic flame retardant makes EMC reach V-0 with a small amount of G-PDA@SiO2@DOPA added;

[0072] Secondly, the PDA coating layer may realize the controlled release of the flame retardant components through its gradient decomposition characteristics, preferentially releasing guanine as a nitrogen-based flame retardant, and gradually releasing DOPA as a phosphorus-based flame retardant with the increase of temperature. This phased release mechanism not only optimizes the flame retardant effect, but also avoids the generation of micro-bubbles in EMC material due to excessive nitrogen-based flame retardant content, which affects the laser printing effect and causes the problem of gray printing color due to the carbonization of excessive phosphorus-based flame retardant content to form a dense carbon protective layer, which prevents the inorganic filler from being exposed. Through the synergistic addition of nitrogen and phosphorus-based flame retardants and gradient release, the inorganic filler is exposed after gasification, thereby ensuring the printing effect.

[0073] From the data comparison of Example 1 and Comparative Example 4 in Table 1, it can be seen that the present application realizes the synergistic optimization of material performance by constructing the dopamine-coated mesoporous silica carrier system. This optimization may be due to the multi-level interface interaction mechanism formed in the material system:

[0074] Among them, the PDA coating layer forms a stable chemical bonding network with each component through the active groups in its molecular structure, improving the uniform dispersion of the flame retardant in the matrix, and the synergistic effect of the PDA coating layer and the DOPA flame retardant may form a more dense carbon protective layer structure and improve the utilization efficiency of laser energy. These synergistic effects of interface interaction together promote the overall improvement of material performance, which embodies the innovation of the present application in material design.

[0075] It should be understood by those skilled in the art that the above discussion of any embodiment is only exemplary and is not intended to limit the scope of the present application to these examples; under the idea of the present application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be brief, they are not provided in detail.

Claims

1. A method for preparing an epoxy resin molding compound, characterized in that, Includes the following steps: Epoxy resin, phenolic resin, inorganic filler, colorant, release agent, coupling agent, curing accelerator, reactive stress modifier, flame retardant-loaded mesoporous silica are mixed evenly, melt-mixed at 90-105℃, and cooled to obtain epoxy resin molding compound. The weight ratio of epoxy resin, phenolic resin, inorganic filler, colorant, release agent, coupling agent, curing accelerator, reactive stress modifier, and flame retardant-supported mesoporous silica is 4-10 parts: 2-10 parts: 70-90 parts: 0.1-0.5 parts: 0.2-0.6 parts: 0.1-0.4 parts: 0.03-0.07 parts: 0.1-0.5 parts: 0.2-0.6 parts; The preparation steps of the flame retardant-supported mesoporous silica are as follows: S1: Dissolve DOPO in ethanol, heat to 85℃, add hydrogen peroxide solution dropwise and react for 12 hours, then purify to obtain DOPA; S2: Mix DOPA with mesoporous silica evenly and react at 130℃ for 30 min to obtain DOPA-mesoporous silica, i.e., SiO2@DOPA; S3: DOPA-mesoporous silica powder was ultrasonically dispersed in deionized water, and after adding dopamine hydrochloride and guanine and dispersing for 10 min, Tris buffer was added to adjust the pH to 8.

5. The mixture was reacted at 40℃ for 12 h and purified to obtain PDA-coated DOPA-mesoporous silica, namely G-PDA@SiO2@DOPA.

2. The preparation method according to claim 1, characterized in that, The ratio of DOPO, ethanol, and hydrogen peroxide solution used in step S1 is 3-5g:100mL:20mL.

3. The preparation method according to claim 1, characterized in that, In step S2, the ratio of DOPA to mesoporous silica is 3-4g:6-8g.

4. The preparation method according to claim 1, characterized in that, The mesoporous silica described in step S2 has an outer diameter of 450-550 nm and a pore size of 2-4 nm.

5. The preparation method according to claim 1, characterized in that, In step S3, the ratio of DOPA-mesoporous silica, dopamine hydrochloride, guanine, and deionized water is 6-8g:6-8g:1.51g:1000mL.

6. The preparation method according to claim 1, characterized in that, The inorganic filler is any one of silicon dioxide, aluminum oxide, boron nitride, boron carbide, and silicon carbide.

7. The preparation method according to claim 1, characterized in that, The epoxy resin is any one of o-cresol-type epoxy resin, dicyclopentadiene-type epoxy resin, biphenyl-type epoxy resin, naphthol-phenolic epoxy resin, and thioether-type epoxy resin; the phenolic resin is any one of phenol ether-phenolic resin, o-methylphenolic resin, biphenyl-phenolic resin, and phenol-arylalkylphenolic resin.

8. The preparation method according to claim 1, characterized in that, The colorant is carbon black; the release agent is a wax-based compound.

9. The preparation method according to claim 1, characterized in that, The coupling agent is any one of mercapto-type siloxane coupling agents, amino-type siloxane coupling agents, and epoxy-type siloxane coupling agents; the curing accelerator is any one of imidazole compounds, tertiary amine compounds, and organophosphorus compounds; and the reactive stress modifier is any one of carboxyl silicone oil, amino silicone oil, and epoxy-type silicone oil.