A spherical glass powder / silane coupling agent composite system for EMC and a preparation method thereof

Abstract

The application discloses a spherical glass powder / silane coupling agent composite system for EMC and a preparation method thereof. The composite system comprises 80-90 wt% of spherical glass powder, 8-15 wt% of prepolymer and 1-5 wt% of cross-linking metal ion source; the prepolymer is formed by the coordination bond and covalent bond coordination connection of perfluoroalkyl modified nitrogen heterocyclic polydentate carboxylic acid ligand, high coordination active metal source compound and silane coupling agent. The spherical glass powder is modified at low temperature by the prepolymer and the cross-linking metal ion source to form a transparent interface modification layer, which can be applied to the low-temperature curing EMC process of 80-120 DEG C. The EMC material prepared by the low-temperature curing process of the spherical glass powder / silane coupling agent composite system has the 550 nm light transmittance of greater than or equal to 90%, the bending strength of greater than or equal to 100 MPa, the interface shear strength of greater than or equal to 17 MPa at-40 DEG C, and the performance retention rate of greater than or equal to 90% after 1000 h of damp-heat aging, and is suitable for the packaging of heat-sensitive optical devices.

Description

Technical Field

[0001] This invention belongs to the field of EMC filler technology, specifically relating to a spherical glass powder / silane coupling agent composite system for EMC and its preparation method. Technical Background

[0002] In the field of electronic packaging, low-temperature curing epoxy molding compounds (EMC) have become a key material for achieving miniaturized and high-reliability packaging of precision optical devices and high-performance integrated circuits because they can effectively prevent damage to heat-sensitive components such as LEDs, sensors, and organic phosphor layers caused by high temperatures. However, there are many bottlenecks in existing technologies that limit their widespread application.

[0003] Conventional EMC requires high-temperature curing above 160℃ to achieve sufficient cross-linking of the resin and thus mechanical strength (flexural strength ≥90MPa). However, the temperature resistance of heat-sensitive elements in optical chips must not exceed 120℃. If cured at low temperatures (≤120℃), insufficient resin cross-linking density leads to decreased interfacial bonding and insufficient flexural strength, failing to meet the high structural strength requirements of packaging applications. Furthermore, low-temperature curing restricts molecular chain activity, easily generating internal stress and reducing interfacial shear strength. During thermal cycling, packaged devices are prone to failure phenomena such as debonding and cracking.

[0004] Spherical glass powder, as an important inorganic filler in EMC, can effectively adjust the coefficient of thermal expansion and improve the mechanical properties of the material. However, due to the difference in polarity, its interfacial compatibility with the organic resin matrix is ​​poor; moreover, the coefficients of thermal expansion of the two are mismatched (CTE of glass powder ≈ 5 × 10⁻⁶). -6 / ℃, epoxy resin ≈60×10 -6 The temperature (°C) can cause microcracks to easily form at the interface, and the interfacial shear strength is usually below 10 MPa, ultimately leading to device packaging failure. Traditional silane coupling agents, such as linear alkylsilanes, can connect glass powder and resin to a certain extent, but they lack sufficient steric hindrance. In humid and hot environments, the surface of the glass powder easily absorbs moisture, which damages the interfacial bonding and leads to the deterioration of material properties.

[0005] In existing technologies, it is difficult to precisely control the thickness and uniformity of the modified layer in glass powder modification processes, leading to unstable quality of the modified layer and affecting the consistency of material properties. Over-modification increases light scattering and reduces light transmittance, failing to meet the stringent requirements of LEDs, optical sensors, and other devices for high light transmittance in optical signal transmission. Some processes that achieve low-temperature curing through special catalysts or complex equipment are costly and incompatible with low-temperature curing processes. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a spherical glass powder / silane coupling agent composite system for EMC and its preparation method, which simultaneously achieves high light transmittance, high strength, and aging resistance of EMC under low-temperature curing conditions.

[0007] In a first aspect, the present invention provides a spherical glass powder / silane coupling agent composite system for EMC, comprising the following components by mass fraction: 80-90 wt% spherical glass powder, 8-15 wt% prepolymer, and 1-5 wt% crosslinked metal ion source;

[0008] The prepolymer is composed of the following components linked together by coordination and covalent bonds:

[0009] (a) Perfluoroalkyl-modified nitrogen-containing heterocyclic polydentate carboxylic acid ligands: general formula: R 1 -XN-(COOH)3, where R 1 It is a C8-C12 alkyl group containing a fluorine group, with a hydrophobicity parameter LogP ≥ 4.5, where X is a nitrogen heterocycle bonded to R via a methylene bond. 1 connect;

[0010] (b) A highly coordinating metal source compound; selected from one or more titanates, zirconates and their hydrolysis products or chelate derivatives; the molar ratio of (b) to (a) is 0.8 to 1.2;

[0011] (c) Silane coupling agent: accounting for 5 wt% to 20 wt% of the total mass of the prepolymer.

[0012] The spherical glass powder / silane coupling agent composite system provided in this patent utilizes branched regulation, multi-bond anchoring, and dynamic buffering synergy:

[0013] R in perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligands 1 The hydrophobicity parameter LogP≥4.5 of branched alkyl groups can form a molecular-level hydrophobic barrier on the surface of glass powder, reducing interfacial light scattering caused by water molecule adsorption; at the same time, the steric hindrance of the branched structure can prevent the close packing of glass powder particles, reduce the polar attraction between glass powder particles, and avoid agglomeration.

[0014] Crosslinked metal ion sources form coordination bonds with carboxyl groups of perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligands to construct a dynamic network; the reversible breaking and recombination of coordination bonds can buffer interfacial stress; at the same time, this strong coordination effect inhibits hydrolysis and improves aging resistance.

[0015] Highly coordinated metal source compounds can act as bridges, connecting organic ligands and inorganic metal centers via carboxyl-O-metal bonds with perfluoroalkyl-modified nitrogen-containing heterocyclic polydentate carboxylic acid ligands to form stable coordination complexes. This constructs an organic-inorganic transition layer, mitigating the polarity difference between glass powder and resin. Silane coupling agents further covalently anchor the glass powder to the resin matrix, significantly improving interfacial adhesion.

[0016] Furthermore, the cross-linked metal ion source is selected from Cu. 2+ Zn2+ Ni 2+ Al 3+ The molar ratio of the carboxyl group of the perfluoroalkyl-modified nitrogen heterocyclic polydentate ligand is 1:2 to 3.

[0017] Further, the titanate is selected from one or more of di(acetylacetone)diisopropoxytitanium, tetraisopropoxytitanium (Ti(OiPr)4), and bis(dioctylpyrophosphoryloxy)ethylene titanate; the zirconate is selected from one or more of tetraisopropoxide zirconium (Zr(OiPr)4), tetra-n-butoxide zirconium (Zr(OnBu)4), tetraisobutoxide zirconium (Zr(OiBu)4), tetra-tert-butoxide zirconium (Zr(OtBu)4), dimethoxydiisopropoxide zirconium (Zr(OMe)2(OiPr)2), and acetylacetone zirconium; the general chemical formula of the silane coupling agent is (R 2 O)3Si-R 3 -Y, where R 2 It is a C1-C2 alkyl group, R 3 It is a C3-C6 alkylene group, and Y is selected from one or more of amino, phenylamino, or epoxypropoxy groups.

[0018] Furthermore, the spherical glass powder has a particle size of 5–10 μm, a refractive index of 1.48–1.52, and a specific surface area of ​​2.0–5.0 m². 2 / g.

[0019] Secondly, the present invention provides a method for preparing the above-mentioned spherical glass powder / silane coupling agent composite system, comprising the following steps:

[0020] (1) Pretreatment of spherical glass powder: vacuum drying at 80-100℃ for 2h, ultrasonic activation in 0.5% dilute hydrochloric acid for 30min, washing with deionized water until neutral, and then drying.

[0021] (2) Preparation of perfluoroalkyl-modified nitrogen-containing heterocyclic polydentate carboxylic acid ligand (a): The ligand (a) was obtained from a nitrogen-containing heterocyclic polydentate carboxylic acid core via esterification with an organic amine condensing agent and aminolysis with a perfluoroalkyl amine; the component (a) had a LogP ≥ 5.8 and a metal chelating capacity ≥ 5.0 mmol Zn. 2+ / g;

[0022] (3) Preparation of prepolymer: Under an inert atmosphere, a perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand (a) and a highly coordinated metal source compound (b) are reacted at 0-40°C for 1-3 h with 0.1-0.5 wt% dibutyltin dilaurate as catalyst to form a polydentate coordination complex; then a silane coupling agent (c) is added and reacted at 40-60°C for 2-4 h to obtain the prepolymer;

[0023] (4) Low-temperature surface modification: Pretreated glass powder, prepolymer and cross-linked metal ion source are reacted in a mixed solvent of haloalkanes-aromatics at -10 to 10℃ for 4 to 8 hours to form a modification layer with a thickness of 5 to 8 nm; centrifugation and washing, vacuum drying at 50 to 100℃ to obtain a spherical glass powder / silane coupling agent composite system.

[0024] Furthermore, step (2) specifically includes the following process:

[0025] S1. Preparation of activated ester: The nitrogen-containing heterocyclic polydentate carboxylic acid core, N-hydroxysuccinimide (NHS), and dicyclohexylcarbodiimide were dissolved in N,N-dimethylformamide at a molar ratio of 1:(3-3.3):(3-3.3). The mixture was stirred at 0-5°C for 2-3 hours. TLC monitoring was performed until the starting material disappeared, yielding the activated ester filtrate. The nitrogen-containing heterocyclic polydentate carboxylic acid core was selected from triazine tricarboxylic acid and pyridine tricarboxylic acid.

[0026] S2. Hydrophobic group modification: The activated ester filtrate from step S1 is subjected to aminolysis reaction with perfluoroalkylamine in tetrahydrofuran medium at 30-40℃ until TLC shows the disappearance of the activated ester and the formation of amide product; the molar amount of the perfluorobranched alkylamine is 3 to 3.3 times that of the activated ester, and its dropping rate is controlled at 0.3 to 0.5 mol / h to avoid local aggregation;

[0027] S3. The amide product from step S2 was purified by acid precipitation and supercritical CO2 extraction to obtain a nitrogen-containing heterocyclic polydentate carboxylic acid ligand.

[0028] Further, in step (3), component (b) is added in three equal portions at 10-20 min intervals, with an addition rate ≤5 mL / min; in step (4), the haloalkane-aromatic hydrocarbon is dichloromethane-toluene or chlorobenzene-n-hexane with a v / v ratio of 7-8:2-3; the water content of the reaction system is ≤200 ppm, and the crosslinked metal ion source is added in three to four portions with an addition rate ≤0.5 g / min.

[0029] The present invention employs a low-temperature, low-water modification process that can suppress excessive hydrolysis of highly coordinated active metal source compounds; and avoids the problems of layer agglomeration and uneven thickness caused by traditional high-temperature modification.

[0030] Thirdly, the present invention provides the application of the above-mentioned spherical glass powder / silane coupling agent composite system in the preparation of EMC materials: the spherical glass powder / silane coupling agent composite system is mixed with epoxy resin, curing agent and accelerator in a mass ratio of (65-70):(15-20):(1.2-2.0):(0.075-0.16), and after curing at 80-120°C, a low-temperature curing EMC material is obtained;

[0031] The EMC material has a transmittance of ≥88% at 550nm, a flexural strength of ≥95MPa, and an interfacial shear strength of ≥15MPa at -40℃.

[0032] Furthermore, the epoxy resin matrix is ​​bisphenol A type, hydrogenated bisphenol A type, alicyclic epoxy resin or a mixture thereof; the curing agent is methylhexahydrophthalic anhydride or methylnadic anhydride; and the accelerator is 2-ethyl-4-methylimidazole or 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0033] Beneficial effects

[0034] 1. High light transmittance: The spherical glass powder / silane coupling agent composite system provided by this invention has a dual regulatory effect of hydrophobicity and steric hindrance of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand; the resulting spherical glass powder / silane coupling agent composite system has good light transmittance (550nm wavelength transmittance ≥90%), and the light transmittance retention rate after resistant to humid heat aging is ≥95%; it is expected to solve the problem of insufficient light transmittance caused by interface scattering and filler agglomeration in traditional low-temperature curing EMC, so as to meet the needs of LED, optical sensors and other optical signal transmission.

[0035] 2. High strength and long-term interfacial stability: In the spherical glass powder / silane coupling agent composite system provided by this invention, the dynamic coordination network of the highly coordinated active metal source compound and the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand, as well as the high bond energy covalent coordination bond of the cross-linked metal ions, enhance the interfacial bonding, thereby improving stability and achieving dynamic coordination buffering to resist hydrolysis and stress fatigue: bending strength ≥95MPa, interfacial shear strength at -40℃ ≥15MPa, and bending strength retention rate and interfacial shear strength retention rate after 1000h of damp heat aging are both ≥94%, which can significantly improve the long-term reliability of the packaged device and extend the device life.

[0036] 3. Low-temperature process compatibility: This invention can achieve high performance by curing at 80-120℃, avoiding the failure of heat-sensitive components (such as organic fluorescent layers and flexible circuits) caused by traditional EMC requiring high-temperature curing above 160℃. It is compatible with heat-sensitive optical device packaging, thus broadening the application scenarios of EMC in precision optical packaging. Attached Figure Description

[0037] Figure 1 The infrared absorption spectra of the spherical glass powder / silane coupling agent composite systems of Example 1 and Comparative Examples 1-3 are shown.

[0038] Figures 2-4 The XPS characteristic spectra and peak division results for Zr 3d, Zn 2p, and Si 2p of the spherical glass powder / silane coupling agent composite systems of Example 1 and Comparative Examples 1-3 are shown respectively. Detailed Implementation

[0039] To more fully demonstrate the practical applications and technical advantages of the present invention, the invention will be further described in detail below with reference to specific embodiments. Those skilled in the art should understand that these embodiments are merely examples and do not constitute a limitation on the scope of protection of the present invention.

[0040] Unless otherwise specified, the experimental methods used in the specific implementation methods are all conventional methods; the materials and reagents used are all commercially available unless otherwise specified.

[0041] The properties and sources of some raw materials used in the examples and comparative examples are as follows:

[0042] Zirconium tetrabutoxide (Zr(OnBu)4), a transparent pale yellow viscous liquid with a refractive index (n20 / D) of 1.465, is manufactured by Wuhan Kemike Biomedical Technology Co., Ltd.

[0043] Zirconium acetylacetonate, white powder, n20D = 1.4494, Hubei Longxin Chemical Industry Co., Ltd.

[0044] NDZ-311 bis(dioctylpyrophosphoryloxy)ethylene titanate, yellow transparent viscous liquid, n20D=1.47, Guangzhou Jianshuang Chemical Technology Co., Ltd.

[0045] Spherical glass powder was purchased from Guangdong Yuanlei Powder Co., Ltd., and its main parameters are shown in Table 1.

[0046] Table 1

[0047] Technical indicators Whiteness density Particle size (D50) Mohs hardness Refractive index Loss on ignition Specific surface area parameter 96 <![CDATA[2.7g / cm 3 ]]> 4μm 7.8 1.49 0.1wt% <![CDATA[2.8m 2 / g]]>

[0048] Preparation Example 1

[0049] Preparation of perfluorooctyl-modified triazine tricarboxylic acid polydentate carboxylic acid ligands.

[0050] S1. Preparation of activated ester: 2,4,6-tricarboxylic acid-1,3,5-triazine (TMT, CAS 6372-14-7, 0.1 mol) + N-hydroxysuccinimide (NHS, CAS 6066-82-6, 0.3 mol) and dicyclohexylcarbodiimide (CAS 538-75-0, 0.3 mol) were dissolved in N,N-dimethylformamide (200 mL); the reaction was stirred at 0 °C for 2 h (TLC monitoring, developing solvent: methanol / dichloromethane = 1:8, starting material Rf≈0.1, product Rf≈0.6). The dicyclohexylurea precipitate was removed by filtration, and the filter cake was washed with 50 mL of cold N,N-dimethylformamide; the filtrate was collected to obtain the activated ester intermediate, abbreviated as TMT-tri(NHS) ester, with a yield of 95%.

[0051] S2. Amine hydrolysis reaction: Transfer the filtrate of TMT-tris(NHS) ester (0.1 mol) obtained in step S1 to a three-necked flask, add tetrahydrofuran (300 mL) and stir to dissolve; slowly add 1H,1H-perfluorooctylamine (CAS: 307-29-9, 0.31 mol) dropwise over 1 hour. Heat the system to 40°C and react at this temperature for 12 hours (TLC showed complete disappearance of the activated ester (Rf≈0.6), with the same developing solvent as above). Remove the tetrahydrofuran by rotary evaporation, add 500 mL of water to the residue, and adjust the pH to 3 with 1 mol / L HCl (stirring while adding to avoid local over-acidity), precipitating a white solid. Supercritical CO2 extraction at 40℃ and 15MPa for 3 h yielded 2,4,6-tris[N-(3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl)acetamido]-1,3,5-triazine, with a yield of 86% and an HPLC purity of 99.2%.

[0052] logP = 5.8, metal chelating capacity = 5.3 mmol Zn 2+ / g.

[0053] Preparation Example 2

[0054] Preparation of perfluorooctyl-modified pyridine tricarboxylic acid polydentate carboxylic acid ligands.

[0055] The polydentate carboxylic acid core used in step S1 was 2,4,6-pyridinetricarboxylic acid (CAS 53686-84-7, 0.1 mol), and the rest was the same as in Preparation Example 1, to obtain the activated ester intermediate: pyridine-2,4,6-tricarboxylic acid tris(N-succinimide ester), with a yield of 93%.

[0056] Step S2 is the same as in Preparation Example 1, yielding solid 2,4,6-tris[N-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl)acetamido]pyridine with a yield of 86% and an HPLC purity of 99.3%.

[0057] The hydrophobicity parameter logP was measured to be 6.0, and the metal chelating capacity was 5.0 mmol Zn. 2+ / g.

[0058] Preparation Example 3

[0059] Preparation of perfluorooctyl-modified hyponitrotriacetic acid polydentate carboxylic acid ligands.

[0060] The difference from Preparation Example 1 is that the polydentate carboxylic acid core used is hypozinogentriacetic acid (CAS 139-13-9, 0.1 mol), otherwise the same as Preparation Example 1; the final product N,N',N”-tris[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl)acetamyl]hypozinogentriacetic acid was obtained in 82% yield.

[0061] The measured LogP was 5.0, and the metal chelating capacity was 4.6 mmol Zn. 2+ / g.

[0062] Example 1

[0063] A composite system of spherical glass powder / silane coupling agent for EMC is prepared as follows:

[0064] (1) Spherical glass powder was vacuum dried at 80℃ for 2 hours, ultrasonically activated with 0.5wt% HCl for 30 minutes, washed with water until neutral, and then dried.

[0065] (2) Preparation of perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligands (a): perfluorooctyl-modified triazine tricarboxylic acid polydentate ligands prepared according to the steps described in Preparation Example 1;

[0066] (3) Preparation of prepolymer: Under nitrogen atmosphere, 60wt% of component (a) obtained in step (2) with Zr(OnBu)4 was reacted with 0.3wt% dibutyltin dilaurate at 0℃ for 2h (Zr source was added in 3 equal portions with an interval of 15min); then 10wt% phenylaminopropyltrimethoxysilane was added, and the reaction system was heated to 50℃ at a rate of 2℃ / min and the reaction was continued for 3h to obtain the prepolymer;

[0067] (4) Low-temperature modification: 90 wt% of pretreated spherical glass powder was ultrasonically dispersed in anhydrous dichloromethane / toluene (v:v = 7:3, containing molecular sieves to prevent Zr source hydrolysis) for 10 min; 8.5 wt% of the prepolymer from step (3) was added dropwise at a rate of 2 mL / min; after the addition was complete, 1.5 wt% of zinc nitrate was added in 4 batches (each batch 1 h apart); the system was reacted in an ice bath at 0 °C for 6 h from the first addition of zinc nitrate. After centrifugation and washing, the mixture was vacuum dried at 60 °C to obtain the spherical glass powder / silane coupling agent composite system.

[0068] Example 2

[0069] The difference from Example 1 is that component (a) in the prepolymer is replaced with the perfluorooctyl-modified pyridine tricarboxylic acid polydentate ligand obtained in Preparation Example 2; the crosslinking metal ion source in the prepolymer is aluminum nitrate (Al). 3+ :NTA carboxyl group = 1:3).

[0070] Example 3

[0071] The difference from Example 1 is that component (b) in the prepolymer is replaced with zirconium acetylacetonate, and the molar ratio of component (a) to component (b) in the prepolymer is 1:1.2; component (c) is replaced with γ-glycidoxypropyltrimethoxysilane.

[0072] Example 4

[0073] The difference from Example 1 is that in the prepolymer, component (b) is replaced with NDZ-311 bis(dioctylpyrophosphoryloxy)ethylene titanate; the crosslinking metal ion source is nickel nitrate (Ni 2+ :TMT carboxyl group = 1:2.5); and the mixed solvent used in step (4) is chlorobenzene / n-hexane (v:v = 8:2).

[0074] Example 5

[0075] The difference from Example 1 is that component (b) in the prepolymer is replaced with NDZ-311 bis(dioctylpyrophosphoryloxy)ethylene titanate; the crosslinking metal ion source is copper nitrate (Cu). 2+ (TMT carboxyl group = 1:2.5), step (4) reaction temperature -5℃, reaction time is 8h.

[0076] Comparative Example 1

[0077] The prepolymer contained no zirconium source or perfluorooctyl modified triazine tricarboxylic acid polydentate ligand, and the spherical glass powder was modified only with phenylaminopropyltrimethoxysilane. The amount and other raw materials were the same as in Example 1.

[0078] Comparative Example 2

[0079] The difference from Example 1 is that step (4) is changed to react at 100°C for 2 hours.

[0080] Comparative Example 3

[0081] The difference from Example 1 is that component (a) in the prepolymer is replaced with pure 2,4,6-tricarboxylic acid-1,3,5-triazine polydentate carboxylic acid ligand without perfluoroalkyl modification.

[0082] Comparative Example 4

[0083] The difference from Example 1 is that the crosslinking metal ion source in the prepolymer is calcium nitrate (Ca). 2+ (Carboxyl group = 1:2.5).

[0084] Comparative Example 5

[0085] The difference from Example 1 is that no cross-linking metal ion source is added to the prepolymer.

[0086] Comparative Example 6

[0087] The difference from Example 1 is that component (a) in the prepolymer is replaced with the perfluorooctyl-modified hyponitrotriacetic acid (NTA) polydentate carboxylic acid ligand obtained in Preparation Example 3, while the other components are from Preparation Example 1.

[0088] I. Routine Performance Testing

[0089] The following tests were performed on the spherical glass powder / silane coupling agent composite systems of Examples 1-5 and Comparative Examples 1-6:

[0090] Light transmittance is a key indicator of a material's transparency, and a higher value is better. Light transmittance is measured using a UV-Vis spectrophotometer at a wavelength of 550 nm, in accordance with ASTM D1003.

[0091] Bending strength is an assessment of mechanical strength; a higher value indicates greater resistance to deformation. It is determined using a three-point bending test (ASTM D790).

[0092] Viscosity reflects processing fluidity. Low viscosity (<500 mPa·s) is more conducive to coating and filling micropores. It is tested with a viscometer at 25°C.

[0093] Metal ion mobility (ppm), a low mobility (<50ppm) indicates good metal ion immobilization, preventing corrosion of electronic devices. Measured by ICP-MS.

[0094] The test results for the above items are shown in Table 2.

[0095] Table 2

[0096] project transmittance / % Bending strength / MPa Viscosity / mPa·s Metal migration rate / ppm Example 1 95.1 90 340 28 Example 2 94.5 85 305 20 Example 3 93 88 380 35 Example 4 91.8 95 390 38 Example 5 92.3 92 320 23 Comparative Example 1 80.5 60 610 95 Comparative Example 2 84.6 73 480 67 Comparative Example 3 81.0 53 625 112 Comparative Example 4 88.7 82 450 65 Comparative Example 5 78.2 54 638 141 Comparative Example 6 86.8 80 520 55

[0097] Table 2 shows that the spherical glass powder / silane coupling agent composite systems constructed from perfluoroalkyl-modified nitrogen-based heterocyclic polydentate carboxylic acid ligands in Examples 1-5 generally outperformed the comparative examples: the transmittance was ≥91%, with Example 1 reaching 95.1%, due to the hydrophobic barrier of the perfluoroalkyl group reducing interfacial light scattering. In Comparative Example 1, the nitrogen-based heterocyclic polydentate carboxylic acid ligand without perfluoroalkyl modification, and Comparative Example 3 or the nitrogen-based heterocyclic polydentate carboxylic acid ligand without perfluoroalkyl modification, experienced increased light scattering due to water vapor adsorption and aggregation caused by the hydrophilic groups, resulting in a transmittance ≤85%.

[0098] The flexural strength of the examples was 85–95 MPa; viscosity ≤390 mPa·s; and metal migration ≤38 ppm. Example 2 was Al. 3+ Coordination, compared to Zn 2+ With high charge density and a denser coordination network, the viscosity is as low as 305 mPa·s, and the metal mobility is as low as 20 ppm. Example 4 achieves 95 MPa, thanks to the synergistic enhancement of interfacial bonding between the NDZ-311 bis(dioctylpyrophosphoryloxy)ethylene titanate coordination network and covalent bonds.

[0099] Comparative Examples 1, 3, and 5 lacked effective coordination structures, resulting in strengths ≤60 MPa; furthermore, particle agglomeration and disordered structures led to poor flowability, with viscosity ≥610 mPa·s; Comparative Example 5 lacked cross-linked metals, resulting in insufficient chemical interaction and significant ion free migration (reaching 141 ppm). Comparative Example 6, due to the insufficient bonding stability of the flexible perfluorooctyl-modified NTA polydentate carboxylic acid ligand compared to the rigid heterocycle, exhibited low chelation capacity and increased metal migration.

[0100] II. Group and Element Analysis

[0101] 1. Infrared spectrum

[0102] The prepolymers obtained in Example 1 and Comparative Examples 1-3 were measured using Fourier transform infrared spectroscopy (FTIR): IZ10 diffuse infrared reflectometer (IR, Thermo Fisher, USA). Wavenumbers: 400–4000 cm⁻¹ -1 4cm resolution -1 The scan count was 32, and the test mode was set to "SmartiTR diamondATR". Results are shown below. Figure 1 .

[0103] Depend on Figure 1 In Example 1, perfluorinated modification and low-temperature processing resulted in a strong CF peak (1240 / 1200 cm⁻¹). -1 ) and Sharp COO - Coordination peak (1650 cm⁻¹) -1 This demonstrates the formation of a hydrophobic barrier and stable coordination bonds. Comparative Example 1, due to the lack of prepolymer, failed to form effective metallic coordination bonds: its 1550 cm⁻¹... -1 The weak absorption peak at 1720 cm⁻¹ is attributed to the asymmetric stretching vibration of free COOH. -1 The weak absorption peaks are attributed to the stretching vibration of free C=O, indicating that the carboxylate did not participate in coordination. A strong Si-OR peak (1080 cm⁻¹) is also present. -1 ) and a broad OH peak (3400 cm⁻¹) -1 The surface interface exhibits water absorption and enrichment, along with structural disorder. Comparative Example 2 shows an anhydride peak (1780 cm⁻¹) generated due to the high-temperature process. -1 ) and ZrO2 peak (910 cm) -1 This demonstrates that high temperature leads to degradation. Comparative Example 3 contains a nitrogen-containing heterocyclic polydentate carboxylic acid ligand that is not modified with a perfluoroalkyl group, hence the appearance of a free COOH peak (1705 cm⁻¹). -1 ) and extremely strong OH broad peak (3400 cm⁻¹) -1 This leads to phase separation.

[0104] 2. XPS spectrum

[0105] XPS elemental analysis was performed on the prepolymers obtained in Example 1 and Comparative Examples 1-3. A monochromatic Al Kα source (1486.6 eV) was used, with charge correction to C1s (284.8 eV), a step size of 0.1 eV, a pass energy of 20 eV, and ≥5 scans to plot narrow scan spectra, including Zr 3d, Zn 2p, and Si 2p orbitals. The chemical state changes of Zr and Zn were also observed. The elemental spectra and peak division results are shown below. Figures 2-4 .

[0106] exist Figure 2 The Zr 3d region (178-188 eV) in Example 1 exhibits a three-peak structure: the main peak at 181.8 eV (Zr 3d5 / 2) is attributed to the Zr-OC bond formed by the coordination of zirconate and carboxyl groups; the peak at 184.1 eV is a spin-orbit splitting satellite peak (Zr 3d3 / 2, spin-orbit splitting distance 2.3 eV). The intensity ratio of these two peaks is 1:0.6; their full width at half maximum (FWHM) are 0.5 eV and 0.6 eV, respectively, demonstrating uniform coordination. Additionally, the shoulder peak at 182.9 eV originates from a weak Zr-N bond coordinated between the TMT amino group and Zr, accounting for 10% of the total intensity. In Comparative Example 2, the Zr 3d region exhibits two sets of peaks: besides the Zr-OC peak at 182.5 eV (accounting for 50%, with a full width at half maximum (FWHM) increasing to 0.7 eV), there is also a ZrO2 impurity phase peak at 184.9 eV and a weak Zr-F bond peak at 185.8 eV (FWHM 0.8 eV) representing the high-temperature pyrolysis product of the perfluorinated chain. This broadening indicates that the high-temperature hydrolysis reaction (Zr(OnBu)4 + 2H2O → ZrO2 + 4BuOH) coexists with the perfluorinated chain pyrolysis, leading to phase separation. In Comparative Example 3, due to incomplete coordination, Zr ions are in a mixed state, resulting in peak broadening. Therefore, in the Zr 3d region, the 181.8 eV peak represents the weakly coordinated Zr-OC bond (FWHM 1.2 eV); the 183.2 eV peak represents the Zr-F bond. 4+ The Zr-COOH bond weakly bound to the free carboxyl group (1.2 eV) and the increased bimodal spacing (1.5 eV) and increased HW, prove that the absence of the alkyl chain leads to coordination disorder.

[0107] exist Figure 3 The Zn 2p region (1010-1050 eV) in Example 1 has a bimodal structure: the main peak is 1022.0 eV (Zn2p3 / 2, half-width at half-maximum 1.5 eV) and belongs to Zn. 2+ The stable [Zn(OOCR)4] is formed by coordination with a carboxyl group modified with a perfluoroalkyl group. 2- The structure, with its perfluorinated chain, reduces the electron cloud density, thus lowering the binding energy by 0.3 eV. Satellite peak at 1044.8 eV (spacing 22.8 eV); no Zn below 1020.0 eV. 0The peak indicates that no reduction occurred. In Comparative Example 2, due to the disruption of coordination caused by high temperature, the peak position shifted: the 2p³ / 2 peak shifted to 1020.5 eV, which is Zn. + Peak (Zn) 2+ +e - →Zn + The full width at half maximum (FWHM) increased to 1.5 eV; a Zn(0) peak appeared at 1019.5 eV (Zn 2+ +2e - →Zn(0)), with a half-width at half-maximum (FWHM) of 1.8 eV. The original Zn was 1022 eV. 2+ The disappearance of the peak proves [Zn(OOCR)4] 2- The structure was disrupted, resulting in perfluorinated chain cleavage and reduction reactions. In Comparative Example 3, due to incomplete coordination, the 2p3 / 2 peak shifted to 1023.5 eV (binding energy +1.5 eV, full width at half maximum 2.2 eV); the broad peak at 1025.0 eV may be [Zn(HOOCR)2]. 2+ The coordination defect has a broad peak, and the absence of the perfluorinated chain leads to carboxyl protonation.

[0108] exist Figure 4 In the Si 2p region (98-108 eV), Example 1 shows a sharp three-peak structure: the main peak is a strong peak at 102.2 eV (70%) with a full width at half maximum (FWHM) of 0.4 eV, representing a Si-O-Zr crosslinked structure; the secondary peak is at 102.8 eV, representing a Si-F peak (20%); and the shoulder peak is at 103.5 eV (10%), belonging to residual Si-OH groups. Comparative Example 1, due to the lack of prepolymer, resulted in incomplete hydrolysis of the silane coupling agent, yielding three sets of peaks: the main peak at 101.8 eV (60%) is unreacted methoxy Si-OCH3, with a FWHM increased to 1.5 eV; the secondary peak at 103.5 eV is a weak mixed peak of Si-OH / Si-O-Si (25%), and a new peak appears at 104.2 eV (15%), representing Si-O-COO chemically adsorbed by carboxylate ions. - Comparative Example 2 shows the following peak structures: 103.6 eV represents the Si-OH group (55%) of the high-temperature hydrolysis product, with a full width at half maximum (FWHM) of 1.0 eV; 102.2 eV represents the peak at the Si-O-Si bond breakage defect site caused by high temperature (25%); and 101.5 eV represents the Si-CF- (20%) of the perfluorinated chain high-temperature cracking product. Comparative Example 3 shows a quartet: 103.6 eV (Si-OH, 50%), 102.8 eV (Si-O-Si, 25%), 101.9 eV (Si-OR, 15%), and 104.8 eV (carboxyl ionization Si-O-, 10%). These findings demonstrate that the absence of alkyl chains leads to phase separation and localized hydrolysis, resulting in chemical state disorder, and that Si exists in a multi-scale chemical environment.

[0109] 1100 cm⁻¹ in the infrared spectrum-1 The strong absorption peak at the point of origin, attributed to the Si-O-Zr / Si-O-Si stretching vibration, cross-validates with the Si 2p 102.2 eV peak and Zr 3d 182.1 eV characteristic peaks from the XPS spectra, demonstrating the successful construction of the dense Si-O-Zr cross-linked network in Example 1. In contrast, the high temperature in Comparative Example 2 resulted in triple damage: excessive Si hydrolysis and oxidation, Zr coordination distortion, and Zn bonding defects. Comparative Example 3 indirectly confirms that alkyl chains suppress phase separation through steric hindrance and stabilize Zn based on electronic effects. 2+ .

[0110] Application Examples 1-5 and Comparative Examples 1-5

[0111] EMC preparation: The spherical glass powder / silane coupling agent composite systems of Examples 1-5 and Comparative Examples 1-5 were mixed with bisphenol A type epoxy resin, methyl hexahydrophthalic anhydride curing agent (1.8 wt%) and 2-ethyl-4-methylimidazolium accelerator at a mass ratio of 68:18:1.6:1.2, respectively, and cured at 80℃ for 1 h + 120℃ for 2 h to obtain EMC materials.

[0112] The EMC samples corresponding to use cases 1-5 and application comparison cases 1-6 were tested for relevant items, and the results are summarized in Table 3.

[0113] Test metrics

[0114] Interlaminar Shear Strength (ILSS) was determined by short beam shear tests conducted at -40°C according to ASTM D2344.

[0115] The 80℃ curing conversion rate reflects the degree of crosslinking of the resin at low temperatures of 80–120℃. Differential scanning calorimetry (DSC) was used.

[0116] Interfacial bonding energy is used to quantitatively characterize the interfacial forces between glass powder and resin. Higher bonding energy indicates stronger peel resistance, determined using a single-particle pull-out test.

[0117] Coefficient of thermal expansion (CTE), reference standard ASTM E831.

[0118] Aging resistance: Following the JEDEC JESD22-A101 standard, the samples were aged in a constant temperature and humidity chamber (85℃, 85%RH) for 1000h, and the transmittance retention rate and ILSS retention rate were calculated after aging.

[0119] Table 3

[0120]

[0121] The EMC materials in Application Examples 1-5 possess high light transmittance, high strength, aging resistance, and low-temperature curing properties. The perfluoroalkyl hydrophobic layer inhibits moisture erosion, resulting in a light transmittance ≥92.5%, with a light transmittance retention rate ≥97.0% after aging. The dynamic coordination network buffers stress, enabling the flexural strength of the application examples to be ≥100 MPa and the interfacial oscillation strength (ILSS) to be ≥17.0 MPa. The high interfacial bonding energy demonstrates the effectiveness of chemical anchoring. Furthermore, the 80℃ curing conversion rate of the application examples is ≥92.3%, and the interfacial bonding energy is ≥210 J / m. 2 CTE≤39.5×10 -6 / ℃, suitable for low-temperature processes.

[0122] Comparative Example 1, which uses only silane coupling agent physical adsorption without prepolymer, has a short water vapor permeation path; however, due to insufficient crosslinking and thermal matching, the conversion rate is only 76.5%; interfacial defects cause its CTE to reach 54.0 × 10⁻⁶. -6 / ℃, ILSS is only 6.5MPa. In Comparative Example 2, the condensation temperature was too high, easily causing prepolymer self-polymerization and aggregation of highly coordinated active metal source compounds, resulting in an uneven modified layer and a decrease in ILSS. In Comparative Example 3, severe phase separation led to increased light scattering, transmittance ≤81.5%, and aging retention ≤88.0%. In Comparative Example 4, due to Ca... 2+ Insufficient bond energy (160 kJ / mol) and large ionic radius ( This also led to a decrease in ILSS. In Comparative Example 5, due to insufficient coordination and weak interfacial binding, the ILSS decreased to 8.5 MPa. In Comparative Example 6, the perfluorooctyl-modified NTA polydentate carboxylic acid ligand had poor hydrophobicity (LogP = 5.0), which intensified phase separation and reduced transmittance.

[0123] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A spherical glass powder / silane coupling agent composite system for EMC, characterized by, comprising the following components in mass percentages: 80-90 wt% spherical glass powder, 8-15 wt% prepolymer, 1-5 wt% crosslinking metal ion source selected from the group consisting of Cu 2+ , Zn 2+ , Ni 2+ , Al 3+ ; The prepolymer is formed by coordination bond and covalent bond from the following components: (a) perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligands: general formula: R 1 X-N-(COOH)3, wherein R 1 is a C8-C12 alkyl group with a fluorine-containing group, the hydrophobic parameter LogP > 4.5, X is a nitrogen heterocycle, and is connected to R 1 through a methylene or thioether bond; (b) high coordination active metal source compound; one or more selected from titanate, zirconate and hydrolysis products thereof; the molar ratio of (b) to (a) is 0.8-1.2; (c) silane coupling agent: 5wt%-20wt% of the total mass of the prepolymer.

2. The composite system of claim 1, wherein, The molar ratio of the cross-linking metal ion source to the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand is 1:2-3.

3. The composite system of claim 1, wherein, the titanates are selected from one or more of di(acetylacetone)diisopropoxy titanium, tetraisopropoxy titanium, bis(dioctylpyrophosphato)ethyl titanate; the zirconates are selected from one or more of tetraisopropyl zirconium, tetra-n-butyl zirconium, tetraisobutyl zirconium, tetra-t-butyl zirconium, dimethoxydiisopropyl zirconium, zirconium acetylacetonate; the silane coupling agents have the general chemical formula (R 2 O)3Si-R 3 -Y, wherein R 2 is a C1-C2 alkyl group, R 3 is a C3-C6 alkylene group, and Y is selected from one or more of an amino group, an anilino group, or a glycidoxypropoxy group.

4. The composite system of claim 1, wherein, The spherical glass powder has a particle size of 5-10 μm, a refractive index of 1.48-1.52, and a specific surface area of 2.0-5.0 m 2 / g.

5. A method for preparing the spherical glass powder / silane coupling agent composite system according to any one of claims 1 to 4, characterized by, The method comprises the following steps: (1) spherical glass powder pretreatment: vacuum drying at 80-100℃, ultrasonic activation in dilute hydrochloric acid, water washing until neutral, and drying; (2) Preparation of the nitrogen-containing heterocyclic polydentate carboxylic acid ligand (a) modified by perfluoroalkyl group: obtained by using the nitrogen-containing heterocyclic polydentate carboxylic acid nucleus as raw material through esterification and aminolysis; the hydrophobic parameter LogP of the component (a) is ≥5.8, and the metal chelating capacity is ≥5.0 mmol Zn / g 2+ / g; (3) preparation of the prepolymer: under an inert atmosphere, the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand (a) and the high coordination active metal source compound (b) are reacted at 0-40℃ for 1-3h under the catalysis of 0.1-0.5wt% dibutyltin dilaurate to form a polydentate coordination complex; then the silane coupling agent (c) is added, and the mixture is reacted at 40-60℃ for 2-4h to obtain the prepolymer; (4) low-temperature surface modification: the pretreated glass powder, the prepolymer and the cross-linking metal ion source are reacted in a halogenated alkane-aromatic hydrocarbon mixed solvent at -10-10℃ for 4-8h to form a modification layer with a thickness of 5-8nm; centrifugal washing, and vacuum drying at 50-100℃ to obtain the spherical glass powder / silane coupling agent composite system.

6. The method of claim 5, wherein, The specific process of step (2) comprises: S1. preparation of activated ester: the nitrogen heterocyclic polydentate carboxylic acid mother nucleus, N-hydroxysuccinimide and dicyclohexyl carbodiimide are dissolved in N,N-dimethylformamide at a molar ratio of 1:(3-3.3):(3-3.3), and stirred at 0-5℃ for 2-3h, and TLC monitoring is performed until the raw material disappears to obtain an activated ester filtrate; the nitrogen heterocyclic polydentate carboxylic acid mother nucleus is selected from triazine tricarboxylic acid and pyridine tricarboxylic acid; S2. hydrophobic group modification: the activated ester filtrate of step S1 is subjected to aminolysis reaction with perfluoroalkyl amine in a tetrahydrofuran medium at 30-40℃ until TLC shows that the activated ester disappears and the amide product is generated; the molar amount of the perfluoroalkyl amine is 3-3.3 times that of the activated ester, and the dropwise addition rate is controlled to be 0.3-0.5mol / h; S3. the amide product of step S2 is subjected to acid precipitation and supercritical CO2 extraction purification to obtain the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand.

7. The method of claim 5, wherein, In step (3), the (b) component is added in three equal amounts with an interval of 10-20min, and the addition rate is ≤5mL / min; in step (4), the halogenated alkane-aromatic hydrocarbon is dichloromethane-toluene or chlorobenzene-n-hexane at v / v=7-8:2-3; the water content in the reaction system is ≤200ppm, the cross-linking metal ion source is added gradually for 3-4 times with an addition rate of ≤0.5g / min.

8. Use of the spherical glass powder / silane coupling agent composite system according to any one of claims 1 to 4 for the production of EMC materials, characterized in that, The spherical glass powder / silane coupling agent composite system is mixed with epoxy resin, curing agent and accelerator in a mass ratio of (65-70):(15-20):(1.2-2.0):(0.075-0.16), and after curing and forming at 80-120 DEG C, an EMC material is obtained; the EMC material has a light transmittance of 550nm of ≥88%, a curing conversion rate of 80 DEG C of ≥90%, and an interface shear strength of -40 DEG C of ≥15MPa.

9. Use according to claim 8, characterized in that The epoxy resin is bisphenol A type, hydrogenated bisphenol A type, alicyclic epoxy resin or a mixture thereof; the curing agent is methyl hexahydrophthalic anhydride or methyl nadic anhydride; and the accelerator is 2-ethyl-4-methyl imidazole or 1-cyanoethyl-2-ethyl-4-methyl imidazole.

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