Spherical glass powder / silane coupling agent composite system for EMC (Electro Magnetic Compatibility) and preparation method of spherical glass powder / silane coupling agent composite system

Abstract

The invention discloses a spherical glass powder / silane coupling agent composite system for EMC (Electro Magnetic Compatibility) and a preparation method of the spherical glass powder / silane coupling agent composite system. The composite system comprises 80-90 wt% of spherical glass powder, 8-15 wt% of a prepolymer and 1-5 wt% of a cross-linked metal ion source; the prepolymer is formed by synergistically connecting a perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand, a high-coordination-activity metal source compound and a silane coupling agent through a coordination bond and a covalent bond. Spherical glass powder is subjected to low-temperature modification through a prepolymer and a cross-linked metal ion source, a transparent interface modification layer is formed, and the interface modification layer can be applied to a low-temperature curing EMC process at the temperature of 80-120 DEG C. The EMC material prepared from the spherical glass powder / silane coupling agent composite system through a low-temperature curing process has the light transmittance of 550 nm of more than or equal to 90%, the bending strength of more than or equal to 100 MPa, the interfacial shear strength of more than or equal to 17 MPa at the temperature of-40 DEG C and the performance retention rate of more than or equal to 90% after being subjected to damp-heat aging for 1000 h, and is suitable for heat-sensitive optical device packaging.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of EMC fillers, and particularly relates to a spherical glass powder / silane coupling agent composite system for EMC and a preparation method thereof. TECHNICAL BACKGROUND

[0002] In the field of electronic packaging, low-temperature curing epoxy molding compound (EMC) becomes a key material for realizing small-sized and high-reliability packaging of precision optical devices and high-performance integrated circuits, because it can effectively avoid damage to heat-sensitive elements such as LEDs, sensors and organic fluorescent layers caused by high temperature. However, there are many bottlenecks in the prior art, which limit its wide application.

[0003] Conventional EMC needs high-temperature curing above 160 DEG C to realize mechanical strength (bending strength >= 90 MPa) through sufficient crosslinking of the resin, while the heat-sensitive elements in the optical chip cannot withstand a temperature higher than 120 DEG C. If low-temperature curing (<= 120 DEG C) is used, the interface bonding force will decrease due to insufficient crosslinking density of the resin, resulting in insufficient bending strength, which cannot meet the packaging scenarios with high requirements for structural strength. At the same time, the molecular chain segments are limited in activity during low-temperature curing, which easily produces internal stress and reduces the interfacial shear strength. In the cold and hot cycle, the packaged device is prone to debonding, cracking and other failure phenomena.

[0004] As an important inorganic filler, spherical glass powder in EMC can effectively adjust the thermal expansion coefficient of the material and improve the mechanical properties, but due to the difference in polarity, the interface compatibility between the glass powder and the organic resin matrix is poor; and the thermal expansion coefficients of the two are not matched (CTE of glass powder = 5 x 10 -6 / ℃, CTE of epoxy resin = 60 x 10 -6 / ℃), which causes microcracks at the interface and the interfacial shear strength is usually lower than 10 MPa, eventually leading to failure of the device packaging. Traditional silane coupling agents, such as linear alkylsilane, can connect the glass powder and the resin to a certain extent, but lack sufficient steric hindrance, and the glass powder surface is easy to adsorb moisture in a humid environment, which destroys the interface bonding and leads to deterioration of the material performance.

[0005] In the prior art, the glass powder modification process is difficult to precisely control the thickness and uniformity of the modified layer, which leads to unstable quality of the modified layer and affects the consistency of the material performance; excessive modification will increase light scattering and reduce the light transmittance, which cannot meet the stringent requirements of LED, optical sensor and other optical signal transmission for high light transmittance. Some process technologies that realize low-temperature curing through special catalysts or complex equipment have high cost and are not compatible with the low-temperature curing process. SUMMARY

[0006] In view of the above problems, the application provides a spherical glass powder / silane coupling agent composite system for EMC and a preparation method thereof, which simultaneously realizes high light transmittance, high strength and aging resistance of EMC under low-temperature curing conditions.

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

[0008] The prepolymer is formed by the coordination bond and covalent bond of the following components:

[0009] (a) perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand: general formula: R 1 -X-N-(COOH)3, wherein R 1 is a C8-C12 alkyl containing fluorine group, the hydrophobic parameter LogP≥4.5, and X is a nitrogen heterocycle connected to R 1 by a methylene bond;

[0010] (b) high coordination activity metal source compound: one or more selected from titanate, zirconate, and hydrolysis products or chelate derivatives thereof; the molar ratio of (b) to (a) is 0.8-1.2;

[0011] (c) silane coupling agent: 5 wt%-20 wt% of the total mass of the prepolymer.

[0012] The spherical glass powder / silane coupling agent composite system provided by the present application is synergized by branched chain regulation-multiple bond anchoring-dynamic buffer:

[0013] R 1 of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand is a branched alkyl with a hydrophobic parameter LogP≥4.5, which can form a molecular level hydrophobic barrier on the surface of the glass powder, reducing the interface light scattering caused by water molecule adsorption; at the same time, the steric hindrance of the branched structure can hinder the close packing of glass powder particles and reduce the polar attraction between glass powder particles, avoiding agglomeration.

[0014] The cross-linking metal ion source forms a coordination bond with the carboxyl group of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand to construct a dynamic network; the reversible rupture and recombination of the coordination bond can buffer the interface stress; at the same time, this strong coordination inhibits hydrolysis, improving the aging resistance.

[0015] The high coordination metal source compound can play a bridging role, connecting the organic ligand and inorganic metal center through the carboxyl-O-metal bond of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand to form a stable coordination complex, constructing an organic-inorganic transition layer to relieve the polarity difference between the glass powder and the resin. The silane coupling agent further covalently anchors and bridges the glass powder to the resin matrix, significantly improving the interface bonding force.

[0016] Further, the cross-linking metal ion source is selected from Cu 2+ , Zn2+ , Ni 2+ , Al 3+ ; and the molar ratio of the carboxyl group of the perfluoroalkyl-modified nitrogen heterocyclic polydentate ligand to the carboxyl group of the carboxylic acid ligand is 1:2-3.

[0017] Further, the titanate is selected from one or more of di(acetylacetone)diisopropoxy titanium, tetraisopropoxy titanium (Ti(OiPr)4), bis(dioctylpyrophosphato)ethylene titanate; the zirconate is selected from one or more of tetraisopropyl zirconium (Zr(OiPr)4), tetra-n-butyl zirconium (Zr(OnBu)4), tetraisobutyl zirconium (Zr(OiBu)4), tetra-tert-butyl zirconium (Zr(OtBu)4), dimethoxydiisopropyl zirconium (Zr(OMe)2(OiPr)2), zirconium acetylacetonate; and the silane coupling agent has 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, a phenylamino group, or a glycidoxypropoxy group.

[0018] Further, 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.

[0019] In a second aspect, the present application provides a preparation method of the spherical glass powder / silane coupling agent composite system described above, comprising the following steps:

[0020] (1) Spherical glass powder pretreatment: vacuum drying at 80-100°C for 2 h, ultrasonic activation in 0.5% dilute hydrochloric acid for 30 min, washing with deionized water until neutral, and drying;

[0021] (2) Preparation of perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand (a): using a nitrogen heterocyclic polydentate carboxylic acid nucleus as a raw material, through an esterification process of an organic amine condensing agent and an aminolysis reaction process of a perfluoroalkyl amine, the (a) component has a LogP≥5.8 and a metal chelating capacity≥5.0 mmol Zn 2+ / g.

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

[0023] (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 DEG C for 4-8 h to form a modification layer with a thickness of 5-8 nm; centrifugal washing, vacuum drying at 50-100 DEG C, and a spherical glass powder / silane coupling agent composite system is obtained.

[0024] Further, the step (2) specifically comprises:

[0025] S1. Preparation of activated ester: an aza-cyclic polydentate carboxylic acid nucleus, N-hydroxysuccinimide (NHS) and dicyclohexyl carbodiimide are dissolved in N,N-dimethylformamide at a molar ratio of 1:(3-3.3):(3-3.3), stirred at 0-5 DEG C for 2-3 h, and TLC monitoring is performed until the raw material disappears, and an activated ester filtrate is obtained; the aza-cyclic polydentate carboxylic acid nucleus is selected from triazine tricarboxylic acid and pyridine tricarboxylic acid;

[0026] 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 DEG C until TLC shows that the activated ester disappears and the amide product is generated; the molar amount of the perfluoro-branched alkyl amine is 3-3.3 times that of the activated ester, and the dropwise addition rate is controlled at 0.3-0.5 mol / h to avoid local agglomeration;

[0027] S3. The amide product of step S2 is subjected to acid precipitation and supercritical CO2 extraction purification to obtain an aza-cyclic polydentate carboxylic acid ligand.

[0028] Further, the component (b) in step (3) is added in three equal amounts with an interval of 10-20 min, and the addition rate is ≤5 mL / min; the halogenated alkane-aromatic hydrocarbon in step (4) is dichloromethane-toluene or chlorobenzene-n-hexane with v / v=7-8:2-3; the water content in the reaction system is ≤200 ppm, and the cross-linking metal ion source is added in 3-4 times with an addition rate of ≤0.5 g / min.

[0029] The low-temperature low-water modification process adopted in the application can inhibit excessive hydrolysis of high-coordination active metal source compounds, and also avoids the problems of agglomeration and uneven thickness of the modification layer caused by traditional high-temperature modification.

[0030] In a third aspect, the application provides application of the spherical glass powder / silane coupling agent composite system in preparation of EMC materials: the spherical glass powder / silane coupling agent composite system is mixed with an epoxy resin, a curing agent, and an accelerator at 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, a low-temperature curing EMC material is obtained.

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

[0032] Further, the epoxy resin matrix 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-methylimidazole or 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0033] Advantages

[0034] 1. High light transmittance: The spherical glass powder / silane coupling agent composite system provided by the application has a hydrophobic-space hindering dual regulation effect of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand; the obtained spherical glass powder / silane coupling agent composite system has good light transmittance (light transmittance of ≥90% at 550 nm wavelength), and the light transmittance retention rate is ≥95% after resistance to humid heat aging; it is expected to solve the problem of insufficient light transmittance of traditional low-temperature curing EMC due to interface scattering and filler aggregation, so as to meet the demand of LED, optical sensor, etc. on optical signal transmission.

[0035] 2. High strength and long-term interface stability: In the spherical glass powder / silane coupling agent composite system provided by the application, the dynamic coordination network of the perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand and the high bond energy covalent coordination bond of the crosslinking metal ion synergistically enhance the interface combination, which can enhance the stability and realize dynamic coordination buffering to resist hydrolysis and stress fatigue: the bending strength is ≥95 MPa, the interface shear strength at -40℃ is ≥15 MPa, and the bending strength retention rate and the interface shear strength retention rate after humid heat aging for 1000 h are both ≥94%, which can significantly improve the long-term reliability of the packaged device and prolong the service life of the device.

[0036] 3. Low-temperature process compatibility: The application can achieve high performance at 80-120℃ curing, avoiding the failure of heat-sensitive elements (such as organic fluorescent layers and flexible circuits) caused by high-temperature curing of traditional EMC at above 160℃, which is suitable for packaging of heat-sensitive optical devices to broaden the application scenarios of EMC in precise optical packaging. BRIEF DESCRIPTION OF DRAWINGS

[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 in the following figures.

[0038] Figures 2 to 4 The Zr 3d, Zn 2p, and Si 2p characteristic spectra and peak separation results of the XPS of the spherical glass powder / silane coupling agent composite systems of Example 1 and Comparative Examples 1-3 are shown in the following figures. DETAILED DESCRIPTION

[0039] In order to more fully demonstrate the practical application and technical advantages of the present application, the present application will be further described below in conjunction with specific examples. Those skilled in the art should understand that these examples are only illustrative and do not constitute a limitation on the scope of protection of the present application.

[0040] The experimental methods used in the specific embodiments are conventional methods unless otherwise specified; the materials, reagents, etc. used are commercially available unless otherwise specified.

[0041] Some of the raw materials used in the examples and comparative examples and their sources are as follows:

[0042] Zirconium tetra-n-butoxide (Zr(OnBu)4), transparent light yellow viscous liquid, refractive index (n20 / D) = 1.465, Wuhan Kemik Biomedical Technology Co., Ltd.

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

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

[0045] Spherical glass powder, purchased from Guangdong Yuanlei Powder Co., Ltd., 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 Parameters 96 2.7 g / cm 3 ]] 4 μm 7.8 1.49 0.1 wt% 2.8m 2 / g]]>

[0048] Preparation Example 1

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

[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 dicyclohexyl carbodiimide (CAS 538-75-0, 0.3 mol) were dissolved in N,N-dimethylformamide (200 mL); stirred at 0°C for 2h (TLC monitoring, developing agent: methanol / dichloromethane = 1:8, raw material Rf≈0.1, product Rf≈0.6). Filter out the dicyclohexyl urea precipitate, wash the filter cake with 50 mL of cold N,N-dimethylformamide; collect the filtrate to obtain the activated ester intermediate, referred to as TMT-tri (NHS) ester, with a yield of 95%.

[0051] S2. Ammonolysis: The filtrate of TMT-tris(NHS) ester from step S1 (0.1 mol) was transferred into a three-necked flask and dissolved in THF (300 mL) by stirring. 1H,1H-Perfluorooctylamine (CAS: 307-29-9, 0.31 mol) was added dropwise slowly, and the dropping time was controlled for 1 h. The system was heated to 40 °C, and the reaction was carried out for 12 h (TLC showed that the activated ester (Rf≈0.6) completely disappeared, and the developing agent was the same as above). THF was removed by rotary evaporation, and the residue was added with 500 mL of water and adjusted to pH = 3 with 1 mol / L HCl (stirring while adding to avoid local over-acidification). White solid was precipitated. The product 2,4,6-tris[N-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)acetamido]-1,3,5-triazine was obtained by supercritical CO2 extraction at 40 °C and 15 MPa for 3 h, 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 ligand.

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

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

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

[0058] Preparation Example 3

[0059] Preparation of perfluorooctyl-modified nitrilotriacetic acid polydentate carboxylic acid ligand.

[0060] The difference from Preparation Example 1 is that the polydentate carboxylic acid mother nucleus used was nitrilotriacetic acid (CAS: 139-13-9, 0.1 mol), and the rest was the same as in Preparation Example 1. The final product N,N',N"-tris[2-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)acetamido]nitrilotriacetic acid was obtained with a yield of 82%.

[0061] LogP = 5.0, metal chelating capacity = 4.6 mmol Zn / g. 2+

[0062] Example 1

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

[0064] (1) The spherical glass powder was vacuum dried at 80°C for 2 h, and then activated with 0.5 wt% HCl by ultrasonic for 30 min, washed with water until neutral, and dried;

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

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

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

[0068] Example 2

[0069] The difference from Example 1 is that the component (a) in the pre-polymer is replaced by the perfluorooctyl-modified pyridine tricarboxylic acid polydentate carboxylic acid ligand obtained in Preparation Example 2; and the cross-linking metal ion source in the pre-polymer is aluminum nitrate (Al 3+ : NTA carboxyl = 1:3).

[0070] Example 3

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

[0072] Example 4​

[0073] The difference from Example 1 is that the component (b) in the prepolymer is replaced by NDZ-311 bis(dioctyl pyrophosphoryloxy) ethylene titanate; the crosslinking metal ion source is nickel nitrate (Ni 2+ : TMT carboxyl = 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 the component (b) in the prepolymer is replaced by NDZ-311 bis(dioctyl pyrophosphoryloxy) ethylene titanate; the crosslinking metal ion source is copper nitrate (Cu 2+ : TMT carboxyl = 1 : 2.5), the reaction temperature in step (4) is -5°C and the reaction time is 8h.

[0076] Comparative Example 1

[0077] The difference from Example 1 is that the prepolymer does not contain zirconium source and perfluorooctyl-modified triazine tricarboxylic acid polydentate carboxylic acid ligand, and the spherical glass powder is only modified by phenylaminopropyl trimethoxysilane, and the amount of the remaining raw materials is the same as in Example 1.

[0078] Comparative Example 2

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

[0080] Comparative Example 3

[0081] The difference from Example 1 is that the component (a) in the prepolymer is replaced by 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 = 1 : 2.5).

[0084] Comparative Example 5

[0085] The difference from Example 1 is that no crosslinking metal ion source is added in the prepolymer.

[0086] Comparative Example 6

[0087] The difference from Example 1 is that the component (a) in the prepolymer is replaced by perfluorooctyl-modified nitrilotriacetic acid (NTA) polydentate carboxylic acid ligand obtained in Preparation Example 3, and the other is the same as in Preparation Example 1.

[0088] I. General performance test

[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] Transmittance, a key indicator of material transparency, the higher the better. Transmittance was tested by UV-Vis spectrophotometer according to ASTM D1003, at a wavelength of 550 nm.

[0091] Flexural strength, an evaluation of mechanical strength, the higher the better, indicating a stronger resistance to deformation. It was determined by three-point bending test (ASTM D790).

[0092] Viscosity, reflecting the processing fluidity. Low viscosity (<500 mPa-s) is more conducive to coating and filling micropores. It was tested at 25°C by a viscometer.

[0093] Metal ion migration rate (ppm), a low migration rate (<50 ppm) indicates good metal ion fixation, avoiding electronic device corrosion. It was determined by ICP-MS.

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

[0095] Table 2

[0096] Items Transmittance / % Bending strength / MPa Viscosity / mPa-s Metal migration / 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] From Table 2, the performance of the spherical glass powder / silane coupling agent composite systems of Examples 1-5 based on perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylate ligands is overall better than that of the comparative examples: the transmittance is all ≥91%, among which Example 1 reaches 95.1%, due to the reduction of interface light scattering by the perfluoroalkyl hydrophobic barrier; the comparative example 1 without perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylate ligand and the comparative example 3 or nitrogen heterocyclic polydentate carboxylate ligand without perfluoroalkyl modification, due to the hydrophilic group leading to water vapor adsorption and agglomeration, light scattering is intensified, and the transmittance is ≤85%.

[0098] The flexural strength of the examples is 85-95 MPa; the viscosity is ≤390 mPa-s, and the metal migration rate is ≤38 ppm. Example 2 is Al 3+ Coordination, Zn 2+ High charge density, more dense coordination network, so low viscosity to 305 mPa-s, low metal migration rate to 20 ppm. Example 4 reaches 95 MPa, benefiting from the synergistic enhancement of the interface bonding of NDZ-311 bis(dioctyl pyrophosphoric acyloxy) titanium acid ester coordination network and covalent bond.

[0099] Comparative Examples 1, 3, and 5 have no effective coordination structure, and the strength is ≤60 MPa; and the particle agglomeration and disordered structure result in poor fluidity, and the viscosity is ≥610 mPa·s; Comparative Example 5 has no cross-linked metal, and the chemical action is insufficient, and the ion free migration is obvious (up to 141 ppm). Comparative Example 6 has a flexible perfluoroalkyl-modified NTA polydentate carboxylic acid ligand, and the bonding stability is relatively poor, the rigidity is insufficient, the chelating capacity is low, and the metal migration rate is increased.

[0100] II. Groups and elemental analysis

[0101] 1. Infrared spectrogram

[0102] The prepolymers obtained in Example 1 and Comparative Examples 1-3 were tested by Fourier transform infrared spectroscopy (FTIR): an iz10 type diffuse infrared reflectometer (IR, Thermo Fisher, USA). The wave number was 400-4000 cm -1 , the resolution was 4 cm -1 , the scanning number was 32 times, and the test mode was set to “SmartiTR diamond ATR”. The results are shown in Figure 1 .

[0103] From Figure 1 , the perfluoro-modification and low-temperature process in Example 1 formed strong C-F peaks (1240 / 1200 cm -1 ) and sharp COO - coordination peaks (1650 cm -1 ), proving the formation of hydrophobic barriers and stable coordination bonds. Comparative Example 1 failed to form effective metal coordination bonds due to the lack of prepolymers: the weak absorption peaks at 1550 cm -1 and 1720 cm -1 belong to free COOH asymmetric stretching vibration and free C=O stretching vibration, respectively, both indicating that the carboxylate is not involved in coordination. And strong Si-OR peaks (1080 cm -1 ) and wide O-H peaks (3400 cm -1 ) appear, indicating surface interface water enrichment and structural disorder. Comparative Example 2 produces anhydride peaks (1780 cm -1 ) and ZrO2 peaks (910 cm -1 ) due to high-temperature process, proving that high temperature leads to degradation. Comparative Example 3 contains a nitrogen heterocyclic polydentate carboxylic acid ligand that is not modified by a perfluoroalkyl group, so free COOH peaks (1705 cm -1 ) and very strong O-H wide peaks (3400 cm -1 ) appear, resulting in phase separation.

[0104] 2. XPS spectrogram

[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 to 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 800-1000 cm-1 belonging to Si-O-Zr / Si-O-Si stretching vibration and the cross-verification of the Si 2p 102.2 eV peak and the Zr 3d 182.1 eV characteristic peak in the XPS spectrum results prove the successful construction of the dense Si-O-Zr crosslinking network of Example 1. The high temperature of Comparative Example 2 leads to triple destruction: excessive hydrolysis and oxidation of Si, distortion of Zr coordination, and Zn bonding defects. Comparative Example 3 indirectly proves that the alkyl chain inhibits phase separation through steric hindrance and stabilizes Zn 2+ .

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

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

[0112] The EMC samples of Application Examples 1-5 and Comparative Examples 1-6 were tested for related items, and the results are summarized in Table 3.

[0113] Test index

[0114] Interlaminar Shear Strength (ILSS), short beam shear test at -40°C according to ASTM D2344.

[0115] Curing conversion rate at 80°C, reflecting the crosslinking degree of the resin at low temperature of 80-120°C. Differential scanning calorimetry (DSC) was used.

[0116] Interfacial bonding energy, quantitatively characterizing the interfacial force between glass powder and resin. The higher the bonding energy, the stronger the anti-peeling ability, and single particle pull-out test was used for determination.

[0117] Thermal expansion coefficient CTE, reference standard ASTM E831.

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

[0119] Table 3

[0120]

[0121] The EMC materials of application examples 1-5 have high light transmittance, high strength, aging resistance and low temperature curing performance. The perfluoroalkyl hydrophobic layer inhibits water vapor erosion, so that the light transmittance is ≥92.5%, and the light transmittance retention rate after aging is ≥97.0%; the dynamic coordination network buffers stress, so that the bending strength of the application examples is ≥100 MPa, and the ILSS is ≥17.0 MPa, and the high interfacial bonding energy proves the effectiveness of chemical anchoring. And the curing conversion rate of the application examples at 80℃ is all ≥92.3%, the interfacial bonding energy is ≥210 J / m 2 , and the CTE is ≤39.5×10 -6 / ℃, which is suitable for low temperature process.

[0122] Application Comparative Example 1 does not contain a prepolymer and only physically adsorbs a silane coupling agent, so the water vapor penetration path is short; due to insufficient crosslinking and thermal matching, the conversion rate is only 76.5%; the interface defects make the CTE reach 54.0×10 -6 / ℃, and the ILSS is only 6.5 MPa. Application Comparative Example 2 has a too high condensation temperature, which easily causes the prepolymer to self-polymerize and the high coordination active metal source compound to agglomerate, so that the modified layer formed is not uniform, and the ILSS decreases. Application Comparative Example 3 is due to serious phase separation, which increases light scattering and reduces the light transmittance to ≤81.5%, and the aging retention rate is ≤88.0%. Application Comparative Example 4 is due to insufficient Ca 2+ bonding energy (160 kJ / mol) and large ionic radius , which also leads to a decrease in ILSS. Application Comparative Example 5 has insufficient coordination and weak interfacial bonding, so the ILSS decreases to 8.5 MPa. The NTA multidentate carboxylic acid ligand of Application Comparative Example 6 is poorly hydrophobic (LogP=5.0), which intensifies phase separation and reduces light transmittance.

[0123] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A spherical glass powder / silane coupling agent composite system for EMC, characterized by, The components include the following mass fractions: 80-90wt% spherical glass powder, 8-15wt% prepolymer, 1-5wt% crosslinking metal ion source; The prepolymer is formed by the coordination and covalent linkage of 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 R 1 is connected via a methylene or thioether bond; (b) high coordination active metal source compound; one or more selected from titanate, zirconate and hydrolysis products or chelated derivatives 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, said cross-linking metal ion source is selected from the group consisting of Cu 2+ , Zn 2+ , Ni 2 + , Al 3+ , and has a molar ratio of 1:2 to 3 to said perfluoroalkyl-modified nitrogen heterocyclic polydentate carboxylic acid ligand.

3. The composite system of claim 1, wherein, The titanate is one or more selected from di(acetylacetone)diisopropoxy titanium, tetraisopropoxy titanium, bis(dioctyl pyrophosphato) ethylene titanate; the zirconate is one or more selected from tetraisopropyl zirconium, tetra-n-butyl zirconium, tetraisobutyl zirconium, tetra-tert-butyl zirconium, dimethoxy diisopropyl zirconium, acetylacetone zirconium; The chemical formula of the silane coupling agent is (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°C, ultrasonic activation in dilute hydrochloric acid, water washing to 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) Prepolymer preparation: under an inert atmosphere, the perfluoroalkyl modified nitrogen heterocyclic polydentate carboxylic acid ligand (a) is reacted with the high coordination active metal source compound (b) at 0-40°C 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 reaction is carried out at 40-60°C for 2-4h to obtain the prepolymer; (4) Low-temperature surface modification: the pretreated glass powder, the prepolymer and the crosslinking metal ion source are reacted in a halogenated alkane-aromatic hydrocarbon mixed solvent at -10-10°C for 4-8h to form a modification layer with a thickness of 5-8nm; centrifugal washing, vacuum drying at 50-100°C, 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 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°C 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 nucleus is selected from triazine tricarboxylic acid, 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°C until TLC shows that the activated ester disappears and the amide product is generated; the molar amount of the perfluoro branched alkyl amine is 3-3.3 times that of the activated ester, and the dropwise addition rate is controlled at 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 each time, and the addition rate is ≤5mL / min; In step (4), the halogenated alkane-aromatic hydrocarbon is dichloromethane-toluene or chlorobenzene-n-hexane with v / v=7-8:2-3; the reaction system contains ≤200 ppm of water, and the cross-linking metal ion source is added 3-4 times successively with an addition rate of ≤0.5 g / 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 at a mass ratio of (65-70):(15-20):(1.2-2.0):(0.075-0.16), and after curing and forming at 80-120 ℃, an EMC material is obtained. The EMC material has a light transmittance of ≥88% at 550 nm, a curing conversion rate of ≥90% at 80 ℃, and an interface shear strength of ≥15 MPa at -40 ℃.

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

Images