Sealant filler as well as preparation method and application thereof

Abstract

The invention provides sealant filler as well as a preparation method and application thereof, the sealant filler comprises silicon dioxide, the surface of the silicon dioxide is coated with a covalent organic framework, and the covalent organic framework has a group which forms non-bond or covalent bond interaction with matrix resin of sealant; the covalent organic framework is obtained by polymerizing at least a first monomer and a second monomer which can react. The sealant filler can be fully dispersed in matrix resin of the sealant, is not easy to settle, and can improve the crosslinking density and mechanical properties of the sealant.

Description

Technical Field

[0001] The invention belongs to the field of sealing materials and relates to a sealant filler and a preparation method and application thereof. Background Art

[0002] As an additive, silica filler mainly plays a role by occupying volume. Due to the presence of filler, the molecular chain of the specific material can no longer occupy the original space, so that the connected chain segments are fixed to some extent, and may cause the orientation of the specific polymer. Due to the dimensional stability of the filler, the movement of the molecular chain in the polymer interface area in the filled polymer is restricted, which increases the glass transition temperature, the heat deformation temperature, the shrinkage rate, and the elastic modulus, hardness, stiffness, and impact strength.

[0003] As an inorganic powder, silica filler has a higher density than the matrix resin and fewer surface active groups. It has poor compatibility with the matrix resin. As the standing time increases, the silica powder gradually settles, causing phase separation. The factors that affect the sedimentation of fillers are mainly: ① Filler particle size: For the same type of thermal conductive filler, the finer the particle size, the better the sedimentation. This is because the fine powder has a large specific surface area, a large content of surface hydroxyl groups, and a strong hydrogen bond between particles, resulting in a higher viscosity, which slows down the sedimentation of the filler. ② Filler addition: Common fillers are inorganic powders. When the powder addition reaches a certain amount, the viscosity of the colloid increases sharply, which will slow down the sedimentation rate of the filler and weaken the phase separation. ③ Surface properties of fillers: The group properties of the surface of the filler particles will affect its wettability in the epoxy resin. At the same time, the surface treatment process can change the polarity of the powder and adjust the interfacial tension between the filler and the resin, thereby affecting the viscosity of the colloid.

[0004] In PCB packaging, Dam & Fill glue is widely used for plastic encapsulation of wire-bonded chips and flip chips, as well as encapsulation and protection of some passive devices. First, the Dam glue (Dam glue) forms a barrier area around the component, and then the Fill glue (Fill glue) is used to fill the space in the area. Among them, since the entire dam area needs to be filled, the amount of fill glue used is large. Therefore, in order to ensure that the thermal expansion of the fill glue does not damage the device, a large amount of nano-spherical silica with a low thermal expansion coefficient needs to be introduced. The dispersibility of silica filler in epoxy resin directly determines the reliability of the device. If the silica filler has poor dispersion and sedimentation or agglomeration occurs in the epoxy resin, defects will occur in the entire fill glue, and the local mechanical properties will drop sharply, which will further lead to device reliability problems. Therefore, improving the dispersibility of silica filler in epoxy resin and inhibiting filler agglomeration and sedimentation are issues that must be faced in the development of board-level fill glue. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a sealant filler and a preparation method and application thereof. The sealant filler can be fully dispersed in the matrix resin of the sealant, is not easy to settle, and can improve the crosslinking density and mechanical properties of the sealant.

[0006] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] One of the purposes of the present invention is to provide a sealant filler, which includes silicon dioxide, and the surface of the silicon dioxide is coated with a covalent organic framework, the covalent organic framework has groups that form non-bonding or covalent bonding with a base resin of the sealant; the covalent organic framework is obtained by polymerizing at least a reactive first monomer and a reactive second monomer.

[0008] As a preferred technical solution of the present invention, the first monomer is a substituted or unsubstituted aromatic compound containing at least two active groups.

[0009] And / or, the second monomer is a substituted or unsubstituted aromatic compound containing at least 3 reactive groups.

[0010] And / or, the active group of the second monomer forms a covalent bond with the active group of the first monomer through polymerization reaction.

[0011] As a preferred technical solution of the present invention, the active groups are symmetrically distributed in the first monomer.

[0012] And / or, the reactive groups are symmetrically distributed in the second monomer.

[0013] As a preferred technical solution of the present invention, the active groups in the first monomers are the same as each other.

[0014] And / or, the reactive groups in the second monomers are the same as each other.

[0015] As a preferred technical solution of the present invention, the first monomer is substituted or unsubstituted

[0016] Any one or a combination of at least two of the following:

[0017] Wherein, R is any one of -NH2, -CONH2, -CONHNH2, -COONHNH2 or -C=NNH2 or a combination of at least two thereof, and n is a natural number not less than 1.

[0018] As a preferred technical solution of the present invention, the substituent of the first monomer includes any one of methyl, vinyl, alkynyl, nitro, hydroxyl, sulfonic acid, aldehyde, cyano, methylthio or halogen atoms, or a combination of at least two thereof.

[0019] As a preferred technical solution of the present invention, the active group in the second monomer includes any one of an aldehyde group, a carboxyl group, an olefin group, an acid anhydride group or an acyl halide group, or a combination of at least two of them.

[0020] As a preferred technical solution of the present invention, the substituent of the second monomer includes any one of methyl, vinyl, alkynyl, nitro, hydroxyl, sulfonic acid, aldehyde, cyano, methylthio or halogen atoms, or a combination of at least two thereof.

[0021] As a preferred technical solution of the present invention, the second monomer is triformyl-trisphenol.

[0022] The second object of the present invention is to provide a method for preparing the sealant filler provided by the first object, the preparation method comprising:

[0023] The catalyst, the solvent and the first monomer are mixed, and silicon dioxide is added to uniformly disperse the silicon dioxide in the solution to obtain a silicon dioxide dispersion;

[0024] The second monomer solution is added dropwise into the silicon dioxide dispersion to carry out a polymerization reaction to obtain a sealant filler.

[0025] The third object of the present invention is to provide an application of the sealant filler provided by the first object, wherein the sealant filler is used for preparing epoxy resin sealant.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] (1) The present invention provides a sealant filler and a preparation method and application thereof. The sealant filler can be fully dispersed in the matrix resin of the sealant, is not easy to settle, and can increase the cross-linking density of the sealant;

[0028] (2) The present invention provides a sealant filler and a preparation method and application thereof, wherein the sealant filler can improve the mechanical properties of the sealant, especially the strength and toughness;

[0029] (3) The present invention provides a sealant filler and a preparation method and application thereof, wherein the sealant filler can improve the heat resistance and smoke suppression performance of the sealant. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the reaction principle of the covalent organic framework;

[0031] Figure 2 Schematic diagram of the process of covalent organic framework coating with silica;

[0032] Figure 3 This is a TEM image of the covalent organic framework-coated silica prepared in Example 1;

[0033] Figure 4 The theoretical schematic diagram of the reinforced composite material of covalent organic framework coated with silica;

[0034] Figure 5 SEM images of the dispersion of silica filler in samples prepared in Application Example 1 and Comparative Application Example 1.

[0035] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0036] The technical solution of the present application is further described below through specific implementation methods.

[0037] A specific embodiment of the present invention provides a sealant filler, which includes silicon dioxide, and a covalent organic framework is coated on the surface of the silicon dioxide. The covalent organic framework has groups that form non-bonding or covalent bonding with the base resin of the sealant; the covalent organic framework is obtained by polymerizing at least a reactive first monomer and a reactive second monomer.

[0038] In the present invention, the covalent organic framework can improve the compatibility of silica with the sealant matrix resin, and improve the dispersibility of the silica filler in the matrix resin. Through non-bonding (such as van der Waals force and hydrogen bond, etc.) and / or covalent bond and the chain segment of the matrix resin, the cross-linked network of the participation and strengthening system is effectively improved, thereby effectively improving the bonding force of the matrix resin system and improving the mechanical properties of the sealant. The stable framework structure of the covalent organic framework also forms a double interpenetrating network with the matrix resin, and the matrix resin chain segment that penetrates into the pores is physically restricted. At the same time, the limited expansion of the covalent organic framework can form a mechanical interlocking effect with the matrix resin, and the formation of hydrogen bonds and covalent bonds between the covalent organic framework and the epoxy resin, thereby improving the strength and toughness of the epoxy resin system. And due to the increase of the cross-linking density and the limited movement of the matrix resin macromolecular chain, the heat resistance of the system can also be effectively improved. In addition, the introduction of the covalent organic framework can also bring about a "maze effect". Due to the high specific surface area and good adsorption of the covalent organic framework, it is difficult for external moisture to penetrate into the material, thereby improving the moisture resistance of the material; when the material burns, the toxic smoke inside will also be captured by the covalent organic framework network, so that the composite material has good smoke suppression performance. Its theoretical schematic diagram is shown below Figure 4 shown.

[0039] In one embodiment of the present invention, the first monomer is a substituted or unsubstituted aromatic compound containing at least two active groups.

[0040] In one embodiment of the present invention, the active groups are symmetrically distributed in the first monomer.

[0041] In one embodiment of the present invention, the active groups in the first monomers are the same.

[0042] In one embodiment of the present invention, the first monomer is substituted or unsubstituted

[0043] Any one or a combination of at least two of the following:

[0044] Wherein, R is any one of -NH2, -CONH2, -CONHNH2, -COONHNH2 or -C=NNH2 or a combination of at least two thereof, and n is a natural number not less than 1.

[0045] In a specific embodiment of the present invention, the substituent of the first monomer includes any one of methyl, vinyl, alkynyl, nitro, hydroxyl, sulfonic acid, aldehyde, cyano, methylthio or halogen atoms, or a combination of at least two thereof.

[0046] In a specific embodiment of the present invention, the first monomer can be: 1,2,4,5-tetrahydroxybenzene, 1,4-diamino-2,5-ethynylbenzene, 2,3,5,6-tetra(amino)-benzoquinone, 2,3,6,7,10,11-hexahydroxytriphenyl, 1,4-diamino-2,5-D dicyanobenzene, 1,4-diamino-2,5-divinylbenzene, 2,5-bis(methylthio)-1,4-phenylenediamine , octahydroxydibenzochrysene, 2,3-dihydroxyterephthaloyl hydrazide, 1,2,4,5-tetrakis(4-formylphenyl)benzene, 2,5-dihydroxyterephthaloyl hydrazide, 2,5-dibromobenzene-1,4-diamine, 2,5-diethoxyterephthaloyl hydrazide, 1,4-benzenedicarboxylic acid amide hydrochloride, [1,1'-biphenyl]-4,4'-dicarboxamide, 2,2'-dinitrobenzidine, 4,4'-diamino-3 ,3'-biphenyldisulfonic acid, 4,4'-diaminoterphenyl, tetraaldehyde phenylporphyrin, 1,3,6,8-tetrakis(4-formaldehyde phenyl)pyrene, 2,7-pyrene diamine, tetrakis(4-formylphenyl)methane, 1,4-naphthalene diamine, 1H-benzo[9,10-d]imidazole-5,10-diamine, tetraaldehyde tetraphenylethylene, 4,4'-(1-methyl-1H-benzimidazole-4,7-diyl)diphenylamine, 3 ,3'-dihydroxybenzidine, 1,3,5,7-tetrakis(4-benzaldehyde)-adamantane, 4,4-diamino-3,3-difluorobiphenyl, 4,4'-diamino-[1,1'-biphenyl]-2,2'-dicarboxylic acid dimethyl ester, 4,4'-biphenyl dicarboxylic acid dihydrazide, 2-hydroxy-1,3,5-benzenetricarboxaldehyde, tetrakis(4-ethynylphenyl)ethylene and (benzene-1,3,5-triacyl)triacetonitrile, etc.

[0047] In a specific embodiment of the present invention, the first monomer is preferably 1,4-diamino-2,5-ethynylbenzene, 1,4-diamino-2,5-D dicyanobenzene, 1,4-diamino-2,5-divinylbenzene, 2,5-bis(methylthio)-1,4-phenylenediamine, 2,3-dihydroxyterephthaloyl hydrazide, 2,5-dihydroxyterephthaloyl hydrazide, 2,5-dibromobenzene-1,4-diamine, 2,5-diethoxyterephthaloyl hydrazide, 1,4-benzenedicarboxylic acid amide hydrochloride, [1,1'-biphenyl]-4,4'-dicarboxamide, 2,2'-dinitrobiphenyl Aniline, 4,4'-diamino-3,3'-biphenyldisulfonic acid, 4,4'-diaminoterphenyl, 2,7-pyrenediamine, 1,4-naphthalenediamine, 1H-benzo[9,10-d]imidazole-5,10-diamine, 4,4'-(1-methyl-1H-benzimidazole-4,7-diyl)diphenylamine, 3,3'-dihydroxybenzidine, 4,4-diamino-3,3-difluorobiphenyl, 4,4'-diamino-[1,1'-biphenyl]-2,2'-dicarboxylic acid dimethyl ester and 4,4'-biphenyldicarboxylic acid dihydrazide are more preferred, and p-phenylenediamine is more preferred.

[0048] In one embodiment of the present invention, the second monomer is a substituted or unsubstituted aromatic compound containing at least three reactive groups.

[0049] In a specific embodiment of the present invention, the active group of the second monomer forms a covalent bond with the active group of the first monomer through polymerization reaction.

[0050] In one embodiment of the present invention, the active groups are symmetrically distributed in the second monomer.

[0051] In one embodiment of the present invention, the active groups in the second monomers are the same.

[0052] In one embodiment of the present invention, the substituent of the second monomer includes any one of methyl, vinyl, alkynyl, nitro, hydroxyl, sulfonic acid, aldehyde, cyano, methylthio or halogen atoms, or a combination of at least two thereof.

[0053] In one specific embodiment of the present invention, the second monomer is preferably triformyl-trisphenol.

[0054] In a specific embodiment of the present invention, "substituted or unsubstituted" means that the first monomer and the second monomer do not contain or contain other groups except the active groups for polymerization reaction.

[0055] In one embodiment of the present invention, the substituent is preferably a group that can form a non-bonding or covalent bond with the base resin.

[0056] In a specific embodiment of the present invention, the active groups in the first monomer and the second monomer are symmetrically arranged, which is beneficial to the formation of the covalent organic framework and the coating of silicon dioxide.

[0057] In a specific embodiment of the present invention, the active groups of the first monomers are interconnected, and the active groups in the second monomers are also identical to each other, which is beneficial to improving the uniformity of the covalent organic framework structure, thereby improving the stability of the covalent organic framework.

[0058] In one specific embodiment of the present invention, the particle size of the silica is spherical silica with a diameter of 100 to 500 nm.

[0059] A specific embodiment of the present invention provides a method for preparing a sealant filler, the preparation method comprising:

[0060] The catalyst, the solvent and the first monomer are mixed, and silicon dioxide is added to uniformly disperse the silicon dioxide in the solution to obtain a silicon dioxide dispersion;

[0061] The second monomer solution is added dropwise into the silicon dioxide dispersion to carry out a polymerization reaction to obtain a sealant filler.

[0062] The reaction diagram of the first monomer and the second monomer is as follows: Figure 1 As shown, the schematic diagram of the process of covalent organic framework coating silica is as follows Figure 2 shown.

[0063] In one embodiment of the present invention, the molar ratio of the first monomer to the second monomer may be 3:2.

[0064] In one specific embodiment of the present invention, the molar ratio of the first monomer to silicon dioxide may be 1:15-30.

[0065] In a specific embodiment of the present invention, the catalyst can be a halogenated alkylpyridine catalyst, such as cetylpyridine bromide (CPB), cetylpyridine chloride, dodecylpyridine bromide or dodecylpyridine chloride.

[0066] In one specific embodiment of the present invention, the solvent may be deionized water.

[0067] In a specific embodiment of the present invention, the second monomer solution is prepared from the second monomer and its good solvent. The good solvent for the second monomer can be selected according to the polarity and other properties of the second monomer, and is not specifically limited here. For example, it can be dichloromethane.

[0068] In a specific embodiment of the present invention, the dripping rate of the second monomer solution can be selected according to the actual catalyst, the first monomer and the second monomer in the reaction, and is not further limited here. For example, it can be 0.5 mL / min.

[0069] In a specific embodiment of the present invention, the polymerization reaction conditions, such as reaction temperature and time, etc., can be selected according to the specific catalyst, the first monomer and the second monomer, and are not further limited herein.

[0070] In one embodiment of the present invention, an anti-solvent is added to the solution after the reaction is completed to precipitate the silicon dioxide coated with the covalent organic framework. The anti-solvent may be, for example, anhydrous ethanol.

[0071] In one embodiment of the present invention, the precipitate is extracted with an extraction solvent to obtain an extract. The extraction solvent may be anhydrous methanol or tetrahydrofuran, etc., and the extraction time may be 12 hours, etc.

[0072] In a specific embodiment of the present invention, the extract is centrifuged, the obtained solid is dried, and then sintered to obtain the final product, wherein the sintering temperature may be 100 to 150° C. and the sintering time may be 6 to 18 hours.

[0073] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0074] Example 1

[0075] This embodiment provides a method for preparing a sealant filler, the preparation method comprising:

[0076] 0.3 g of cetylpyridinium bromide (CPB), 300 ml of deionized water and 0.48 g of p-phenylenediamine were mixed, and 50 g of spherical silica with a particle size of 100 to 500 nm was added to uniformly disperse the silica in the solution to obtain a silica dispersion;

[0077] A 0.043 M dichloromethane solution of triformyl-triphenol was prepared and added dropwise to the silica dispersion at 0.5 mL / min. The polymerization reaction was carried out at room temperature for 15 min. 300 ml of anhydrous ethanol was added to precipitate the precipitate. The precipitate was extracted with anhydrous methanol and tetrahydrofuran for 12 hours respectively, then centrifuged and dried in a vacuum oven, and then baked at 110 degrees for 12 hours to obtain the final product.

[0078] The final product prepared in Example 1 was subjected to TEM test, and the test results are as follows: Figure 3 As shown, the coating structure outside the silica can be seen, proving that the first monomer and the second monomer are polymerized on the silica surface and generate a covalent organic framework structure.

[0079] Example 2

[0080] This embodiment provides a method for preparing a sealant filler, the preparation method comprising:

[0081] 0.3 g of cetylpyridinium bromide (CPB), 300 ml of deionized water and 0.70 g of 1,4-naphthalenediamine were mixed, and 50 g of spherical silica with a particle size of 100 to 500 nm was added to uniformly disperse the silica in the solution to obtain a silica dispersion;

[0082] A 0.043 M dichloromethane solution of triformyl-triphenol was prepared and added dropwise to the silica dispersion at 0.5 mL / min. The polymerization reaction was carried out at room temperature for 15 min. 300 ml of anhydrous ethanol was added to precipitate the precipitate. The precipitate was extracted with anhydrous methanol and tetrahydrofuran for 12 hours respectively, then centrifuged and dried in a vacuum oven, and then baked at 110 degrees for 12 hours to obtain the final product.

[0083] Example 3

[0084] This embodiment provides a method for preparing a sealant filler, the preparation method comprising:

[0085] 0.3 g of cetylpyridinium bromide (CPB), 300 ml of deionized water and 1.156 g of 4,4'-diaminoterphenyl were mixed, and 50 g of spherical silica with a particle size of 100 to 500 nm was added to uniformly disperse the silica in the solution to obtain a silica dispersion;

[0086] A 0.043 M dichloromethane solution of triformyl-triphenol was prepared and added dropwise to the silica dispersion at 0.5 mL / min. The polymerization reaction was carried out at room temperature for 15 min. 300 ml of anhydrous ethanol was added to precipitate the precipitate. The precipitate was extracted with anhydrous methanol and tetrahydrofuran for 12 hours respectively, then centrifuged and dried in a vacuum oven, and then baked at 110 degrees for 12 hours to obtain the final product.

[0087] Example 4

[0088] This embodiment provides a method for preparing a sealant filler, the preparation method comprising:

[0089] 0.3 g of cetylpyridinium bromide, 300 ml of deionized water and 1.06 g of 2,7-pyrene diamine were mixed, and 50 g of spherical silica with a particle size of 100 to 500 nm was added to uniformly disperse the silica in the solution to obtain a silica dispersion;

[0090] A 0.043 M dichloromethane solution of triformyl-triphenol was prepared and added dropwise to the silica dispersion at 0.5 mL / min. The polymerization reaction was carried out at room temperature for 15 min. 300 ml of anhydrous ethanol was added to precipitate the precipitate. The precipitate was extracted with anhydrous methanol and tetrahydrofuran for 12 hours respectively, then centrifuged and dried in a vacuum oven, and then baked at 110 degrees for 12 hours to obtain the final product.

[0091] Example 5

[0092] This embodiment provides a method for preparing a sealant filler, the preparation method comprising:

[0093] 0.3 g of cetylpyridine bromide, 300 ml of deionized water and 1.09 g of 1H-benzo[9,10-d]imidazole-5,10-diamine were mixed, and spherical silica with a particle size of 100 to 500 nm was added to uniformly disperse the silica in the solution to obtain a silica dispersion;

[0094] A 0.043 M dichloromethane solution of triformyl-triphenol was prepared and added dropwise to the silica dispersion at 0.5 mL / min. The polymerization reaction was carried out at room temperature for 15 min. 300 ml of anhydrous ethanol was added to precipitate the precipitate. The precipitate was extracted with anhydrous methanol and tetrahydrofuran for 12 hours respectively, then centrifuged and dried in a vacuum oven, and then baked at 110 degrees for 12 hours to obtain the final product.

[0095] Application Example 1

[0096] After epoxy resin A, epoxy resin B and epoxy resin C are mixed, they are mixed with the sealant filler and ordinary silica filler (mass ratio 1:2) prepared in Example 1 and a silane coupling agent, and then an anhydride curing agent and an accelerator are added and mixed; the prepared liquid filling glue is injected into a mold to prepare a sample of 35 mm in length × 7 mm in width × 3 mm in thickness.

[0097] Application Example 2

[0098] After epoxy resin A, epoxy resin B and epoxy resin C are mixed, they are mixed with the sealant filler and ordinary silica filler (mass ratio 2:1) prepared in Example 1 and a silane coupling agent, and then an anhydride curing agent and an accelerator are added and mixed; the prepared liquid filling glue is injected into a mold to prepare a sample of 35 mm in length × 7 mm in width × 3 mm in thickness.

[0099] Application Example 3

[0100] Epoxy resin A, epoxy resin B and epoxy resin C were mixed, and then mixed with the sealant filler and silane coupling agent prepared in Example 1, and then anhydride curing agent and accelerator were added and mixed; the prepared liquid filling glue was injected into a mold to prepare a sample of 35 mm in length × 7 mm in width × 3 mm in thickness.

[0101] Comparative application example 1

[0102] Epoxy resin A, epoxy resin B and epoxy resin C are mixed, mixed with common silica filler and silane coupling agent, and then anhydride curing agent and accelerator are added and mixed; the prepared liquid filling glue is injected into a mold to prepare a sample with a length of 35 mm, a width of 7 mm and a thickness of 3 mm.

[0103] In the corresponding examples 1-3 and comparative application example 1, epoxy resin A is bisphenol A epoxy resin with an epoxy equivalent of 158; epoxy resin B is bisphenol F epoxy resin with an epoxy equivalent of 158; epoxy resin C is a naphthalene ring epoxy resin with an epoxy equivalent of 143; the curing agent is methyl hexahydrophthalic anhydride; the silane coupling agent is γ-glycidyloxypropyltrimethoxysilane; the accelerator is latent imidazole; and the particle size d50 of the ordinary silica filler is 8.409 μm.

[0104] Sedimentation performance and K of the samples prepared in Example 1-3 and Comparative Example 1 IC The weight of each component in the sample and the test results are shown in Table 1.

[0105] The sedimentation performance test method is to cut and grind the cured sample, and then observe the sedimentation using a scanning electron microscope (Apreo2) from ThermoFisher.

[0106] K IC The test method is to use the sample to measure using an electronic universal testing machine (Shimadzu AGX-10kNVD), and a crack is introduced in the middle with a blade when making the sample.

[0107] The testing method for Tg is to use a dynamic thermomechanical analyzer DMA (TADMA850) in double cantilever mode with a vibration frequency of 1 Hz, an amplitude of 10 μm, and a heating rate of 3°C / min.

[0108] Table 1

[0109] Comparative Example 1 Example 1 Example 2 Example 3 Epoxy resin (A) 1.2128 1.2128 1.2128 1.2128 Epoxy resin (B) 0.9064 0.9064 0.9064 0.9064 Epoxy resin (C) 9.6962 9.6962 9.6962 9.6962 Curing agent 12.2846 12.2846 12.2846 12.2846 Ordinary silica filler 75 50 25 0 Modified silica filler 0 25 50 75 Silane coupling agent 0.6 0.6 0.6 0.6 Accelerator 0.2 0.2 0.2 0.2 total 100 100 100 100 Whether there is subsidence have none none none <![CDATA[K IC (MPa.m 1 / 2 )]]> 2.9 3.2 3.6 3.8 Tg(℃) 164 167 171 172

[0110] The samples of Example 3 and Comparative Application Example 1 were tested by SEM, and the results are as follows: Figure 5As shown, it can be seen that compared with ordinary silica fillers, the covalent organic framework-capped silica fillers are more evenly distributed in the matrix resin, proving that the covalent organic framework has good compatibility with the matrix resin, making the covalent organic framework-capped silica fillers more dispersed in the matrix resin than ordinary silica fillers.

[0111] Application Example 4

[0112] Compared with Application Example 3, the only difference is that the sealant filler is substituted for the sealant filler prepared in Example 2-5, and the other conditions are the same as those in Application Example 3.

[0113] The same test method as in Application Example 4 was used to test the sedimentation performance and K IC The test results are shown in Table 2.

[0114] Table 2

[0115] Example 2 Example 3 Example 4 Example 5 Whether there is subsidence none none none none <![CDATA[K IC (MPa.m 1 / 2 )]]> 3.7 3.6 3.6 3.9 Tg(℃) 170 172 171 169

[0116] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0117] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0118] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0119] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A sealant filler, characterized in that: The sealant filler comprises silicon dioxide, the surface of the silicon dioxide is coated with a covalent organic framework, and the covalent organic framework has a group that forms a non-bonding or covalent bond with the base resin of the sealant; The covalent organic framework is obtained by polymerizing at least a first reactive monomer and a second reactive monomer.

2. The sealant filler according to claim 1, characterized in that: The first monomer is a substituted or unsubstituted aromatic compound containing at least two active groups; and / or, the second monomer is a substituted or unsubstituted aromatic compound containing at least 3 active groups; And / or, the active group of the second monomer forms a covalent bond with the active group of the first monomer through polymerization reaction.

3. The sealant filler according to claim 2, characterized in that: The active groups are symmetrically distributed in the first monomer; And / or, the active groups are symmetrically distributed in the second monomer.

4. The sealant filler according to claim 2, characterized in that: The active groups in the first monomers are identical to each other; And / or, the active groups in the second monomers are the same as each other.

5. The sealant filler according to claim 4, characterized in that: The first monomer is substituted or unsubstituted Any one or a combination of at least two of the following: Wherein, R is any one of -NH2, -CONH2, -CONHNH2, -COONHNH2 or -C=NNH2 or a combination of at least two thereof, and n is a natural number not less than 1.

6. The sealant filler according to claim 2, characterized in that: The substituent of the first monomer includes any one of a methyl group, a vinyl group, an alkynyl group, a nitro group, a hydroxyl group, a sulfonic acid group, an aldehyde group, a cyano group, a methylthio group or a halogen atom, or a combination of at least two of them.

7. The sealant filler according to claim 2, characterized in that: The active group in the second monomer includes any one or a combination of at least two of an aldehyde group, a carboxyl group, an olefin group, an anhydride group or an acyl halide group; And / or, the substituent of the second monomer includes any one or a combination of at least two of a methyl group, a vinyl group, an alkynyl group, a nitro group, a hydroxyl group, a sulfonic acid group, an aldehyde group, a cyano group, a methylthio group or a halogen atom.

8. The sealant filler according to claim 7, characterized in that: The second monomer is triformyl-trisphenol.

9. A method for preparing the sealant filler according to any one of claims 1 to 8, characterized in that: The preparation method comprises: Mixing a catalyst, a solvent and a first monomer, adding silicon dioxide, and uniformly dispersing the silicon dioxide in the solution to obtain a silicon dioxide dispersion; The second monomer solution is added dropwise into the silicon dioxide dispersion to carry out a polymerization reaction to obtain the sealant filler.

10. An application of the sealant filler according to any one of claims 1 to 8, characterized in that: The sealant filler is used for preparing epoxy resin sealant.

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