High-heat-resistance low-dielectric epoxy compound and preparation method thereof

Abstract

The invention belongs to the technical field of materials, and relates to a high-heat-resistance and low-dielectric epoxy compound and a preparation method thereof, and the high-heat-resistance and low-dielectric epoxy compound is prepared from monofunctional polyhedral oligomeric silsesquioxane (POSS) and a bifunctional epoxy compound through functional group reaction. The monofunctional polyhedral oligomeric silsesquioxane modified epoxy compound, namely the high-heat-resistance and low-dielectric epoxy compound, is prepared from the monofunctional polyhedral oligomeric silsesquioxane and the bifunctional epoxy compound through functional group reaction, the preparation method is simple, a metal catalyst does not need to be added, and the cost is low. The heat resistance, the toughness and the dielectric property of the epoxy resin material are improved.

Description

Technical Field

[0001] The invention belongs to the field of material technology, and in particular relates to a high-heat-resistant and low-dielectric epoxy compound and a preparation method thereof. Background Art

[0002] Cage-like oligomeric silsesquioxane, abbreviated as POSS, is a typical inorganic-organic nano-hybrid material. It not only has good compatibility with organic materials, but also has excellent heat resistance, flame retardancy and reinforcement functions. Therefore, POSS is used to modify epoxy resin. While maintaining the performance advantages of traditional epoxy resin such as good adhesion, wear resistance, mechanical properties, etc., it can also improve the heat and weather resistance of epoxy resin and improve the hardness and impact resistance of resin coating.

[0003] In recent years, hybrid modification of epoxy resins with oligomeric silsesquioxanes has been a research hotspot in the field of polymer materials, resins and coatings.

[0004] CN104356284 hydrolyzes and polycondenses γ-(2,3-epoxypropoxy)propyltrimethoxysilane to prepare cage-type octahydroxy polysilsesquioxane (POSS-OH), and then converts POSS-OH into a macromolecular initiator and conducts atom transfer radical polymerization with methyl methacrylate, glycidyl methacrylate, etc., to prepare a hybrid polymer nano-enhancer with POSS-OH as the core, acrylate copolymer chain segments as the arms, and epoxy functional groups in the molecule. The reinforcing agent is added to epoxy resin and then cross-linked and cured. Compared with the modified epoxy resin before modification, the impact strength can be increased by 1.8 to 2.9 times, the glass transition temperature is increased by 21°C, and the tensile strength is increased by 44%. However, the product is an insoluble yellow solid and can only be used in solid epoxy resin. It is processed by heating and melting and physical blending. It has poor compatibility with epoxy resin and is not suitable for cast epoxy.

[0005] In addition, the study found that since the octa-epoxy POSS contains 8 reactive epoxy groups in its molecular structure, there are too many active reaction points in the molecule. Therefore, when the epoxy resin hybridized with the POSS is reacted with the curing agent, it is easy for the system to become brittle due to excessive cross-linking density, causing the resin or coating to become brittle, thereby resulting in a decrease in the flexibility of the epoxy resin and a decrease in the physical and mechanical properties. This urgently needs to be improved.

[0006] Therefore, CN109735203 uses a semi-enclosed caged trifunctional epoxy ether-based POSS to prepare a coating with good transparency, and the impact resistance, heat stability and dielectric properties are all beneficially improved. However, in the preparation of trifunctional epoxy ether-based oligomeric silsesquioxane in this reaction, a hydrosilylation addition reaction is used, and the platinum catalyst used has a greater impact on the electrical properties of the epoxy material. Summary of the invention

[0007] In view of the deficiencies of the above-mentioned prior art, the present invention provides a high heat-resistant and low dielectric epoxy compound and a preparation method thereof. The specific technical scheme is as follows:

[0008] A high heat-resistant and low-dielectric epoxy compound, prepared by a functional group reaction of a monofunctional cage-type silsesquioxane (POSS) and a bifunctional epoxy compound;

[0009] The monofunctional cage-type silsesquioxane structure is shown in formula (I):

[0010]

[0011] R is an inert terminal group such as hydrogen, alkyl, aryl, etc.; X is an terminal group such as amino, carboxyl, mercapto, etc. that can react with the epoxy functional group.

[0012] The high heat-resistant and low dielectric epoxy compound of the present invention adopts a monofunctional cage-type silsesquioxane and a bifunctional epoxy compound to carry out a functional group reaction, thereby reducing the active reaction points in the octaepoxy POSS molecule, and obtaining a monofunctional cage-type silsesquioxane-modified epoxy compound with lower viscosity and better solubility, which can reduce the crosslinking degree of the epoxy compound and obtain an epoxy material with high heat resistance, high toughness and low dielectric properties.

[0013] Furthermore, the molar ratio of the monofunctional cage-type silsesquioxane (POSS) to the difunctional epoxy compound is 1:(1-3).

[0014] Furthermore, the X is -(CH 2 ) 2 NH 2 or -(CH 2 ) 2 SH.

[0015] Furthermore, the bifunctional epoxy compound is an epoxy compound with epoxy groups at both ends.

[0016] Furthermore, the bifunctional epoxy compound is neopentyl glycol diglycidyl ether, 1.4-butanediol diglycidyl ether or E51 epoxy resin.

[0017] The present invention also provides a method for preparing the above-mentioned high heat-resistant and low dielectric epoxy compound, comprising the following steps:

[0018] The monofunctional cage-type silsesquioxane, the bifunctional epoxy compound and the catalyst are dissolved in a solvent, stirred and mixed, heated to 80-150° C. for reaction for 2-9 hours, and after the reaction is completed, the solvent is removed by reduced pressure distillation to obtain the high heat-resistant and low dielectric epoxy compound.

[0019] Furthermore, the catalyst is tris-(dimethylaminomethyl)phenol (DMP-30) or benzyldimethylamine (BDMA).

[0020] Furthermore, the solvent is toluene, tetrahydrofuran or acetone.

[0021] Furthermore, the mass concentration of the monofunctional cage-type silsesquioxane is 5-20%.

[0022] Furthermore, the amount of the catalyst used is 0.1% of the mass of the monofunctional cage-type silsesquioxane.

[0023] The beneficial effects of the present invention are:

[0024] The invention adopts monofunctional cage-type silsesquioxane and bifunctional epoxy compound to prepare monofunctional cage-type silsesquioxane-modified epoxy compound through functional group reaction. The method is simple, does not need to add metal catalyst, and improves the heat resistance, toughness and dielectric properties of epoxy resin material. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] Embodiment 1:

[0027] A method for preparing a high heat-resistant and low-dielectric epoxy compound comprises the following steps:

[0028] In the POSS used in this embodiment, R is isooctyl, X is aminopropyl isooctyl cage-type silsesquioxane (Xi'an Qiyue Biotechnology Co., Ltd.), and the epoxy compound used is 1.4-butanediol diglycidyl ether. 10g of aminopropyl isooctyl cage-type silsesquioxane, 3.2g of 1.4-butanediol diglycidyl ether, 0.01g of DMP-30 and 200mL of toluene solvent were stirred and mixed, heated to 80°C for 5 hours, and the solvent was removed by reduced pressure distillation after the reaction to obtain a high heat-resistant and low-dielectric epoxy compound-monofunctional cage-type silsesquioxane modified epoxy glycidyl ether.

[0029] Embodiment 2:

[0030] In the POSS used in this embodiment, R is isooctyl, X is aminopropyl phenylated cage-type silsesquioxane of aminopropyl, and the epoxy compound used is E51 epoxy resin. 10g aminopropyl phenylated cage-type silsesquioxane, 20g E51 epoxy resin, 0.01g DMP-30 and 200mL toluene solvent were stirred and mixed, and refluxed at 120°C for 5 hours. After the reaction was completed, the solvent was removed by reduced pressure distillation to obtain a high heat-resistant and low-dielectric epoxy compound-monofunctional cage-type silsesquioxane modified epoxy resin.

[0031] Embodiment 3:

[0032] In the POSS used in this embodiment, R is phenyl, X is aminopropyl phenylated cage silsesquioxane, and the epoxy compound used is E51 epoxy resin. 10g aminopropyl phenylated cage silsesquioxane, 20g E51 epoxy resin, 0.01g DMP-30 and 200mL tetrahydrofuran solvent were stirred and mixed, and refluxed at 80°C for 5 hours. After the reaction was completed, the solvent was removed by reduced pressure distillation to obtain a high heat-resistant and low-dielectric epoxy compound-monofunctional cage silsesquioxane modified epoxy resin.

[0033] The epoxy compound with high heat resistance and low dielectric constant prepared in Examples 1-3 was cured by mixing the unmodified epoxy resin E51 with epoxy resin and curing agent at 10 wt % to obtain a high heat resistance and low dielectric constant epoxy material.

[0034] Among them, epoxy resin: bisphenol A epoxy resin (EP) with an epoxy value of 0.52 / 100g; curing agent: methyltetrahydrophthalic anhydride (Me-THPA); catalyst: benzyldimethylamine (BDMA). The epoxy resin and epoxy compound are in an equivalent ratio with the curing agent, and the catalyst dosage is 0.1%.

[0035] The specific steps include:

[0036] 1) After spraying the release agent, assemble the mold and put it in a 130°C oven for preheating for two hours;

[0037] 2) Add the measured resin, curing agent and epoxy compound into the reaction kettle, stir and degas for 30 minutes under vacuum at a temperature of 120°C;

[0038] 3) Pour the casting material into the preheated mold and put it into a vacuum box for degassing for 5 minutes;

[0039] 4) Place the mold in an oven for curing. The curing conditions are: pre-curing at 130°C / 4h and post-curing at 140°C / 24h.

[0040] Table 1 Test results

[0041]

[0042] Among them, the glass transition temperature (°C) is tested in accordance with GB / T 22567-2008; the dielectric constant is tested in accordance with GB / T 1409-2006 (normal temperature, power frequency 50 Hz); and the tensile strength is tested in accordance with GB / T 2567-2008.

[0043] As shown in the data of Table 1, the high heat-resistant and low dielectric epoxy compound prepared by the present invention increases the heat resistance, toughness and dielectric properties of the epoxy resin material.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high heat-resistant and low dielectric epoxy compound, It is characterized in that It is prepared by functional group reaction of monofunctional cage-type silsesquioxane and difunctional epoxy compound; The monofunctional cage-type silsesquioxane structure is shown in formula (I): R is hydrogen, alkyl or aryl; X is amino, carboxyl or mercapto.

2. The high heat-resistant and low dielectric epoxy compound according to claim 1, It is characterized in that The molar ratio of the monofunctional cage-type silsesquioxane to the difunctional epoxy compound is 1:(1-3).

3. The high heat-resistant and low dielectric epoxy compound according to claim 1, It is characterized in that The X is -(CH 2 ) 2 NH 2 or -(CH 2 ) 2 SH.

4. The high heat-resistant and low dielectric epoxy compound according to claim 1, It is characterized in that The bifunctional epoxy compound is an epoxy compound with epoxy groups at both ends.

5. The high heat-resistant and low dielectric epoxy compound according to claim 4, It is characterized in that The bifunctional epoxy compound is neopentyl glycol diglycidyl ether, 1.4-butanediol diglycidyl ether or E51 epoxy resin.

6. A method for preparing the high heat-resistant and low dielectric epoxy compound according to any one of claims 1 to 5, It is characterized in that The steps include: The monofunctional cage-type silsesquioxane, the bifunctional epoxy compound and the catalyst are dissolved in a solvent, stirred and mixed, heated to 80-150° C. for reaction for 2-9 hours, and after the reaction is completed, the solvent is removed by reduced pressure distillation to obtain the high heat-resistant and low dielectric epoxy compound.

7. The method for preparing the high heat-resistant and low dielectric epoxy compound according to claim 6, It is characterized in that The catalyst is tris-(dimethylaminomethyl)phenol or benzyldimethylamine.

8. The method for preparing the high heat-resistant and low dielectric epoxy compound according to claim 6, It is characterized in that The solvent is toluene, tetrahydrofuran or acetone.

9. The method for preparing the high heat-resistant and low dielectric epoxy compound according to claim 6, It is characterized in that The mass concentration of the monofunctional cage-type silsesquioxane is 5-20%.

10. The method for preparing the high heat-resistant and low dielectric epoxy compound according to claim 6, It is characterized in that The amount of the catalyst used is 0.1% of the mass of the monofunctional cage-type silsesquioxane.

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