Cured epoxy resin composition and preparation method thereof

Abstract

The invention relates to the technical field of epoxy glue, provides a cured epoxy resin composition and a preparation method thereof, and solves the technical problem of improving the adhesive property of a product. The cured epoxy resin composition comprises modified epoxy resin, and the modified epoxy resin is prepared from the following raw materials in parts by weight: 100 parts of epoxy resin; 0.05 to 1 part of modified fumed silica; 5-20 parts of hot melt particles; the modified fumed silica is characterized in that the modified fumed silica is prepared by the following steps: S1, plasma activation of fumed silica; s2, the fumed silica and nanometer aluminum oxide are jointly dispersed in a coupling agent-ethanol solution, a reaction is conducted for 3 h at the temperature of 60 DEG C, the mass ratio of the fumed silica to the nanometer aluminum oxide is 7: 3-6: 4, and the mass ratio of the fumed silica to a coupling agent is 1: 1; and S3, drying to obtain the modified silicon dioxide.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy adhesives, and in particular to a cured epoxy resin composition and a preparation method thereof. Background Art

[0002] The applicant's prior patent application CN202211404060.0 discloses a modified epoxy resin, the formula of which is as follows:

[0003]

[0004] Hot-melt particles are large and easy to agglomerate. They are not well dispersed in the resin system and are prone to sedimentation. By freezing and crushing the hot-melt particles at low temperature and adding fumed silica to modify the surface during the crushing process, sedimentation and agglomeration can be reduced. At the same time, it also has a certain reinforcing effect.

[0005] During subsequent research and development, the applicant discovered that by modifying the fumed silica and optimizing its dispersion process, the adhesive properties of the product can be effectively improved. To this end, we proposed a cured epoxy resin composition and a preparation method thereof. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a cured epoxy resin composition and a preparation method thereof, which solves the technical problem of improving the bonding performance of products.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A cured epoxy resin composition comprises a modified epoxy resin, wherein the modified epoxy resin is prepared from the following raw materials in parts by weight:

[0009] 100 parts of epoxy resin;

[0010] 0.05-1 part of modified fumed silica;

[0011] 5-20 parts of hot melt particles;

[0012] Its characteristics are:

[0013] The modified fumed silica is prepared by the following method:

[0014] S1, plasma activated fumed silica;

[0015] S2, dispersed together with nano-alumina in a coupling agent-ethanol solution, reacted at 60°C for 3 hours, the mass ratio of fumed silica to nano-alumina was 7:3-6:4, and the mass ratio of fumed silica to coupling agent was 1:1;

[0016] S3. After drying, modified silica is obtained.

[0017] Furthermore, in step S1, the conditions for plasma activation are O2, 150W, and 8 minutes.

[0018] Furthermore, in step S2, the parameters of the fumed silica are a specific surface area of ​​150±20m 2 / g, primary particle size 12nm, and the parameters of nano-alumina are specific surface area 138mm 2 / g, average particle size 20nm;

[0019] The coupling agent-ethanol solution is prepared by dissolving 2 parts by weight of the coupling agent in 98 parts by weight of anhydrous ethanol.

[0020] Furthermore, in step S3, the product is first dried at 60° C. under normal pressure for 2 h, and then dried at 80° C. under vacuum for 4 h.

[0021] Furthermore, the modified epoxy resin is prepared by the following method:

[0022] S11, mixing the hot-melt particles with modified fumed silica and then performing air flow freezing and pulverization to obtain modified hot-melt particles;

[0023] S12, mixing the modified hot-melt particles with epoxy resin to obtain a modified epoxy resin.

[0024] Furthermore, after screening, the modified hot-melt particles in step S11 have a particle size range of 3 to 8 μm.

[0025] Furthermore, in step S12, a planetary mixing and degassing machine is used for mixing under the following conditions: temperature of 20-25° C., rotation speed of 2000 rpm, time of 2 minutes, and continuous mixing for 3 times.

[0026] The present invention provides a cured epoxy resin composition and a preparation method thereof, which have the following beneficial effects: by modifying fumed silica, optimizing its dispersion process, and optimizing the specification parameters of fumed silica and nano-alumina, the bonding performance of the product is improved by more than 13% compared with the original patented product. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] Material Description:

[0029]

[0030]

[0031] Example 1

[0032] A cured epoxy resin composition comprises a modified epoxy resin, wherein the modified epoxy resin is prepared from the following raw materials in parts by weight:

[0033] 100 parts of epoxy resin;

[0034] 0.05-1 part of modified fumed silica;

[0035] Polymethyl methacrylate elastomer (hot-melt particles) 5-20 parts.

[0036] The modified fumed silica is prepared by the following method:

[0037] S1, plasma activated fumed silica, plasma activation conditions are O2, 150W, 8 minutes;

[0038] S2, dispersed together with nano-alumina in a coupling agent-ethanol solution, reacted at 60°C for 3 hours; wherein,

[0039] The mass ratio of fumed silica to nano-alumina is 7:3 to 6:4, and the mass ratio of fumed silica to coupling agent is 1:1.

[0040] The parameters of fumed silica are surface area 150±20m 2 / g, primary particle size 12nm, and the parameters of nano-alumina are specific surface area 138mm 2 / g, average particle size 20nm; coupling agent-ethanol solution is prepared by dissolving 2 parts by weight of coupling agent in 98 parts by weight of anhydrous ethanol;

[0041] S3. Drying: first drying at 60° C. under normal pressure for 2 h, then drying at 80° C. under vacuum for 4 h to obtain modified silica.

[0042] The modified epoxy resin is prepared by the following method:

[0043] S11, mixing the hot-melt particles with modified fumed silica and then performing air flow freezing and crushing to obtain modified hot-melt particles, wherein the modified hot-melt particles are screened to have a particle size range of 3 to 8 μm;

[0044] S12. The modified hot-melt particles are mixed with epoxy resin to obtain modified epoxy resin. The mixing is carried out using a planetary mixing and degassing machine under the following conditions: a temperature of 20-25° C., a rotation speed of 2000 rpm, a time of 2 minutes, and continuous mixing for 3 times.

[0045] High temperature storage accelerated test: Temperature: 60±2℃, stored in sealed glass jars, test period 3 months.

[0046]

[0047] Therefore, the ratio of fumed silica to nano-alumina in the present application is preferably in the range of 7:3-6:4.

[0048] The components and performance test results of Comparative Examples 1-5 differ from those of Example 2, as shown in the table below. The main difference lies in the specifications of the fumed silica and nano-alumina. This modified epoxy resin adhesive, referred to as epoxy resin adhesive A, is mixed with adhesive B. Adhesive B consists of 8 parts by weight of ultrafine dicyandiamide and 3 parts by weight of an organic urea accelerator. It is prepared by mixing the two components. The mixing process can be compared to adhesive A, i.e., step S12 in the preparation of the modified epoxy resin.

[0049]

[0050] Note: Specific surface area unit (2 / g), particle size unit (nm);

[0051] All nano-alumina are γ-nano-alumina;

[0052] The surface tension of PP substrate is 29-31mN / m; the surface tension of LCP substrate is 42mN / m; the surface tension of PA66 substrate is 33mN / m.

[0053] Therefore, the parameter of the fumed silica in this application is selected as the specific surface area of ​​150±20m 2 / g, primary particle size 12nm, the parameters of nano-alumina are selected as specific surface area 138mm 2 / g, average particle size 20nm.

[0054] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A cured epoxy resin composition comprising a modified epoxy resin, wherein the modified epoxy resin is prepared from the following raw materials in parts by weight: 100 parts of epoxy resin; 0.05-1 part of modified fumed silica; 5-20 parts of hot melt particles; Its characteristics are: The modified fumed silica is prepared by the following method: S1, plasma activated fumed silica; S2, dispersed together with nano-alumina in a coupling agent-ethanol solution, reacted at 60°C for 3 hours, the mass ratio of fumed silica to nano-alumina was 7:3-6:4, and the mass ratio of fumed silica to coupling agent was 1:1; S3. After drying, modified silica is obtained.

2. A cured epoxy resin composition according to claim 1, characterized in that: In step S1, the plasma activation conditions are O2, 150W, and 8 minutes.

3. A cured epoxy resin composition according to claim 2, characterized in that: In step S2, the parameters of the fumed silica are a specific surface area of ​​150±20m 2 / g, primary particle size 12nm, and the parameters of nano-alumina are specific surface area 138mm 2 / g, average particle size 20nm; The coupling agent-ethanol solution is prepared by dissolving 2 parts by weight of the coupling agent in 98 parts by weight of anhydrous ethanol.

4. A cured epoxy resin composition according to claim 3, characterized in that: In the step S3, the product is first dried at 60° C. under normal pressure for 2 h, and then dried at 80° C. under vacuum for 4 h.

5. The method for preparing a cured epoxy resin composition according to any one of claims 1 to 4, wherein: The preparation of the modified epoxy resin includes the following steps: S11, mixing the hot-melt particles with modified fumed silica and then performing air flow freezing and pulverization to obtain modified hot-melt particles; S12, mixing the modified hot-melt particles with epoxy resin to obtain a modified epoxy resin.

6. The method for preparing a cured epoxy resin composition according to claim 5, wherein: After screening, the modified hot-melt particles in step S11 have a particle size range of 3 to 8 μm.

7. The method for preparing a cured epoxy resin composition according to claim 6, wherein: In step S12, a planetary mixing and degassing machine is used for mixing under the following conditions: temperature of 20-25° C., rotation speed of 2000 rpm, time of 2 minutes, and continuous mixing for 3 times.

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