CN117264375A - Epoxy resin composition and preparation method thereof - Google Patents

Abstract

This application discloses an epoxy resin composition and its preparation method, which is prepared from raw materials including the following weight parts: 60 to 100 parts of epoxy resin, 6 to 15 parts of toughening agent, 10 to 18 parts of nanofillers, and silane coupling 1 to 2 parts of agent, 3 to 10 parts of curing agent, 1 to 4 parts of accelerator, and 5 to 10 parts of surfactant. Through resin adjustment and improvement, while maintaining the excellent comprehensive properties of epoxy resin, it can further improve its dielectric properties and shorten its curing time to meet its needs in aerospace, lightweight and other fields.

Description

An epoxy resin composition and its preparation method

Technical field

The present application relates to the technical field of composite materials, and specifically to an epoxy resin composition and its preparation method.

Background technique

Epoxy resin and its composite materials have excellent mechanical properties, insulation properties, corrosion resistance, small dimensional shrinkage and stability, and strong adhesion to materials. They can be widely used in the preparation of thermosetting composite materials, adhesives and coatings. etc., used in the automotive industry, aerospace and other fields.

The commonly used type of epoxy resin is bisphenol A. Its cured product has a high cross-linking density and has shortcomings such as flammability, brittleness, and insufficient toughness. It needs to be toughened and modified. And due to the rigid and brittle structure of epoxy resin, its impact resistance is poor. In order to improve the impact resistance of epoxy resin, epoxy resin/nano clay composite materials can be prepared, and organic/inorganic nanotechnology can be used to prepare polymer-based nanocomposites. The good properties of nanomaterials can be combined with polymers to give the matrix Superior performance in all aspects of materials.

Traditional epoxy resin composition composite materials have long curing times, long molding cycles, and low production efficiency, which severely limits their large-scale application of prepregs in the automotive industry, aerospace and other fields. Moreover, the dielectric constant and dielectric loss of traditional epoxy resin are relatively large and cannot meet the special electrical performance requirements of related structural materials such as intelligent electronic equipment, radomes, and aircraft.

Contents of the invention

In order to solve the above-mentioned deficiencies in the art, this application aims to provide an epoxy resin composition and a preparation method thereof. Through resin adjustment and improvement, while maintaining the excellent comprehensive properties of epoxy resin, it can further improve its dielectric properties and shorten its curing time to meet its needs in aerospace, lightweight and other fields.

According to one aspect of the present application, an epoxy resin composition is provided, which is prepared from raw materials including the following parts by weight:

Epoxy resin, toughener, nanofiller, silane coupling agent, curing agent, accelerator.

In some embodiments of the present application, the dosage of the epoxy resin is 60 to 100 parts, the dosage of the toughening agent is 6 to 15 parts, the dosage of the nanofiller is 10 to 18 parts, and the silane The amount of coupling agent is 1 to 2 parts, the amount of surfactant is 5 to 10 parts, the amount of curing agent is 3 to 10 parts, and the amount of accelerator is 1 to 4 parts.

In some embodiments of the present application, the epoxy resin is selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, o-cresol epoxy resin, trifunctional epoxy resin and tetrafunctional epoxy resin. one or more of them.

Optionally, the bisphenol A-type epoxy resin includes but is not limited to: CYD-128, CYD-127, CYD-011, NPEL128, NPEL127, and E51.

Optionally, the bisphenol F epoxy resin includes but is not limited to: NPEF170, NPEF171, and NPEF175.

Optionally, the trifunctional epoxy resin includes but is not limited to: AFG-90, EPM-386, and TDE-85.

Optionally, the four-functional epoxy resin includes but is not limited to: AG-80 and EPM-420.

In some embodiments of the present application, the toughening agent is selected from one or more of phenoxy resin, polyethylene resin and nitrile rubber.

In some embodiments of the present application, the nanofiller is selected from one or more of silica, boron nitride, glass beads, insulating and thermally conductive compound powder, and modified montmorillonite.

Preferably, the modified montmorillonite is octadecyltrimethylammonium bromide modified montmorillonite.

The mass ratio of the octadecyltrimethylammonium bromide to the montmorillonite is (23.5-47.1):100.

In some embodiments of the present application, the curing agent is selected from one or more of dicyandiamide, diaminodiphenyl sulfone, and imidazole; the accelerator is selected from one or more of urea and imidazole compounds. or more;

Optionally, the dicyandiamide includes but is not limited to: Ecure4, Dyhard 100, Dyhard 100s, Dyhard100SF.

Alternatively, the imidazole includes but is not limited to: 2-methylimidazole, polymeric imidazole GY6601, Ajinomoto imidazole PN-23, and Ajinomoto imidazole PN-50.

Optionally, the ureas include but are not limited to: Dyhard 100, Dyhard 100S, Dyhard 100SF.

In some embodiments of the present application, the raw materials further include: surfactants and silane coupling agents.

Optionally, the surfactant includes but is not limited to: dodecylphenol, fluorocarbon surfactant (FS-8500).

Optionally, the silane coupling agent includes but is not limited to: KH550, KH560, KH570.

The preparation method of the epoxy resin composition provided in this application includes:

Mix the bisphenol A/F liquid epoxy resin and the toughening agent evenly at the first temperature, then add the bisphenol A solid epoxy and o-cresol epoxy resin, and stir evenly to obtain the first component;

Disperse and mix a certain amount of bisphenol A/F liquid epoxy resin and nanofillers through a high-speed disperser to obtain the second component;

Take a certain amount of bisphenol A/F epoxy resin and a certain amount of curing agent and accelerator and grind them with a three-roller grinder until they are evenly mixed to obtain the third component.

Mix the first component, the second component, the silane coupling agent, the surfactant and the third component evenly at the second temperature. After lowering to the third temperature, add the third component and mix evenly to obtain the result.

In some embodiments of the present application, the first temperature is 140-160°C; the second temperature is 80-150°C; and the third temperature is 60-80°C.

Compared with the prior art, this application at least includes the following beneficial effects:

This application provides an epoxy resin composition, which uses a cationic surfactant to modify sodium-based montmorillonite to prepare organic montmorillonite, and uses organic montmorillonite and other nanofillers as dielectric modifiers to improve The dielectric properties of epoxy resin. At the same time, the curing time of the epoxy resin was shortened by adjusting the type and proportion of the curing agent and accelerator, thereby preparing an epoxy resin composition system.

This application also provides a method for preparing epoxy resin composition composite materials. The method has a simple preparation process, simple production equipment, high production efficiency, low production cost, and can be produced on an industrial scale.

Description of the drawings

Figure 1 is a flow chart of the preparation process of the epoxy resin composition according to the exemplary embodiment of the present application.

Detailed ways

The technical solution of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of this application.

It should be noted in particular that similar substitutions and modifications made for this application are obvious to those skilled in the art, and they are all deemed to be included in this application. Relevant persons can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of this application, to implement and apply the technology of this application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments.

If no specific conditions are specified in this application, the application will be carried out in accordance with conventional conditions or conditions recommended by the manufacturer. The raw materials or excipients used, as well as the reagents or instruments used, if the manufacturer is not indicated, are all conventional products that can be purchased commercially. .

This application is described in detail below.

Rapid solidification molding technology is one of the rapidly developing technologies in the world. This method can break through the traditional epoxy resin system processing model, shorten the product molding cycle, and has very important value in composite structural parts processing technology.

Through resin adjustment and improvement, while maintaining the excellent comprehensive properties of epoxy resin, it can further improve its dielectric properties and shorten its curing time to meet its needs in aerospace, lightweight and other fields.

This application found that the organic montmorillonite prepared by modifying sodium montmorillonite with a cationic surfactant, and using organic montmorillonite and other nanofillers as dielectric modifiers can improve the dielectric properties of epoxy resin. properties, but the amount of montmorillonite or other nanofillers added will affect the specific properties of the final epoxy resin composition. The more nanofillers added to the resin system, may lead to agglomeration of the nanofillers, uneven dispersion in the internal structure of the resin and an increase in interface defects, resulting in a certain reduction in the mechanical properties and dielectric properties of the composite material.

Example 1

Weigh 20 parts of bisphenol liquid epoxy resin (NPEL-128) and 10 parts of phenoxy resin (PKHH) into the container, raise the temperature to 145°C, stir mechanically for 4 hours and then add 13 parts of bisphenol A solid epoxy resin ( CYD-011) and 18 parts of o-cresol epoxy resin (CYDCN-200), mix evenly to obtain the first component.

Weigh 25 parts of bisphenol liquid epoxy resin (NPEL-128), 8 parts of boron nitride (10~15um), and 8 parts of glass beads (density 0.21g/cm ³ ), and disperse them evenly through a high-speed disperser to obtain the first Two components.

Weigh 8 parts of bisphenol liquid epoxy resin (NPEL-128), 6 parts of dicyandiamide (DYHARD 100S), and 2 parts of organic urea (DYHARD UR500) and grind them with a three-roller mill until evenly mixed to obtain the third component.

At 100°C, mix the first component, the second component, 2 parts of silane coupling agent (KH550), and 5 parts of dodecylphenol evenly, then lower the temperature to 70°C, add the third component, and mix thoroughly A uniform epoxy resin composition was obtained.

Inject the epoxy resin composition into the corresponding mold, perform vacuum degassing, put it into an oven, raise the temperature to 150°C and cure for 10 minutes to obtain an epoxy resin casting.

The epoxy resin composition obtained above is prepared into a glue film through a film coating machine, and then the obtained glue film and quartz fiber woven cloth QWB110 are impregnated and compounded to obtain a prepreg. The fiber area density is 110g/m ² and the resin content is 40±2%.

Cut and lay the above-mentioned prepreg, for example, lay 24 layers at the same angle, and then cure to obtain a composite laminate. The curing process is: curing at 150°C for 10 minutes, using molding for curing and molding, and the entire pressure is not less than 5MPa. .

The above material ratios are all mass ratios.

Perform performance testing on epoxy resin compositions and composite materials. Performance testing includes:

Dielectric performance test: GB/T 5597-1999, test frequency is 7-18GHz;

Glass transition temperature test: ASTM D7028-2007(2005).

Flexural strength test: ASTM D7264.

Interlaminar shear strength test: ASTM D2344.

Example 2

Weigh 20 parts of bisphenol liquid epoxy resin (CYD-128) and 12 parts of toughening agent (VINYLE-C) into the container, raise the temperature to 145°C, mechanically stir for 4 hours, then add 12 parts of bisphenol A solid epoxy Resin (CYD-011) and 16 parts of o-cresol epoxy resin (CYDCN-200), mix evenly to get the first component.

Weigh 25 parts of bisphenol liquid epoxy resin (CYD-128), 6 parts of octadecyltrimethylammonium bromide modified montmorillonite (montmorillonite CEC = 86mmol/100g), 6 parts of glass beads ( Density 0.21g/cm ³ ), disperse evenly through a high-speed disperser to obtain the second component.

Weigh 8 parts of bisphenol liquid epoxy resin (CYD-128), 5.5 parts of dicyandiamide (DYHARD 100S), and 1.5 parts of organic urea (DYHARD UR500) and grind them with a three-roller mill until evenly mixed to obtain the third component.

Under the condition of 100°C, mix the first component, the second component and 5 parts of dodecylphenol evenly, then lower the temperature to 70°C and add the third component, and mix thoroughly to obtain an epoxy resin composition.

Inject the epoxy resin composition into the corresponding mold, perform vacuum degassing, put it into an oven, raise the temperature to 130°C and cure for 30 minutes to obtain an epoxy resin casting.

The epoxy resin composition obtained above is prepared into a glue film through a film coating machine, and then the obtained glue film and quartz fiber woven cloth QWB220 are impregnated and compounded to obtain a prepreg. Its fiber surface density is 220g/m ² and its resin content is 40±2%.

Cut and lay the above-mentioned prepreg, for example, lay 12 layers at the same angle, and then cure to obtain a composite laminate. The curing process is: curing at 130°C for 30 minutes, using molding for curing and molding, and the entire pressure is not less than 5MPa. .

Perform performance tests on the epoxy resin composition and composite materials, and the performance tests are the same as those in Example 1.

Example 3

Weigh 25 parts of bisphenol liquid epoxy resin (E51) and 10 parts (VINYLE-C) into the container, raise the temperature to 145°C, mechanically stir for 4 hours, then add 12 parts of bisphenol A solid epoxy resin (CYD-011 ) and 16 parts of o-cresol epoxy resin (NPCN-702), mix evenly to get the first component.

Weigh 20 parts of bisphenol liquid epoxy resin, 6 parts of boron nitride (5-10um), and 6 parts of glass beads (density 0.39g/cm ³ ), and disperse them evenly through a high-speed disperser to obtain the second component.

Weigh 8 parts of bisphenol liquid epoxy resin (E51), 6 parts of dicyandiamide (DYHARD 100S), and 1.5 parts of Ajinomoto imidazole (PN-23) and grind them with a three-roller grinder until evenly mixed to obtain the third component. .

At 100°C, mix the first component, the second component, 1.5 parts of KH560, and 6 parts of dodecylphenol evenly, then lower the temperature to 70°C and add the third component, and mix thoroughly to obtain an epoxy resin combination. things.

Inject the epoxy resin composition into the corresponding mold, perform vacuum degassing, put it into an oven, raise the temperature to 150°C and cure for 8 minutes to obtain an epoxy resin casting.

The laying of adhesive film, prepreg, and composite material laminate is the same as in Example 2. The curing process is: curing at 150°C for 8 minutes, using molding for curing and molding, and the whole process is pressurized not less than 5MPa.

Perform performance tests on the epoxy resin composition and composite materials, and the performance tests are the same as those in Example 1.

Example 4

Weigh 25 parts of bisphenol liquid epoxy resin (CYD-128) and 8 parts of phenoxy resin (PKHH) into the container, raise the temperature to 145°C, mechanically stir for 4 hours, then add 12 parts of bisphenol A solid epoxy resin ( E-20) and 20 parts of o-cresol epoxy resin (NPCN-702), mix evenly to get the first component.

Weigh 20 parts of bisphenol liquid epoxy resin (CYD-128), 5 parts of octadecyltrimethylammonium bromide modified montmorillonite (montmorillonite CEC = 90mmol/100g), 5 parts of glass beads ( Density 0.21g/cm ³ ), disperse evenly through a high-speed disperser to obtain the second component.

Weigh 8 parts of bisphenol liquid epoxy resin (CYD-128), 5.5 parts of dicyandiamide (DYHARD 100S), and 1 part of substituted urea (HUA-5300) and grind them with a three-roller mill until evenly mixed to obtain the third component. .

At 100°C, mix the first component, the second component, 1 part of KH560, and 8 parts of dodecylphenol evenly, then lower the temperature to 70°C and add the third component, mix thoroughly to obtain an epoxy resin combination things.

Inject the epoxy resin composition into the corresponding mold, perform vacuum degassing, put it into an oven, raise the temperature to 150°C and cure for 30 minutes to obtain an epoxy resin casting.

The laying of adhesive film, prepreg, and composite material laminate is the same as in Example 1. The curing process is: curing at 150°C for 30 minutes, using molding for curing and molding, and the whole process is pressurized not less than 5MPa.

Perform performance tests on the epoxy resin composition and composite materials, and the performance tests are the same as those in Example 1.

Comparative example 1

In this comparative example, the added amount of organic urea (DYHARD UR500) is 0.5 parts, and the curing process is: curing at 130°C for 150 minutes. The rest is the same as Example 1.

Comparative example 2

This comparative example does not add octadecyltrimethylammonium bromide modified montmorillonite, and the rest is the same as Example 2.

Comparative example 3

In this comparative example, the addition amount of octadecyltrimethylammonium bromide modified montmorillonite was 3.5 parts, and the rest was the same as in Example 2.

Comparative example 4

In this embodiment, the addition amount of octadecyltrimethylammonium bromide modified montmorillonite is 8.2 parts, and the rest is the same as in Example 2.

The relevant test results of the epoxy resin composition prepared in this application are shown in Table 1:

content DMA measures Tg(℃) Dielectric constant ε Dielectric loss tanδ Bending strength(MPa) Example 1 140 2.615 0.0175 92.7 Example 2 138 2.542 0.0161 93.1 Example 3 136 2.824 0.0186 88.5 Example 4 134 2.698 0.0181 89.0 Comparative example 1 139 2.663 0.0180 91.6 Comparative example 2 138 3.126 0.0229 94.5 Comparative example 3 137 2.866 0.0207 93.8 Comparative example 4 137 2.997 0.0185 92.2

The relevant performance test results of the epoxy resin composition composite laminate prepared in this application are shown in Table 2:

The dielectric constant of the epoxy resin composition first decreases and then increases as the modified montmorillonite content increases. This may be related to the interaction between montmorillonite and epoxy resin. When the added amount is small, there are fewer interfaces for interaction between epoxy resin and montmorillonite, and the inhibitory effect on the steering polarization of epoxy resin is not obvious. When larger amounts are added, the cumulative effect of interfacial polarization may increase the dielectric constant of the epoxy resin composition. Moreover, too much montmorillonite will affect the degree of cross-linking of the epoxy resin and hinder the formation of a network structure. This will increase the ability of the dipole of the epoxy resin to turn toward polarization, leading to an increase in the dielectric constant. .

When the added amount of montmorillonite is 6 parts (5%), the dielectric constant of the epoxy resin composition and its composite material is the lowest. It may be because the dielectric of the interaction between epoxy resin and montmorillonite reaches a certain critical value at this time.

The more fillers introduced into the resin system, this may lead to uneven dispersion of the fillers in the internal structure of the resin and an increase in dielectric defects, which will lead to a certain reduction in the mechanical properties of the epoxy resin composition and its composite materials. Comparative Example 2 does not add montmorillonite, therefore, the mechanical properties of Comparative Example 2 are enhanced to a certain extent.

From the above examples and comparative examples, it can be seen that by adding a certain amount of organic montmorillonite and other nanofillers, and adjusting the type and proportion of the curing agent and accelerator, the dielectric properties of the epoxy resin can be further improved and the cycle time shortened. Curing time of oxy resin. In addition, the prepared epoxy resin composite material also has excellent dielectric properties and good mechanical properties, which can meet the special requirements of the automotive industry, aerospace and other fields.

The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art, several improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims (10)

1. An epoxy resin composition, characterized in that it is prepared from raw materials including the following parts by weight: 60 to 100 parts of epoxy resin, 6 to 15 parts of toughening agent, 10 to 18 parts of nanofiller, 1 to 2 parts of silane coupling agent, 3 to 10 parts of curing agent, 1 to 4 parts of accelerator, and 5 surfactants ~10 servings. 2. The epoxy resin composition according to claim 1, characterized in that the epoxy resin is selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, o-cresol epoxy resin, trisphenol novolac epoxy resin, and bisphenol F type epoxy resin. One or more of functional epoxy resin and tetrafunctional epoxy resin. 3. The epoxy resin composition according to claim 1, wherein the toughening agent is selected from one or more of phenoxy resin, polyethylene resin and nitrile rubber. 4. The epoxy resin composition according to claim 1, characterized in that the nanofiller is selected from the group consisting of silicon dioxide, boron nitride, glass beads, insulating and thermally conductive compound powder and modified montmorillonite. one or more; Montmorillonite is preferred. 5. The epoxy resin composition according to claim 4, characterized in that the modified montmorillonite is octadecyltrimethylammonium bromide modified montmorillonite. 6. The epoxy resin composition according to claim 5, wherein the mass ratio of the octadecyltrimethylammonium bromide to the montmorillonite is (23.5-47.1): 100. 7. The epoxy resin composition according to claim 1, wherein the curing agent is selected from one or more of dicyandiamide, diaminodiphenyl sulfone, and imidazole; The accelerator is selected from one or more types of ureas and imidazole compounds. 8. The epoxy resin composition according to claim 1, characterized in that the surfactant is selected from one or more of dodecylphenol and fluorocarbon surfactants; Preferably, the silane coupling agent includes: KH550, KH560, KH570. 9. The preparation method of the epoxy resin composition according to any one of claims 1 to 8, characterized in that it includes: Mix the bisphenol A/F liquid epoxy resin and the toughening agent evenly at the first temperature, then add the bisphenol A solid epoxy and o-cresol epoxy resin, and stir evenly to obtain the first component; Disperse and mix a certain amount of bisphenol A/F liquid epoxy resin and nanofillers through a high-speed disperser to obtain the second component; Take a certain amount of bisphenol A/F epoxy resin and a certain amount of curing agent and accelerator and grind them with a three-roller mill until they are evenly mixed to obtain the third component; Mix the first component, the second component, the silane coupling agent, the surfactant and the third component evenly at the second temperature. After lowering to the third temperature, add the third component and mix evenly to obtain the result. 10. The preparation method according to claim 9, wherein the first temperature is 140-160°C; the second temperature is 80-150°C; and the third temperature is 60-80°C.