High-temperature-resistant and high-wetting epoxy resin, preparation method and application thereof

Abstract

The application discloses a high-temperature-resistant and high-wetting epoxy resin as well as a preparation method and application thereof. The high-temperature-resistant and high-wetting epoxy resin comprises an A component and a B component. The A component comprises an epoxy resin, a diluent and a coupling agent. The B component comprises a curing agent, a curing accelerator and a toughening agent. The curing agent is a composite system of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride. The high-temperature-resistant and high-wetting epoxy resin prepared by the application has the characteristics of toughness and strength, short curing time, low cost and easy production expansion.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin technology, specifically to a high-temperature resistant, highly wettable epoxy resin, its preparation method, and its applications. Background Technology

[0002] Epoxy resins possess excellent mechanical properties, thermal stability, chemical resistance, fatigue resistance, insulation properties, low dielectric properties, low shrinkage during curing, and dimensional stability. They are widely used as polymer matrices in various fields such as construction, aerospace, automotive, electronics, and medical devices.

[0003] Epoxy resin molecules contain highly reactive cyclic epoxy groups and various polar groups. These characteristic groups give epoxy resins strong adhesion to a variety of polar materials such as plastics, metals, glass, cement, and wood. Furthermore, the cured epoxy product has high cohesive strength, resulting in high adhesive strength. In recent years, epoxy resins have developed rapidly, and their applications have placed higher demands on them. For example, epoxy resin adhesives used as impregnating materials for carbon fibers must possess good wettability to ensure complete fusion between the resin and the fiber, thereby imparting superior strength, wear resistance, and toughness to carbon fiber composites. In addition, practical application environments require epoxy resins to have good high-temperature resistance, ensuring stable and excellent performance of the final product even in high-temperature environments.

[0004] Existing epoxy resin adhesives are difficult to combine excellent bonding performance and high strength with good toughness. Furthermore, the long curing time during the preparation of epoxy resin adhesives will affect their application. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a high-temperature resistant, highly wettable epoxy resin, its preparation method, and its applications. The high-temperature resistant, highly wettable epoxy resin of this invention achieves curing and forms a cross-linked network structure by adding tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride, while maintaining certain high-temperature resistance. A silane coupling agent is used to improve interfacial bonding and increase the wettability between the epoxy resin adhesive and the composite material. The high-temperature resistant, highly wettable epoxy resin prepared by this invention possesses both toughness and strength, and features short curing time, low cost, and ease of large-scale production. Its preparation method is simple, safe, and environmentally friendly, and can be used for large-scale industrial production.

[0006] One objective of this invention is to provide a high-temperature resistant, highly wettable epoxy resin comprising component A and component B; component A includes epoxy resin, diluent, and coupling agent; component B includes curing agent, curing accelerator, and toughening agent; the curing agent is a composite system of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride.

[0007] In a preferred embodiment of the present invention,

[0008] In the composite system of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride, the molar ratio of tetrahydrophthalic anhydride to methyltetrahydrophthalic anhydride is 1:(0.05-50).

[0009] In a preferred embodiment of the present invention,

[0010] The epoxy resin preferably includes at least one of bisphenol A type epoxy resin and bisphenol F type epoxy resin; and / or

[0011] The diluent is at least one of glycidyl ethers, preferably 1,4-butanediol diglycidyl ether. The diluent can reduce the viscosity of the epoxy resin and improve its processing performance.

[0012] In a preferred embodiment of the present invention,

[0013] The coupling agent is at least one of silane coupling agents, preferably KH560. The coupling agent can improve the bonding strength of the epoxy adhesive and enhance the wettability of the epoxy resin with other materials.

[0014] In a preferred embodiment of the present invention,

[0015] The curing accelerator is at least one of alkyl ammonium chloride curing accelerators, preferably benzyltriethylammonium chloride. The curing accelerator can speed up the reaction process and promote the completion of the curing reaction.

[0016] In a preferred embodiment of the present invention,

[0017] The toughening agent is at least one of polyether polyols, preferably polyether polyol 450. The toughening agent can improve the toughness of brittle epoxy resins.

[0018] In a preferred embodiment of the present invention,

[0019] The components in component A are calculated based on 100 parts by weight of the total epoxy resin.

[0020] Diluent 10-50 parts by weight;

[0021] Coupling agent 0.1-10 parts by weight;

[0022] The components in component B are calculated based on 100 parts by weight of the total weight of the curing agent.

[0023] Curing accelerator: 0.1-10 parts by weight;

[0024] Toughening agent 5-50 parts by weight.

[0025] In a preferred embodiment of the present invention,

[0026] The mass ratio of component A to component B is 1:(0.1-10).

[0027] The second objective of this invention is to provide a method for preparing a high-temperature resistant and highly wettable epoxy resin, which is one of the objectives of this invention. The method includes first mixing component A and component B according to the respective amounts of each component, and then mixing component A and component B according to the mass ratio to obtain the high-temperature resistant and highly wettable epoxy resin.

[0028] The preparation method of the high-temperature resistant and highly wettable epoxy resin of the present invention can adopt the following specific technical solutions:

[0029] (1) Preparation of component A

[0030] Component A is primarily epoxy resin. Due to its high viscosity, epoxy resin has poor flowability, making it difficult to process. Furthermore, high viscosity results in poor wettability with carbon fibers. Therefore, this invention adjusts the viscosity to a suitable level by adding an appropriate amount of diluent. The epoxy resin and diluent are added to a stirred tank at a weight ratio and thoroughly dissolved and mixed in a constant-temperature oil bath at 80°C. Then, a coupling agent is added, and after thorough mixing and cooling, component A is obtained.

[0031] (2) Preparation of component B

[0032] Component B is primarily a curing agent, and this invention uses an acid anhydride as the curing agent system. First, methyltetrahydrophthalic anhydride and tetrahydrophthalic anhydride are added to a stirred tank and heated to 80°C in an oil bath, then stirred until fully mixed. The mixture is then cooled to below 50°C, and a toughening agent is added and stirred. Finally, a curing accelerator is added and stirred until fully mixed and cooled completely to obtain component B.

[0033] (3) Preparation of high temperature resistant and highly wettable epoxy resin

[0034] Before use, mix component A and component B at a mass ratio of 1:(0.1-10) to obtain a high-temperature resistant and highly wettable epoxy resin adhesive.

[0035] A third objective of this invention is to provide an application of a high-temperature resistant, highly wettable epoxy resin, either as described in one objective of this invention or prepared by a method described in another objective of this invention, in the field of carbon fiber composite materials.

[0036] The present invention has the following beneficial effects:

[0037] Component A of this invention uses epoxy resin as the main body, and a silane coupling agent is added to the epoxy resin. The silane coupling agent contains two types of functional groups with different properties. One type of group can hydrolyze and chemically react with the bonding surface and hydroxyl groups. In this invention, the epoxy resin adhesive is used to impregnate carbon fibers, which can improve the interfacial bonding force between the two, thereby improving the adhesion and wettability. The other type of group reacts chemically with the adhesive to form long molecular chains that enhance the strength and toughness of the colloid. The coupling agent can improve the adhesive's adhesion, weather resistance, and mechanical properties in the wet state; improve material dispersibility and processing performance; and improve the wettability of the adhesive with other substances.

[0038] In this invention, methyltetrahydrophthalic anhydride is used as the main curing agent and tetrahydrophthalic anhydride as the auxiliary curing agent in component B. Neither of them contains rigid structures such as benzene rings in their molecular structure. At room temperature, they are basically liquid or low-melting-point solids. They can be mixed or cured with epoxy resin at low temperatures, have a long working time, and are easy to operate.

[0039] A toughening agent was added to component B to address the brittleness of the cured epoxy system. Furthermore, the presence of polyether polyol toughening agents facilitates cross-linking with the epoxy resin, promoting the formation of a three-dimensional network cross-linked structure. Additionally, the addition of a curing accelerator lowers the activation energy of the reaction, increasing the degree of cross-linking in the epoxy adhesive and improving curing efficiency.

[0040] The method for preparing epoxy resin according to the present invention is simple, easy to control, relatively environmentally friendly, requires simple equipment, and is easy to industrialize. Detailed Implementation

[0041] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0042] All raw materials used in the examples are commercially available.

[0043] The high-temperature resistant, high-wetting epoxy resin prepared in the examples was subjected to performance tests. The curing conditions were 90℃ / 2h + 110℃ / 3h. After full curing, tensile properties were tested according to ASTM D 638-08 test standard. Viscosity was tested according to GB / T 7124-2008 test standard. The viscosity of components A and B of the high-temperature resistant, high-wetting epoxy resin was measured using a DV-2 rotational viscometer. The glass transition temperature was determined using a differential scanning calorimeter to measure the high-temperature resistance of the high-temperature resistant, high-wetting epoxy resin. The wettability of the high-temperature resistant, high-wetting epoxy resin with carbon fiber was tested using a contact angle tester.

[0044] Example 1

[0045] A method for preparing a high-temperature resistant and highly wettable epoxy resin, which is prepared by mixing component A and component B in a 1:1 weight ratio;

[0046] (1) Preparation of component A: 50 parts by weight of bisphenol A type epoxy resin and 50 parts by weight of bisphenol F type epoxy resin and 18 parts by weight of diluent 1,4-butanediol diglycidyl ether were fully dissolved and mixed evenly in a constant temperature oil bath at 80°C. Then, 1.5 parts by weight of silane coupling agent KH560 were added, mixed evenly, and then cooled and packaged at room temperature.

[0047] (2) Preparation of component B: First, add 80 parts by weight of methyltetrahydrophthalic anhydride and 20 parts by weight of tetrahydrophthalic anhydride to a stirred tank, heat the oil bath to 80°C and stir for 20 minutes to mix thoroughly. After cooling to below 50°C, add 10 parts by weight of polyether polyol 450 and stir for 10 minutes. Then add 2 parts by weight of triethylammonium chloride and stir for 10 minutes. After fully dissolving and mixing, cool and package.

[0048] (3) Mix components A and B thoroughly: When using, mix components A and B in a mass ratio of 1:1, and allow the epoxy resin to fully cure and function according to the construction conditions, at a suitable temperature and curing time.

[0049] The preferred embodiments of the present invention disclosed above are only used to better explain the significance of the present invention and help readers fully understand it. The preferred embodiments do not describe all details exhaustively, and many other embodiments different from those described herein can be used for preparation. This invention is not limited to the specific embodiments described. Other researchers and technicians can make many modifications and changes based on the content of this specification, using similar techniques, raw materials, and preparation methods, but without departing from the technical content of the present invention, they still fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant, highly wettable epoxy resin comprising component A and component B; wherein component A comprises epoxy resin, diluent, and coupling agent; wherein component B comprises curing agent, curing accelerator, and toughening agent; wherein the curing agent is a composite system of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride.

2. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: In the composite system of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride, the molar ratio of tetrahydrophthalic anhydride to methyltetrahydrophthalic anhydride is 1:(0.05-50).

3. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: The diluent is at least one of glycidyl ethers, preferably 1,4-butanediol diglycidyl ether.

4. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: The coupling agent is at least one of silane coupling agents.

5. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: The curing accelerator is at least one of alkyl ammonium chloride curing accelerators, preferably benzyltriethylammonium chloride.

6. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: The toughening agent is at least one of polyether polyols.

7. The high-temperature resistant, highly wettable epoxy resin as described in claim 1, characterized in that: The components in component A are calculated based on 100 parts by weight of the total epoxy resin. Diluent 10-50 parts by weight; Coupling agent 0.1-10 parts by weight; The components in component B are calculated based on 100 parts by weight of the total weight of the curing agent. Curing accelerator: 0.1-10 parts by weight; Toughening agent 5-50 parts by weight.

8. The high-temperature resistant, highly wettable epoxy resin as described in any one of claims 1-7, characterized in that: The mass ratio of component A to component B is 1:(0.1-10).

9. A method for preparing a high-temperature resistant, highly wettable epoxy resin as described in any one of claims 1-8, comprising first mixing component A and component B according to the respective amounts of each component, and then mixing component A and component B according to the mass ratio to obtain the high-temperature resistant, highly wettable epoxy resin.

10. The application of a high-temperature resistant, high-wetting epoxy resin as described in any one of claims 1-8 or a high-temperature resistant, high-wetting epoxy resin prepared by the method described in claim 9 in the field of carbon fiber composite materials.