An epoxy prepreg, a high-transparency glass fiber cloth-based epoxy plate and a preparation method and application thereof

Abstract

The application discloses an epoxy prepreg, a high-transparency glass fiber cloth-based epoxy plate and a preparation method and application thereof. The epoxy prepreg comprises a glass fiber cloth and an epoxy glue solution attached to the glass fiber cloth. Raw material components of the epoxy glue solution comprise, in parts by weight, 50-70 parts of an epoxy resin, 10-20 parts of a curing agent, 3-5 parts of an acrylate compound or a methacrylate compound, 0.02-0.06 parts of an initiator, 0.02-0.04 parts of an accelerator and 20-40 parts of a solvent. The epoxy prepreg can be used to prepare the glass fiber cloth-based epoxy plate with high light transmittance and high toughness after lamination and heat curing.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin composite materials technology, specifically to an epoxy prepreg, a high-transparency glass fiber cloth-based epoxy board, and their preparation methods and applications. Background Technology

[0002] In the field of materials science and engineering, transparent materials have attracted much attention due to their wide application in optics, electronics, decoration, and high-end structural components. Currently, the most common transparent materials on the market include traditional inorganic glass and organic glass (such as polymethyl methacrylate (PMMA)). While traditional glass has high light transmittance and hardness, its density is relatively high (approximately 2.5 g / cm³). 3 It is significantly brittle and prone to breakage during processing. Furthermore, subsequent processing such as cutting and drilling requires specialized equipment, hindering the achievement of lightweight and complex structural designs. On the other hand, while PMMA (polymethyl methacrylate) exhibits good transparency and processing performance, its heat resistance is poor, with long-term operating temperatures generally not exceeding 100°C. It is also susceptible to corrosion and deformation in organic solvent environments such as acetone and alcohol, limiting its application in high-temperature, high-humidity, or chemically resistant environments.

[0003] Composite materials with fiberglass cloth as reinforcement and epoxy resin as matrix have shown great potential in the field of lightweight structural components due to their excellent mechanical strength, dimensional stability and designability. In particular, in applications that require transparency, such as front panels of photovoltaic modules and housings of transparent electronic devices, the demand for high light transmittance is becoming increasingly prominent. To improve the light transmittance of such composite materials, Chinese patent application CN120865597A modifies the refractive index of the resin system by adding a refractive index regulator and modified nano-silica to match the high-transmittance glass fiber. It is further supplemented by an antireflective double-coating structure (including a high refractive index layer of titanium dioxide and silica, and a low refractive index layer of porous silica and / or magnesium fluoride), enabling the composite glass fiber board to achieve dual light management and significantly improve light transmittance. However, the use of nano-inorganic fillers in this scheme inevitably makes the resin matrix brittle and may introduce more stress concentration sources and potential interface defects at the microscale, resulting in a deterioration of the material's toughness (impact resistance and bending performance). Under actual dynamic loads or complex stress environments, it is prone to brittle fracture or microcrack propagation, affecting its long-term reliability as a structural component. To improve material toughness, existing technologies mainly involve adding rubber toughening agents to the resin system. For example, Chinese patent application CN110202862A discloses a unidirectional yarn composite board, which selects nitrile rubber, acrylate rubber, etc. as toughening agents and adds them to the resin solution, which can improve toughness to a certain extent. However, research has found that the light transmittance of the existing rubber-toughened resin system is not ideal when it is combined with glass fiber cloth, making it difficult to meet the requirements of high light transmittance materials for applications such as transparent electronic device housings.

[0004] Currently, for glass fiber cloth reinforced epoxy resin composites, optimizing light transmittance often comes at the cost of toughness, while conventional methods for enhancing toughness are difficult to achieve ideal light transmittance. Overcoming this bottleneck and developing a glass fiber cloth-based epoxy board that can simultaneously achieve high light transmittance and excellent mechanical toughness (high impact strength and high flexural strength) has become a key technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, the present invention aims to provide an epoxy prepreg that, after lamination and thermosetting, can produce a glass fiber cloth-based epoxy board with both high light transmittance and high toughness.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides an epoxy prepreg, comprising a glass fiber cloth and an epoxy adhesive attached to the glass fiber cloth; The raw material composition of the epoxy adhesive, by weight, includes: 50-70 parts epoxy resin; 10-20 parts of curing agent; 3-5 parts of acrylate or methacrylate compounds; Initiator 0.02-0.06 parts; Accelerator 0.02-0.04 parts; Solvent 20-40 parts.

[0008] Furthermore, the epoxy resin is selected from bisphenol A type epoxy resin.

[0009] Furthermore, the curing agent is selected from amine curing agents; the amine curing agent is preferably diaminodiphenyl sulfone.

[0010] Furthermore, the acrylate compound is selected from at least one of methyl acrylate and butyl acrylate; the methacrylate compound is selected from at least one of methyl methacrylate and butyl methacrylate.

[0011] Furthermore, the initiator is selected from dicumyl peroxide.

[0012] Furthermore, the accelerator is selected from imidazole accelerators; the imidazole accelerator is preferably dimethylimidazole.

[0013] Furthermore, the solvent is selected from xylene.

[0014] Furthermore, the fiberglass cloth is electronic grade fiberglass cloth; the specification of the fiberglass cloth is 1080.

[0015] Secondly, the present invention provides a method for preparing the epoxy prepreg, comprising the following steps: according to the raw material composition ratio of the epoxy adhesive, each component is put into a mixing device for thorough mixing to obtain the epoxy adhesive; glass fiber cloth is impregnated in the epoxy adhesive to obtain glass fiber cloth with a uniformly impregnated surface of epoxy adhesive, and then dried to obtain the epoxy prepreg.

[0016] Furthermore, the drying process is hot air drying at 160-180℃.

[0017] Thirdly, the present invention provides a high-transparency glass fiber cloth-based epoxy board, which is obtained by laminating and thermosetting the epoxy prepreg described in the present invention.

[0018] Fourthly, the present invention provides the application of the epoxy prepreg or the high-transparency glass fiber cloth-based epoxy board in the preparation of transparent electronic device housings.

[0019] The present invention has the following beneficial effects: This invention introduces acrylate or methacrylate compounds into an epoxy resin system, along with an initiator, enabling in-situ polymerization during epoxy resin curing. These compounds form an interpenetrating polymer network as a toughening phase, effectively initiating crazes and terminating crack propagation, significantly improving the material's impact resistance and fracture toughness. Simultaneously, this homogeneous toughening mechanism maximizes the optical uniformity of the resin matrix and the refractive index matching with the glass fiber cloth, achieving high light transmittance. The glass fiber cloth-based epoxy board made from the epoxy prepreg of this invention simultaneously achieves high light transmittance and excellent mechanical toughness (high impact strength and high flexural strength), demonstrating outstanding application potential in fields with stringent requirements for both optical and mechanical properties, such as transparent electronic device housings. Detailed Implementation

[0020] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0021] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0022] The materials used in the embodiments and comparative examples of this invention are described below, but are not limited to these materials.

[0023] Fiberglass cloth: Zhuhai Zhubo Electronic Materials Co., Ltd., 1080-127; Epoxy resin: Bisphenol A type epoxy resin, Nan Ya 901A80; Curing agent: diaminodiphenyl sulfone; Methacrylate compound 1: Butyl methacrylate; 2. Methacrylate compound: Methyl methacrylate; Acrylates: Butyl acrylate; Rubber toughening agent: Kanekachi MX-125 (Japan); Initiator: dicumyl peroxide; Accelerator: Dimethylimidazole; Solvent: Xylene.

[0024] Preparation method of epoxy semi-cured sheets in the examples and comparative examples: According to the raw material composition ratio of epoxy adhesive in Table 1, each component is put into a mixing device and stirred at 1000 rpm for 2 hours until fully mixed to obtain epoxy adhesive; the epoxy adhesive is transferred to a coating machine, and then the glass fiber cloth is placed on the coating machine. The glass fiber cloth is impregnated in the epoxy adhesive by the coating machine to obtain glass fiber cloth with a uniformly impregnated surface of epoxy adhesive. It is then dried with hot air at 170℃ to obtain epoxy semi-cured sheets.

[0025] Table 1. Epoxy resin raw material composition of epoxy prepregs in Examples 1-5 and Comparative Examples 1-4 (by weight parts)

[0026] Glass fiber cloth-based epoxy boards were prepared by laminating and thermosetting the prepreg sheets of the examples and comparative examples. The preparation method is as follows: the epoxy prepreg sheets were prepared according to a size of 1060. Cut the epoxy prepreg to 1260mm (cutting with the radial direction of the fiberglass cloth as the short side of the production board and the weft direction as the long side of the production board). Combine the four layers of the cut epoxy prepreg and perform hot pressing according to the specified hot pressing process (170℃, 2hr, pressure 340psi). Then follow with cold pressing to ensure the flatness of the board thickness, thus producing a fiberglass cloth-based epoxy board.

[0027] The obtained glass fiber cloth-based epoxy board was subjected to the following performance tests: 1. Light transmittance: The transmittance was tested using an LS155 color difference haze transmittance meter, in accordance with standard GB / T 2410-2008.

[0028] 2. Impact strength: Tested according to standard ASTM D2794.

[0029] 3. Bending performance: Tested according to method 2.4.4 of IPC-TM-650.

[0030] The performance test results are shown in Table 2.

[0031] Table 2 Performance test results of glass fiber cloth-based epoxy boards prepared in Examples 1-5 and Comparative Examples 1-4

[0032] The results above show that the glass fiber cloth-based epoxy board made from the epoxy prepreg of this invention can simultaneously achieve high light transmittance (≥90%) and high toughness (impact strength ≥50kJ / m). 2 With its excellent bending properties, it shows outstanding application potential in fields such as transparent electronic device housings where there are stringent requirements for both optical and mechanical properties.

[0033] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An epoxy prepreg, characterized in that, Includes fiberglass cloth and epoxy adhesive adhering to the fiberglass cloth; The raw material composition of the epoxy adhesive, by weight, includes: 50-70 parts epoxy resin; 10-20 parts of curing agent; 3-5 parts of acrylate or methacrylate compounds; Initiator 0.02-0.06 parts; Accelerator 0.02-0.04 parts; Solvent 20-40 parts.

2. The epoxy prepreg according to claim 1, characterized in that, The epoxy resin is selected from bisphenol A type epoxy resin.

3. The epoxy prepreg according to claim 1, characterized in that, The curing agent is selected from amine curing agents; the amine curing agent is selected from diaminodiphenyl sulfone.

4. The epoxy prepreg according to claim 1, characterized in that, The acrylate compound is selected from at least one of methyl acrylate and butyl acrylate; the methacrylate compound is selected from at least one of methyl methacrylate and butyl methacrylate.

5. The epoxy prepreg according to claim 1, characterized in that, The accelerator is selected from imidazole accelerators; the imidazole accelerator is selected from dimethylimidazolium.

6. The epoxy prepreg according to claim 1, characterized in that, The initiator is selected from dicumyl peroxide; the solvent is selected from xylene.

7. The epoxy prepreg according to claim 1, characterized in that, The fiberglass cloth is electronic grade fiberglass cloth; the specification of the fiberglass cloth is 1080.

8. The method for preparing epoxy prepreg according to any one of claims 1-7, characterized in that, Includes the following steps: According to the raw material composition ratio of epoxy adhesive, each component is put into a mixing device for thorough mixing to obtain epoxy adhesive; Fiberglass cloth is impregnated with epoxy resin to obtain fiberglass cloth with a uniformly impregnated surface. After drying, epoxy semi-cured sheet is obtained.

9. A high-transparency glass fiber cloth-based epoxy board, characterized in that, It is prepared by laminating and thermosetting the epoxy prepreg as described in any one of claims 1-7.

10. The use of the epoxy prepreg according to any one of claims 1-7 or the high transparency glass fiber cloth-based epoxy board according to claim 9 in the preparation of transparent electronic device housings.

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