Degradable vacuum infusion composite material and application thereof

Abstract

The invention discloses a degradable vacuum infusion composite material and application thereof in a battery box shell. The raw materials comprise the following components in percentage by mass: 30-40% of degradable epoxy resin composition, 1-3% of release agent and the balance of fiber raw material. The invention provides a composite material which can simultaneously meet the performance design requirements of a battery box shell part prepared by a high-pressure vacuum infusion process and has good degradability. The preparation method has a good application prospect in the field of battery case body parts in a high-pressure vacuum infusion process; the prepared battery box shell composite material part has good degradability, the degraded resin material and fiber material can be recycled, scraped products and leftover materials generated in the production process of an existing battery box shell composite material part and scraped products with expired service life can be effectively avoided, and the production cost is reduced. And the harm to the environment in the post-treatment process is avoided.

Description

Technical Field

[0001] The invention relates to a degradable vacuum infusion composite material and application thereof in a battery box shell component, belonging to the technical field of composite material components. Background Art

[0002] With the rise of new energy vehicles, driven by national policies, new energy vehicles are developing rapidly. They are gradually occupying a mainstream position in the domestic automobile industry. Electrification has become the development direction of the global automobile industry. With the explosive growth trend of new energy vehicles around the world, composite materials for electric vehicle battery box shells have also ushered in great development opportunities.

[0003] Composite materials have gained wide attention in the new energy industry as they help reduce battery weight while meeting stringent mechanical and impact requirements.

[0004] Compared with other processes, the high-pressure vacuum infusion process uses automated laying technology, which greatly improves efficiency and reduces manufacturing costs. Compared with traditional metal processes, high-pressure vacuum infusion process composite materials can combine safety, efficiency and lightweight, and gradually become the mainstream production process for battery box shells.

[0005] However, the battery box shell composite material uses thermosetting resin as raw material, and its subsequent treatment after scrapping faces severe environmental problems, which will have a significant impact on the environment and the sustainable development of human equipment now and in the future.

[0006] Therefore, developing a degradable vacuum high-pressure infusion composite battery box shell can greatly improve this problem. After the battery box shell is scrapped, the cured resin can be degraded in an appropriate manner to separate it from the fiber raw material. The separated resin can be put back into the formula for use, and the fiber raw material can also be re-arranged and reused, achieving carbon neutrality benefits and minimizing environmental damage. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a degradable vacuum infusion composite material that can meet the performance requirements of battery box shell parts, so as to solve the environmental problems caused by the subsequent treatment of battery box shell parts.

[0008] In order to solve the above technical problems, the present invention provides a degradable vacuum infusion composite material, the raw materials of which include 30-40% by mass of a degradable epoxy resin composition, 1-3% by mass of a release agent and the remainder of a fiber raw material; the degradable epoxy resin composition contains a degradable modified resin as shown in Formula I:

[0009]

[0010] In formula I, n is a natural number.

[0011] Preferably, the degradable epoxy resin composition comprises 65-85% by mass of an epoxy resin composition and 15-35% by mass of an amine curing agent; wherein, the epoxy resin composition comprises 90-95% by mass of an epoxy resin and 5-10% by mass of the degradable modified resin.

[0012] Preferably, the degradable epoxy resin composition has characteristic peaks at 1760-1710 cm -1 in infrared spectroscopy.

[0013] Preferably, the fiber raw material is selected from any one or more of glass fiber and carbon fiber.

[0014] Preferably, the release agent is selected from any one of fatty acid esters, fatty alcohol phosphates, fatty alcohols, and fatty alcohol polyoxyethylene ether phosphates.

[0015] Preferably, the degradable vacuum infusion composite material can be heated and degraded with an amine compound in an alkaline environment to separate the fibers.

[0016] More preferably, the temperature range for the heating degradation is 60-180 °C and the time is 1-48 h.

[0017] The present invention also provides an application of the above-mentioned degradable vacuum infusion composite material in a battery box housing, and the battery box housing comprises a battery box lower box body, a module housing, a bracket, and a battery box upper box body.

[0018] Preferably, the application comprises the following steps:

[0019] Step 1): Put the fiber raw material into a battery box housing preforming device, and preform the fiber raw material using a hot pressing process to form a fiber preform;

[0020] Step 2): Put the fiber preform into a forming mold of the battery box housing, turn on a vacuum pump to extract air from the forming mold and the laminated structure of the fiber preform. After reaching a vacuum, mix the degradable epoxy resin composition and the release agent evenly and then vacuum and pressurize them into the forming mold of the battery box housing;

[0021] Step 3): After heating and holding for curing, form a hot battery box housing, and cool and shape it at room temperature to form a battery box housing product.

[0022] Preferably, in the step 1), the temperature of the hot pressing process is 40 - 60°C, and the time is 3 - 10 min; in the step 2), the vacuum degree of the molding die reaching vacuum ranges from 20 to 40 mbar, and the temperature when the degradable epoxy resin composition and the release agent are mixed and injected is 50 - 80°C; in the step 3), the heating temperature for heating and heat preservation is 100 - 140°C, and the heat preservation time is 3 - 10 min.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The present invention uses degradable vacuum infusion composites, and the prepared battery box housing has excellent mechanical properties, meeting the design requirements and industry specifications of the battery box housing;

[0025] (2) The present invention uses a degradable epoxy resin composition as the main resin of the composite material, which can not change the existing process parameters and can seamlessly switch and replace the commonly used non - degradable epoxy resin compositions;

[0026] (3) The present invention uses degradable vacuum infusion composites, and the prepared battery box housing can achieve the degradation and separation of the resin and fiber raw materials under appropriate conditions. The recovered resin liquid and fiber raw materials can be reused, realizing green environmental protection and sustainable development. Description of the Drawings

[0027] Figure 1 It is an infrared analysis diagram of the degradable epoxy resin composition; wherein, (a) is epoxy resin, and (b) is degradable modified resin. Detailed Embodiments

[0028] To make the present invention more obvious and understandable, preferred embodiments are given below in conjunction with the drawings for detailed description as follows.

[0029] In the following embodiments, the degradable modified resin used has the structure of formula Ⅰ:

[0030]

[0031] The components and their corresponding mass percentages of each component in the raw materials used in Examples 1 - 6 and Comparative Examples 1 - 3 are shown in Table 1.

[0032] Table 1

[0033]

[0034]

[0035] Example 1

[0036] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1, and it is obtained by the following steps:

[0037] (1) Put the fiber raw material into the battery box housing preforming equipment. The fiber raw material is selected as 5 layers of square glass fiber cloth, and the fiber raw material is hot-pressed at 50 °C for 10 min to form a fiber preform with a specific structure and shape;

[0038] Step 2: Put the fiber preform into the battery box housing forming mold, turn on the vacuum pump to extract the air in the mold and the fiber preform laminate structure. The vacuuming time is 2 min and the vacuum degree is 30 mbar. After reaching complete vacuum, mix the degradable epoxy resin composition and the release agent evenly at 70 °C and then vacuum and pressurize them into the battery box housing forming mold;

[0039] Step 3: At a temperature of 110 °C, keep warm and cure for 5 min to form a hot battery box housing, and then cool and shape it at room temperature to form a battery box housing product.

[0040] Example 2

[0041] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that in Step 3, after the degradable epoxy resin composition and the release agent are injected into the battery box housing forming mold, they are cured at a temperature of 120 °C for 3 min to obtain a hot battery box housing, and then cooled and shaped at room temperature.

[0042] Example 3

[0043] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that in Step 3, after the degradable epoxy resin composition and the release agent are injected into the battery box housing forming mold, they are cured at a temperature of 100 °C for 10 min to obtain a hot battery box housing, and then cooled and shaped at room temperature.

[0044] Example 4

[0045] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the fiber raw material is selected as 4 layers of square glass fiber cloth and 1 layer of plain weave carbon fiber fabric. The carbon fiber fabric is located at the top layer. It is cured at a temperature of 110 °C for 5 min to obtain a hot battery box housing, and then cooled and shaped at room temperature.

[0046] Example 5

[0047] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the fiber raw material is 3 layers of square glass fiber cloth.

[0048] Example 6

[0049] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the fiber raw material is 2 layers of square glass fiber cloth.

[0050] Comparative Example 1

[0051] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the degradable modified resin is not added, and the addition amount of bisphenol A epoxy resin composition is increased.

[0052] Comparative Example 2

[0053] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the addition amount of degradable modified resin is increased, and the addition amount of bisphenol A epoxy resin composition is reduced.

[0054] Comparative Example 3

[0055] A degradable vacuum infusion composite material, the components and their corresponding mass percentages in the preparation raw materials are shown in Table 1. The difference from Example 1 is that the addition amount of degradable modified resin is increased, and the addition amount of flame-retardant epoxy resin composition is reduced.

[0056] Performance detection experiment

[0057] Experimental samples: Examples 1 - 6 were sequentially numbered as test samples 1 - 6; Comparative Examples 1 - 3 were sequentially numbered as control samples 1 - 3.

[0058] Judgment method: The experimental samples were respectively cut into appropriate sizes for degradation operations (under alkaline conditions, heated and degraded with amine compounds, and the amine group combined with the acetoacetate group in the degradable modified resin in Formula Ⅰ to form a dynamic enamine bond to achieve the separation effect). After degradation, the recovered liquid and solid recovered materials (containing residual resin and fiber) were obtained. The weight of the total solid recovered materials was weighed, and the solid recovery ratio was calculated.

[0059] Calculation formula:

[0060] Solid recovery ratio (%) = (original plate weight - recovered solid weight) / original plate weight

[0061] Compare the theoretical solid proportion with the actual recovery proportion to obtain the separation rate.

[0062] Separation rate (%) = 1 - ((Actual recovery ratio - Theoretical composite ratio) / Theoretical resin ratio) × 100%.

[0063] The analysis results are shown in Table 2.

[0064] Table 2

[0065] Sample Theoretical proportion of composite material (%) Actual proportion of recycled solid (%) Separation rate (%) Example 1 75 83 68 Example 2 75 82 72 Example 3 75 83 68 Example 4 73 80 74 Example 5 64.3 71 81.2 Example 6 54.5 63 81.3 Comparative Example 1 75 100 0 Comparative Example 2 75 80 80 Comparative Example 3 75 81 76

[0066] As can be seen from Table 2, by comparing the test results of Example 1 and Comparative Example 1, the composite material prepared from the degradable epoxy resin composition provided by the present invention can be degraded compared with traditional epoxy resins, and the degradation separation rate is greater than 60%. Using the degradation method provided by the present invention, the thermosetting epoxy resin and fibers in most of the composite materials can be separated.

[0067] By comparing the test results of Example 1, Example 2, and Example 3, increasing the curing temperature and shortening the curing time result in a better degradation effect of the cured product, and the separation rates are all greater than 60%, indicating that most of the resin can be recycled.

[0068] By comparing the test results of Example 1 and Example 4, the composite material composed of the degradable epoxy resin composition provided by the present invention and carbon fiber has a better degradation effect compared with glass fiber.

[0069] By comparing the test results of Example 1, Example 5, and Example 6, increasing the resin content can effectively improve the degradation effect, and the degradation separation rate can reach up to 81%.

[0070] By comparing the test results of Example 1, Comparative Example 2, and Comparative Example 3, increasing the proportion of degradable modified epoxy resin can further improve the degradation effect of the composite material.

Claims

1. A degradable vacuum infusion composite material, characterized in that, The raw materials include 30-40% of a degradable epoxy resin composition by mass percentage, 1-3% of a release agent, and the balance of fiber raw materials; the degradable epoxy resin composition contains a degradable modified resin represented by Formula I: In Formula I, n is a natural number.

2. The degradable vacuum infusion composite material according to claim 1, wherein, The degradable epoxy resin composition includes 65-85% of an epoxy resin composition by mass percentage and 15-35% of an amine curing agent; among them, the epoxy resin composition includes 90-95% of an epoxy resin and 5-10% of the degradable modified resin by mass percentage.

3. The degradable vacuum infusion composite material according to claim 1, wherein, The described degradable epoxy resin composition has characteristic peaks at 1760 - 1710 cm in infrared spectroscopic analysis. -1 Characteristic peaks.

4. The degradable vacuum infusion composite material according to claim 1, wherein The fiber raw materials are selected from any one or more of glass fiber and carbon fiber.

5. The degradable vacuum infusion composite material according to claim 1, wherein, The release agent is selected from any one of fatty acid esters, fatty alcohol phosphates, fatty alcohols, and fatty alcohol polyoxyethylene ether phosphates.

6. The degradable vacuum infusion composite material according to claim 1, wherein The degradable vacuum infusion composite material can be heated and degraded with an amine compound in an alkaline environment to separate the fibers.

7. The degradable vacuum infusion composite material according to claim 6, wherein The temperature range of the heating degradation is 60-180°C, and the time is 1-48 h.

8. Use of the degradable vacuum infusion composite material according to any one of claims 1-7 in a battery box housing, characterized in that, The battery box housing includes a battery box lower housing, a module housing, a bracket, and a battery box upper housing.

9. The application according to claim 8, wherein It includes the following steps: Step 1): Put the fiber raw materials into the preforming equipment of the battery box housing, and preform the fiber raw materials using a hot pressing process to form a fiber preform; Step 2): Put the fiber preform into the forming mold of the battery box housing, turn on the vacuum pump to extract the air in the forming mold and the laminated structure of the fiber preform. After reaching vacuum, mix the degradable epoxy resin composition and the release agent evenly and then inject them into the forming mold of the battery box housing under vacuum and pressure; Step 3): After heating and holding for curing, form a hot battery box housing, and cool and shape it at room temperature to form a battery box housing product.

10. The application according to claim 9, characterized in that, In Step 1), the temperature of the hot pressing process is 40-60°C, and the time is 3-10 min; in Step 2), the vacuum degree range for the forming mold to reach vacuum is 20-40 mbar, and the temperature when the degradable epoxy resin composition and the release agent are mixed and injected is 50-80°C; in Step 3), the heating temperature for heating and holding is 100-140°C, and the holding time is 3-10 min.

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