Heat-resistant flame-retardant environment-friendly EVA composite material and preparation method thereof

Abstract

The invention relates to the technical field of EVA films, in particular to a heat-resistant flame-retardant environment-friendly EVA composite material and a preparation method thereof. The invention relates to a heat-resistant flame-retardant environment-friendly EVA (Ethylene Vinyl comprising the following raw materials in parts by mass: 30-40 parts of an ethylene-vinyl acetate copolymer, 10-20 parts of low-density polyethylene, 15-25 parts of a halogen flame retardant, 10-20 parts of an inorganic flame retardant, 5-10 parts of a maleic anhydride grafted ethylene-ethyl acrylate copolymer, 2-4 parts of triethylene glycol di-2-ethylhexoate, 1-2 parts of octadecanol polyoxyethylene ether, 1-2 parts of iso-tridecanol polyoxyethylene ether and 1-3 parts of an antioxidant. According to the heat-resistant flame-retardant environment-friendly EVA composite material, through specific components and proportions, good heat-resistant flame-retardant performance is achieved, and meanwhile the original mechanical performance of the EVA composite material is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of EVA films, and particularly to a heat-resistant, flame-retardant and environmentally friendly EVA composite material and a preparation method thereof. Background Art

[0002] EVA, namely ethylene-vinyl acetate copolymer, is a thermoplastic elastomer. The content of vinyl acetate (VA) in EVA is generally 15%-70%, and the glass transition temperature is about 30°C, which endows it with good flexibility, impact resistance, adhesiveness and chemical corrosion resistance. Therefore, EVA is widely used in packaging materials, architectural decoration, shoe materials, wire and cable sheaths, photovoltaic module encapsulation, automotive interiors and other fields. For example, in photovoltaic modules, the EVA film as an encapsulation material can effectively protect solar cells and improve the light transmittance and reliability of the modules; in medical devices, due to its biocompatibility, it is also used in disposable medical devices.

[0003] However, traditional EVA materials have the problem of insufficient flame retardancy. They are prone to softening and deformation at high temperatures, which affects the product life and performance stability, and they do not have self-extinguishing properties. When encountering a fire source, they may burn and spread rapidly, increasing the fire risk. In order to improve the flame retardancy of EVA materials, researchers have carried out a large number of explorations and practices, and improved their performance by adding various flame retardants and modifiers. In the prior art, inorganic nanoparticles are usually introduced as fillers to enhance the thermal stability and flame retardancy of EVA. However, uneven dispersion of the nanoparticles may lead to an increase in internal structural defects of the EVA material, thus affecting the quality of the final product. Therefore, it is necessary to develop a new type of heat-resistant, flame-retardant and environmentally friendly EVA composite material, which can not only significantly improve the flame retardancy of EVA, but also maintain the original excellent physical and chemical properties of EVA, and effectively solve the problem of internal defects of EVA materials caused by uneven dispersion of nanoparticles. Summary of the Invention

[0004] In order to effectively solve the problem of internal defects of EVA materials caused by uneven dispersion of nanoparticles, the present application provides a heat-resistant, flame-retardant and environmentally friendly EVA composite material and a preparation method thereof. A heat-resistant, flame-retardant and environmentally friendly EVA composite material achieves good heat-resistant and flame-retardant properties through specific components and ratios, while maintaining the original mechanical properties of the EVA composite material.

[0005] In a first aspect, a heat-resistant, flame-retardant and environmentally friendly EVA composite material provided by the present application adopts the following technical solution: A heat-resistant, flame-retardant and environmentally friendly EVA composite material, comprising the following raw materials in parts by mass: 30 to 40 parts of ethylene-vinyl acetate copolymer, 10 to 20 parts of low-density polyethylene, 15 to 25 parts of halogen-based flame retardant, 10 to 20 parts of inorganic flame retardant, 5 to 10 parts of maleic anhydride-grafted ethylene-ethyl acrylate copolymer, 2 to 4 parts of triethylene glycol diisooctoate, 1 to 2 parts of octadecyl alcohol polyoxyethylene ether, 1 to 2 parts of isomeric tridecyl alcohol polyoxyethylene ether, and 1 to 3 parts of antioxidant.

[0006] In the above technical solution, ethylene-vinyl acetate copolymer and low-density polyethylene serve as the base materials of the EVA composite material, providing good flexibility and processing performance; the synergistic effect of the halogen-based flame retardant and the inorganic flame retardant effectively enhances the flame retardant performance of the EVA composite material; maleic anhydride-grafted ethylene-ethyl acrylate copolymer serves as a compatibilizer, improving the compatibility between the raw materials, making the nanoparticles more evenly dispersed in the EVA composite material and reducing internal defects; triethylene glycol diisooctoate, octadecyl alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene ether are added as additives, and through their synergistic effect, the flame retardancy and smoke suppression of the EVA composite material are significantly improved. First of all, the synergistic effect of the three jointly enhances the interfacial compatibility and dispersibility, making the flame retardant, especially the inorganic flame retardant, more evenly distributed in the polymer matrix, forming a denser and more uniform layer structure, so that oxygen can be effectively isolated and the flame spread can be blocked during the combustion process. At the same time, they can quickly form a protective film on the surface of the EVA composite material, hinder the heat transfer path, and promote the development of the carbonized layer by regulating the crystallization behavior, further improving the self-extinguishing property and combustion resistance.

[0007] Preferably, the inorganic flame retardant is a mixture of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers, and the mass ratio of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers is 1:(0.8 to 1.2):(0.1 to 0.5).

[0008] In the above technical solution, the present application selects aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers as the inorganic flame retardants of the EVA composite material, and through the combined use of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers, the effective improvement of the flame retardant performance is achieved. Aluminum hydroxide and magnesium hydroxide decompose at high temperatures to produce water vapor, dilute combustible gases and absorb heat, thereby reducing the combustion temperature; aluminum borate whiskers can form a strong carbonized layer during the combustion process, effectively isolating oxygen and preventing the flame from spreading further. In addition, the addition of aluminum borate whiskers can further enhance the mechanical strength and heat resistance of the EVA composite material, so that the EVA composite material can still maintain excellent physical and chemical properties in a high-temperature environment.

[0009] Preferably, the halogen-based flame retardant is one or more of decabromodiphenylethane, brominated epoxy resin, and melamine polyphosphate.

[0010] In the above technical solution, by selecting these halogen-based flame retardants and adding them to the EVA composite material, hydrogen halide gas can be generated by decomposition at high temperature, capturing free radicals generated by combustion and interrupting the combustion chain reaction, thereby achieving the purpose of flame retardancy. It can cooperate well with inorganic flame retardants to further enhance the flame retardant performance of the composite material.

[0011] Preferably, the halogen-based flame retardant is a mixture of decabromodiphenylethane and brominated epoxy resin in a mass ratio of 1:(0.3 - 0.5).

[0012] In the above technical solution, by adjusting the halogen-based flame retardant in the EVA composite material to decabromodiphenylethane and brominated epoxy resin, the flame retardant performance and processing performance of the composite material can be further optimized. Among them, decabromodiphenylethane has high thermal stability and flame retardant efficiency, can stably exist at high temperature and effectively prevent flame spread; brominated epoxy resin has good compatibility and processing performance, can be evenly dispersed in the substrate, and improve the overall flame retardant performance of the material. The combined use of decabromodiphenylethane and brominated epoxy resin can give full play to their respective advantages and maximize the flame retardant performance.

[0013] Preferably, the antioxidant is one or more of antioxidant 168, antioxidant 1010, antioxidant 1076, and antioxidant 1035.

[0014] In the above technical solution, by adding the above antioxidants to the EVA composite material, they can effectively prevent the material from degrading due to oxidation during processing and use, and improve the weather resistance and service life of the material.

[0015] Preferably, the mass ratio of triethylene glycol diisooctate, octadecanol polyoxyethylene ether, and isomeric tridecanol polyoxyethylene ether is 3:1.7:1.4.

[0016] In the above technical solution, by adjusting the mass ratio of triethylene glycol diisooctate, octadecanol polyoxyethylene ether, and isomeric tridecanol polyoxyethylene ether, the uniformity of the inorganic flame retardant in the EVA composite material can be further improved, the flame retardant and smoke suppression performance of the EVA composite material can be further optimized, and the overall performance of the material can be improved.

[0017] In the second aspect, the preparation method of a heat-resistant, flame-retardant and environmentally friendly EVA composite material provided by this application adopts the following technical solution: A preparation method of a heat-resistant, flame-retardant and environmentally friendly EVA composite material, comprising the following steps: Step 1: Mix all raw materials and put them into the mixing tank. Start stirring. After stirring evenly, the materials can be discharged and sent to the production workshop. Step 2: Preheat the machine in the production workshop to 200 - 220 °C and keep it warm for 1.5 - 2 hours. Then, the materials obtained in Step 1 can be normally put into the machine hopper to start extrusion. Step 3: Adjust the clamping pressure to 18% kg and blow - mold with 6 kg air pressure.

[0018] Preferably, the stirring speed in Step 1 is 800 r / min.

[0019] In the above - mentioned technical solution, through the above - mentioned preparation process, the present application ensures the uniformity and stability of the EVA composite material. The stirring speed in Step 1 is 800 r / min, which can effectively promote the mixing and dispersion of all raw materials, laying a good foundation for subsequent processing and forming. The temperature control and pressure regulation in Steps 2 and 3 ensure the stability and uniformity of the material during the extrusion and blow - molding processes, thus obtaining a heat - resistant, flame - retardant, and environmentally friendly EVA composite material with good comprehensive performance.

[0020] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, triethylene glycol diisooctoate, octadecyl alcohol polyoxyethylene ether, and isomeric tridecyl alcohol polyoxyethylene ether enhance the interfacial compatibility and dispersibility through their synergistic effects, form a denser and more uniform layer structure, and can hinder the heat transfer path, promoting the development of the char layer, significantly improving the flame - retardant and smoke - suppressing properties of the EVA composite material.

[0021] 2. By selecting aluminum hydroxide, magnesium hydroxide, and aluminum borate whiskers as the inorganic flame retardants for the EVA composite material, through the combined use of aluminum hydroxide, magnesium hydroxide, and aluminum borate whiskers, the flame - retardant performance is effectively improved. At the same time, the addition of aluminum borate whiskers can further enhance the mechanical strength and heat - resistant performance of the EVA composite material, enabling the EVA composite material to still maintain excellent physical and chemical properties in a high - temperature environment. Specific Embodiments

[0022] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0023] Example 1 A heat - resistant, flame - retardant, and environmentally friendly EVA composite material, comprising the following raw materials in parts by mass: 35 kg of ethylene - vinyl acetate copolymer, 15 kg of low - density polyethylene, 20 kg of halogen - based flame retardant, 15 kg of inorganic flame retardant, 8 kg of maleic anhydride - grafted ethylene - ethyl acrylate copolymer, 3 kg of triethylene glycol diisooctoate, 1.7 kg of octadecyl alcohol polyoxyethylene ether, 1.4 kg of isomeric tridecyl alcohol polyoxyethylene ether, and 2 kg of antioxidant.

[0024] Among them, the halogen-based flame retardant is a mixture of decabromodiphenylethane and brominated epoxy resin in a mass ratio of 1:0.4.

[0025] Among them, the inorganic flame retardant is a mixture of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers in a mass ratio of 1:1:0.4.

[0026] Among them, the antioxidant is antioxidant 1010.

[0027] Among them, ethylene-vinyl acetate copolymer is purchased from ExxonMobil in the United States, grade: UL15019CC.

[0028] Among them, low-density polyethylene is purchased from Lanzhou Petrochemical, product number: LDPE 2426H.

[0029] Among them, decabromodiphenylethane is purchased from Henan Duohui Chemical Products Co., Ltd.

[0030] Among them, brominated epoxy resin is purchased from Hubei Xingyan New Materials Technology Co., Ltd.

[0031] Among them, aluminum hydroxide is purchased from Shijiazhuang Baijiang Mineral Products Co., Ltd.

[0032] Among them, magnesium hydroxide is purchased from Jinan Henghan Chemical Co., Ltd.

[0033] Among them, aluminum borate whiskers are purchased from Hubei Watson Chemical Technology Co., Ltd.

[0034] Among them, maleic anhydride grafted ethylene-ethyl acrylate copolymer is purchased from DuPont in the United States, grade: 21E830.

[0035] Among them, triethylene glycol diisooctate is purchased from Shandong Xuchen Chemical Technology Co., Ltd.

[0036] Among them, octadecanol polyoxyethylene ether is purchased from Wuhan Karnos Technology Co., Ltd.

[0037] Among them, isomeric tridecanol polyoxyethylene ether is purchased from Jining Tangyi Chemical Co., Ltd., product number: E-1320.

[0038] Among them, antioxidant 1010 is purchased from BASF in Germany.

[0039] Among them, the preparation method of the heat-resistant flame-retardant and environmentally friendly EVA composite material includes the following steps: Step 1: Mix the raw materials and put them into the mixing tank, start stirring, and the stirring speed is 800 r / min. After stirring evenly, the material can be discharged and sent to the production workshop.

[0040] Step 2: Preheat the machine in the production workshop to 200 - 220 °C and keep it warm for 1.5 - 2 h. Then, the material obtained in Step 1 can be normally put into the machine hopper to start extrusion.

[0041] Step 3: Adjust the clamping pressure to 18% kg and blow molding with 6 kg air pressure.

[0042] Example 2 A heat-resistant, flame-retardant and environmentally friendly EVA composite material, different from Example 1, includes the following raw materials in parts by mass: 30 kg ethylene-vinyl acetate copolymer, 20 kg low-density polyethylene, 15 kg halogen-based flame retardant, 20 kg inorganic flame retardant, 5 kg maleic anhydride-grafted ethylene-ethyl acrylate copolymer, 2 kg triethylene glycol diisooctoate, 2 kg octadecyl alcohol polyoxyethylene ether, 2 kg isomeric tridecyl alcohol polyoxyethylene ether, and 1 kg antioxidant.

[0043] Among them, the halogen-based flame retardant is a mixture of decabromodiphenylethane and brominated epoxy resin in a mass ratio of 1:0.3.

[0044] Among them, the inorganic flame retardant is a mixture of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers in a mass ratio of 1:1.2:0.1.

[0045] Among them, the preparation method of the heat-resistant, flame-retardant and environmentally friendly EVA composite material includes the following steps: Step 1: Mix all the raw materials and put them into the mixing cylinder, start stirring, and the stirring speed is 800 r / min. After stirring evenly, the material can be discharged and sent to the production workshop.

[0046] Step 2: Preheat the machine in the production workshop to 200 °C and keep it warm for 2 h. Then, the material obtained in Step 1 can be normally put into the machine hopper to start extrusion.

[0047] Step 3: Adjust the clamping pressure to 18% kg and blow molding with 6 kg air pressure.

[0048] Example 3 A heat-resistant, flame-retardant and environmentally friendly EVA composite material, different from Example 1, includes the following raw materials in parts by mass: 40 kg ethylene-vinyl acetate copolymer, 10 kg low-density polyethylene, 25 kg halogen-based flame retardant, 10 kg inorganic flame retardant, 10 kg maleic anhydride-grafted ethylene-ethyl acrylate copolymer, 4 kg triethylene glycol diisooctoate, 1 kg octadecyl alcohol polyoxyethylene ether, 1 kg isomeric tridecyl alcohol polyoxyethylene ether, and 3 kg antioxidant.

[0049] Among them, the halogen-based flame retardant is a mixture of decabromodiphenylethane and brominated epoxy resin in a mass ratio of 1:0.5.

[0050] Among them, the inorganic flame retardant is a mixture of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers in a mass ratio of 1:0.8:0.5.

[0051] Among them, the preparation method of the heat-resistant flame-retardant and environmentally friendly EVA composite material includes the following steps: Step 1: Mix the raw materials and put them into the mixing cylinder, start stirring, and the stirring speed is 800 r / min. After stirring evenly, the material can be discharged and sent to the production workshop.

[0052] Step 2: Preheat the machine in the production workshop to 220 °C and keep it warm for 1.5 h, and then the material obtained in Step 1 can be normally put into the machine hopper to start extrusion.

[0053] Step 3: Adjust the clamping pressure to 18% kg and blow molding with 6 kg air pressure.

[0054] Example 4 A heat-resistant flame-retardant and environmentally friendly EVA composite material, different from Example 1, the inorganic flame retardant is a mixture of aluminum hydroxide and magnesium hydroxide in a mass ratio of 1:1.

[0055] Comparative Example 1 An EVA composite material, different from Example 1, triethylene glycol diisooctate is replaced with diisononyl phthalate in equal amount.

[0056] Comparative Example 2 An EVA composite material, different from Example 1, octadecyl alcohol polyoxyethylene ether is replaced with sodium dodecyl sulfate in equal amount.

[0057] Comparative Example 3 An EVA composite material, different from Example 1, isomeric tridecyl alcohol polyoxyethylene ether is replaced with sodium dodecylbenzenesulfonate in equal amount.

[0058] Comparative Example 4 An EVA composite material, different from Example 1, does not contain triethylene glycol diisooctate, octadecyl alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene ether.

[0059] Performance testing Test the thermal stability, combustion performance and mechanical properties of the EVA composite materials of the above examples and comparative examples.

[0060] Thermal stability: Use a thermogravimetric analyzer to measure the residual rate (%) after the material decomposes under different atmospheres. The detection conditions are a nitrogen atmosphere, a heating rate of 20 °C / min, from room temperature to 600 °C.

[0061] Combustion performance: Refer to GB / T 2406-2009 to detect the limiting oxygen index (LOI / %), and refer to GB / T 2408-2008 to detect the vertical burning grade. Mechanical properties: Refer to GB / T 16421-1996 to detect the elongation at break (%). The test data of the elongation at break are as follows: The above test results are shown in Table 1.

[0062] Table 1: Combined with the analysis of the experimental results in Table 1, it can be seen that the heat-resistant, flame-retardant and environmentally friendly EVA composites in Examples 1-4 perform well in terms of thermal stability, combustion performance and mechanical properties, indicating that the EVA composites in Examples 1-4 have good thermal stability, decomposition resistance, flame retardancy and flexibility.

[0063] Combined with the analysis of the EVA composites in Example 1 and Example 4, compared with Example 1, in Example 4, the inorganic flame retardant only contains aluminum hydroxide and magnesium hydroxide, and no aluminum borate whiskers are added. The combustion performance and mechanical properties of Example 1 are good, which further proves the important role of aluminum borate whiskers in improving the flame retardancy and mechanical properties of EVA composites.

[0064] Combined with the analysis of the EVA composites in Example 1 and Comparative Examples 1-4, in Comparative Examples 1-4, triethylene glycol diisooctate, octadecyl alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene ether are respectively replaced or not added. The thermal stability, combustion performance and mechanical properties of Example 1 are good, indicating that the combined use of triethylene glycol diisooctate, octadecyl alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene ether plays a key role in improving the overall performance of EVA composites. By optimizing the dispersibility and compatibility of inorganic flame retardants in the substrate, triethylene glycol diisooctate, octadecyl alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene ether not only improve the flame retardancy and smoke suppression performance of the material, but also enhance the mechanical properties and thermal stability of the material.

[0065] This specific embodiment is only an explanation of the present application, and it does not limit the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A heat-resistant, flame-retardant and environmentally friendly EVA composite material, characterized in that: The invention comprises the following raw materials in parts by weight: 30-40 parts of ethylene-vinyl acetate copolymer, 10-20 parts of low-density polyethylene, 15-25 parts of halogen flame retardant, 10-20 parts of inorganic flame retardant, 5-10 parts of maleic anhydride grafted ethylene-ethyl acrylate copolymer, 2-4 parts of triethylene glycol diisooctanoate, 1-2 parts of octadecyl alcohol polyoxyethylene ether, 1-2 parts of isotridecyl alcohol polyoxyethylene ether and 1-3 parts of antioxidant.

2. The heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 1, characterized in that: The inorganic flame retardant is a mixture of aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers, and the mass ratio of the aluminum hydroxide, magnesium hydroxide and aluminum borate whiskers is 1: (0.8-1.2): (0.1-0.5).

3. The heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 1, characterized in that: The halogen flame retardant is one or more of decabromodiphenylethane, brominated epoxy resin, and melamine polyphosphate.

4. A heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 1, characterized in that: The halogen flame retardant is prepared by mixing decabromodiphenylethane and brominated epoxy resin in a mass ratio of 1: (0.3-0.5).

5. The heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 168, antioxidant 1010, antioxidant 1076, and antioxidant 1035.

6. The heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 1, characterized in that: The mass ratio of triethylene glycol diethylhexanoate, octadecyl alcohol polyoxyethylene ether and isomeric tridecanol polyoxyethylene ether is 3:1.7:1.

4.

7. A method for preparing a heat-resistant, flame-retardant and environmentally friendly EVA composite material, characterized in that: The following steps are involved: Step 1: Mix all the raw materials and put them into the mixing tank, start stirring, and after stirring evenly, release the materials and send them to the production workshop; Step 2: The machine in the production workshop is heated to 200-220°C in advance and kept warm for 1.5-2 hours before the material obtained in step 1 can be put into the machine hopper to start extrusion; Step 3: Adjust the clamping pressure to 18%kg and use 6kg air pressure for blow molding.

8. The method for preparing a heat-resistant, flame-retardant and environmentally friendly EVA composite material according to claim 7, characterized in that: The stirring speed of step 1 is 800 r / min.

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