Anti-ultraviolet halogen-free flame-retardant TPV (thermoplastic vulcanizate) material and preparation method thereof

Abstract

The invention belongs to the technical field of TPV materials, and particularly relates to an anti-ultraviolet halogen-free flame-retardant TPV material and a preparation method thereof. The TPV material comprises the following components in parts by weight: 100 parts of ethylene propylene diene monomer, 10-30 parts of an ethylene-vinyl acetate copolymer, 20-30 parts of polypropylene, 50-100 parts of paraffin oil, 1-5 parts of an antioxidant, 1-3 parts of a cross-linking agent, 1-5 parts of a lubricant and 10-20 parts of functional phosphate. According to the invention, a phosphate structure with a flame-retardant effect and a benzimidazole structure with an ultraviolet absorption function are introduced into the same molecule to realize multi-functionalization of the modifier, so that the prepared TPV material has excellent flame-retardant and anti-ultraviolet properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of TPV materials, and in particular relates to an anti-ultraviolet halogen-free flame-retardant TPV material and a preparation method thereof. Background Art

[0002] Dynamically vulcanized thermoplastic elastomer, or TPV for short, consists primarily of two parts: a plastic phase serving as the continuous phase and a rubber phase serving as the dispersed phase. TPV is a relatively unique thermoplastic elastomer among blended thermoplastic elastomers. As a high-performance elastomer, it is produced using dynamic vulcanization technology, using a large number of highly cross-linked rubber particles as the dispersed phase, which are dispersed within a small amount of plastic serving as the continuous phase during the blending process. This unique "sea-island" structure gives TPV the excellent elasticity and mechanical properties of cross-linked rubber, combined with the good processability and recyclability of thermoplastics. Due to this combination of rubber's elasticity and thermoplastic's recyclability, TPV is known as "green rubber" and is widely used in automotive, sensor, and acoustic materials.

[0003] Thermoplastic elastomers (TPVs) have become the most widely used polyolefin thermoplastic elastomers. However, TPVs have a low limiting oxygen index (LOI), making them not only extremely flammable but also accelerating combustion and producing toxic gases during combustion, posing a serious threat to human life. Traditionally, flame retardancy of thermoplastic elastomers has been primarily achieved with brominated flame retardants. However, these flame retardants produce carcinogenic dioxins and hydrogen bromide gases, posing a serious threat to human life and the environment, and have been gradually banned in various countries. Phosphorus-based flame retardants are considered the best alternative to halogenated flame retardants. However, most existing small-molecule phosphate flame retardants suffer from poor thermal stability, water resistance, and flame retardant effectiveness, limiting their application in TPVs. Furthermore, in practical applications, TPVs require not only flame retardant modification but also UV resistance to prevent aging and performance degradation. Traditionally, these two issues have been addressed by adding single-function flame retardants and light stabilizers, respectively. However, this method often reduces the processing performance of TPV, makes the processing technology complicated and the cost high. Therefore, developing multifunctional additives to achieve multifunctionalization is a new way to solve the above problems. The simplest multifunctionalization is to start from the molecular structure and introduce different functional groups into the same molecular structure to achieve the multifunctionalization of the molecule. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention introduces a flame-retardant phosphate structure and a UV-absorbing benzimidazole structure into the same molecule to achieve multifunctionality, combining flame retardancy and UV absorption, and has broad application prospects. To achieve the above objectives, the present invention adopts the following technical solutions: A UV-resistant, halogen-free, flame-retardant TPV material comprising the following raw materials in parts by weight: 100 parts of EPDM rubber 10-30 parts of ethylene-vinyl acetate copolymer Polypropylene 20~30 parts 50~100 parts paraffin oil 1-5 parts antioxidant 1~3 parts crosslinking agent 1~5 parts of lubricant 10~20 parts of functionalized phosphate Wherein, the structure of the functionalized phosphate is: .

[0005] In some embodiments, the EPDM rubber is selected from one or more of LANXESS 5469Q, SKS552, Dow 4640E, and Mitsui 3092.

[0006] In some embodiments, the lubricant is selected from one or more of polyethylene wax, erucamide, calcium stearate, and zinc stearate.

[0007] In some embodiments, the crosslinking agent is a peroxide crosslinking agent or a phenolic resin crosslinking agent.

[0008] In some embodiments, the crosslinking agent is selected from one or more of dicumyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperoxy-2-ethylhexyl carbonate, and tert-butylperoxyisopropyl carbonate.

[0009] In some embodiments, the antioxidant is selected from one or more of antioxidant BHT, antioxidant 2246, antioxidant 330, antioxidant 3114, antioxidant 1010, antioxidant 1076, antioxidant 1035, antioxidant 168, antioxidant PEP-36, and antioxidant S9228.

[0010] The present invention also provides a method for preparing an anti-ultraviolet halogen-free flame-retardant TPV material, characterized in that the preparation method comprises the following steps: 1) Weighing: Accurately weigh EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant, and functionalized phosphate ester according to the above weight parts; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer, and polypropylene into an internal mixer; then add paraffin oil, antioxidant, lubricant, and functionalized phosphate ester and mix to obtain a premix; 3) Vulcanization: Add a cross-linking agent to the premix, mix thoroughly, and place it in a twin-screw extruder for dynamic vulcanization. Extrusion granulation and cooling are performed to obtain UV-resistant halogen-free flame-retardant TPV material.

[0011] In some embodiments, the mixing temperature in step 2 is 100-150° C., and the mixing time is 20-60 min.

[0012] In some embodiments, the extrusion conditions of the twin-screw extruder in step 2 are: the extruder aspect ratio is 40-50, the main screw speed is 100-150r / min, and the processing temperature is 180-200°C. Compared with the prior art, the present invention has the following beneficial effects: The present invention introduces a flame-retardant phosphate structure and a UV-absorbing benzimidazole structure into the same molecule to achieve multifunctionality of the modifier, so that the prepared TPV material has both excellent flame retardancy and UV resistance and has broad application prospects. DETAILED DESCRIPTION

[0013] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following are merely illustrative of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0014] When numerical ranges are given in the examples, it should be understood that, unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the invention belongs. The various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels unless otherwise specified.

[0015] Basic Preparation Example 1 Preparation of Functionalized Phosphate

[0016] 2-Mercaptobenzimidazole (2.2 mol) was added to a three-necked round-bottom flask and completely dissolved in anhydrous THF (200 mL). Triethylamine (2.5 mol) was then added, and the mixture was stirred under nitrogen for 20 min. Chlorinated spirocyclic phosphate (1.0 mol) was then slowly added in an ice-water bath. The temperature was raised to 60°C and the reaction was stirred for 10 h. After the reaction, the reaction solution was cooled to room temperature and extracted with water (100 mL) and ethyl acetate (300 mL). The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified on a silica gel column (eluent: ethyl acetate:petroleum ether (v / v) = 1:10) to obtain the functionalized phosphate in an 83.4% yield with an HPLC purity of 99.5%.

[0017] .

[0018] .

[0019] Example 1 A UV-resistant, halogen-free, flame-retardant TPV material comprising the following raw materials in parts by weight: EPDM rubber (brand: Sinopec Mitsui 3092) 100 parts Ethylene-vinyl acetate copolymer (brand: Zhongke Refining and Chemical UE2806) 10 parts Polypropylene (brand: Korean LG M540) 30 parts Paraffin oil (brand: KP6030) 60 parts 3 parts of Antioxidant 1076 Crosslinking agent 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane 3 parts 5 parts of lubricant calcium stearate Functionalized phosphate (obtained in Preparation Example 1) 15 parts The preparation method of the above-mentioned anti-ultraviolet halogen-free flame retardant TPV material comprises the following steps: 1) Weighing: Accurately weigh EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant, and functionalized phosphate ester (obtained in Preparation Example 1) according to the above parts by weight; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer, and polypropylene to an internal mixer at 30°C and mix for 5 minutes. Then, add paraffin oil, antioxidant, lubricant, and functionalized phosphate ester and mix at 100°C for 20 minutes to obtain a premix. 3) Vulcanization: Add a cross-linking agent to the premix, mix thoroughly, and place it in a twin-screw extruder for dynamic vulcanization (the extruder aspect ratio is 50, the main screw speed is 150r / min, and the processing temperature is 180-200°C). Extrusion granulation and cooling are then performed to obtain TPV material.

[0020] Example 2 A UV-resistant, halogen-free, flame-retardant TPV material comprising the following raw materials in parts by weight: EPDM rubber (brand: Sinopec Mitsui 3092) 100 parts Ethylene-vinyl acetate copolymer (brand: Zhongke Refining UE2806) 20 parts Polypropylene (brand: Korean LG M540) 25 parts Paraffin oil (brand: KP6030) 50 parts 5 parts of antioxidant BHT Cross-linking agent dicumyl peroxide 3 parts 5 parts of lubricant zinc stearate Functionalized phosphate (obtained in Preparation Example 1) 12 parts The preparation method of the above-mentioned anti-ultraviolet halogen-free flame retardant TPV material comprises the following steps: 1) Weighing: Accurately weigh EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant, and functionalized phosphate ester (obtained in Preparation Example 1) according to the above parts by weight; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer, and polypropylene to an internal mixer at 30°C and mix for 5 minutes. Then, add paraffin oil, antioxidant, lubricant, and functionalized phosphate ester and mix at 100°C for 20 minutes to obtain a premix. 3) Vulcanization: Add a cross-linking agent to the premix, mix thoroughly, and place it in a twin-screw extruder for dynamic vulcanization (the extruder aspect ratio is 50, the main screw speed is 150r / min, and the processing temperature is 180-200°C). Extrusion granulation and cooling are then performed to obtain TPV material.

[0021] Example 3 A UV-resistant, halogen-free, flame-retardant TPV material comprising the following raw materials in parts by weight: EPDM rubber (brand: Sinopec Mitsui 3092) 100 parts Ethylene-vinyl acetate copolymer (brand: Zhongke Refining UE2806) 25 parts Polypropylene (brand: Korean LG M540) 25 parts Paraffin oil (brand: KP6030) 80 parts 3 servings of Antioxidant 168 Crosslinking agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane 3 parts 5 parts of lubricant zinc stearate Functionalized phosphate (obtained in Preparation Example 1) 15 parts The preparation method of the above-mentioned anti-ultraviolet halogen-free flame retardant TPV material comprises the following steps: 1) Weighing: Accurately weigh EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant, and functionalized phosphate ester (obtained in Preparation Example 1) according to the above parts by weight; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer, and polypropylene to an internal mixer at 30°C and mix for 5 minutes. Then, add paraffin oil, antioxidant, lubricant, and functionalized phosphate ester and mix at 100°C for 20 minutes to obtain a premix. 3) Vulcanization: Add a cross-linking agent to the premix, mix thoroughly, and place it in a twin-screw extruder for dynamic vulcanization (the extruder aspect ratio is 50, the main screw speed is 150r / min, and the processing temperature is 180-200°C). Extrusion granulation and cooling are then performed to obtain TPV material.

[0022] Comparative Example 1 On the basis of Example 1, the functionalized phosphate (obtained in Preparation Example 1) was replaced with a spirocyclic phosphate flame retardant commonly used in the art. , other conditions and operations are the same as in Example 1.

[0023] Comparative Example 2 On the basis of Example 1, the functionalized phosphate (obtained in Preparation Example 1) was replaced with UV326, a common ultraviolet absorber in the art. , other conditions and operations are the same as in Example 1.

[0024] Performance Testing For the above embodiment and comparative example The prepared TPV material was sampled according to the method specified in the performance test standard, and its tensile strength, limiting oxygen index, and flame retardancy were tested before and after UV aging. The test standards are as follows: Tensile strength: GB / T1040.22006 standard; Limiting Oxygen Index (LOI): GB / T2406-2009 standard is adopted and tested by JF-3 oxygen index meter.

[0025] Flame retardant grade: According to ANSL-UL94-2009 standard, tested with CZF-5 vertical combustion apparatus.

[0026] UV aging conditions: The test sample was placed in a UV accelerated aging tester for UV aging for 240 hours. The UV lamp wavelength was 340nm and the radiation intensity was 0.74W / m 2 , relative humidity was 40%, and the temperature of the experimental chamber was 60°C. The results are shown in Table 1.

[0027] Table 1 TPV material performance test results

[0028] From the data in Table 1, it can be seen that the present invention uses functionalized phosphate The modified TPV material exhibits both excellent UV resistance and flame retardancy. This is primarily due to the following: Firstly, the functionalized phosphate ester prepared by the present invention is a highly effective charring agent. Upon combustion, it decomposes to produce metaphosphoric acid, polyphosphoric acid, and other substances, which form a protective char layer covering the substrate surface, isolating oxygen and heat transfer, thereby achieving excellent flame retardancy. Secondly, the functionalized phosphate ester prepared by the present invention contains a benzimidazole structure, which has strong UV absorption properties, thus achieving excellent UV resistance.

[0029] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A UV-resistant, halogen-free, flame-retardant TPV material comprising the following raw materials in parts by weight: 100 parts of EPDM rubber 10-30 parts of ethylene-vinyl acetate copolymer Polypropylene 20~30 parts 50~100 parts paraffin oil 1-5 parts antioxidant 1~3 parts crosslinking agent 1~5 parts of lubricant 10-20 parts of functionalized phosphate in, The structure of the functionalized phosphate is: .

2. The UV-resistant halogen-free flame-retardant TPV material according to claim 1, characterized in that: The EPDM rubber is selected from one or more of Lanxess 5469Q, SKS552, Dow 4640E and Mitsui 3092.

3. The UV-resistant halogen-free flame-retardant TPV material according to claim 1, characterized in that: The lubricant is selected from one or more of polyethylene wax, erucamide, calcium stearate and zinc stearate.

4. The UV-resistant halogen-free flame-retardant TPV material according to claim 1, characterized in that: The cross-linking agent is a peroxide cross-linking agent or a phenolic resin cross-linking agent.

5. The UV-resistant halogen-free flame-retardant TPV material according to claim 4, characterized in that: The crosslinking agent is selected from one or more of dicumyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperoxy-2-ethylhexyl carbonate and tert-butylperoxyisopropyl carbonate.

6. The UV-resistant halogen-free flame-retardant TPV material according to claim 1, characterized in that: The antioxidant is selected from one or more of antioxidant BHT, antioxidant 2246, antioxidant 330, antioxidant 3114, antioxidant 1010, antioxidant 1076, antioxidant 1035, antioxidant 168, antioxidant PEP-36 and antioxidant S9228.

7. A method for preparing the UV-resistant halogen-free flame-retardant TPV material according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: 1) Weighing: Accurately weigh EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant, and functionalized phosphate ester according to the above weight parts; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer, and polypropylene into an internal mixer; then add paraffin oil, antioxidant, lubricant, and functionalized phosphate ester and mix to obtain a premix; 3) Vulcanization: Add a cross-linking agent to the premix, mix thoroughly, and place it in a twin-screw extruder for dynamic vulcanization. Extrusion granulation and cooling are performed to obtain UV-resistant halogen-free flame-retardant TPV material.

8. The preparation method according to claim 7, characterized in that The mixing temperature in step 2 is 100-150° C., and the mixing time is 20-60 min.

9. The preparation method according to claim 7, characterized in that The extrusion conditions of the twin-screw extruder in step 2 are: the extruder aspect ratio is 40-50, the main screw speed is 100-150 r / min, and the processing temperature is 180-200°C.

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