An ultraviolet resistant halogen-free flame-retardant TPV material and a preparation method thereof

Abstract

The application belongs to the technical field of TPV material, 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 by weight: 100 parts of ternary ethylene-propylene rubber, 10-30 parts of ethylene-vinyl acetate copolymer, 20-30 parts of polypropylene, 50-100 parts of paraffin oil, 1-5 parts of antioxidant, 1-3 parts of crosslinking agent, 1-5 parts of lubricant, and 10-20 parts of functionalized phosphate ester.The phosphate ester structure with flame-retardant effect and the benzimidazole structure with ultraviolet absorption are introduced into the same molecule to realize multifunctionalization of the modifier, so that the prepared TPV material has excellent flame-retardant and anti-ultraviolet properties.

Description

Technical Field

[0001] This invention belongs to the field of TPV material technology, specifically relating to an UV-resistant halogen-free flame-retardant TPV material and its preparation method. Background Technology

[0002] Dynamically vulcanized thermoplastic elastomers, abbreviated as TPV, are mainly composed of two parts: a plastic phase as the continuous phase and a rubber phase as the dispersed phase. TPV is a special type of blended thermoplastic elastomer. As a high-performance elastomer, it is prepared using dynamic vulcanization technology, with a large number of highly cross-linked rubber particles as the dispersed phase, dispersed within a small amount of plastic as the continuous phase during blending. This unique "sea-island" structure gives TPV the excellent elasticity and mechanical properties of cross-linked rubber as well as the good processability and recyclability of thermoplastics. Due to the combination of rubber elasticity and thermoplastic recyclability, TPV is known as "green rubber" and is widely used in the automotive, sensor, and acoustic materials industries.

[0003] Thermoplastic elastomers (TPVs) have become one of the most widely used polyolefin thermoplastic elastomers. However, TPVs have a low limiting oxygen index (LOI), making them extremely flammable, accelerating the combustion process, and producing toxic gases during combustion, seriously threatening human safety. Traditionally, flame retardancy of thermoplastic elastomers has been achieved mainly through brominated flame retardants. Phosphorus-based flame retardants are considered the best alternative to halogenated flame retardants. However, most existing small-molecule phosphate ester flame retardants have poor thermal stability, poor water resistance, and poor flame retardant effect, limiting their application in TPVs. In addition, in practical applications, besides flame retardant modification, UV resistance modification is also required to prevent TPV from aging and degrading in performance. The traditional method to solve these two problems is to add single-function flame retardants and light stabilizers respectively. However, this method often leads to decreased processing performance of TPVs, complex processing technology, and high cost. Therefore, developing multifunctional additives to achieve multifunctionality is a new approach to solving the above problems. The simplest multifunctionality is to start from the molecular structure and introduce different functional groups into the same molecular structure to achieve molecular multifunctionality. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention introduces a flame-retardant phosphate ester structure and a benzimidazole structure with ultraviolet absorption into the same molecule to achieve multifunctionality, combining both flame-retardant and ultraviolet absorption properties, thus possessing broad application prospects. To achieve the above objectives, this invention adopts the following technical solution: A UV-resistant, halogen-free, flame-retardant TPV material, comprising the following raw materials by weight: 100 parts of EPDM rubber 10-30 parts of ethylene-vinyl acetate copolymer 20-30 parts of polypropylene 50-100 parts of paraffin oil 1-5 parts antioxidant 1-3 parts of crosslinking agent 1-5 parts lubricant 10-20 parts of functionalized phosphate ester The structure of the functionalized phosphate ester is as follows: .

[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-butylperoxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, and tert-butylperoxycarbonate isopropyl ester.

[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 a UV-resistant halogen-free flame-retardant TPV material, characterized in that the preparation method includes the following steps: 1) Weighing: Accurately weigh the EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant and functionalized phosphate ester according to the above weight proportions; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer and polypropylene to a mixer; then add paraffin oil, antioxidant, lubricant and functionalized phosphate ester and mix to obtain a premix. 3) Vulcanization: Add crosslinking agent to the premix, mix thoroughly, and then put it into a twin-screw extruder for dynamic vulcanization. Extrusion granulation and cooling yield UV-resistant halogen-free flame-retardant TPV material.

[0011] In some implementations, the mixing temperature in step 2 is 100~150℃ and the mixing time is 20~60min.

[0012] In some embodiments, the extrusion conditions of the twin-screw extruder in step 2 are: an extruder length-to-diameter ratio of 40-50, a main screw speed of 100-150 r / min, and a processing temperature of 180-200℃. Compared with the prior art, the beneficial effects of the present invention are as follows: This invention introduces a phosphate ester structure with flame retardant properties and a benzimidazole structure with ultraviolet absorption into the same molecule to achieve multifunctionality of the modifier. This results in TPV materials with excellent flame retardant and ultraviolet resistance properties, and have broad application prospects. Detailed Implementation

[0013] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0014] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All chemical reagents used in the embodiments of this invention, unless otherwise specified, are obtained through conventional commercial means.

[0015] Basic Preparation Example 1: Preparation of Functionalized Phosphate Esters

[0016] 2-Mercaptobenzimidazole (2.2 mol) was added to a three-necked round-bottom flask, and anhydrous THF (200 mL) was added to completely dissolve it. Then, triethylamine (2.5 mol) was added, nitrogen gas was purged, and the mixture was stirred for 20 min. Subsequently, spirocyclic phosphate chloride (1.0 mol) was slowly added under ice-water bath conditions, and the mixture was heated to 60 °C and stirred for 10 h. After the reaction was completed, the reaction solution was cooled to room temperature, and then extracted with water (100 mL) and ethyl acetate (300 mL). The organic phase was washed with saturated sodium bicarbonate, dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate: petroleum ether (v / v) = 1:10) to obtain the functionalized phosphate ester with a yield of 83.4% and 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 by weight: EPDM rubber (brand name: Sinopec Mitsui 3092) 100 parts 10 parts of ethylene-vinyl acetate copolymer (brand name: Sinopec Refining & Chemical UE2806) Polypropylene (brand name: LG M540, Korea) 30 parts Paraffin oil (brand name: KP6030) 60 parts Antioxidant 1076 3 parts Crosslinking agent: 3 parts of 1,1-di-tert-butylperoxide-3,3,5-trimethylcyclohexane 5 parts calcium stearate lubricant Functionalized phosphate ester (obtained from Preparation Example 1) 15 parts The preparation method of the above-mentioned UV-resistant halogen-free flame-retardant TPV material includes the following steps: 1) Weighing: Accurately weigh the 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 weight parts. 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer and polypropylene to a mixer at 30°C and mix for 5 min; then add paraffin oil, antioxidant, lubricant and functionalized phosphate ester, and mix at 100°C for 20 min to obtain premix. 3) Vulcanization: Add crosslinking agent to the premix, mix thoroughly, and then put it into a twin-screw extruder for dynamic vulcanization (extruder length-to-diameter ratio is 50, main screw speed is 150 r / min, processing temperature is 180~200℃), extrusion granulation, and cooling to obtain TPV material.

[0020] Example 2 A UV-resistant, halogen-free, flame-retardant TPV material, comprising the following raw materials by weight: EPDM rubber (brand name: Sinopec Mitsui 3092) 100 parts Ethylene-vinyl acetate copolymer (brand name: Sinopec Refining & Chemical UE2806) 20 parts Polypropylene (brand name: LG M540, Korea) 25 parts Paraffin oil (brand name: KP6030) 50 parts Antioxidant BHT 5 parts Crosslinking agent: 3 parts dicumyl peroxide Lubricant: 5 parts zinc stearate Functionalized phosphate ester (obtained from Preparation Example 1) 12 parts The preparation method of the above-mentioned UV-resistant halogen-free flame-retardant TPV material includes the following steps: 1) Weighing: Accurately weigh the 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 weight parts. 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer and polypropylene to a mixer at 30°C and mix for 5 min; then add paraffin oil, antioxidant, lubricant and functionalized phosphate ester, and mix at 100°C for 20 min to obtain premix. 3) Vulcanization: Add crosslinking agent to the premix, mix thoroughly, and then put it into a twin-screw extruder for dynamic vulcanization (extruder length-to-diameter ratio is 50, main screw speed is 150 r / min, processing temperature is 180~200℃), extrusion granulation, and cooling to obtain TPV material.

[0021] Example 3 A UV-resistant, halogen-free, flame-retardant TPV material, comprising the following raw materials by weight: EPDM rubber (brand name: Sinopec Mitsui 3092) 100 parts Ethylene-vinyl acetate copolymer (brand name: Sinopec Refining & Chemical UE2806) 25 parts Polypropylene (brand name: LG M540, Korea) 25 parts Paraffin oil (brand name: KP6030) 80 parts Antioxidant 168 3 parts 3 parts of crosslinking agent 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane Lubricant: 5 parts zinc stearate Functionalized phosphate ester (obtained from Preparation Example 1) 15 parts The preparation method of the above-mentioned UV-resistant halogen-free flame-retardant TPV material includes the following steps: 1) Weighing: Accurately weigh the 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 weight parts. 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer and polypropylene to a mixer at 30°C and mix for 5 min; then add paraffin oil, antioxidant, lubricant and functionalized phosphate ester, and mix at 100°C for 20 min to obtain premix. 3) Vulcanization: Add crosslinking agent to the premix, mix thoroughly, and then put it into a twin-screw extruder for dynamic vulcanization (extruder length-to-diameter ratio is 50, main screw speed is 150 r / min, processing temperature is 180~200℃), extrusion granulation, and cooling to obtain TPV material.

[0022] Comparative Example 1 Based on Example 1, the functionalized phosphate ester (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 Based on Example 1, the functionalized phosphate ester (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 Regarding the above embodiments and comparative examples The prepared TPV material was sampled according to the methods specified in the performance testing standards, and its tensile strength, limiting oxygen index, and flame retardancy rating were tested before and after UV aging. The testing standards are as follows: Tensile strength: conforming to GB / T1040.22006 standard; Limiting Oxygen Index (LOI): The standard GB / T2406-2009 was adopted, and the test was conducted using a JF-3 oxygen index analyzer.

[0025] Flame retardancy rating: Tested using a CZF-5 vertical flame tester according to ANSL-UL94-2009 standard.

[0026] UV aging conditions: The test samples were placed in an accelerated UV aging tester for 240 hours of UV aging. The UV lamp wavelength was 340 nm and the radiation intensity was 0.74 W / m². 2 The relative humidity was 40%, and the temperature of the experimental chamber was 60℃. The results are shown in Table 1.

[0027] Table 1 Test results of TPV material properties

[0028] As can be seen from the data in Table 1, this invention utilizes functionalized phosphate esters. The modified TPV material exhibits both excellent UV resistance and flame retardant properties. This is primarily due to two factors: Firstly, the functionalized phosphate ester prepared in this invention is an excellent charring agent. During combustion, it decomposes to produce substances such as metaphosphoric acid and polyphosphoric acid, which can generate a protective char layer covering the surface of the substrate, isolating oxygen and heat transfer, thereby achieving excellent flame retardant effects. Secondly, the functionalized phosphate ester prepared in this invention contains a benzimidazole structure, which has strong UV absorption properties, thus achieving excellent UV resistance.

[0029] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A UV-resistant, halogen-free, flame-retardant TPV material, comprising the following raw materials by weight: 100 parts of EPDM rubber 10-30 parts of ethylene-vinyl acetate copolymer 20-30 parts of polypropylene 50-100 parts of paraffin oil 1-5 parts antioxidant 1-3 parts of crosslinking agent 1-5 parts lubricant 10-20 parts of functionalized phosphate ester in, The structure of the functionalized phosphate ester is as follows: ; The EPDM rubber is selected from one or more of Lanxess 5469Q, SKS552, Dow 4640E and Mitsui 3092; The lubricant is selected from one or more of polyethylene wax, erucamide, calcium stearate, and zinc stearate; The crosslinking agent is selected from one or more of dicumyl peroxide, 1,1-di-tert-butylperoxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, and tert-butylperoxycarbonate isopropyl ester. The antioxidant is selected from one or more of the following: antioxidant BHT, antioxidant 2246, antioxidant 330, antioxidant 3114, antioxidant 1010, antioxidant 1076, antioxidant 1035, antioxidant 168, antioxidant PEP-36, and antioxidant S9228.

2. A method for preparing the UV-resistant halogen-free flame-retardant TPV material according to claim 1, characterized in that, The preparation method includes the following steps: 1) Weighing: Accurately weigh the EPDM rubber, ethylene-vinyl acetate copolymer, polypropylene, paraffin oil, antioxidant, crosslinking agent, lubricant and functionalized phosphate ester according to the above weight proportions; 2) Mixing: Add EPDM rubber, ethylene-vinyl acetate copolymer and polypropylene to a mixer; then add paraffin oil, antioxidant, lubricant and functionalized phosphate ester and mix to obtain a premix. 3) Vulcanization: Add crosslinking agent to the premix, mix thoroughly, and then put it into a twin-screw extruder for dynamic vulcanization. Extrusion granulation and cooling yield UV-resistant halogen-free flame-retardant TPV material.

3. The preparation method according to claim 2, characterized in that, The mixing temperature in step 2 is 100~150℃ and the mixing time is 20~60min.

4. The preparation method according to claim 2, characterized in that, The extrusion conditions of the twin-screw extruder in step 2 are: an extruder length-to-diameter ratio of 40~50, a main screw speed of 100~150 r / min, and a processing temperature of 180~200℃.

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