High-yellowing-resistance continuously-reinforced flame-retardant polypropylene long glass fiber composite material for charging pile

Abstract

The invention relates to a high-yellowing-resistance continuously-reinforced flame-retardant polypropylene long glass fiber composite material for a charging pile and a preparation method of the composite material. The composite material is prepared from PP-LGF50 and flame retardant master batch in a ratio of 3: 2. The PP-LGF50 is prepared from 20%-60% of polypropylene; 20%-40% of continuous glass fiber; 0.1%-1.5% of a compatilizer; 0.1%-5% of an antioxidant; 0.1%-2% of a lubricant; 0.5%-2% of hydrotalcite; 0.5%-2% of a deodorant; 0.5%-1.5% of black master batch; and 10%-20% of a toughening agent. The flame-retardant master batch comprises 20%-60% of polypropylene; 30%-45% of a flame retardant; 10%-15% of antimony trioxide; and 0.1%-5% of an antioxidant. The material is low in density, low in cost and easy to polish and process, shrinkage is reduced, the stability of the material is improved, the yellowing phenomenon of the material during high-temperature injection molding is reduced, and precipitation cannot be caused due to the fact that the adding amount of an antioxidant system is small.

Description

TECHNICAL FIELD

[0001] The present application relates to long glass fiber polypropylene composites, in particular to a high yellowing resistance continuous reinforced flame-retardant polypropylene long glass fiber composite material for charging piles and a preparation method thereof. BACKGROUND

[0002] The shell of the charging pile needs to have good weather resistance, impact resistance and fireproof performance. Composite materials, especially long glass fiber reinforced plastics (LFT), with their lightweight, high strength, corrosion resistance, easy molding and other characteristics, have become an ideal material for manufacturing charging pile shells. They not only effectively reduce the weight of the charging pile, reduce transportation and installation costs, but also significantly improve the durability and safety of the charging pile.

[0003] The charging pile contains many complex structural parts, such as supports, fixtures, etc. These components need to withstand large mechanical and thermal stresses. LFT materials, with their excellent mechanical properties and thermal stability, can meet these requirements while reducing material usage and production costs.

[0004] In the future, with the continuous expansion of the new energy vehicle market and the continuous progress of technology, long glass fiber reinforced plastics (LFT) will be more widely and deeply applied in the charging pile industry. Through reasonable material selection and proportioning, molding process optimization, and the implementation of environmental protection and sustainability strategies, the performance and quality of charging piles can be further improved, production costs and energy consumption can be reduced, and the sustainable and healthy development of the new energy vehicle charging pile industry can be promoted. Due to the large size of the main components of the charging pile, the high processing temperature, and the high requirement for material heat-oxidative aging resistance, many efficient antioxidants fail in flame-retardant formulations due to the requirement for flame-retardant performance. In addition, excessive addition of flame retardants can also lead to precipitation, which can affect the electrical performance requirements of the charging pile. Therefore, improving the heat-oxidative aging performance of flame-retardant materials through means other than antioxidant systems is a new technology, and the high-temperature heat-oxidative aging problem of bromine-based flame retardants is a technical pain point and difficulty. SUMMARY

[0005] The present application aims to overcome the defects of the prior art and provide a high yellowing resistance continuous reinforced flame-retardant polypropylene long glass fiber composite material for charging piles and a preparation method and application thereof.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A high yellowing resistance continuous reinforced flame-retardant polypropylene long glass fiber composite material for charging piles is made from the following weight percentage of raw materials (PP-LGF50 and flame retardant masterbatch account for 3:2): PP-LGF50: Polypropylene 20%~60% Continuous glass fiber 20%~40% Compatibilizer 0.1%~1.5% Antioxidant 0.1 %~5 % Lubricant 0.1 %~2 % Hydrotalcite 0.5%~2% Deodorant 0.5%~2% Black masterbatch 0.5%~1.5% Toughening agent 10%~20%; Flame retardant masterbatch Polypropylene 20%~60 % Flame retardant 30%~45% Antimony trioxide 10%~15% Antioxidant 0.1 %~5 %.

[0007] The application adopts specific content of each component combination, and specific polypropylene is selected again under the premise of guaranteeing mechanical properties, so that the yellowing phenomenon of the composite material in the injection molding process is greatly reduced by using the compounding of hydrotalcite and deodorant. In order to obtain better application effect, the following is preferred: The melt index of the PP is 50-150; further preferably, Korean SK BX3920 is specifically adopted.

[0008] The glass fiber is one of high modulus alkali-free glass fiber, Taishan T838LP type, Owens Corning SE4805 type and Sichuan Weiyuan glass fiber EW758 type.

[0009] The compatibilizer is one or more of polypropylene-maleic anhydride graft (PP-g-MAH), polypropylene-acrylic acid graft (PP-g-MAA) and polypropylene-methacrylic acid graft (PP-g-MAA). The above compatibilizer can effectively improve the compatibility of the polymer and the long glass fiber.

[0010] The antioxidant, lubricant, black masterbatch, toughening agent, antimony trioxide and the like are commercially available, as a preferred, the raw material composition further includes antioxidant, lubricant and black masterbatch. The auxiliary antioxidant is phosphite and thioester, preferably antioxidant 168 and DSTP; the main antioxidant is hindered phenol, preferably antioxidant 1076; the lubricant is silicone powder, preferably medium blue morning light GM-100; the black masterbatch takes PE as a carrier, preferably Cabot 2718, the flame retardant is bromine-based flame retardant, preferably ethylene bis-tetrabromophthalimide in Shandong; the hydrotalcite is preferably MA-1 of bentonite, the toughening agent is preferably Dow 8842, and the deodorant is preferably 1035T of Xiuhu, Basoplast® 410 D of BASF, XW-17 of Shijiazhuo, JH20A of Ningbo Jiahe, and zinc ricinoleate of Huaxiangkehao.

[0011] The application further discloses a preparation method of the high-yellowing-resistance V0 flame-retardant continuous reinforced polypropylene long glass fiber composite material. Preparation of the PP-LGF50: polypropylene, a compatilizer, an antioxidant, hydrotalcite, a deodorant, a lubricant and black masterbatch are uniformly mixed, then are added into a double-screw extruder from a main feeding hopper, then long glass fibers are inserted into the polypropylene through a side cavity die, in the process of the melting impregnation, the hydrotalcite and the deodorant can effectively adsorb small molecules causing yellowing, and then the mixture is subjected to water cooling, granulation and drying to obtain the PP-LGF50.

[0012] Preferably, the mixing is performed in a blender at a speed of 600-800 rpm for 3-6 min, and more preferably at a speed of 800 rpm for 6 min.

[0013] The temperature of the double-screw extruder is set to 100-280 DEG C from the first temperature zone to the ninth temperature zone of the feeding section to the die head, and the temperature of the die head is 230-290 DEG C.

[0014] Preparation of the flame-retardant masterbatch: polypropylene, a flame retardant, antimony trioxide and an antioxidant are uniformly mixed, then are added into a double-screw extruder from a main feeding hopper, and then are subjected to water cooling, granulation and drying to obtain the flame-retardant masterbatch.

[0015] Preferably, the mixing is performed in a blender at a speed of 300-400 rpm for 4-6 min, and more preferably at a speed of 300 rpm for 4 min.

[0016] The temperature of the double-screw extruder is set to 100-180 DEG C from the first temperature zone to the seventh temperature zone of the feeding section to the die head, and more preferably 100 DEG C, 150 DEG C, 160 DEG C, 170 DEG C, 170 DEG C, 175 DEG C and 180 DEG C for the first temperature zone to the seventh temperature zone for the production of the flame-retardant masterbatch.

[0017] The PP-LGF50: the flame-retardant masterbatch is compounded at a ratio of 3:2 to obtain the high-yellowing-resistance V0 flame-retardant continuous reinforced polypropylene long glass fiber composite material for charging piles.

[0018] The high-yellowing-resistance V0 flame-retardant continuous reinforced polypropylene long glass fiber composite material prepared by the method has smooth and flat particle surfaces, good glass fiber dispersion and no yellowing in high-temperature injection molding.

[0019] Compared with the prior art, the application has the following advantages: The material of the present application has low density, low cost, easy polishing, easy processing, reduced shrinkage, improved material stability, reduced yellowing phenomenon of high-temperature injection molding of the material, and no precipitation caused by less addition of the antioxidant system. DETAILED DESCRIPTION

[0020] The examples and comparative examples of the present application are further described below.

[0021] The glass fiber reinforced polypropylene composite materials obtained in the examples and comparative examples were processed into test samples by an injection machine at different temperatures, and the mechanical properties and surface yellowing were observed.

[0022] The formulations of the comparative examples and examples (according to the ratio of PP-LGF50 and flame-retardant masterbatch 3:2) are shown in Table 1, and the test results of the corresponding mechanical properties and other properties of the comparative examples and examples are shown in Tables 2-3: Formulation Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Example 1 Example 2 Example 3 Example 4 Example 5 BX3920 32.2 31.2 31.2 31.2 31.2 30.2 30.2 30.2 30.2 30.2 30.2 30.2 Continuous glass fiber 30 30 30 30 30 30 30 30 30 30 30 30 Toughener 10 10 10 10 10 10 10 10 10 10 10 10 Compatibilizer 3 3 3 3 3 3 3 3 3 3 3 3 Flame retardant 16 16 16 16 16 16 16 16 16 16 16 16 Antimony trioxide 6 6 6 6 6 6 6 6 6 6 6 6 Antioxidant combination 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Lubricant 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Black masterbatch 1 1 1 1 1 1 1 1 1 1 1 1 Hydrotalcite 0 1 0 0 0 0 0 0.5 0.5 0.5 0.5 0.5 Zinc ricinoleate 1 0.5 Odor scavenger XW-17 1 0.5 Odor scavenger JH20A 1 0.5 Odor scavenger Basoplast® 410 D 1 0.5 Odor scavenger 1035T 1 0.5 Note: The ratio in Table 1 is calculated after mixing PP-LGF50 and flame-retardant masterbatch.

[0023] Test item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength (MPa) 80 82 83 84 85 81 81 81 81 81 83 82 Flexural strength (MPa) 118 120 121 121 122 119 120 121 121 122 121 123 Flexural modulus (MPa) 5601 5731 5735 5889 5972 5768 5801 5797 5889 5914 5998 5834 Charpy notched impact strength (kJ / m2) 35 36 35 38 40 37 38 36 37 37 39 40 Charpy unnotched impact strength (kJ / m2) 65 66 66 67 68 68 66 65 67 66 69 67 Flame retardance 1.6 mm V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 PP-LGF50 exudation (120°C oven storage for one week) No exudation No exudation No exudation No exudation No exudation No exudation No exudation No exudation No exudation No exudation No exudation Injection molding conditions Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Example 1 Example 2 Example 3 Example 4 Example 5 Injection molding temperature 220°C Injection molding temperature 250°C 0.32 0.32 0.31 0.30 0.31 0.30 0.32 0.31 0.32 0.39 0.34 0.11 Injection molding temperature 280°C 8.98 6.71 6.83 6.77 6.59 6.65 5.32 5.11 4.33 5.28 5.29 2.54 ​ 12.71 9.67 9.72 9.70 9.58 8.37 8.02 8.04 6.54 6.99 7.11 3.83 The surface yellowing of the flame-retardant material is mainly caused by free bromide ions, and reducing free bromide ions can effectively reduce the yellowing of the material.

[0024] From the test results of Comparative Examples 1-7 and Examples 1-5, it can be seen that the yellowness color difference of the material is small under the conditions of injection molding temperature 220℃ and 3 minutes residence, and the severity of yellowing deepens with increasing temperature. From Comparative Examples 1-7, it can be seen that a single hydrotalcite or a single addition of odor removal agent cannot improve the yellowing problem of the material. The odor masking agent is zinc ricinoleate, which is a long-chain organic compound. The activated zinc atom can form a strong chemical bond with nitrogen and sulfur atoms in the odor, thereby reducing the odor of the material. From the test results of Comparative Example 3 and Example 1, it can be seen that the simultaneous addition of hydrotalcite and odor masking agent does not effectively improve the yellowing of the material. XW-17 and JH20A are a kind of adsorption type odor removal agent, which has the characteristics of large specific surface area and strong adsorption capacity. The ions between the mineral layers can produce strong chemical adsorption on aldehydes, ketones, amines, organic sulfides, organic chlorides and halogen hydrides. It is non-toxic and non-corrosive, has good thermal stability, rheological property and thixotropy, and has good dispersibility and heat conduction resistance. The hydrotalcite MA-1 of bentonite is a kind of anionic layered functional inorganic material with layered structure, which has adjustable chemical composition and unique structure and performance. From the test results of Comparative Examples 4 and 5 and Examples 2 and 3, it can be seen that the single addition of odor removal agent XW-17 or JH20A can slightly improve the yellowing effect of the product. However, XW-17 or JH20A can improve the efficiency of adsorbing free bromine ions under the action of MA-1, which can partially improve the yellowing effect of the product. Basoplast® 410 D and 1035T are extraction and devolatilization odor removal agents. 1035T is a master batch loaded with high content of low boiling point volatile components on a porous polymer carrier. From the test results of Comparative Examples 6 and 4, it can be seen that the single addition of odor removal agent Basoplast® 410 D can slightly improve the yellowing effect of the product. Basoplast® 410 D in the synergistic action of MA-1, but the effect is not as good as Examples 2 and 3. From the test results of Comparative Example 7 and Example 5, it can be seen that the single addition of odor removal agent 1035T can slightly improve the yellowing effect of the product. However, under the synergistic action of MA-1, the carrier releases low boiling point solvents under the action of heat and shear force, and the bromine ions in the material tend to dissolve in the extractant, and another part is absorbed by the porous polymer. Compared with single adsorption type odor removal agent and other extraction type odor removal agents, the combination of 1035T and MA-1 can greatly improve the yellowing effect of the product.

Claims

1.A high-weather-resistant continuous-reinforced flame-retardant polypropylene long-glass-fiber composite material for charging piles, which is made of raw materials in the following weight percentages (PP-LGF50 and flame retardant master batch in a ratio of 3:2) : PP-LGF50: polypropylene 20%-60% continuous glass fiber 20%-40% compatibilizer 0.1%-1.5% antioxidant 0.1%-5% lubricant 0.1%-2% hydrotalcite 0.5%-2% odor removal agent 0.5%-2% black masterbatch 0.5%-1.5% toughening agent 10%-20%; flame retardant master batch: polypropylene 20%-60% flame retardant 30%-45% antimony trioxide 10%-15% antioxidant 0.1%-5%. The melt index of the PP is 50-150. The glass fiber is high-modulus alkali-free glass fiber, one of Taishan T838LP, Owens Corning SE4805, and Sichuan Weiyuan Glass Fiber EW758. The compatibilizer is one or more of polypropylene-maleic anhydride graft (PP-g-MAH), polypropylene-acrylic acid graft (PP-g-MAA), and polypropylene-methacrylic acid graft (PP-g-MAA). The antioxidant, lubricant, black masterbatch, toughening agent, and antimony trioxide are commercially available. The flame retardant is a bromine-based flame retardant. The odor removal agent is one of Basf 410 D, Century Zhaonong XW-17, and Ningbo Jiahe JH20A. The odor removal agent is Xiuhu 1035T. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​ 3. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​ 4. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​ 5. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​ 6. The high-weather-resistant continuous-reinforced flame-retardant polypropylene long glass fiber composite material for charging piles according to claim 1, characterized in that, ​ 7. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​ 8. The high-weather-resistant, continuously reinforced, flame-retardant polypropylene long-glass-fiber composite material for charging piles according to claim 1, characterized in that, ​