Halogen-free flame-retardant polypropylene composite material, preparation method and application thereof

Abstract

This invention provides a halogen-free flame-retardant polypropylene composite material, its preparation method, and its application. The halogen-free flame-retardant polypropylene composite material includes polypropylene resin, a halogen-free intumescent flame retardant, a quaternary ammonium salt compound, and an anti-dripping agent. The halogen-free intumescent flame retardant includes melamine-based and piperazine-based halogen-free intumescent flame retardants. Through the rational combination of the above components, especially by introducing the quaternary ammonium salt compound, the stability of the halogen-free intumescent flame retardant under long-term humid heat conditions is effectively improved. This results in a polypropylene composite material that, in addition to excellent flame-retardant properties, also possesses excellent voltage breakdown resistance, humid heat aging resistance, and mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a halogen-free flame-retardant polypropylene composite material, its preparation method, and its application. Background Technology

[0002] Polypropylene, as one of the five major general-purpose plastics, boasts advantages such as wide availability of raw materials, low price, and superior overall performance compared to other general-purpose plastics. It is easy to process, has good heat and chemical resistance, and offers diverse modification options, making it widely used in industries such as home appliances, automobiles, and electronics. However, polypropylene itself is flammable. When used in household appliances such as refrigerators, washing machines, and kitchen and bathroom appliances, flame-retardant modification is often necessary to improve safety.

[0003] Currently, there are many studies and reports on flame-retardant polypropylene materials. For example, CN109721838A discloses a polypropylene composite material, which is composed of 55-60 parts by weight of polypropylene, 20-25 parts of flame retardant, 2-5 parts of flame retardant synergist, 1-3 parts of aromatic plant essential oil, 6-10 parts of modified expanded vermiculite, 0.2-0.5 parts of antioxidant, 0.3-0.6 parts of lubricant, and 0.1-0.3 parts of anti-dripping agent. The flame retardant is a nitrogen-phosphorus intumescent flame retardant composed of ammonium polyphosphate and cage-like phosphate ester in a mass ratio of 4:1. The flame retardant synergist is ultrafine silica powder. The flame-retardant polypropylene material provided by this invention overcomes the problems of low glow wire ignition temperature and easy exudation in specific environments of ordinary flame-retardant polypropylene, and has excellent flame retardancy. For example, CN112442236A discloses a low-temperature impact-resistant flame-retardant polypropylene composition and its preparation method, the components of which include: polypropylene, flame retardant, and compatibilizer; the low-temperature impact-resistant flame-retardant polypropylene composition provided by this invention has excellent flame-retardant properties while maintaining good mechanical properties, especially low-temperature impact resistance.

[0004] However, in the fields of automobiles, home appliances, and electronics, materials often need to be used for a long time in hot and humid environments. Therefore, high requirements are placed on the high temperature and high humidity aging performance of materials, requiring materials to have excellent resistance to damp heat aging and voltage breakdown. However, the flame-retardant polypropylene materials provided in the prior art, including the invention mentioned above, often only focus on the flame-retardant performance of the materials, without addressing the improvement of the resistance to damp heat aging and high voltage breakdown of flame-retardant polypropylene materials.

[0005] Therefore, it remains crucial to develop a halogen-free flame-retardant polypropylene composite material that combines excellent flame retardant properties, resistance to damp heat aging, and resistance to voltage breakdown. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a halogen-free flame-retardant polypropylene composite material, its preparation method and application. The halogen-free flame-retardant polypropylene composite material has excellent flame-retardant properties, as well as excellent resistance to voltage breakdown, resistance to damp heat aging and mechanical properties.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a halogen-free flame-retardant polypropylene composite material, wherein the halogen-free flame-retardant polypropylene composite material comprises the following components in parts by weight:

[0009] 55-75 parts by weight of polypropylene resin;

[0010] 15-32 parts by weight of halogen-free intumescent flame retardant;

[0011] 0.01 to 4 parts by weight of quaternary ammonium salt compounds;

[0012] Anti-dripping agent: 0.1~0.3 parts by weight;

[0013] The halogen-free intumescent flame retardants include melamine-based halogen-free intumescent flame retardants and piperazine-based halogen-free intumescent flame retardants.

[0014] The halogen-free flame-retardant polypropylene composite material provided by this invention comprises polypropylene resin, a halogen-free intumescent flame retardant, a quaternary ammonium salt compound, and an anti-dripping agent. The halogen-free intumescent flame retardant includes melamine-based and piperazine-based halogen-free intumescent flame retardants. On one hand, by selecting and combining melamine-based and piperazine-based halogen-free intumescent flame retardants, and supplementing with an anti-dripping agent, the resulting polypropylene composite material exhibits excellent flame-retardant properties. On the other hand, by adding the quaternary ammonium salt compound, the stability of the halogen-free intumescent flame retardant under long-term humid heat conditions is effectively improved. Therefore, the resulting polypropylene composite material, while possessing excellent flame retardancy, also exhibits excellent voltage breakdown resistance, humid heat aging resistance, and excellent mechanical properties.

[0015] The polypropylene resin content can be 55 parts by weight, 57 parts by weight, 59 parts by weight, 61 parts by weight, 63 parts by weight, 65 parts by weight, 67 parts by weight, 69 parts by weight, 71 parts by weight, 73 parts by weight, or 75 parts by weight, etc.; and the mass percentage of polypropylene resin in the halogen-free flame-retardant polypropylene composite material is not less than 30%.

[0016] The content of the halogen-free intumescent flame retardant can be 15 parts by weight, 17 parts by weight, 19 parts by weight, 21 parts by weight, 23 parts by weight, 25 parts by weight, 27 parts by weight, 29 parts by weight, or 30 parts by weight, etc.

[0017] The content of the quaternary ammonium salt compound can be 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.4 parts by weight, 0.6 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.4 parts by weight, 1.6 parts by weight, 1.8 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, or 3.5 parts by weight, etc.

[0018] The anti-dripping agent is present in amounts of 0.1 parts by weight, 0.12 parts by weight, 0.14 parts by weight, 0.16 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.24 parts by weight, 0.26 parts by weight, 0.28 parts by weight, or 0.3 parts by weight.

[0019] Preferably, the melt index of the polypropylene resin at 230°C and 2.16 kg is 1~150 g / 10min, for example 3 g / 10min, 5 g / 10min, 7 g / 10min, 9 g / 10min, 11 g / 10min, 13 g / 10min, 15 g / 10min, 17 g / 10min, 19 g / 10min, 20 g / 10min, 40 g / 10min, 60 g / 10min, 80 g / 10min, 100 g / 10min, 120 g / 10min, 140 g / 10min, or 150 g / 10min, and more preferably 5~20 g / 10min. g / 10min; If the melt index of the polypropylene resin is too high, the voltage breakdown resistance and tensile strength of the resulting halogen-free flame-retardant polypropylene composite material will decrease slightly. If the melt index of the polypropylene resin is too low, although it will not affect the performance of the final halogen-free flame-retardant polypropylene composite material, it may make the material more difficult to process.

[0020] In this invention, the melt index of the polypropylene resin can be tested with reference to the GB / T 3682.1-2018 standard.

[0021] In this invention, there are no special requirements for the specific type of polypropylene resin, as long as its melt index meets the above-mentioned limitations. For example, homopolymer polypropylene, copolymer polypropylene, or a combination of the two can be selected.

[0022] Preferably, the mass ratio of the melamine-based halogen-free intumescent flame retardant to the piperazine-based halogen-free flame retardant is 1:(1~5), for example, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, or 1:5. By adding the melamine-based halogen-free intumescent flame retardant and the piperazine-based halogen-free intumescent flame retardant within the above mass ratio, the resulting halogen-free flame-retardant polypropylene composite material can have more excellent flame-retardant properties.

[0023] Preferably, the melamine-based halogen-free intumescent flame retardant includes melamine pyrophosphate and / or melamine polyphosphate.

[0024] Preferably, the piperazine-based halogen-free intumescent flame retardant includes piperazine pyrophosphate.

[0025] Preferably, the mass percentage of quaternary ammonium salt compound in the halogen-free flame-retardant polypropylene composite material is 0.05~5%, for example, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1%, 2%, 3%, 4% or 5%, and more preferably 1~2%. If the mass percentage of the quaternary ammonium salt compound is lower than the above range, the voltage breakdown resistance of the obtained halogen-free flame-retardant polypropylene composite material will be worse. If the mass percentage of the quaternary ammonium salt compound exceeds the above range, although the obtained halogen-free flame-retardant polypropylene composite material can be guaranteed to have excellent voltage breakdown resistance and damp heat aging resistance, it will lead to a significant decrease in its tensile strength and a deterioration in its mechanical properties.

[0026] Preferably, the quaternary ammonium salt compound has the general chemical formula [R1R2R3R4N]. + X - R1 to R3 are each independently selected from at least one of C1 to C6 (e.g., C1, C2, C3, C4, C5 or C6) alkyl and C6 to C20 (e.g., C6, C8, C10, C12, C14, C16, C18 or C20, etc.) aryl, R4 is selected from C10 to C30 (e.g., C10, C14, C18, C22, C24, C26, C28 or C30, etc.) alkyl, and X is a halogen (e.g., F, Cl, Br, I, At, etc.).

[0027] Preferably, the quaternary ammonium salt compound includes at least one of dimethyloctadecylbenzylammonium chloride, trimethylhexadecylammonium bromide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, eicosyltrimethylammonium chloride, dodecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, triacontyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, eicosyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tridecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tridecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tridecyltrimethylammonium bromide, triacontyltrimethylammonium bromide, or triacontyltrimethylammonium bromide, and more preferably dimethyloctadecylbenzylammonium chloride.

[0028] Preferably, at least one of R1 to R3 is selected from C6 to C20 aryl groups, X is selected from Cl or Br, and the quaternary ammonium salt compound is further preferably dimethyl octadecyl benzyl ammonium chloride.

[0029] Preferably, the anti-dripping agent comprises at least one of polytetrafluoroethylene, polyarylethersulfone, poly(p-phenylene terephthalamide), organosilicon compounds, or ultra-high molecular weight polyethylene.

[0030] Preferably, the halogen-free flame-retardant polypropylene composite material also includes other additives.

[0031] Preferably, the content of other additives in the halogen-free flame-retardant polypropylene composite material is not higher than 5 parts by weight, such as 5 parts by weight, 4.5 parts by weight, 4 parts by weight, 3.5 parts by weight, 3 parts by weight, 2.5 parts by weight, 2 parts by weight, 1.5 parts by weight, 1 part by weight, or 0.5 parts by weight.

[0032] Preferably, the other additives include at least one of antioxidants, lubricants, or ultraviolet absorbers.

[0033] In this invention, any one of antioxidants, lubricants, or ultraviolet absorbers can be added as needed, and there are no special requirements on the types of antioxidants, lubricants, and ultraviolet absorbers.

[0034] For example, the antioxidant may be selected from di(3,5-di-tert-butyl-4-hydroxyphenyl)methane, 4,4'-methylenebis(2,6-di-tert-butylphenol), 330-2,6-di-tert-butyl-4-methoxyphenol, 4,4'-ethylidenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-tert-butylphenol), 2,6-di-tert-butyl-p-methylphenol, tris(2,4-di-tert-butylphenyl) phosphite, tris(2-ethylhexyl) phosphite, tris(phenyl) phosphite, tris(octyl) phosphite, etc.

[0035] For example, the lubricant may be selected from higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, higher fatty acid amides, etc.

[0036] The higher fatty acids mentioned are not limited to the following substances, but can include, for example, saturated or unsaturated, straight-chain or branched aliphatic monocarboxylic acids with 8 to 40 carbon atoms, such as stearic acid, palmitic acid, benzolic acid, erucic acid, oleic acid, lauric acid or linalic acid; and among these substances, stearic acid and linalic acid are preferred from the viewpoint of suppressing gas generation during melt processing and suppressing mold fouling in the mold during molding processing.

[0037] The metal salt of the higher fatty acid refers to the metal salt of the higher fatty acid. The metal element constituting the metal salt is preferably an element of Group I, II, or III of the periodic table, zinc or aluminum, etc., and more preferably calcium, sodium, potassium, magnesium, etc. Furthermore, the metal salt of the higher fatty acid is not limited to the following substances, and examples include: calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium lignite, sodium lignite, calcium palmitate, etc. Among these substances, from the viewpoint of suppressing gas generation during melting and suppressing mold fouling in the mold during molding, the metal salt of lignite acid and the metal salt of stearic acid are preferred.

[0038] The term "higher fatty acid ester" refers to an esterification of the higher fatty acid and an alcohol. From the viewpoint of suppressing gas generation during melt processing and suppressing mold fouling during molding, an ester of an aliphatic carboxylic acid with 8 to 40 carbon atoms and an aliphatic alcohol with 8 to 40 carbon atoms is preferred. Here, the aforementioned fatty acid can be used as the higher fatty acid. The aliphatic alcohol is not limited to the following substances, but can be exemplified by: stearyl alcohol, betaine alcohol, lauryl alcohol, etc. The term "higher fatty acid ester" is not limited to the following substances, but can be exemplified by: stearyl stearate, betaine acid, etc.

[0039] The term "higher fatty acid amide" refers to an amide compound of higher fatty acids; it is not limited to the following substances, but can be listed as: stearamide, oleamide, mustardamide, ethylene bis-stearamide, ethylene bis-oleamide, N-stearyl stearamide, N-stearyl mustardamide, etc.; and among these substances, from the viewpoint of suppressing gas generation during melt processing and suppressing mold fouling in the mold during molding processing, stearamide, mustardamide, ethylene bis-stearamide, and N-stearyl mustardamide are preferred, and ethylene bis-stearamide and N-stearyl mustardamide are more preferred.

[0040] In addition, each of these higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty amides can be used alone or in combination of two or more.

[0041] For example, the ultraviolet absorber may be selected from salicylate, benzotriazole, benzophenone, etc.

[0042] Preferably, the halogen-free flame-retardant polypropylene composite material further includes fillers, and there are no special requirements for the type of fillers.

[0043] For example, the filler may be selected from glass fiber, glass microspheres, talc, wollastonite or magnesium hydroxide, and may be used alone or in combination of two or more.

[0044] Preferably, the filler content in the halogen-free flame-retardant polypropylene composite material is no more than 40 parts by weight, such as 40 parts by weight, 35 parts by weight, 30 parts by weight, 25 parts by weight, 20 parts by weight, 15 parts by weight, 10 parts by weight, or 5 parts by weight.

[0045] In a second aspect, the present invention provides a method for preparing a halogen-free flame-retardant polypropylene composite material as described in the first aspect, the method comprising: mixing the various components, and performing compounding, melting and extrusion granulation in an extruder to obtain the halogen-free flame-retardant polypropylene composite material.

[0046] Preferably, the mixing time is 3 to 5 minutes, such as 3 minutes, 3.2 minutes, 3.4 minutes, 3.6 minutes, 3.8 minutes, 4 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes, or 5 minutes.

[0047] Preferably, the extruder is a twin-screw extruder.

[0048] Preferably, the screw length-to-diameter ratio of the twin-screw extruder is (25~48):1, for example, 25:1, 27:1, 29:1, 31:1, 33:1, 35:1, 37:1, 39:1, 41:1, 43:1, 45:1, 47:1 or 48:1, etc.

[0049] Preferably, the operating temperatures of each zone of the twin-screw extruder are as follows: Zone 1 is 80~120℃ (e.g., 80℃, 90℃, 100℃, 110℃ or 120℃, etc.), Zones 2~6 are each independently 160~200℃ (e.g., 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃ or 200℃, etc.), and Zone 7 is 180~200℃ (e.g., 180℃, 185℃, 190℃, 195℃ or 200℃, etc.).

[0050] Thirdly, the present invention provides a component comprising the halogen-free flame-retardant polypropylene composite material as described in the first aspect.

[0051] Preferably, the component includes at least one of household appliances, automotive parts, medical device parts, or electronic appliances.

[0052] In particular, the above-mentioned halogen-free flame-retardant polypropylene composite material can be used to prepare parts with excellent resistance to voltage breakdown, resistance to damp heat aging, and mechanical properties. More specifically, it can be used to prepare battery covers for new energy vehicles, casings for energy storage batteries, wire harness sheaths, fireproof insulation panels, interior trim for high-speed trains / subways, etc.

[0053] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The halogen-free flame-retardant polypropylene composite material provided by this invention includes polypropylene resin, a halogen-free intumescent flame retardant, a quaternary ammonium salt compound, and an anti-dripping agent. The halogen-free intumescent flame retardant includes melamine-based and piperazine-based halogen-free intumescent flame retardants. Through the rational combination of the above components, especially the introduction of the quaternary ammonium salt compound, the stability of the halogen-free intumescent flame retardant under long-term humid heat conditions is effectively improved. This results in a polypropylene composite material that, while possessing excellent flame-retardant properties, also exhibits excellent electrical breakdown resistance, humid heat aging resistance, and mechanical properties, making it highly suitable for applications in electronic and electrical appliances. Detailed Implementation

[0056] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0057] Information on some of the raw materials involved in the following examples and comparative examples is shown below:

[0058] (1) Polypropylene resin

[0059] PP-A: Melt index of 10 g / 10 min (230℃ / 2.16 kg), purchased from Taiwan Petrochemical Fiber Co., Ltd., brand name TAIRIPRO K9010;

[0060] PP-B: Melt index of 8 g / 10 min (230℃ / 2.16 kg), purchased from ExxonMobil (China) Investment Co., Ltd., grade 7033N;

[0061] PP-C: Melt index of 17 g / 10 min (230℃ / 2.16 kg), purchased from Taiwan Chemical Fiber Co., Ltd., grade K9017;

[0062] PP-D: Melt index of 3 g / 10 min (230℃ / 2.16 kg), purchased from Ningxia Baofeng Energy Group Co., Ltd., grade K8003;

[0063] PP-E: Melt index of 29 g / 10 min (230℃ / 2.16 kg), purchased from ExxonMobil (China) Investment Co., Ltd., grade 8285E1.

[0064] (2) Halogen-free intumescent flame retardant

[0065] Melamine pyrophosphate: purchased from Chemische Fabrik Budenheim KG, grade MPP 3141;

[0066] Melamine polyphosphate: purchased from Shandong Weidong Chemical Technology Co., Ltd., brand name FR-NP;

[0067] Piperazine pyrophosphate: purchased from Sichuan Fine Chemical Research and Design Institute Co., Ltd., brand name JNP-2.

[0068] (3) Quaternary ammonium salt compounds

[0069] Trimethylhexadecylammonium bromide: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., brand name CTAB;

[0070] Dimethyloctadecylbenzylammonium chloride: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., grade 1827;

[0071] Dodecyltrimethylammonium chloride: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., brand name DTAC;

[0072] Dodecyltrimethylammonium bromide: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., brand name DTAB.

[0073] (4) Anti-dripping agent

[0074] Polytetrafluoroethylene: purchased from Shanghai Sanai New Materials Co., Ltd., brand name FR301. (5) Antioxidant

[0075] Antioxidant 1010: Hindered phenolic antioxidant, commercially available.

[0076] Examples 1-16, Comparative Examples 1-4

[0077] Examples 1-16 and Comparative Examples 1-4 each provide a halogen-free flame-retardant polypropylene composite material, the components of which are shown in Table 1 and Table 2, and in Table 1 and Table 2, the amount of each component is in "parts by weight".

[0078] Table 1

[0079]

[0080] Table 2

[0081]

[0082] The preparation methods of the halogen-free flame-retardant polypropylene composite materials provided in Examples 1-16 and Comparative Examples 1-4 include: mixing each component for 5 min, and then performing compounding, melting, and extrusion granulation in a twin-screw extruder. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, and the operating temperatures of each zone are: 100°C for zone 1, 180°C for zones 2-6, and 200°C for zone 7, thereby obtaining the halogen-free flame-retardant polypropylene composite material.

[0083] Performance testing:

[0084] (1) Tensile strength: Tested in accordance with ISO527-1:2019 standard.

[0085] (2) Flame retardant performance: The test was conducted in accordance with UL94:2018 standard, and the sample thickness was 2 mm.

[0086] (3) Electrical breakdown resistance: A 100 mm × 100 mm × 1 mm test sample was used. It was placed at 35℃ / 96% for 96 h, and then the dielectric strength was tested in accordance with GB / T 1408.1-2016 standard.

[0087] (4) Electrical breakdown performance after damp heat aging: A test sample of 100 mm × 100 mm × 1 mm was first placed at 85℃ / 85% for 1000 h, and then tested for whether it would break down under 5000 V voltage in accordance with GB / T 2423.3-2016 standard.

[0088] The halogen-free flame-retardant polypropylene composite materials provided in Examples 1-16 and Comparative Examples 1-4 were tested according to the above test methods. The test results are shown in Table 3.

[0089] Table 3

[0090]

[0091] According to the data in Table 3:

[0092] (1) The halogen-free flame-retardant polypropylene composite materials provided in Examples 1 to 16 have a tensile strength of 17.3 MPa or higher, a flame retardant rating of V-1 or higher, a dielectric strength of 10 kV / mm or higher in the voltage breakdown test, and will not be broken down by 5000 V voltage after 1000h of damp heat aging treatment. They have excellent mechanical properties, flame retardant properties, voltage breakdown resistance and damp heat aging resistance.

[0093] (2) Comparing the data of Example 1 and Comparative Example 1, it can be seen that when no quaternary ammonium salt compound is added, the resulting halogen-free flame-retardant polypropylene composite material has very poor voltage breakdown resistance and will be directly broken down by 5000V voltage after 1000 h of damp heat aging treatment, indicating very poor damp heat aging performance.

[0094] (3) Comparing the data of Example 1 and Comparative Examples 2 to 4, it can be seen that the absence of anti-dripping agent (Comparative Example 2), the absence of piperazine-based halogen-free intumescent flame retardant (Comparative Example 3), and the absence of melamine-based halogen-free intumescent flame retardant (Comparative Example 4) all result in the flame retardant rating of the obtained halogen-free flame-retardant polypropylene composite material being NR, i.e., it does not have a flame retardant rating.

[0095] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A halogen-free flame-retardant polypropylene composite material, characterized in that, The halogen-free flame-retardant polypropylene composite material comprises the following components by weight: 55-75 parts by weight of polypropylene resin; 15-32 parts by weight of halogen-free intumescent flame retardant; 0.01 to 4 parts by weight of quaternary ammonium salt compounds; Anti-dripping agent 0.1~0.3 parts by weight; The halogen-free intumescent flame retardants include melamine-based halogen-free intumescent flame retardants and piperazine-based halogen-free intumescent flame retardants.

2. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The polypropylene resin has a melt index of 1~150 g / 10min at 230℃ and 2.16 kg.

3. The halogen-free flame-retardant polypropylene composite material according to claim 2, characterized in that, The melt index of the polypropylene resin at 230°C and 2.16 kg is 5~20 g / 10min.

4. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The mass ratio of the melamine-based halogen-free intumescent flame retardant to the piperazine-based halogen-free intumescent flame retardant is 1:(1~5).

5. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The melamine-based halogen-free intumescent flame retardant includes melamine pyrophosphate and / or melamine polyphosphate.

6. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The piperazine-based halogen-free intumescent flame retardant includes piperazine pyrophosphate.

7. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The general chemical formula of the quaternary ammonium salt compound is [R1R2R3R4N]. + X - R1 to R3 are each independently selected from at least one of C1 to C6 alkyl and C6 to C20 aryl, R4 is selected from C10 to C30 alkyl, and X is a halogen.

8. The halogen-free flame-retardant polypropylene composite material according to claim 7, characterized in that, The quaternary ammonium salt compound includes at least one of dimethyloctadecylbenzylammonium chloride, trimethylhexadecylammonium bromide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, eicosyltrimethylammonium chloride, dodecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, triacontyltrimethylammonium chloride, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, eicosyltrimethylammonium bromide, dodecyltrimethylammonium bromide, triacontyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tridecyltrimethylammonium bromide, triacontyltrimethylammonium bromide, or triacontyltrimethylammonium bromide.

9. The halogen-free flame-retardant polypropylene composite material according to claim 8, characterized in that, The quaternary ammonium salt compound is dimethyloctadecylbenzylammonium chloride.

10. The halogen-free flame-retardant polypropylene composite material according to claim 7, characterized in that, At least one of R1 to R3 is selected from C6 to C20 aryl groups, and X is selected from Cl or Br.

11. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The anti-dripping agent includes at least one of polytetrafluoroethylene, polyarylether sulfone, poly(p-phenylene terephthalamide), organosilicon compounds, or ultra-high molecular weight polyethylene.

12. The halogen-free flame-retardant polypropylene composite material according to claim 1, characterized in that, The halogen-free flame-retardant polypropylene composite material also includes other additives.

13. The halogen-free flame-retardant polypropylene composite material according to claim 12, characterized in that, The content of other additives in the halogen-free flame-retardant polypropylene composite material is no more than 5 parts by weight.

14. The halogen-free flame-retardant polypropylene composite material according to claim 12, characterized in that, The other additives include at least one of antioxidants, lubricants, or ultraviolet absorbers.

15. A method for preparing a halogen-free flame-retardant polypropylene composite material as described in any one of claims 1 to 14, characterized in that, The preparation method includes: mixing the various components, kneading, melting and extruding granulation in an extruder to obtain the halogen-free flame-retardant polypropylene composite material.

16. The preparation method according to claim 15, characterized in that, The mixing time is 3 to 5 minutes.

17. The preparation method according to claim 15, characterized in that, The extruder is a twin-screw extruder.

18. The preparation method according to claim 17, characterized in that, The screw length-to-diameter ratio of the twin-screw extruder is (25~48):

1.

19. The preparation method according to claim 17, characterized in that, The operating temperatures of each zone of the twin-screw extruder are as follows: Zone 1 is 80~120℃, Zones 2~6 are 160~200℃ independently, and Zone 7 is 180~200℃.

20. A component, characterized in that, The component comprises a halogen-free flame-retardant polypropylene composite material as described in any one of claims 1 to 14.

21. The part according to claim 20, characterized in that, The component includes at least one of household appliances, automotive parts, medical equipment parts, or electronic appliances.

Images