Flame-retardant synergist, preparation method thereof and flame-retardant polypropylene composite material

Abstract

The invention discloses a flame-retardant synergist, a preparation method thereof and a flame-retardant polypropylene composite.The preparation method of the flame-retardant synergist comprises the steps that soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone are taken and added into a reaction solvent, stirring is conducted for 0.5-2 h, and a mixed solution is obtained; the mixed solution is subjected to a reaction for 12-24 h at the temperature of 150-200 DEG C, and a lamellar nickel phenyl phosphate material, namely the flame retardant synergist, is prepared. The lamellar nickel phenyl phosphate material prepared in the invention can be used as a flame retardant synergist to be added into a polypropylene system, can reinforce the polypropylene material, and also can cooperate with a flame retardant to significantly improve the flame retardant property of the polypropylene material.

Description

Technical Field

[0001] The present application belongs to the technical field of flame retardant functional additive preparation, and specifically relates to a flame retardant synergist and a preparation method thereof, and also relates to the application of the flame retardant synergist in the preparation of flame retardant polypropylene composite materials. Background Art

[0002] Flame-retardant polypropylene material is a polypropylene (PP) plastic with flame retardants added. By adding a certain amount of flame retardants to the polypropylene base material, the combustion process of the material can be slowed down or stopped, thereby improving the safety of the material. Among them, halogen-free flame retardants mainly include magnesium-aluminum series, phosphorus series, intumescent flame retardants, etc. Since their ingredients do not contain halogens (such as chlorine and bromine), less toxic gases and corrosive substances are produced during combustion, which has less impact on the environment and human health, and is widely used.

[0003] At present, in order to improve the flame retardant properties of halogen-free flame retardant polypropylene composite materials, a certain amount of flame retardant synergists are generally introduced to improve the flame retardant effect of halogen-free flame retardants. For example, phenylphosphonic acid, as a common synergist, can improve the effect of halogen-free flame retardants, improve carbonization ability, and reduce heat release rate, thereby improving the flame retardant effect of the material. On the one hand, since halogen-free flame retardants and synergists are generally poorly compatible with polypropylene substrates, the mechanical properties of the material will decrease; on the other hand, in order to achieve the ideal flame retardant effect, the amount of flame retardant added also needs to be larger, which will also affect the mechanical properties of polypropylene materials.

[0004] Therefore, it is urgent to develop new flame retardant synergists to improve the flame retardant properties while maintaining the mechanical properties of polypropylene materials as much as possible. Summary of the invention

[0005] In view of this, the primary purpose of the present application is to provide a method for preparing a flame retardant synergist. The method provided in the present application can prepare a nickel phenyl phosphate material grown into a lamellar structure, which is the flame retardant synergist in the present application. It can not only enhance the polypropylene material, but also cooperate with the flame retardant to significantly improve the flame retardant properties of the polypropylene material.

[0006] One aspect of the present application provides a method for preparing a flame retardant synergist, comprising the following steps:

[0007] Add soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone into the reaction solvent and stir for 0.5 to 2 hours to obtain a mixed solution;

[0008] The mixed solution is placed at 150-200° C. to react for 12-24 hours to obtain a nickel phenyl phosphate sheet material, which is the flame retardant synergist.

[0009] Another aspect of the present application provides a flame retardant synergist, which is prepared using the preparation method described above.

[0010] Another aspect of the present application provides use of the flame retardant synergist as described above in the preparation of a flame retardant polypropylene composite material.

[0011] Another aspect of the present application provides a flame retardant polypropylene composite material, which is prepared from the following components in parts by weight:

[0012] Polypropylene 73.8-82.6 parts; flame retardant 14-20 parts; flame retardant synergist mentioned above 3-5 parts; antioxidant 0.2-0.6 parts; processing aid 0.2-0.6 parts.

[0013] Another aspect of the present application provides a method for preparing the flame retardant polypropylene composite material as described above, comprising the following steps:

[0014] According to weight parts, 73.8-82.6 parts of polypropylene, 14-20 parts of flame retardant, 3-5 parts of flame retardant synergist, 0.2-0.6 parts of antioxidant and 0.2-0.6 parts of processing aid are fully mixed to obtain a uniform mixture;

[0015] The mixed material is added into a twin-screw extruder and granulated through melt extrusion to obtain a flame-retardant polypropylene composite material.

[0016] Beneficial effects of this application:

[0017] The nickel phenyl phosphate material prepared in the present application is in the form of a lamellar layer, which is added to the flame-retardant polypropylene composite material as a flame retardant synergist, and can significantly improve the performance of the flame-retardant polypropylene composite material. Specifically, the prepared lamellar nickel phenyl phosphate material is distributed in the polypropylene base material under normal circumstances, and its lamellar structure can transmit stress when subjected to force, hinder the expansion of silver streaks, and play a reinforcing role. When the material is burning, the lamellar nickel phenyl phosphate can decompose to produce substances such as NiO, H3PO4, H4P2O7, and C6H6, among which C6H6 is easily dehydrogenated to form a carbon layer under the catalytic action of the catalyst NiO. Since the decomposition product of NiPP has good catalytic ability, a dense solid protective carbonaceous layer is formed, which acts as a barrier to prevent heat and mass transfer, thereby significantly improving the flame retardant properties of the polypropylene composite material. In addition, HPO· and PO· in H3PO4 and H4P2O7 interfere with combustion in the gas phase, and the synergistic flame suppression of phosphorus and nickel further improves the flame retardant efficiency. The formation of the residual layer during the combustion process is the key to protecting the internal matrix and suppressing smoke. Therefore, the flame-retardant polypropylene material of the present invention, the added nickel phenyl phosphate can significantly increase the density and cross-linking rate of the outer coke surface. At the same time, the internal residual layer becomes thick and solid, which can prevent the volatilization of the internal combustible components. In addition, the effective solid slag layer plays a role of heat resistance, improves the flame retardant efficiency, and greatly reduces the smoke volume. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the implementation methods of the present application. The technical solutions in the implementation methods described below are exemplary and are only possible technical implementations of the present application, not all possible implementations. Those skilled in the art can fully combine the implementation methods of the present application to obtain other implementation methods without creative work, and these implementation methods are also within the scope of protection of the present application.

[0019] The first aspect of the present application discloses a method for preparing a flame retardant synergist, which is characterized by comprising the following steps:

[0020] Add soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone into the reaction solvent and stir for 0.5 to 2 hours to obtain a mixed solution;

[0021] The mixed solution is placed at 150-200° C. to react for 12-24 hours to obtain a nickel phenyl phosphate sheet material, which is the flame retardant synergist.

[0022] The preparation method mainly undergoes ion reaction in solution, autocatalytic reaction and surface adsorption and diffusion. First, the nickel ions in the solution, as metal cations, have the ability to accept electron pairs to form coordination bonds, while the phenyl phosphate ions can provide electron pairs to coordinate with the nickel ions, and form complexes through ion reactions, which is the starting step for the growth of lamellar nickel phenyl phosphate. Secondly, similar to chemical nickel plating, the growth of lamellar nickel phenyl phosphate involves autocatalytic reactions. Once a small amount of nickel phenyl phosphate nuclei are formed on the surface of the substrate, these nuclei will act as catalysts to accelerate the subsequent reduction and deposition reactions of nickel ions and phenyl phosphate ions, so that the crystals continue to grow. Furthermore, the ions in the solution will first be adsorbed on the surface of the substrate or the surface of the formed crystals, and then diffuse on the surface; during the diffusion process of the nickel ions and phenyl phosphate ions on the surface, they will find suitable positions for combination and deposition, thereby prompting the crystals to gradually grow in the two-dimensional direction to form a lamellar structure. Through the above process, a nickel phenyl phosphate material grown in a lamellar state can be prepared.

[0023] In the present application, the reaction solvent is obtained by thoroughly mixing deionized water, ethanol and ethylene glycol in a volume ratio of 5:(40-50):(40-60).

[0024] In the present application, the specific ratio of each reaction raw material can be determined according to needs or by experimental methods, so there is no special limitation. In some specific implementation cases of the present application, the mass ratio of the soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone is 3: (1.3-1.7): (0.4-0.6): (0.7-0.9).

[0025] In the present application, the soluble nickel salt may be nickel nitrate, nickel acetate, nickel chloride, etc. In some specific embodiments of the present application, the soluble nickel salt is nickel nitrate.

[0026] In addition, it is understood that after the reaction is completed, the steps of filtering, washing and drying are also included, and since these are conventional operating methods in the art, there is no particular limitation. In some specific embodiments of the present application, the number of washings is 2 to 4 times, the drying temperature is 50 to 70° C., and the drying time is 12 to 20 hours.

[0027] The second aspect of the present application discloses a flame retardant synergist, which is prepared by the preparation method described above.

[0028] The third aspect of the present application discloses the use of the flame retardant synergist as described above in the preparation of a flame retardant polypropylene composite material.

[0029] The fourth aspect of the present application discloses a flame retardant polypropylene composite material, which is prepared from the following components in parts by weight:

[0030] Polypropylene 73.8-82.6 parts; flame retardant 14-20 parts; flame retardant synergist mentioned above 3-5 parts; antioxidant 0.2-0.6 parts; processing aid 0.2-0.6 parts.

[0031] There is no special requirement for the type of polypropylene, and any common polypropylene in the art can be used in the present application, such as at least one of copolymer polypropylene and homopolymer polypropylene.

[0032] In the present application, the antioxidant is a type of auxiliary agent that can improve the antioxidant capacity of polypropylene materials. It is a common functional auxiliary agent in the art and is not particularly limited. Specific examples include at least one of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants, but are not limited thereto.

[0033] In the present application, the flame retardant is a halogen-free flame retardant, and preferably, the halogen-free flame retardant is a phosphorus-nitrogen intumescent flame retardant.

[0034] In the present application, the processing aid refers to a type of additive that can improve the melt fluidity of polypropylene materials, reduce flow resistance, reduce melt viscosity, etc., thereby improving its processing performance. For example, it can be a lubricant. Specific examples of the lubricant include at least one of metal soaps or amides, but are not limited to these.

[0035] The fifth aspect of the present application discloses a method for preparing the flame-retardant polypropylene composite material as described above, comprising the following steps:

[0036] According to weight parts, 73.8-82.6 parts of polypropylene, 14-20 parts of flame retardant, 3-5 parts of flame retardant synergist, 0.2-0.6 parts of antioxidant and 0.2-0.6 parts of processing aid are fully mixed to obtain a uniform mixture;

[0037] The mixed material is added into a twin-screw extruder and granulated through melt extrusion to obtain a flame-retardant polypropylene composite material.

[0038] There is no particular limitation on the mixing method, and conventional mechanical mixing in the art may be used to obtain a uniform mixture.

[0039] In the present application, the parameters of the twin-screw extruder require that those skilled in the art can make specific selections according to specific needs or through known methods, composition of raw materials, etc. In some specific embodiments of the present application, the aspect ratio of the twin-screw extruder is (36-45): 1; and / or, the screw speed is 250-500 rpm; and / or, the processing temperature is 180-215°C.

[0040] The following are specific embodiments of the present application. It should be noted that the following specific embodiments are only for illustrative purposes and do not limit the scope of the present application in any way.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] In addition, unless otherwise specified, methods without specific conditions or steps are conventional methods, and the reagents and materials used are all commercially available.

[0043] In the following examples, the specific steps for preparing the flame retardant synergist sheet nickel phenyl phosphate material are as follows:

[0044] (1) Add deionized water: ethanol: ethylene glycol in a volume ratio of 5:45:50 into a beaker and stir evenly at room temperature;

[0045] (2) 3 g nickel nitrate hexahydrate, 1.5 g phenylphosphonic acid, 0.5 g hexamethylenetetramine, and 0.8 g polyvinylpyrrolidone were dissolved in sequence and added to the above mixed solution, and stirred vigorously for 1.5 h;

[0046] (3) adding the above mixed solution into a reaction kettle and reacting in an oven at 180°C for 18 hours;

[0047] (4) The precipitate was collected by centrifugation, washed three times with deionized water, and dried in an oven at 60° C. for 15 hours to obtain a nickel phenyl phosphate sheet material.

[0048] Embodiment 1:

[0049] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0050] According to weight parts, 79.3 parts of copolymer polypropylene PP BX3800 (SK, South Korea), 16 parts of halogen-free flame retardant FP-2200 (ADK, Japan), 4 parts of flake nickel phenyl phosphate material, 0.2 parts of antioxidant 1010 (BASF), 0.2 parts of antioxidant 168 (BASF) and 0.3 parts of processing aid calcium stearate (Jiangxi Hongyuan Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0051] Among them, the aspect ratio of the twin-screw extruder is 36:1, and the processing temperatures from the feeding section to the die are 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, 210°C, 215°C, 215°C, 200°C, and the screw speed is 400rpm.

[0052] Embodiment 2:

[0053] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0054] According to weight parts, 77.1 parts of homopolymer polypropylene PP S2040 (Sinopec), 18 parts of halogen-free flame retardant WR02B (Suzhou Anhongtai), 4 parts of flake nickel phenyl phosphate material, 0.3 parts of antioxidant 168 (BASF), 0.2 parts of antioxidant 1010 (BASF) and 0.4 parts of processing aid erucamide (Jiangxi Weike Oil Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0055] Among them, the aspect ratio of the twin-screw extruder is 42:1, and the processing temperatures from the feeding section to the die are 180°C, 180°C, 180°C, 190°C, 190°C, 195°C, 195°C, 200°C, 205°C, and 205°C, respectively, and the screw speed is 500rpm.

[0056] Embodiment 3:

[0057] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0058] According to weight parts, 77.2 parts of copolymer polypropylene PP EA5076 (LyondellBasell), 17 parts of halogen-free flame retardant WR02B (Suzhou Anhongtai), 5 parts of lamellar nickel phenyl phosphate material, 0.2 parts of antioxidant 1010 (BASF) and 0.1 parts of antioxidant DSTDP (Tianjin Lisheng Chemical Co., Ltd.) and 0.5 parts of processing aid zinc stearate (Jiangxi Hongyuan Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0059] Among them, the aspect ratio of the twin-screw extruder is 45:1, and the temperatures from the feeding section to the die are 210°C, 210°C, 215°C, 215°C, 220°C, 220°C, 210°C, 200°C, 190°C, and 190°C, respectively, and the screw speed is 360rpm.

[0060] Embodiment 4:

[0061] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0062] According to weight parts, 82.6 parts of copolymer polypropylene PP BX3800 (SK, South Korea), 14 parts of halogen-free flame retardant ANTI-610 (Shanghai Petrochemical Research Institute), 3 parts of lamellar nickel phenyl phosphate material, 0.1 parts of antioxidant 1010 (BASF), 0.1 parts of antioxidant 168 (BASF) and 0.2 parts of processing aid erucamide (Jiangxi Weike Oil Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0063] Among them, the aspect ratio of the twin-screw extruder is 40:1, and the temperatures from the feeding section to the die are 180°C, 180°C, 190°C, 190°C, 200°C, 210°C, 210°C, 195°C, 195°C, 195°C, and the screw speed is 250rpm.

[0064] Embodiment 5:

[0065] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0066] According to weight parts, 73.8 parts of homopolymer polypropylene PP Z30S (Sinopec), 20 parts of halogen-free flame retardant FP-2200 (Japan ADK), 5 parts of lamellar nickel phenyl phosphate material, 0.3 parts of antioxidant 1010 (BASF), 0.3 parts of antioxidant 168 (BASF) and 0.3 parts of processing aid zinc stearate (Jiangxi Hongyuan Chemical), 0.3 parts of processing aid erucamide (Jiangxi Weike Oil Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0067] Among them, the aspect ratio of the twin-screw extruder is 38:1, and the temperatures from the feeding section to the die are 170°C, 180°C, 190°C, 190°C, 190°C, 210°C, 195°C, 195°C, 180°C, and 180°C, respectively, and the screw speed is 500rpm.

[0068] Comparative Example 1:

[0069] This comparative example discloses another flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0070] According to weight parts, 83.3 parts of copolymer polypropylene PP BX3800 (SK, South Korea), 16 parts of halogen-free flame retardant FP-2200 (ADK, Japan), 0.2 parts of antioxidant 1010 (BASF), 0.2 parts of antioxidant 168 (BASF) and 0.3 parts of processing aid calcium stearate (Jiangxi Hongyuan Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0071] Among them, the aspect ratio of the twin-screw extruder is 36:1, and the temperatures from the feeding section to the die are 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, 210°C, 215°C, 215°C, 200°C, and the screw speed is 400rpm.

[0072] Comparative Example 2:

[0073] This comparative example discloses another flame retardant polypropylene composite material, which adopts the same implementation as Example 1, except that: the flame retardant synergist sheet nickel phenyl phosphate material is not added, and the number of added parts of the halogen-free flame retardant FP-2200 is 24 parts. The other process steps and condition parameters are the same as those in Example 1.

[0074] The specific preparation method of the flame retardant polypropylene composite material in this comparative example is as follows:

[0075] According to weight parts, 75.3 parts of copolymer polypropylene PP BX3800 (SK, South Korea), 24 parts of halogen-free flame retardant FP-2200 (ADK, Japan), 0.2 parts of antioxidant 1010 (BASF), 0.2 parts of antioxidant 168 (BASF) and 0.3 parts of processing aid calcium stearate (Jiangxi Hongyuan Chemical) were mixed evenly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0076] Among them, the aspect ratio of the twin-screw extruder is 36:1, and the temperatures from the feeding section to the die are 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, 210°C, 215°C, 215°C, 200°C, and the screw speed is 400rpm.

[0077] Comparative Example 3:

[0078] This embodiment discloses a flame retardant polypropylene composite material, and the specific preparation method is as follows:

[0079] According to weight parts, 79.3 parts of copolymer polypropylene PP BX3800 (SK, South Korea), 16 parts of halogen-free flame retardant FP-2200 (ADK, Japan), 4 parts of phenylphosphonic acid, 0.2 parts of antioxidant 1010 (BASF), 0.2 parts of antioxidant 168 (BASF) and 0.3 parts of processing aid calcium stearate (Jiangxi Hongyuan Chemical) were mixed uniformly in a high-speed mixer, added into a twin-screw extruder for melt mixing and dispersion, and extruded into granules to obtain a flame-retardant polypropylene composite material.

[0080] Among them, the aspect ratio of the twin-screw extruder is 36:1, and the processing temperatures from the feeding section to the die are 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, 210°C, 215°C, 215°C, 200°C, and the screw speed is 400rpm.

[0081] Performance Test:

[0082] The flame retardant polypropylene composite materials in Examples 1-5 and Comparative Examples 1-3 were subjected to the following performance tests:

[0083] (1) Smoke density: Tested according to GB / T 8627 standard, sample size: 75×75×4mm;

[0084] (2) Flame retardant performance: measured according to UL94 standard, sample size 127×12.7×3.2mm;

[0085] (3) Tensile strength: Tested according to ISO 527, specimen size 150×10×4 mm;

[0086] (4) Flexural strength and flexural modulus: Tested according to ISO 178, specimen size 80×10×4 mm;

[0087] (5) Izod notched impact strength: tested according to ISO 180, with a specimen size of 80×10×4 mm.

[0088] The test results are shown in Table 1.

[0089] Table 1 Flame retardant polypropylene composite material performance test results

[0090]

[0091] It can be seen from the test results in Table 1 that the flame retardant polypropylene composite material prepared in the present application has lower smoke density and higher flame retardant efficiency.

[0092] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a flame retardant synergist, characterized in that: The following steps are involved: Add soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone into the reaction solvent and stir for 0.5 to 2 hours to obtain a mixed solution; The mixed solution is placed at 150-200° C. to react for 12-24 hours to obtain a nickel phenyl phosphate sheet material, which is the flame retardant synergist.

2. The preparation method according to claim 1, characterized in that The mass ratio of the soluble nickel salt, phenylphosphonic acid, hexamethylenetetramine and polyvinylpyrrolidone is 3: (1.3-1.7): (0.4-0.6): (0.7-0.9).

3. The preparation method according to claim 1, characterized in that: The soluble nickel salt is nickel nitrate.

4. The preparation method according to claim 1, characterized in that: The reaction solvent is obtained by fully and uniformly mixing deionized water, ethanol and ethylene glycol in a volume ratio of 5:(40-50):(40-60).

5. A flame retardant synergist, characterized in that: The method is prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the flame retardant synergist as claimed in claim 5 in the preparation of a flame retardant polypropylene composite material.

7. A flame retardant polypropylene composite material, characterized in that: It is prepared from the following components in parts by weight: Polypropylene 73.8-82.6 parts; flame retardant 14-20 parts; flame retardant synergist as claimed in claim 5 3-5 parts; antioxidant 0.2-0.6 parts; processing aid 0.2-0.6 parts; Preferably, the polypropylene is at least one of copolymer polypropylene and homopolymer polypropylene; Preferably, the antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant, and a thioester antioxidant.

8. The flame retardant polypropylene composite material according to claim 7, characterized in that: The flame retardant is a halogen-free flame retardant; Preferably, the halogen-free flame retardant is a phosphorus-nitrogen intumescent flame retardant.

9. The flame retardant polypropylene composite material according to claim 7, characterized in that: The processing aid is a lubricant; Preferably, the lubricant is at least one of metal soaps or amides.

10. A method for preparing the flame-retardant polypropylene composite material according to any one of claims 7 to 9, characterized in that: The following steps are involved: According to weight parts, 73.8-82.6 parts of polypropylene, 14-20 parts of flame retardant, 3-5 parts of flame retardant synergist, 0.2-0.6 parts of antioxidant and 0.2-0.6 parts of processing aid are fully mixed to obtain a uniform mixture; The mixed material is added into a twin-screw extruder and subjected to melt extrusion and granulation to obtain a flame-retardant polypropylene composite material; Preferably, the aspect ratio of the twin-screw extruder is (36-45):1; and / or, the screw speed is 250 to 500 rpm; And / or, the processing temperature is 180-215°C.

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