A low-cost halogen-containing flame-retardant polypropylene composite material and preparation method thereof

Abstract

The present invention relates to a low-cost halogen-containing flame-retardant polypropylene composite material and a preparation method thereof. The low-cost halogen-containing flame-retardant polypropylene composite material comprises 35-50 parts of polypropylene, 25-30 parts of glass fiber, 19 parts of flame retardant, 2-5 parts of antimony trioxide, 5-10 parts of flame retardant synergist, 3 parts of compatibilizer and 1 part of processing aid by weight; the flame retardant is decabromodiphenylethane; the flame retardant synergist is a mixture of talcum powder, wollastonite and kaolin; the flame retardant grade of the low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0; the preparation method is: after mixing the components uniformly by weight ratio, adding them into a twin-screw extruder for extrusion molding, and obtaining the low-cost halogen-containing flame-retardant polypropylene composite material. The preparation method of the present invention has a simple process, can replace 60% of antimony trioxide under the premise of ensuring flame retardant performance, and greatly reduces the material cost; at the same time, the prepared flame retardant polypropylene composite material has excellent flame retardant performance.

Description

Technical Field

[0001] The invention belongs to the technical field of functional polymer composite materials, and particularly relates to a low-cost halogen-containing flame-retardant polypropylene composite material and a preparation method thereof. Background Art

[0002] As one of the most widely used thermoplastic materials, polypropylene has good chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and high wear resistance. At the same time, due to its low price and easy processing and molding, it has been widely developed and applied in home appliances, kitchen and bathroom, automobiles, electronic appliances and other fields.

[0003] Generally, the flame retardant systems of flame retardant polypropylene composite materials are divided into two types: halogen-containing flame retardant system and halogen-free flame retardant system. At present, the flame retardant system commonly used by various modified plastics companies to produce and prepare halogen-containing flame retardant polypropylene composite materials is mainly bromine-antimony system, in which the interaction between antimony trioxide and halogen has a good flame retardant effect, and antimony trioxide plays a good flame retardant synergistic role in the system. If the amount of antimony trioxide is reduced and the amount of bromine flame retardant is increased, the flame retardant stability of the composite material will be reduced, and the cost of the composite material will still be high.

[0004] At present, the price of antimony trioxide remains high: on the one hand, it is due to the rise in the price of antimony trioxide raw materials. Antimony is a rare earth element, mainly produced from antimony ore, which is a non-renewable resource; on the other hand, antimony trioxide causes great pollution to the environment during the production process, and the production and processing costs of antimony trioxide are getting higher and higher, especially the treatment of pollutants. In addition to the above two reasons, the rapid increase in market demand for antimony trioxide has also kept its price high.

[0005] Chinese patent CN102212207B prepared an environmentally friendly, inexpensive synergistic flame retardant suitable for halogen / antimony flame retardant system, and the composite material prepared by synergistically replacing part of antimony trioxide in the halogen / antimony flame retardant system with magnesium oxide, aluminum oxide, and silicon dioxide has good flame retardant properties. However, this solution can only replace 30% to 40% of antimony trioxide in flame-retardant polypropylene composite materials. Replacing more than 40% of antimony trioxide will lead to a decrease in the flame retardant properties of polypropylene composite materials, and the reduction of the overall cost of materials is limited.

[0006] Therefore, it is of great significance to study a low-cost halogen-containing flame-retardant polypropylene composite material and a preparation method thereof to solve the problems existing in the prior art. Summary of the invention

[0007] The purpose of the present invention is to solve the problems existing in the prior art and provide a low-cost halogen-containing flame-retardant polypropylene composite material and a preparation method thereof.

[0008] In order to achieve the above object, the technical solution of the present invention is as follows:

[0009] A low-cost halogen-containing flame-retardant polypropylene composite material comprises the following components in parts by weight:

[0010]

[0011] The flame retardant is decabromodiphenylethane;

[0012] The flame retardant synergist is a mixture of talc, wollastonite and kaolin; the particle size of the talc, wollastonite and kaolin is at least 3000 mesh, and the smaller the particle size, the better the dispersibility in the flame retardant polypropylene composite material;

[0013] The flame retardant grade of the low-cost halogen-containing flame-retardant polypropylene composite material is 1.6 mm V0.

[0014] The present invention uses a mixture of talcum powder, wollastonite and kaolin as a flame retardant synergist, and can replace up to 60% of antimony trioxide while ensuring the flame retardant grade V0. Replacing 60% of antimony trioxide with a low-cost flame retardant synergist greatly reduces the cost of the flame retardant polypropylene composite material, and the prepared flame retardant polypropylene composite material still has excellent flame retardancy.

[0015] As the preferred technical solution:

[0016] As described above, in a low-cost halogen-containing flame-retardant polypropylene composite material, the weight ratio of talcum powder, wollastonite and kaolin is 2:1:1; when the weight ratio of talcum powder, wollastonite and kaolin in the flame retardant synergist is 2:1:1, the synergistic effect between the flame retardant synergist, decabromodiphenylethane and antimony trioxide is the best, and the prepared halogen-containing flame-retardant polypropylene composite material has the best flame retardant performance.

[0017] The low-cost halogen-containing flame-retardant polypropylene composite material as described above, wherein the polypropylene is one or more of homopolymer polypropylene and copolymer polypropylene.

[0018] The low-cost halogen-containing flame-retardant polypropylene composite material as described above has a melt index of 1 to 60 g / 10 min under the test conditions of 230° C. and 2.16 kg.

[0019] In the low-cost halogen-containing flame-retardant polypropylene composite material as described above, the processing aids are coupling agent, anti-dripping agent, dispersant and antioxidant.

[0020] In the low-cost halogen-containing flame-retardant polypropylene composite material as described above, the antioxidant is antioxidant 168 and / or antioxidant 1010, and the dispersant is SG-200A.

[0021] In the low-cost halogen-containing flame-retardant polypropylene composite material as described above, the coupling agent is silane coupling agent KH-550, and the anti-dripping agent is PTFE.

[0022] The present invention also provides a method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material as described in any of the above items, wherein the components are uniformly mixed according to weight ratio, added into a twin-screw extruder for extrusion granulation, and the low-cost halogen-containing flame-retardant polypropylene composite material is obtained.

[0023] As the preferred technical solution:

[0024] The method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material as described above, wherein the mixing is performed using a high-speed mixer, the mixing time is 10 to 15 minutes, the speed of the high-speed mixer is 300 rpm; and the temperature range of each zone of the twin-screw extruder is 160 to 170°C. Principle of the invention:

[0025] On the one hand, when the flame-retardant polypropylene composite material is heated, the brominated flame retardant undergoes thermal decomposition, absorbs heat and cools down, releases hydrogen bromide, dilutes the concentration of oxygen in the air, exhausts the air, forms a barrier protection, slows down the combustion speed and extinguishes the combustion, and plays a gas-phase barrier flame retardant effect. On the other hand, antimony trioxide reacts with brominated flame retardants to form antimony tribromide, which is a flame inhibitor and captures free radicals generated during the reaction. Gaseous antimony tribromide further dilutes the concentration of oxygen in the air, and at the same time can isolate the heat generated on the polymer surface and reduce the decomposition temperature of the polymer.

[0026] The talcum powder, wollastonite and kaolin used in the flame retardant synergist of the present invention all have the common feature of containing silicon. When used with a bromine-based flame retardant, the silicon in the flame retardant synergist forms a synergistic effect with the bromine-based flame retardant to improve the flame retardant efficiency. After adding a small molecule silicon-based flame retardant synergist to a polymer material, the small molecule silicon-based flame retardant synergist will migrate to the surface of the material. During the combustion process, as the temperature of the flame-retardant polypropylene composite material increases, a stable carbon-silicate protective layer is formed on the polymer surface, which can reduce contact with oxygen in the air, hinder the further generation of free radicals, and play a flame retardant effect of gas phase shielding. The flame retardant synergist will also promote the carbonization of the polymer, thereby reducing the degradation rate of the polymer, making it less likely to undergo thermal decomposition at high temperatures.

[0027] Furthermore, the talcum powder and kaolin with a lamellar structure used in the present invention, combined with wollastonite with a needle-like structure, improve the dispersibility of the flame retardant in the composite material. In the polypropylene composite material, the flame retardant and the needle-like wollastonite are attached to the lamellar structure of talcum powder and kaolin, isolating them to hinder their agglomeration, showing an excellent barrier effect, which greatly improves the dispersibility of the flame retardant and the flame retardant synergist in the polypropylene composite material. During the combustion process, a more dense silicon-carbonate protective layer is formed, which reduces the contact with oxygen in the air and hinders the further generation of free radicals. In addition, talcum powder also absorbs part of the heat, reduces the decomposition temperature of the polymer, and improves the flame retardant efficiency. The low concentration of aluminum oxide contained in kaolin decomposes at high temperature, takes away most of the heat, thereby reducing the surface temperature of the material and improving the flame retardant efficiency.

[0028] Beneficial Effects

[0029] (1) A low-cost halogen-containing flame-retardant polypropylene composite material of the present invention, the flame retardant synergist plays a good synergistic role in the bromine antimony system, can replace up to 60% of antimony trioxide, and the flame retardant grade of the flame retardant polypropylene composite material is still V0; when the weight ratio of talcum powder, wollastonite and kaolin in the flame retardant synergist is 2:1:1, the effect is best, and the prepared polypropylene composite material has the best flame retardant performance;

[0030] (2) The method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material of the present invention has a simple process and low cost, and has broad application prospects in the fields of home appliances, kitchen and bathroom, automobiles, and electronic appliances, and has good promotion value. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0032] The test methods involved in the embodiments and comparative examples are as follows:

[0033] Flame retardant grade: Tested in accordance with GB / T 2408-2021: Five specimens are tested in each group, and the total afterflame time of the five specimens is t f (Unit: s) is calculated according to the following formula:

[0034]

[0035] Where: t 1,i is the first afterflame time of the ith sample, in seconds; t 2,i is the second afterflame time of the ith sample, in seconds.

[0036] The raw material information used in the examples and comparative examples of the present invention is as follows:

[0037] Homopolymer polypropylene A: Zhenhai Refining and Chemical PPH-T03, the melt index at 230°C and 2.16kg load is 2.0g / 10min.

[0038] Homopolymer polypropylene B: Zhenhai Refining and Chemical M60T, with a melt index of 60.0 g / 10 min at 230° C. and a load of 2.16 kg.

[0039] Copolymer polypropylene C: Yanshan Petrochemical K8003, the melt index at 230°C and 2.16 kg load is 3.0 g / 10 min.

[0040] Copolymer polypropylene D: Shanghai Secco K7926, with a melt index of 26.0 g / 10 min at 230° C. and a load of 2.16 kg.

[0041] Glass fiber: Manufacturer: Jushi, Brand: 960A.

[0042] Talc: particle size is 3000 mesh.

[0043] Wollastonite: particle size is 3000 mesh.

[0044] Kaolin: particle size is 3000 mesh.

[0045] Calcium carbonate: particle size is 3000 mesh.

[0046] Compatibilizer: Manufacturer: Jiayirong, brand: CMG9801.

[0047] Coupling agent: silane coupling agent KH-550.

[0048] Anti-drip agent: PTFE, commercially available.

[0049] Dispersant: The manufacturer is Zhejiang Jiahua, the brand is SG-200A.

[0050] Antioxidant: BASF, a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 1:1.

[0051] Example 1

[0052] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0053] (1) Preparation of raw materials:

[0054] By weight, it includes the following components:

[0055]

[0056] (2) After mixing the components uniformly for 13 minutes using a high-speed mixer according to the weight ratio, the components were added to a twin-screw extruder for extrusion and granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0057] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0058] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f It is 17s.

[0059] Example 2

[0060] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0061] (1) Preparation of raw materials:

[0062] By weight, it includes the following components:

[0063]

[0064]

[0065] (2) mixing the components uniformly for 12 minutes using a high-speed mixer according to the weight ratio, and then adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0066] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0067] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f is 22s.

[0068] Example 3

[0069] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0070] (1) Preparation of raw materials:

[0071] By weight, it includes the following components:

[0072]

[0073] (2) mixing the components uniformly for 10 minutes using a high-speed mixer according to the weight ratio, and then adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0074] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0075] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f It is 27s.

[0076] Example 4

[0077] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0078] (1) Preparation of raw materials:

[0079] By weight, it includes the following components:

[0080]

[0081] (2) mixing the components uniformly for 11 minutes using a high-speed mixer according to the weight ratio, and then adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0082] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0083] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f For 30 seconds.

[0084] Example 5

[0085] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0086] (1) Preparation of raw materials:

[0087] By weight, it includes the following components:

[0088]

[0089] Dispersant 0.2 parts;

[0090] 0.3 parts of antioxidant;

[0091] (2) mixing the components uniformly for 14 minutes using a high-speed mixer according to the weight ratio, and then adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0092] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0093] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f It is 32s.

[0094] Comparative Example 1

[0095] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that no talc is added to the flame retardant synergist, the weight portion of the mixture of wollastonite and kaolin is 5 parts, and the weight portion ratio of wollastonite to kaolin is 1:1.

[0096] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm V1, and the total afterflame time is t f It is 57s.

[0097] Comparative Example 2

[0098] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that wollastonite is not added to the flame retardant synergist, the weight proportion of the mixture of talcum powder and kaolin is 5 parts, and the weight proportion ratio of talcum powder to kaolin is 2:1.

[0099] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm V1, and the total afterflame time is t f For 60s.

[0100] Comparative Example 3

[0101] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that no kaolin is added to the flame retardant synergist, the weight portion of the mixture of talcum powder and wollastonite is 5 parts, and the weight portion ratio of talcum powder to wollastonite is 2:1.

[0102] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm V1, and the total afterflame time is t f It is 62s.

[0103] Comparing Comparative Examples 1 to 3 with Example 5, it can be found that no matter any of the components of talcum powder, wollastonite, or kaolin is missing in the flame retardant synergist, the flame retardant grade of the material is reduced to V1. This is because Comparative Examples 1 to 3 cannot exert the synergistic effect between the three to promote its flame retardant efficiency: lack of talcum powder and kaolin, the heat absorption effect of the composite material during combustion is weakened; lack of wollastonite, its barrier effect is reduced, and the dispersion of the filler is deteriorated, which will reduce the flame retardant efficiency of the polypropylene composite material during combustion. Therefore, the total afterflame time of the material increases and the flame retardant grade decreases.

[0104] Comparative Example 4

[0105] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that the weight ratio of the three components in the mixture of talcum powder, wollastonite and kaolin is 1:1:1.

[0106] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm V0, and the total afterflame time is t f It is 41s.

[0107] By comparing Comparative Example 4 with Example 5, it can be found that when the weight ratio of talc, wollastonite and kaolin is 2:1:1, the synergistic effect between the flame retardant synergist, decabromodiphenylethane and antimony trioxide is better, and the flame retardant performance of the prepared halogen-containing flame retardant polypropylene composite material is the best. Therefore, compared with Example 5, the total afterflame time of the halogen-containing flame retardant polypropylene composite material prepared in Comparative Example 4 is increased.

[0108] Comparative Example 5

[0109] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that the mixture of talcum powder, wollastonite and kaolin is replaced by calcium carbonate.

[0110] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm HB, and the total afterflame time is t f >250s.

[0111] Comparing Comparative Example 5 with Example 5, it can be found that when calcium carbonate is used to replace the flame retardant synergist in the present invention, the flame retardant grade of the material becomes HB grade. This is because calcium carbonate does not contain silicon and cannot form a stable carbon-silicate protective layer on the polymer surface during combustion. In addition, calcium carbonate does not absorb heat during combustion to reduce the decomposition temperature of the polymer, which reduces the flame retardant efficiency of the polypropylene composite material.

[0112] Comparative Example 6

[0113] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that the weight portion of antimony trioxide is 1 part and the weight portion of copolymerized polypropylene D is 46 parts.

[0114] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm V1, and the total afterflame time is t f It is 105s.

[0115] Comparing Comparative Example 6 with Example 5, it can be found that when more antimony trioxide is replaced by the flame retardant synergist, the flame retardancy level decreases and the total afterflame time increases.

[0116] Comparative Example 7

[0117] A halogen-containing flame-retardant polypropylene composite material is basically the same as Example 5, except that: no flame-retardant synergist is added, and the weight fraction of copolymerized polypropylene D is 50 parts.

[0118] The flame retardant grade of the halogen-containing flame-retardant polypropylene composite material is 1.6 mm HB, and the total afterflame time is t f >250s.

[0119] Comparing Comparative Example 7 with Example 5, it can be found that when no flame retardant synergist is added to the system, the flame retardancy level decreases and the total afterflame time increases. This is because without the addition of a silicon-based flame retardant synergist, a stable carbon-silicate protective layer cannot be formed on the polymer surface during combustion, which greatly reduces the flame retardancy efficiency of the polypropylene composite material.

[0120] Example 6

[0121] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0122] (1) Preparation of raw materials:

[0123] By weight, it includes the following components:

[0124]

[0125]

[0126] (2) mixing the components uniformly by weight ratio using a high-speed mixer for 15 minutes, adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0127] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0128] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f It is 29s.

[0129] Example 7

[0130] A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material, the specific steps are as follows:

[0131] (1) Preparation of raw materials:

[0132] By weight, it includes the following components:

[0133]

[0134] (2) mixing the components uniformly by weight ratio using a high-speed mixer for 15 minutes, adding the components to a twin-screw extruder for extrusion granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material;

[0135] Among them, the rotation speed of the high mixer is 300rpm; the temperatures in each zone of the twin-screw extruder are 160℃, 160℃, 170℃, 170℃, 170℃, 170℃, 170℃, 170℃, and 170℃ respectively.

[0136] The flame retardant grade of the finally obtained low-cost halogen-containing flame-retardant polypropylene composite material is 1.6mm V0, and the total afterflame time t f It is 13s.

Claims

1. A low-cost halogen-containing flame-retardant polypropylene composite material, characterized in that The composition comprises the following components in parts by weight: The flame retardant is decabromodiphenylethane; The flame retardant synergist is a mixture of talc, wollastonite and kaolin; The flame retardant grade of the low-cost halogen-containing flame-retardant polypropylene composite material is 1.6 mm V0.

2. A low-cost halogen-containing flame-retardant polypropylene composite material according to claim 1, characterized in that: The weight ratio of talc powder, wollastonite and kaolin is 2:1:

1.

3. The low-cost halogen-containing flame-retardant polypropylene composite material according to claim 1, characterized in that: The polypropylene is one or more of homopolypropylene and copolymer polypropylene.

4. A low-cost halogen-containing flame-retardant polypropylene composite material according to claim 3, characterized in that: The polypropylene has a melt index of 1 to 60 g / 10 min under the test conditions of 230° C. and 2.16 kg.

5. The low-cost halogen-containing flame-retardant polypropylene composite material according to claim 1, characterized in that: The processing aids are coupling agents, anti-dripping agents, dispersants and antioxidants.

6. The low-cost halogen-containing flame-retardant polypropylene composite material according to claim 5, characterized in that: The antioxidant is antioxidant 168 and / or antioxidant 1010, and the dispersant is SG-200A.

7. The low-cost halogen-containing flame-retardant polypropylene composite material according to claim 5, characterized in that: The coupling agent is silane coupling agent KH-550, and the anti-dripping agent is PTFE.

8. A method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material according to any one of claims 1 to 7, characterized in that: After the components are uniformly mixed according to the weight ratio, they are added into a twin-screw extruder for extrusion and granulation to obtain a low-cost halogen-containing flame-retardant polypropylene composite material.

9. The method for preparing a low-cost halogen-containing flame-retardant polypropylene composite material according to claim 8, characterized in that: The mixing is performed using a high-speed mixer, the mixing time is 10 to 15 minutes, and the rotation speed of the high-speed mixer is 300 rpm; the temperature range of each zone of the twin-screw extruder is 160 to 170°C.

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