阅读说明：本技术 一种中高温快速陶瓷化的pe基聚烯烃耐火线缆护套料复合粒子及其制备方法 (Medium-high temperature rapid ceramic PE-based polyolefin fire-resistant cable sheath material composite particle and preparation method thereof ) 是由 严俊 严雪俊 韩延刚 许闽 张旭 方诗彬 刘晋华 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种中高温快速陶瓷化PE基聚烯烃耐火线缆护套料复合粒子及其制备方法,包括以下重量份的原料：叶蜡石微粉30-70份、紫金土5-15份、白炭黑5-15份、含硼磷酸盐玻璃粉10-30份、锂瓷石粉5-15份、PE粉料40-90份、复合表面改性剂1-4份、润滑剂1-20份、阻燃剂1-5份。该陶瓷化PE基聚烯烃耐火线缆护套料复合粒子具有较宽温域下的陶瓷化性能能,能实现在600℃左右开始板结,900℃下实现快速成瓷,瓷体结构致密、不开裂,机械强度高,抗震抗水淋。陶瓷化复合粒子制备工艺简单、原料易得,应用于线缆材料制备时加工性能优异。(The invention discloses a middle-high temperature rapid ceramic PE-based polyolefin fire-resistant cable sheath material composite particle and a preparation method thereof, wherein the composite particle comprises the following raw materials in parts by weight: 30-70 parts of pyrophyllite micro powder, 5-15 parts of gilt clay, 5-15 parts of white carbon black, 10-30 parts of boron-containing phosphate glass powder, 5-15 parts of lithium china stone powder, 40-90 parts of PE powder, 1-4 parts of composite surface modifier, 1-20 parts of lubricant and 1-5 parts of flame retardant. The ceramization PE-based polyolefin fire-resistant cable sheath material composite particle has the ceramization performance in a wider temperature range, can be hardened at about 600 ℃, can be rapidly made into porcelain at 900 ℃, and has the advantages of compact structure, no cracking, high mechanical strength, shock resistance and water spray resistance. The ceramic composite particles have simple preparation process and easily obtained raw materials, and have excellent processing performance when being applied to the preparation of cable materials.)

1. A middle-high temperature rapid ceramic PE-based polyolefin fire-resistant cable sheath material composite particle is characterized in that the composite particle is obtained by banburying, plasticizing and granulating a ceramic powder material and PE modified composite powder;

the ceramic powder material comprises the following raw materials in parts by weight: 30-70 parts of pyrophyllite micro powder, 5-15 parts of gilt clay, 5-15 parts of white carbon black, 10-30 parts of boron-containing phosphate glass powder and 5-15 parts of lithium china stone powder;

the PE modified composite powder comprises the following raw materials in parts by weight: 40-90 parts of PE powder, 1-4 parts of composite surface modifier, 1-20 parts of lubricant, 1-5 parts of stabilizer and 1-5 parts of flame retardant.

2. The middle-high temperature rapid ceramization PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling assisted with spray drying method, and the particle size D of the pyrophyllite micro powder₅₀Is 5-10 μm, D₉₇Is 20-25 μm.

3. The middle-high temperature rapidly-ceramized PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the particle size of the purple kaolin is 1250-₅₀Is 5-10 μm.

4. The middle-high temperature rapid ceramization PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the white carbon black is white carbon black prepared by vapor deposition method, and the particle size D of the white carbon black₉₇Is 1500-.

5. The middle-high temperature rapidly-ceramized PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the particle size of the boron phosphate-containing glass powder is 200-1000 mesh, and the glass transition temperature T is_gThe temperature is 430-500 ℃, and the glass softening temperature is 450-550 ℃.

6. The middle-high temperature rapidly-ceramized PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the particle size D of the lithium china stone powder₉₇500-1000 meshes.

7. The middle-high temperature rapid ceramization PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 1, wherein the composite surface modifier is prepared by compounding a surface coupling agent and an impact modifier according to a weight ratio of 2: 1; the surface coupling agent is one or more of titanate, aluminate and stearic acid, and the impact modifier is ACR-401.

8. The middle-high temperature rapidly-ceramicized PE-based polyolefin fire-resistant cable sheath material composite particle according to claim 1, wherein the lubricant is one or more of polyethylene wax, chlorinated paraffin wax, paraffin wax; the stabilizer is a calcium zinc stabilizer; the flame retardant is one or more of triphenyl phosphate (TPP), triisopropylphenyl phosphate (IPPP) and trioctyl phosphate.

9. The method for preparing the composite particles of the PE-based polyolefin fire-resistant cable sheath material with the medium-high temperature rapid ceramic coating as claimed in any one of claims 1 to 8, characterized by comprising the following steps:

1) weighing pyrophyllite micro powder, violet gold soil, white carbon black, boron-containing phosphate glass powder and lithium china stone powder according to the formula ratio, respectively putting the pyrophyllite micro powder, the violet gold soil, the white carbon black, the boron-containing phosphate glass powder and the lithium china stone powder into a drying oven for drying treatment, putting the dried powders into a high-speed mixer for stirring and mixing to obtain a vitrified powder material;

2) weighing PE powder, a composite surface modifier, a lubricant, a stabilizer and a flame retardant according to the formula ratio, respectively putting the PE powder, the composite surface modifier, the lubricant, the stabilizer and the flame retardant into a high-speed mixing stirrer for high-speed mixing, fully drying the PE powder, and fully and uniformly mixing the PE powder, the composite surface modifier, the lubricant, the stabilizer and the flame retardant to obtain PE modified composite powder;

3) mixing the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the vitrified powder: PE modified composite powder =2: 3-3: 2, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) performing secondary plasticizing extrusion on the mixed material obtained in the step 3) through a double-screw extruder, and performing bracing, air cooling and granulating to obtain the composite particles.

10. The method for preparing the middle-high temperature rapidly-ceramized PE-based polyolefin fire-resistant cable sheath material composite particle as claimed in claim 8, wherein the temperature of the oven drying treatment in step 1) is 105-120 ℃, the drying time is 2-3h, and the stirring time of the high-speed mixer is 15-120 min.

Technical Field

The invention belongs to the technical field of modification composite processing of organic polymers and inorganic powder and application of composite materials thereof, and particularly relates to PE (polyethylene) based polyolefin fire-resistant cable sheath material composite particles capable of being rapidly ceramized at medium and high temperature and a preparation method thereof.

Background

Statistically, the electrical fire accounts for more than one third of the total fire, and the short circuit of the cable is the main cause of the electrical fire. Therefore, the development of the high-performance fireproof and fire-resistant cable technology has wide application prospect and great social and economic benefits. Ceramic fire-resistant cables and ceramic building fireproof plates are novel fireproof materials which are rapidly developed in recent years.

The fire-resistant cable is a special wire and cable product which can ensure that the circuit can maintain normal power supply for more than 90 minutes under the condition that the fire temperature reaches 750-1000 ℃, and the circuit is kept complete and normally electrified. The use of the fire-resistant cable plays a key role in continuous power supply of fire-fighting electric equipment such as automatic alarm devices, automatic fire extinguishing devices, smoke prevention and discharge equipment, evacuation signs and illumination, fire elevators, escape ways and the like in high-rise and super high-rise buildings in fire disasters, and plays an important role in transmitting various control signals and alarm signals in special occasions such as large-capacity power plants, nuclear power plants, underground railways and the like during fire disasters and ensuring illumination, emergency broadcasting and the like of the ways.

At present, the ceramic fire-resistant cable mainly uses silicon rubber materials, however, the ceramic silicon rubber products have the defects of complex process, high cost, poor processing performance, only low-voltage products and the like. Therefore, the preparation process is simple and mature, environment-friendly and low in production cost, and the ceramic polyolefin which can be used for medium and high pressure products is a necessary trend for replacing ceramic silicon rubber materials.

Compared with ceramic silicon rubber materials, ceramic polyolefin materials have two outstanding advantages: firstly, the process of manufacturing the electric wire and the electric cable is simplified, and the efficiency is greatly improved; secondly, the cost can be greatly reduced. However, the ceramic polyolefin material in the prior art still has a plurality of 'neck-blocking' problems which limit the industrial development of the ceramic polyolefin material, especially the problems of high ceramic sintering temperature, poor fire-resistant stability, low mechanical property of a ceramic system and the like are difficult to solve, and the ceramic powder is a core factor which influences the application performance of the terminal composite material. Therefore, the research and development of the high-performance ceramic powder become the core work of the development and application of the ceramic polyolefin material product.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to design and provide the technical scheme of the PE-based polyolefin fire-resistant cable sheath material composite particles capable of being rapidly ceramized at medium and high temperature and the preparation method thereof.

The polyolefin fire-resistant cable sheath material capable of being rapidly ceramized at medium and low temperatures is prepared by taking polyolefin resin as an organic base material, adding functional filler mainly comprising high-performance ceramization powder, and carrying out mixing, plasticizing and granulating. The ceramic polyolefin cable sheath material disclosed by the invention can generate a hard ceramic hard shell under the condition of flame burning or high temperature, the hard shell does not crack, melt or drip, can resist water spraying and mechanical vibration, has a very good heat insulation and fire insulation effect, can ensure smooth control of electric power and information under the condition of fire, and further strives for precious time for personnel escape, property transfer and fire rescue.

The invention is realized by the following technical scheme:

the PE-based polyolefin fire-resistant cable sheath material composite particle capable of being rapidly ceramized at medium and high temperatures is characterized in that the composite particle is obtained by banburying, plasticizing and granulating a ceramization powder material and PE modified composite powder;

the ceramic powder material comprises the following raw materials in parts by weight: 30-70 parts of pyrophyllite micro powder, 5-15 parts of gilt clay, 5-15 parts of white carbon black, 10-30 parts of boron-containing phosphate glass powder and 5-15 parts of lithium china stone powder;

the PE modified composite powder comprises the following raw materials in parts by weight: 40-90 parts of PE powder, 1-4 parts of composite surface modifier, 1-20 parts of lubricant, 1-5 parts of stabilizer and 1-5 parts of flame retardant.

Further, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by adopting wet ball milling and spray drying, and the granularity D of the pyrophyllite micro powder₅₀Is 5-10 μm, D₉₇Is 20-25 μm.

Further, the granularity of the purple gold soil is 1250-1500 meshes, D₅₀Is 5-10 μm.

Further, the white carbon black is prepared by adopting a vapor deposition method, and the granularity D of the white carbon black₉₇Is 1500-.

Further, the granularity of the boron-containing phosphate glass powder is 200-1000 meshes, and the glass transition temperature T_gThe temperature is 430-500 ℃, and the glass softening temperature is 450-550 ℃.

Further, the particle size D of the lithium china stone powder₉₇500-1000 meshes.

Further, the composite surface modifier is prepared by compounding a surface coupling agent and an impact modifier according to the weight ratio of 2: 1; the surface coupling agent is one or more of titanate, aluminate and stearic acid, and the impact modifier is ACR-401.

Further, the lubricant is one or more of polyethylene wax, chlorinated paraffin and paraffin; the stabilizer is a calcium zinc stabilizer; the flame retardant is one or more of triphenyl phosphate (TPP), triisopropylphenyl phosphate (IPPP) and trioctyl phosphate.

The preparation method of the PE-based polyolefin fire-resistant cable sheath material composite particles capable of being rapidly ceramized at the medium and high temperature is characterized by comprising the following steps of:

1) weighing pyrophyllite micro powder, violet gold soil, white carbon black, boron-containing phosphate glass powder and lithium china stone powder according to the formula ratio, respectively putting the pyrophyllite micro powder, the violet gold soil, the white carbon black, the boron-containing phosphate glass powder and the lithium china stone powder into a drying oven for drying treatment, putting the dried powders into a high-speed mixer for stirring and mixing to obtain a vitrified powder material;

2) weighing PE powder, a composite surface modifier, a lubricant, a stabilizer and a flame retardant according to the formula ratio, respectively putting the PE powder, the composite surface modifier, the lubricant, the stabilizer and the flame retardant into a high-speed mixing stirrer for high-speed mixing, fully drying the PE powder, and fully and uniformly mixing the PE powder, the composite surface modifier, the lubricant, the stabilizer and the flame retardant to obtain PE modified composite powder;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder =2: 3-3: 2, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) performing secondary plasticizing extrusion on the mixed material obtained in the step 3) through a double-screw extruder, and performing bracing, air cooling and granulating to obtain the composite particles.

Further, the temperature of the drying treatment in the drying oven in the step 1) is 105-.

Compared with the prior art, the invention has the following beneficial effects:

firstly, dispersed pyrophyllite powder prepared by wet ball milling and spray drying is used as a main ceramic medium, wherein the pyrophyllite is mainly presented as nanoparticles in two-dimensional directions, and is shown in figure 1. The pyrophyllite with the nanoscale in the two-dimensional direction improves the rapid ceramic forming property in the sintering process and the mechanical property of a terminal sintering product.

And secondly, according to the particle size effect and the heat transfer efficiency of ceramic sintering, the purple gold soil and the fumed silica are preferably selected as composite ceramic skeleton materials, the granularity of the filler is further refined, and the effect of sintering the ceramic is obviously improved.

Thirdly, the sintering temperature of the traditional ceramic is higher and usually needs more than 1000 ℃, and the boron-containing phosphate glass powder and the lithium china stone powder fluxing agent are selected in the application, so that the sintering and molding of a ceramic system at a lower temperature are promoted, and a compact protective shell is formed.

Finally, the ceramic powder has stable property at normal temperature, can be hardened at about 600 ℃ when meeting high temperature, can realize rapid ceramic formation at 850-900 ℃, and has compact structure, no cracking and high strength.

Drawings

FIG. 1 is an SEM photograph of the powder of the pyrophyllite raw material after grinding;

FIG. 2 is a sheet made of a ceramified composite.

Detailed Description

The present invention will be further described with reference to the following specific examples to better understand the technical solution.

Example 1

The composite particles of the PE-based polyolefin fire-resistant cable sheath material which is rapidly ceramic at medium and high temperature are obtained through the following steps:

1) weighing 50 parts of a pyrophyllite micro powder and purple gold soil mixed material (the weight ratio of the pyrophyllite micro powder to the purple gold soil is 3: 1), 10 parts of white carbon black, 15 parts of boron-containing phosphate glass powder and 5 parts of lithium porcelain stone powder, putting the mixture into a drying box at the temperature of 105-120 ℃ for drying for 2-3h, putting the dried powder into a high-speed mixer for high-speed stirring and mixing for 15-120min, and obtaining a porcelain powder material;

in the step, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling and spray drying, and has a particle size D₅₀About 7.85 μm, D₉₇22.45 μm; the particle size of the zijin soil is 10.45 mu m, D₅₀About 8.40 μm; the white carbon black is prepared by a vapor deposition method and has the granularity D₉₇8.45 μm; the boron-containing phosphate glass powder has a particle size of about 32.20 mu m and a glass transition temperature T_gThe temperature is 430-550 ℃, and the glass softening temperature is 450-550 ℃; lithium porcelain stone powder granularity D₉₇About 27.34 μm;

2) 55 parts of PE powder, 2 parts of a composite surface modifier (surface coupling agent: 1) impact modifier =2: 1), 3 parts of flame retardant, 12 parts of lubricant and 3 parts of stabilizer are mixed at a high speed in a high-speed mixer, so that the composite material system is fully dried and fully and uniformly mixed with the flame retardant and the lubricant to obtain PE modified composite powder;

in the step, the surface coupling agent is stearic acid; the impact modifier is ACR-401; the flame retardant is TPP; the stabilizer is calcium zinc stabilizer; the lubricant is polyethylene wax;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder =2: 3, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) and performing secondary plasticizing extrusion on the mixed material through a double-screw extruder, and performing bracing and air cooling granulation to prepare the composite particles.

Example 2

The composite particles of the PE-based polyolefin fire-resistant cable sheath material which is rapidly ceramic at medium and high temperature are obtained through the following steps:

1) weighing 50 parts of a pyrophyllite micro powder and purple gold soil mixed material (the weight ratio of the pyrophyllite micro powder to the purple gold soil is 3: 1), 15 parts of white carbon black, 10 parts of boron-containing phosphate glass powder and 10 parts of lithium porcelain stone powder, putting the mixture into a drying box at the temperature of 105-120 ℃ for drying for 2-3h, putting the dried powder into a high-speed mixer for high-speed stirring and mixing for 15-120min, and obtaining a porcelain powder material;

in the step, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling and spray drying, and has a particle size D₅₀8.04 μm, D₉₇21.89 μm; the particle size of the zijin soil is 10.46 mu m, D₅₀8.35 μm; the white carbon black is prepared by a vapor deposition method and has the granularity D₉₇8.25 μm; the granularity of the boron-containing phosphate glass powder is 32.42 mu m, and the glass transition temperature T_gThe temperature is 430-550 ℃, and the glass softening temperature is 450-550 ℃; lithium porcelain stone powder granularity D₉₇26.49 μm;

2) 55 parts of PE powder, 2 parts of a composite surface modifier (surface coupling agent: impact modifier =2: 1), 3 parts of flame retardant, 12 parts of lubricant and 3 parts of stabilizer are mixed at high speed in a high-speed mixer, so that the composite material system is fully dried and fully and uniformly mixed with the stabilizer and the lubricant to obtain PE modified composite powder;

in the step, the surface coupling agent is stearic acid; the impact modifier is ACR-401; the flame retardant is TPP and IPPP; the stabilizer is calcium zinc stabilizer; the lubricant is a mixture of polyethylene wax and paraffin wax;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder = 4: 3, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) and performing secondary plasticizing extrusion on the mixed material through a double-screw extruder, and performing bracing and air cooling granulation to prepare the composite particles.

Example 3

The composite particles of the PE-based polyolefin fire-resistant cable sheath material which is rapidly ceramic at medium and high temperature are obtained through the following steps:

1) weighing 50 parts of a pyrophyllite micro powder and purple gold soil mixed material (the weight ratio of the pyrophyllite micro powder to the purple gold soil is 3: 1), 5 parts of white carbon black, 10 parts of boron-containing phosphate glass powder and 15 parts of lithium porcelain stone powder, putting the mixture into a drying box at the temperature of 105-120 ℃ for drying for 2-3h, putting the dried powder into a high-speed mixer for high-speed stirring and mixing for 15-120min, and obtaining a porcelain powder material;

in the step, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling and spray drying, and has a particle size D₅₀About 7.57 μm, D₉₇22.25 μm; the particle size of the zijin soil is 10.75 mu m, D₅₀About 8.30 μm; the white carbon black is prepared by a vapor deposition method and has the granularity D₉₇8.72 μm; the particle size of the boron-containing phosphate glass powder is about 31.89 mu m, and the glass transition temperature T_gThe temperature is 430-550 ℃, and the glass softening temperature is 450-550 ℃; lithium porcelain stone powder granularity D₉₇About 27.14 μm;

2) 55 parts of PE powder, 2 parts of a composite surface modifier (surface coupling agent: 1) impact modifier =2: 1), 3 parts of flame retardant, 12 parts of lubricant and 3 parts of stabilizer are mixed at a high speed in a high-speed mixer, so that the composite material system is fully dried and fully and uniformly mixed with the flame retardant and the lubricant to obtain PE modified composite powder;

in the step, the surface coupling agent is stearic acid; the impact modifier is ACR-401; the flame retardant is trioctyl phosphate; the stabilizer is calcium zinc stabilizer; the lubricant is a mixture of chlorinated paraffin and paraffin;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder =2: 3, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) and performing secondary plasticizing extrusion on the mixed material through a double-screw extruder, and performing bracing and air cooling granulation to prepare the composite particles.

Example 4

The composite particles of the PE-based polyolefin fire-resistant cable sheath material which is rapidly ceramic at medium and high temperature are obtained through the following steps:

1) weighing 50 parts of a pyrophyllite micro powder and purple gold soil mixed material (the weight ratio of the pyrophyllite micro powder to the purple gold soil is 4: 1), 10 parts of white carbon black, 30 parts of boron-containing phosphate glass powder and 15 parts of lithium porcelain stone powder, putting the mixture into a drying box at the temperature of 105-120 ℃ for drying for 2-3h, putting the dried powder into a high-speed mixer for high-speed stirring and mixing for 15-120min, and obtaining a porcelain powder material;

in the step, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling and spray drying, and has a particle size D₅₀About 7.55 μm, D₉₇21.75 μm; the particle size of the zijin soil is 10.55 mu m, D₅₀About 8.36 μm; the white carbon black is prepared by a vapor deposition method and has the granularity D₉₇8.78 μm; the particle size of the boron-containing phosphate glass powder is about 31.79 mu m, and the glass transition temperature T_gThe temperature is 430-550 ℃, and the glass softening temperature is 450-550 ℃; lithium porcelain stone powder granularity D₉₇About 27.18 μm;

2) 70 parts of PE powder, 2 parts of a composite surface modifier (surface coupling agent: 1) impact modifier =2: 1), 3 parts of flame retardant, 12 parts of lubricant and 3 parts of stabilizer are mixed at a high speed in a high-speed mixer, so that the composite material system is fully dried and fully and uniformly mixed with the flame retardant and the lubricant to obtain PE modified composite powder;

in the step, the surface coupling agent is stearic acid; the impact modifier is ACR-401; the flame retardant is TPP; the stabilizer is calcium zinc stabilizer; the lubricant is polyethylene wax;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder = 3: 2, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) and performing secondary plasticizing extrusion on the mixed material through a double-screw extruder, and performing bracing and air cooling granulation to prepare the composite particles.

Example 5

The composite particles of the PE-based polyolefin fire-resistant cable sheath material which is rapidly ceramic at medium and high temperature are obtained through the following steps:

1) weighing 50 parts of a pyrophyllite micro powder and purple gold soil mixed material (the weight ratio of the pyrophyllite micro powder to the purple gold soil is 5: 1), 10 parts of white carbon black, 15 parts of boron-containing phosphate glass powder and 5 parts of lithium porcelain stone powder, putting the mixture into a drying box at the temperature of 105-120 ℃ for drying for 2-3h, putting the dried powder into a high-speed mixer for high-speed stirring and mixing for 15-120min, and obtaining a porcelain powder material;

in the step, the pyrophyllite micro powder is dispersed pyrophyllite micro powder prepared by wet ball milling and spray drying, and has a particle size D₅₀About 7.45 μm, D₉₇21.78 μm; the particle size of the zijin soil is 10.56 mu m, D₅₀About 8.26 μm; the white carbon black is prepared by a vapor deposition method and has the granularity D₉₇8.70 μm; the boron-containing phosphate glass powder has a particle size of about 31.74 mu m and a glass transition temperature T_gThe temperature is 430-550 ℃, and the glass softening temperature is 450-550 ℃; lithium porcelain stone powder granularity D₉₇About 27.22 μm;

2) 40 parts of PE powder, 2 parts of a composite surface modifier (surface coupling agent: 1) impact modifier =2: 1), 5 parts of flame retardant, 20 parts of lubricant and 5 parts of stabilizer are mixed at a high speed in a high-speed mixer, so that the composite material system is fully dried and fully and uniformly mixed with the flame retardant and the lubricant to obtain PE modified composite powder;

in the step, the surface coupling agent is stearic acid; the impact modifier is ACR-401; the flame retardant is TPP; the stabilizer is calcium zinc stabilizer; the lubricant is a mixture of polyethylene wax and chlorinated paraffin;

3) carrying out vitrification powder on the vitrified powder material obtained in the step 1) and the PE modified composite powder obtained in the step 2) according to the mass ratio: PE modified composite powder =2: 3, placing the mixture in an internal mixer for internal mixing and plasticizing until the mixture is uniformly mixed to obtain a mixed material;

4) and performing secondary plasticizing extrusion on the mixed material through a double-screw extruder, and performing bracing and air cooling granulation to prepare the composite particles.

Comparative example: the commercial ceramic polyolefin composite particles are used as comparative examples (the particles are subjected to internal mixing and plasticizing and then are extruded by a screw to be granulated).

The SEM photograph of the powder after grinding the pyrophyllite starting material in each of the above examples is shown in fig. 1, and the sheet finally obtained is shown in fig. 2.

The composite particles prepared from examples 1-5 above and the comparative commercially available ceramized polyolefin composite particles were subjected to performance tests under the same environmental conditions, and the test results are shown in table 1.

Table 1: performance test results of the composite particles obtained in each of examples and comparative examples

The invention is funded by an open topic fund of the technical research center of non-metal mining engineering in Zhejiang province.