阅读说明：本技术 一种高熔指无卤阻燃聚丙烯材料及其制备方法 (High-melt-index halogen-free flame-retardant polypropylene material and preparation method thereof ) 是由 肖雄 胡爽 叶文 许肖丽 林倬仕 李平阳 尹亮 于 2019-09-02 设计创作，主要内容包括：本发明涉及高熔指无卤阻燃聚丙烯材料及其制备方法,包括以下组分及重量份含量：聚丙烯基材60-80份；焦磷酸哌嗪0.1-20份；表面改性聚磷酸铵0.1-20份；三聚氰胺或其盐0-10份；偶联剂0.1-3份；相容剂0.1-3份；抗氧剂0.1-3份；光稳定剂0.1-3份；白油0.1-1份。按重量份称取原料,将烘干的聚丙烯基材和白油在双运动混合机中预混合5-8分钟,实现均匀混合；按重量份再加入焦磷酸哌嗪、表面改性聚磷酸铵、三聚氰胺或其盐、偶联剂、相容剂、抗氧剂、光稳定剂,继续混合5-8分钟,得到均匀混合物；置于双螺杆挤出机加料口,物料经螺杆混炼挤出后,从模头挤出。与现有技术相比,本发明无卤聚丙烯材料能有效解决传统三嗪成炭剂体系高污染、阻燃剂与基体相容性差、阻燃效率低等问题。(The invention relates to a high-melt-index halogen-free flame-retardant polypropylene material and a preparation method thereof, wherein the high-melt-index halogen-free flame-retardant polypropylene material comprises the following components in parts by weight: 60-80 parts of a polypropylene base material; 0.1-20 parts of piperazine pyrophosphate; 0.1-20 parts of surface modified ammonium polyphosphate; 0-10 parts of melamine or melamine salt; 0.1-3 parts of a coupling agent; 0.1-3 parts of a compatilizer; 0.1-3 parts of antioxidant; 0.1-3 parts of light stabilizer; 0.1-1 part of white oil. Weighing the raw materials according to the weight parts, premixing the dried polypropylene base material and the white oil in a double-motion mixer for 5-8 minutes, and realizing uniform mixing; adding piperazine pyrophosphate, surface modified ammonium polyphosphate, melamine or salt thereof, a coupling agent, a compatilizer, an antioxidant and a light stabilizer according to the weight parts, and continuously mixing for 5-8 minutes to obtain a uniform mixture; placing the mixture into a feed inlet of a double-screw extruder, mixing and extruding the mixture by a screw, and extruding the mixture from a die head. Compared with the prior art, the halogen-free polypropylene material can effectively solve the problems of high pollution, poor compatibility of a flame retardant and a matrix, low flame retardant efficiency and the like of the traditional triazine charring agent system.)

1. The high-melt-index halogen-free flame-retardant polypropylene material is characterized by comprising the following components in parts by weight:

2. the high-melt index halogen-free flame-retardant polypropylene material according to claim 1, which comprises the following components in parts by weight:

3. the high-melt index halogen-free flame retardant polypropylene material according to claim 1 or 2, wherein the polypropylene base material is one of homo polypropylene or co-polypropylene material.

4. The high melt index halogen-free flame retardant polypropylene material of claim 3, wherein the polypropylene substrate is one of the designations K8303, K1105, K8003, K1505, T300, 1600D.

5. The high-melt index halogen-free flame-retardant polypropylene material as claimed in claim 1 or 2, wherein the piperazine pyrophosphate has a particle size D₅₀＜20μm、D₉₀Less than 50 μm, degree of polymerization greater than 20, and P content>23 wt% piperazine pyrophosphate (poly) phosphate.

6. The high-melt index halogen-free flame-retardant polypropylene material of claim 5, wherein the piperazine pyrophosphate is piperazine pyrophosphate with P content of 20 wt% -25 wt% and degree of polymerization of more than 20.

7. The high-melt index halogen-free flame retardant polypropylene material according to claim 1 or 2, wherein the surface modified ammonium polyphosphate is an ammonium polyphosphate microencapsulated by a silane coupling agent; the ammonium polyphosphate is a crystal phase II type ammonium polyphosphate with the whiteness of more than 95, the P content of 30-32 wt% and the polymerization degree of more than 1000.

The general formula of the adopted silane coupling agent is RSiX₃Wherein R represents a hydrophobic group including an amino group, a vinyl group or an epoxy group; x represents a hydrolysable group including an alkoxy group: including gamma-aminopropyltriethoxysilane (KH550), gamma-glycidoxypropyltrimethoxysilane (KH560) or gamma- (methacryloyloxy) propyltrimethoxysilane (KH 570).

8. High melt index halogen free flame retardant polypropylene material according to claim 1 or 2, wherein the melamine or salt thereof is melamine, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine cyanurate, melam polyphosphate, melem polyphosphate and/or melon polyphosphate and/or a melamine condensation product.

9. The high-melt index halogen-free flame retardant polypropylene material according to claim 1 or 2, wherein the coupling agent is selected from one or two of aluminate coupling agent or titanate coupling agent;

the compatilizer is selected from any one of maleic anhydride grafted ethylene-vinyl acetate high polymer, acrylic acid grafted ethylene-vinyl acetate high polymer, maleic anhydride grafted ethylene-octene copolymer, maleic anhydride grafted styrene-butadiene block copolymer, acrylic acid grafted ethylene-octene copolymer or maleic anhydride grafted isoprene-styrene block copolymer;

the antioxidant is any one of tris (2, 4-di-tert-butylphenol) and bis (3, 5-tertiary butyl-4-hydroxyphenyl) thioether;

the light stabilizer is selected from one or two of salicylate, benzophenone, benzotriazole, substituted acrylonitrile, triazine and organic complex light stabilizers.

The white oil is a mixture of normal isoparaffin of C10-C31, and is used for reducing the temperature of the auxiliary agent and the matrix material in the twin-screw extruder, which is increased due to friction.

10. The preparation method of the high-melt index halogen-free flame retardant polypropylene material according to claim 1 or 2, characterized by comprising the following steps:

(1) weighing the raw materials according to the parts by weight, premixing the dried polypropylene base material and the white oil in a double-motion mixer for 5-8 minutes, wherein the rotating speed of a machine body of the double-motion mixer is 15-30rpm, the rotating speed of an internal blade is 20-40rpm, and the inclination angle of the machine body is 0 degree, so that uniform mixing is realized;

(2) adding piperazine pyrophosphate, surface modified ammonium polyphosphate, melamine or salt thereof, a coupling agent, a compatilizer, an antioxidant and a light stabilizer according to the weight parts, continuously mixing for 5-8 minutes at the rotating speed of a double-motion mixer body of 30-40rpm, the rotating speed of internal blades of 30-45rpm and the inclination angle of the mixer body of 0 DEG to obtain a uniform mixture;

(3) and (3) placing the mixture prepared in the step (2) in a feed inlet of a double-screw extruder, mixing and extruding the materials by a screw, and extruding the materials from a die head.

11. The method for preparing the high-melt index halogen-free flame retardant polypropylene material according to claim 10, wherein the double-motion mixer in the step (1) is a cross-rotating shaft double-cone co-directional double-motion mixer, and the internal structure of the double-motion mixer is a full-size blade set;

the surface modified ammonium polyphosphate in the step (2) is obtained by the following method: adding 100 parts by weight of ammonium polyphosphate into a high-speed mixer, heating to 100-130 ℃, continuously dropping 2-4 parts of KH550, KH560 or KH570, continuously reacting at high speed for 10-20 minutes, controlling the rotating speed at 50-80rpm, and obtaining KH550 surface modified ammonium polyphosphate (APP-50), KH560 surface modified ammonium polyphosphate (APP-60) and KH570 surface modified ammonium polyphosphate (APP-70);

the double-screw extruder in the step (3) is a 20-type co-rotating double-screw extruder and comprises a melting section, a conveying section, a mixing section, a homogenizing section and a metering section which are sequentially arranged; wherein the temperature from the melting section to the metering section is as follows: 180 ℃ 190 ℃, 200 ℃ 220 ℃ and 200 ℃ 230 ℃; the main machine rotating speed of the double-screw extruder is 200-350 rpm; the feeding frequency is 10-15 Hz.

12. The preparation method of the high-melt-index halogen-free flame-retardant polypropylene material as claimed in claim 11, wherein the melting section of the twin-screw extruder is provided with a small-lead conveying screw, the conveying section is provided with a large-lead conveying screw, the mixing section is provided with a structure of sequentially overlapping 45 °, 60 ° and 90 ° shearing screws, the homogenizing section is provided with a structure of overlapping 45 ° or 60 ° shearing screws and the small-lead conveying screw, and the metering section is provided with a structure of overlapping the large-lead conveying screw and a reverse screw;

a vacuum port is arranged between the mixing section and the homogenizing section, and the vacuum pressure is 20-40 MPa.

Technical Field

The invention belongs to the technical field of flame-retardant materials, and particularly relates to a high-melt-index halogen-free flame-retardant polypropylene material and a preparation method thereof.

Background

Polypropylene (PP) is one of the most rapidly developed general-purpose plastics, and has the advantages of excellent impact resistance, acid and alkali resistance, corrosion resistance, temperature resistance, low density and excellent mechanical properties. The preparation raw materials mainly come from petroleum byproducts, are low in price, and the excellent processing performance of the raw materials enables the raw materials to become excellent substitutes for products such as wood, ceramics, metal, glass and the like, and the raw materials are widely applied to the fields of electronic appliances, packaging, automobile parts, textiles, household appliances, buildings and the like. In particular, the polypropylene material with higher fluidity has more remarkable advantages in the preparation of larger products. The larger molded part has longer material flow channel and larger injection pressure, thus the higher requirement is put on the melt index of polypropylene. Particularly in the automotive and appliance industries.

The polypropylene is polymerized by propylene under certain conditions, the main chain in the molecular structure is a combustible hydrocarbon chain, and the side chain contains unsaturated hydrocarbon elements, so that the polypropylene has great fire hazard. Meanwhile, the Limiting Oxygen Index (LOI) of polypropylene is only 17-18%, the polypropylene has no level in vertical combustion, and the polypropylene has large combustion flame, is easy to melt and drip, has high heat productivity and is very easy to cause continuous fire.

Typically, multiple additives are used simultaneously, each of which undertakes one task. For example antioxidants and stabilizers, whereby the plastic can withstand processing without chemical damage and then have long-term stability to external influences, such as heat, uv light, weathering and oxygen. In addition to improving the flow behavior, lubricants avoid excessively strong adhesion of the plastic melt to the machine parts and serve as dispersing agents for pigments, fillers and reinforcing agents.

The most common polypropylene halogen-free flame retardant system is the compounding of triazine charring agent (CFA) and ammonium polyphosphate system, however, the triazine charring agent involves a large amount of cyanuric chloride in the synthesis process, the process pollution is serious, and a large amount of toxic waste liquid is generated. The invention relates to a preparation method of a triazine charring agent in the invention patent 'a macromolecule triazine charring agent and a preparation method thereof' (CN 20120209288.4). although a triazine charring agent with a novel structure is synthesized, the reaction process is still complicated from cyanuric chloride, and chlorine-containing toxic waste liquid is inevitably generated and needs to be subjected to post-treatment.

Meanwhile, in the traditional APP and CFA flame-retardant system, as the CFA is a micromolecular substance, strong polarity action and interface action force exist in the mixing process of the CFA and the material, the compatibility between the CFA and the polypropylene material is poor, and the melting of the material is seriously influenced, so that the traditional APP and CFA flame-retardant system has great limitation on the preparation of larger products. Particularly, for the copolymerized polypropylene with higher melt index, the influence on the material mechanics and the fluidity is more obvious. The APP/CFA system is mainly a char-forming flame-retardant mechanism, and has a good effect on the homo-polypropylene, but in the co-polypropylene, the effect is not obvious. Therefore, modifications and alternatives to this system are constantly sought. It has been found that the gas phase flame retardant mechanism is more effective for the polypropylene copolymer. Melamine and its salt have high N content, are obvious gas phase flame retardants, can release a large amount of incombustible gas in the combustion process of the material, dilute the concentration of the combustible gas in the gas phase, achieve the goal of inhibiting combustion. Therefore, with the growing awareness of environmental protection in recent years, many researchers are actively searching for alternatives to CFA.

The 'trinity' flame retardant has been proved to have higher flame retardant effect, and particularly, the complementary synergy of the compounded phosphorus-containing or nitrogen-containing flame retardant is carried out according to the P/N ratio of the 'trinity' flame retardant, so that the flame retardant effect can be better played. Also, the APP/CFA system has strong interfacial force with polypropylene, so that the flame retardant is easy to peel off from the material. The 'three-in-one' flame retardant and the complex system thereof are assisted by a special processing preparation process after effective surface treatment is carried out, so that the dispersibility and the flame retardant effect of the flame retardant on a substrate can be greatly improved. Therefore, the material with better fluidity and better melt index can be prepared, and particularly, the advantages are remarkable for products with larger products. Therefore, aiming at the expansion type flame retardant mechanism, the novel 'three-in-one' flame retardant is increasingly paid more and more attention by the industry. For compatibility between the flame retardant system and the matrix material, surface modification or synthesis with native macromolecules is generally performed to reduce surface polarity and increase compatibility. Aiming at the gas-phase flame retardant mechanism, the research of exploring the combined action of an acid source, a carbon source and a gas source and embodying the optimal synergistic effect is also accelerated continuously. Therefore, the research on the substitute of the traditional APP/CFA system and the overcoming of the water absorption defect and the environmental pollution of the system are the subjects of future development.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a high-melt-index halogen-free flame-retardant polypropylene material with better flame-retardant effect and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme: the high-melt-index halogen-free flame-retardant polypropylene material is characterized by comprising the following components in parts by weight:

further preferably, the composition comprises the following components in parts by weight:

preferably, the polypropylene substrate is one of homo-polypropylene or co-polypropylene materials.

Further preferably:

the grade of the homo-polypropylene or co-polypropylene material is one of K8303 (limited Beijing Yanshan petrochemical company), K1105 (limited Beijing Yanshan petrochemical company), K8003 (limited Shanghai petrochemical company), K1505 (limited Beijing Yanshan petrochemical company), T300 (limited Shanghai petrochemical company) and 1600D (limited Taiwan plastic industry).

The piperazine pyrophosphate has a particle size D₅₀＜20μm、D₉₀Less than 50 μm, degree of polymerization greater than 20, P content>23 wt% piperazine pyrophosphate (poly) phosphate.

Further preferably: the pyrophosphoric piperazine is pyro (poly) phosphoric piperazine with P content of 23-25 wt% and polymerization degree greater than 20.

Piperazine pyrophosphate (poly) phosphate was synthesized by the prior art (method disclosed in patent publication No. CN102304100A), and was prepared by the following synthetic route:

the preparation method of the piperazine pyrophosphate (poly) phosphate comprises the following specific steps:

(1) introducing nitrogen into a reactor with a stirring paddle for 0.5-1 hour, evacuating the internal air, then weighing phosphoric acid and piperazine phosphate (the molar ratio is n phosphoric acid: n piperazine phosphate is 1:1), adding into the reactor, heating in a water bath to 80-100 ℃, continuously introducing nitrogen for protection, starting stirring, the stirring speed is 40-60rpm, the reaction time is 2-3 hours, cooling to room temperature after the reaction is completed, filtering, drying and crushing to obtain white intermediate product piperazine diphosphate;

(2) weighing piperazine diphosphate and phosphoric acid (the molar ratio is that the piperazine diphosphate to the n-phosphoric acid is 1:1), adding the piperazine diphosphate and the phosphoric acid into a reactor, heating the mixture in an oil bath to 180-.

The surface modified ammonium polyphosphate is ammonium polyphosphate coated by a silane coupling agent in a microcapsule way; the ammonium polyphosphate is a crystal phase II type ammonium polyphosphate with the whiteness of more than 95, the P content of 30-32 wt% and the polymerization degree of more than 1000, and the trade mark is APP-II (Zhejiang Xuanshen Smoke elimination Co., Ltd.).

The general formula of the adopted silane coupling agent is RSiX₃Wherein R represents a hydrophobic group including an amino group, a vinyl group or an epoxy group; x represents a hydrolysable group including an alkoxy group: including gamma-aminopropyltriethoxysilane (KH550), gamma-glycidoxypropyltrimethoxysilane (KH560) or gamma- (methacryloyloxy) propyltrimethoxysilane (KH 570).

After the silane coupling agent and the flame retardant react, the silane coupling agent can be grafted on the surface of the flame retardant, so that a large number of hydrophobic groups are formed on the surface of the flame retardant, the moisture absorption defect of the flame retardant is greatly improved, and the compatibility of the flame retardant and a high polymer material is increased.

Further preferably:

the grade of the gamma-aminopropyl triethoxysilane (KH550) is KH550 (limited chemical products of Henan Feng Conn Co.);

the gamma-glycidoxypropyltrimethoxysilane (KH560) is KH560 (Henan Feng chemical products, Co., Ltd.);

the gamma- (methacryloyloxy) propyl trimethoxy silane (KH570) is KH570 (Henan Feng chemical products, Ltd.).

The melamine or its salt is melamine, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine cyanurate, melam polyphosphate, melem polyphosphate and/or cyanuramide polyphosphate and/or a melamine condensation product.

Further preferably:

the melamine or the salt thereof is one of melamine, melamine cyanurate, dimelamine phosphate, melamine pyrophosphate and melamine polyphosphate.

The coupling agent is selected from one or two of aluminate coupling agent or titanate coupling agent;

further preferably:

the aluminate coupling agent is of the brand QX-131 or QX-132 (the full-scope chemical company, Ltd.);

the titanate coupling agent is of the brand number DL-411 or DL-412 (Fujian Yuan Ke new type fine materials Limited company).

The compatilizer is selected from any one of maleic anhydride grafted ethylene-vinyl acetate high polymer, acrylic acid grafted ethylene-vinyl acetate high polymer, maleic anhydride grafted ethylene-octene copolymer, maleic anhydride grafted styrene-butadiene block copolymer, acrylic acid grafted ethylene-octene copolymer or maleic anhydride grafted isoprene-styrene block copolymer;

the antioxidant is any one of tris (2, 4-di-tert-butylphenol) and bis (3, 5-tertiary butyl-4-hydroxyphenyl) thioether;

further preferably:

the antioxidant is any one of LENOX 1010 (LeNOX New materials Co., Ltd.) or LENOX 1076 (LeNOX New materials Co., Ltd.).

The light stabilizer is selected from one or two of salicylate, benzophenone, benzotriazole, substituted acrylonitrile, triazine and organic complex light stabilizers.

Further preferably:

the salicylate light stabilizer is light stabilizer 508 (Beijing Tiangang assistant, LLC);

the benzophenone light stabilizer is light stabilizer 788 (Beijing Tiangang assistant, Ltd.);

the benzotriazole light stabilizer is light stabilizer 292 (Beijing Tiangang assistant, LLC);

the substituted acrylonitrile-based light stabilizer is light stabilizer 3808 (Beijing Tiangang assistant limited responsibility company);

the triazine light stabilizer is light stabilizer 770 (Beijing Tiangang assistant, LLC);

the organic complex light stabilizer is light stabilizer 783 (Beijing Tiangang assistant, Ltd.).

Preferably, the white oil is a mixture of normal isoparaffins of C16-C31.

Further preferably:

the white oil is white oil with the kinematic viscosity of 10.0-15.0.

The preparation method of the high-melt-index halogen-free flame-retardant polypropylene material is characterized by comprising the following steps of:

(1) weighing the raw materials according to the parts by weight, pre-mixing the dried polypropylene base material and the white oil in a double-motion mixer for 5-8 minutes to reduce the temperature raised by friction in the preparation process of the materials, wherein the rotating speed of a machine body of the double-motion mixer is 15-30rpm, the rotating speed of internal blades is 20-40rpm, and the inclination angle of the machine body is 0 degree, so that uniform mixing is realized;

(2) adding piperazine pyrophosphate, surface modified ammonium polyphosphate, melamine or salt thereof, a coupling agent, a compatilizer, an antioxidant and a light stabilizer according to the weight parts, continuously mixing for 5-8 minutes at the rotating speed of a double-motion mixer body of 30-40rpm, the rotating speed of internal blades of 30-45rpm and the inclination angle of the body of 0 DEG to obtain a uniform mixture;

(3) and (3) placing the mixture prepared in the step (2) in a feed inlet of a double-screw extruder, mixing and extruding the materials by a screw, and extruding the materials from a die head.

Preferably, the double-motion mixer in the step (1) is a cross-rotating-shaft double-cone same-direction double-motion mixer, and the internal structure of the double-motion mixer is a full-size blade set;

the surface modified ammonium polyphosphate in the step (2) is obtained by the following method: adding 100 parts by weight of ammonium polyphosphate into a high-speed mixer, heating to 100-130 ℃, continuously dropping 2-4 parts of KH550, KH560 or KH570, continuously reacting at high speed for 10-20 minutes, controlling the rotating speed at 50-80rpm, and obtaining KH550 surface modified ammonium polyphosphate (APP-50), KH560 surface modified ammonium polyphosphate (APP-60) and KH570 surface modified ammonium polyphosphate (APP-70);

the double-screw extruder in the step (3) is a 20-type co-rotating double-screw extruder and comprises a melting section, a conveying section, a mixing section, a homogenizing section and a metering section which are sequentially arranged; wherein the temperature from the melting section to the metering section is as follows: 180 ℃ 190 ℃, 200 ℃ 220 ℃ and 200 ℃ 230 ℃; the main machine rotating speed of the double-screw extruder is 200-350 rpm; the feeding frequency is 10-15 Hz.

Further preferably, the melting section of the twin-screw extruder adopts a small-lead conveying screw thread, the conveying section adopts a large-lead conveying screw thread, the mixing section adopts a structure of sequentially overlapping 45-, 60-and 90-degree shearing screw threads, the homogenizing section adopts a structure of overlapping 45-or 60-degree shearing screw threads and the small-lead conveying screw threads, and the metering section adopts a structure of overlapping the large-lead conveying screw threads and the reverse screw threads;

a vacuum port is arranged between the mixing section and the homogenizing section, and the vacuum pressure is 20-40 MPa.

The invention aims to prepare a comprehensive functional composite material with excellent flame retardant property, good fluidity and no precipitation yellowing. The piperazine pyrophosphate molecular structure contains an acid source, a carbon source and a gas source, has a macromolecular structure, has excellent compatibility with a matrix material, and can maintain the physical properties of the material to a great extent. Meanwhile, the triazine carbon forming agent has extremely strong carbon forming performance, the synthesis process is a two-step dehydration condensation reaction, no by-product is generated, and the triazine carbon forming agent is an excellent substitute. Ammonium polyphosphate has a good effect of promoting char formation, but the surface of the molecular structure thereof is hydrophilic hydroxyl, and the ammonium polyphosphate is easily precipitated after being added into a material, so that the material performance is weakened or disappeared. Particularly, in some fields with severe use environments or strict requirements on weather resistance, the method is greatly limited. The surface of the flame retardant is coated and modified, and hydrophobic silane substances are introduced, so that hydrophobic modification and interface coupling are realized, the compatibility with materials is effectively improved, and the precipitation performance of the flame retardant is reduced.

Meanwhile, on the basis of a three-source compounding mechanism, melamine or melamine salt with a gas-phase dilution mechanism is introduced to form a large amount of non-combustible gas in a gas phase to dilute the concentration of the combustible gas. The flame-retardant system is effectively enhanced, the purpose of inhibiting combustion is achieved, and the high-melt-index halogen-free flame-retardant polypropylene material with excellent comprehensive performance is prepared. Meanwhile, a flame retardant synergist and other auxiliary agents are introduced, so that the interface effect is improved, the dispersion performance is improved, the agglomeration effect is reduced, and the lost physical performance is increased on the basis. Various synergists and flame retardants interact to form an organic whole, and the high-melt-index halogen-free flame-retardant polypropylene material with excellent comprehensive performance can be better obtained.

Meanwhile, in the preparation process of the material, the mixing process and the screw structure are adjusted, so that the flame retardant and the material are mixed more stably and uniformly.

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

1) compared with a CFA system, the self-charring performance is obviously improved and the promoting effect of ammonium polyphosphate is weakened by adopting the piperazine pyrophosphate as the charring agent, so that the proportion of the ammonium polyphosphate in the system is reduced, and the precipitation performance of the composite material is effectively reduced. Meanwhile, a triazine charring agent is not used, so that the environmental pollution caused by the use of CFA is greatly reduced.

2) The silane molecules are adopted to effectively coat the ammonium polyphosphate, the hydrophilic property of the surface of the ammonium polyphosphate molecule is converted into the oleophylic property, the coupling of the flame retardant and the molecular layer of the matrix material is realized, and the dispersion property of the flame retardant in the material is improved. Meanwhile, the improvement of the compatibility is beneficial to the material melt index, and the preparation of the high melt index halogen-free flame-retardant polypropylene material is realized.

3) The use of the gas-phase dilution effect flame retardant effectively performs performance synergism on the flame retardant system, adopts a three-source compounding mechanism, increases the synergistic effect among all the components, and achieves the optimal flame retardant effect. The defect that the traditional APP/CFA system has poor flame retardant effect on high-fluidity polypropylene materials is overcome. Meanwhile, a novel mixing technology and a screw process are adopted, so that the prepared material powder has better dispersibility and better physical properties.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.