Flame-retardant functional filler, preparation method thereof and flame-retardant composite material

Abstract

This invention belongs to the field of functional filler technology, specifically relating to a flame-retardant functional filler and its preparation method, as well as flame-retardant composite materials. The flame-retardant functional filler provided by this invention is uniformly dispersed in a substrate, significantly improving the oxygen index (flame-retardant performance) of the substrate, while simultaneously improving the tensile strength and elongation at break, achieving a synergistic improvement in both flame-retardant and mechanical properties. Its color is close to pure white, making it suitable for flame-retardant modification of polymer materials such as polyethylene sheathing materials, PVC wire and cable materials, and low-smoke halogen-free flame-retardant cables, with broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of functional filler technology, specifically relating to a flame-retardant functional filler and its preparation method, and flame-retardant composite materials. Background Technology

[0002] Mineral-derived magnesium hydroxide, as an environmentally friendly inorganic flame retardant, possesses advantages such as halogen-free, low-smoke, non-toxic, and smoke-suppressing properties, making it widely used in the field of flame retardant polymer materials. However, mineral-derived magnesium hydroxide itself has characteristics such as high specific surface area and strong surface polarity. When directly added to polymer substrates, it is prone to agglomeration, resulting in poor dispersibility. This not only affects the flame retardant efficiency but also severely damages the mechanical properties of the substrate (such as reduced tensile strength and elongation at break). At the same time, existing mineral-derived magnesium hydroxide filler masterbatches generally suffer from poor color (such as bluish or reddish hues), resulting in insufficient compatibility with polymer substrates and limiting its application in products with high requirements for appearance and performance (such as wire and cable sheathing materials).

[0003] To address the aforementioned issues, existing technologies often employ single coupling agent modification or simple compounding of flame retardants, but the effects are limited, failing to achieve synergistic optimization of flame retardant performance, mechanical properties, and color. For example, while using silane coupling agents to modify mineral-derived magnesium hydroxide can improve dispersibility, its effect on improving mechanical properties is not significant; combining it with aluminum hydroxide as a synergist offers limited improvement in flame retardant efficiency and cannot resolve color defects. Therefore, developing a composite flame-retardant functional filler masterbatch for mineral-derived magnesium hydroxide that combines excellent flame retardant performance, good mechanical compatibility, and optimized color has become an urgent need in the industry. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant functional filler, its preparation method, and a flame-retardant composite material. The flame-retardant functional filler provided by this invention can improve the dispersion uniformity in a polymer matrix, prevent agglomeration, and achieve a synergistic improvement in flame-retardant performance and mechanical properties.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a flame-retardant functional filler, comprising the following components in parts by weight: The composition includes 60-80 parts of magnesium hydroxide obtained from mining, 5-15 parts of flame retardant synergist, 3-8 parts of toughening agent, 1-5 parts of dispersant, 0.5-3 parts of coupling agent, 0.3-2 parts of color modifier, and 0.2-1 parts of antioxidant. The flame retardant synergist includes aluminum hydroxide and nano-montmorillonite; The toughening agents include SEBS and POE.

[0006] Preferably, the mass ratio of aluminum hydroxide to nano-montmorillonite is 3~5:1.

[0007] Preferably, the mass ratio of SEBS to POE is 1~2:1.

[0008] Preferably, the dispersant comprises stearic acid and polyethylene wax; the mass ratio of stearic acid to polyethylene wax is 2~3:1.

[0009] Preferably, the coupling agent includes at least one of silane coupling agents and titanate coupling agents; The silane coupling agent includes γ-aminopropyltriethoxysilane; The titanate coupling agent includes KR-46B coupling agent.

[0010] Preferably, the hue modifier includes nano-titanium dioxide and fluorescent whitening agent OB-1; The mass ratio of the nano-titanium dioxide to the fluorescent whitening agent OB-1 is 5~8:1.

[0011] Preferably, the antioxidant includes antioxidant 1010 and antioxidant 168; the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0012] This invention also provides a method for preparing the flame-retardant functional filler described in the above technical solution, comprising the following steps: Magnesium hydroxide obtained from mining is mixed with a coupling agent and then modified to obtain modified magnesium hydroxide obtained from mining. The modified mineral-derived magnesium hydroxide and the remaining components are mixed and then extruded to obtain the flame-retardant functional filler.

[0013] Preferably, the modification treatment is carried out under stirring conditions, wherein the stirring temperature is 80~100℃, the stirring time is 15~30min, and the stirring speed is 800~1200rpm; The modified mineral magnesium hydroxide and the remaining components are mixed under stirring conditions, wherein the stirring temperature is 60~80℃, the stirring speed is 600~1000rpm, and the stirring time is 10~20min; The extrusion is carried out in a twin-screw extruder, which includes four temperature zones: the temperature of the first temperature zone is 140~150℃, the temperature of the second temperature zone is 150~160℃, the temperature of the third temperature zone is 160~170℃, and the temperature of the fourth temperature zone is 170~180℃. The screw speed of the twin-screw extruder is 200~300 rpm.

[0014] The present invention also provides a flame-retardant composite material, comprising a polymer matrix and additives; The additive is the flame-retardant functional filler described in the above technical solution or the flame-retardant functional filler prepared by the preparation method described in the above technical solution; The polymer matrix material includes at least one of polyolefin, polyvinyl chloride, polyamide, and polyurethane; the polyolefin includes polyethylene and / or polypropylene; The additive has a mass percentage content of 20-50% in the flame-retardant composite material.

[0015] Compared with the prior art, the present invention has the following advantages: (1) Excellent flame retardant performance: The composite flame retardant system of magnesium hydroxide from mining, aluminum hydroxide and nano montmorillonite has a significant synergistic effect. The oxygen index of the polyethylene composite material with the filler of this invention can be increased to more than 32%, reaching the UL94V-0 flame retardant standard, and the smoke release is low. (2) Synergistic improvement of mechanical properties: Through the synergistic effect of SEBS-POE composite toughening agent and coupling agent, the problem of the decline in mechanical properties of the substrate caused by the traditional mineral method magnesium hydroxide filling is solved. The tensile strength retention rate of the composite material with the filler of this invention is ≥88% (tensile strength of the test sample / tensile strength of blank resin), and the elongation at break retention rate is ≥100%, achieving a balance between flame retardancy and mechanical properties. (3) Significant color optimization: By combining nano titanium dioxide with fluorescent whitening agent, the color of the filler is close to pure white, avoiding the blue and red defects of traditional mineral magnesium hydroxide masterbatch, and meeting the application requirements of products such as wires and cables that have high requirements for appearance. (4) Good dispersibility and convenient processing: The addition of dispersant effectively inhibits the agglomeration of magnesium hydroxide from mineral processing. The filler is evenly dispersed in the substrate and the preparation process is simple. It can be industrialized using conventional twin-screw extrusion equipment, with low production cost and wide applicability. Attached Figure Description

[0016] Figure 1 This is a color comparison diagram of the filler of Example 1 (right) and the filler of Comparative Example 1 (left); Figure 2 This is a cross-sectional scanning electron microscope image of the composite material obtained in Example 1. Detailed Implementation

[0017] This invention provides a flame-retardant functional filler, comprising the following components in parts by weight: The composition includes 60-80 parts of magnesium hydroxide obtained from mining, 5-15 parts of flame retardant synergist, 3-8 parts of toughening agent, 1-5 parts of dispersant, 0.5-3 parts of coupling agent, 0.3-2 parts of color modifier, and 0.2-1 parts of antioxidant. The flame retardant synergist includes aluminum hydroxide and nano-montmorillonite; The toughening agents include SEBS and POE.

[0018] The flame-retardant functional filler provided by this invention comprises 60-80 parts by weight of mineral-derived magnesium hydroxide, specifically 60, 65, 70, 75, or 80 parts. In this invention, the particle size of the mineral-derived magnesium hydroxide is preferably 1-5 μm. In this invention, mineral-derived magnesium hydroxide, as the core flame-retardant component, not only ensures flame-retardant efficiency but also improves compatibility with the substrate through synergistic effects with other components.

[0019] Based on the mass fraction of the mineral-derived magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 5-15 parts of a flame-retardant synergist, specifically 5 parts, 10 parts, or 15 parts; the flame-retardant synergist includes aluminum hydroxide and nano-montmorillonite. In this invention, the preferred mass ratio of aluminum hydroxide to nano-montmorillonite is 3-5:1, specifically 3:1, 4:1, or 5:1; wherein, aluminum hydroxide and mineral-derived magnesium hydroxide form a synergistic flame-retardant system, increasing the oxygen index; nano-montmorillonite can construct a layered barrier structure, inhibiting flue gas release, while enhancing mechanical properties.

[0020] Based on the mass fraction of the mineral-processed magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 3-8 parts of toughening agent, specifically 3, 4, 5, 6, 7, or 8 parts. In this invention, the toughening agent includes SEBS and POE; the preferred mass ratio of SEBS to POE is 1-2:1. In this invention, SEBS has both toughening and compatibility effects, while POE can improve the toughness of the masterbatch and its integration with the substrate, synergistically improving the elongation at break of the substrate.

[0021] Based on the mass fraction of the mineral-derived magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 1 to 5 parts of dispersant, specifically 1, 2, 3, 4, or 5 parts. In this invention, the dispersant preferably includes stearic acid and polyethylene wax; the mass ratio of stearic acid to polyethylene wax is preferably 2 to 3:1. In this invention, stearic acid can reduce the surface tension of the raw material; polyethylene wax can improve the fluidity of the melt system, and the two work synergistically to promote uniform dispersion of the components and prevent agglomeration.

[0022] Based on the mass fraction of the mineral-derived magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 0.5 to 3 parts of coupling agent, specifically 0.5 parts, 1 part, 2 parts, or 3 parts. In this invention, the coupling agent preferably includes at least one of a silane coupling agent and a titanate coupling agent; the silane coupling agent preferably includes γ-aminopropyltriethoxysilane (KH-550); the titanate coupling agent preferably includes KR-46B coupling agent. Selecting the above coupling agents can further improve the compatibility of mineral-derived magnesium hydroxide with the organic phase and enhance the interfacial bonding force.

[0023] Based on the mass fraction of the mineral-processed magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 0.3 to 2 parts of a color modifier, specifically 0.3, 0.5, 1, 1.5, or 2 parts. In this invention, the color modifier preferably includes nano-titanium dioxide and fluorescent whitening agent OB-1; the mass ratio of nano-titanium dioxide to fluorescent whitening agent OB-1 is preferably 5 to 8:1, specifically 5:1, 6:1, 7:1, or 8:1. In this invention, nano-titanium dioxide improves whiteness, and the fluorescent whitening agent corrects discoloration such as cyan and red hues, making the masterbatch color close to pure white.

[0024] Based on the mass fraction of the mineral-processed magnesium hydroxide, the flame-retardant functional filler provided by this invention includes 0.2 to 1 part of antioxidant, specifically 0.2 parts, 0.5 parts, 0.8 parts, and 1.0 parts. In this invention, the antioxidant preferably includes antioxidant 1010 and antioxidant 168; the mass ratio of antioxidant 1010 to antioxidant 168 is preferably 1:1. Selecting the above antioxidants can delay the oxidative aging of polymer materials during processing and use, extending the product's service life.

[0025] This invention also provides a method for preparing the flame-retardant functional filler described in the above technical solution, comprising the following steps: Magnesium hydroxide obtained from mining is mixed with a coupling agent and then modified to obtain modified magnesium hydroxide obtained from mining. The modified mineral-derived magnesium hydroxide and the remaining components are mixed and then extruded to obtain the flame-retardant functional filler.

[0026] This invention involves mixing mineral-derived magnesium hydroxide with a coupling agent and then modifying the mixture to obtain modified mineral-derived magnesium hydroxide.

[0027] Before mixing, the present invention preferably includes drying the mineral-derived magnesium hydroxide; the drying temperature is preferably 105~120℃, and the drying time is preferably 2~4h; after drying, the present invention preferably includes cooling to room temperature. In the present invention, the modification treatment is preferably carried out under stirring conditions; the stirring temperature is preferably 80~100℃, specifically 80℃, 90℃, or 100℃; the stirring time is preferably 15~30min, specifically 15min, 20min, 25min, or 30min; the stirring speed is preferably 800~1200rpm, specifically 800rpm, 900rpm, 1000rpm, 1100rpm, or 1200rpm.

[0028] After obtaining the modified mineral-derived magnesium hydroxide, the present invention mixes the modified mineral-derived magnesium hydroxide with the remaining components and then extrudes it to obtain the flame-retardant functional filler.

[0029] In this invention, the mixing is preferably carried out in a high-speed mixer; the preferred mixing order is as follows: modified mineral-derived magnesium hydroxide, flame retardant synergist, toughening agent, dispersant, color modifier, and antioxidant are added sequentially to the high-speed mixer. In this invention, the mixing is preferably carried out under stirring conditions, wherein the stirring temperature is preferably 60-80°C, the stirring speed is preferably 600-1000 rpm, and the stirring time is preferably 10-20 minutes.

[0030] In this invention, the extrusion is preferably carried out in a twin-screw extruder, which preferably includes four temperature zones: the temperature of the first temperature zone is preferably 140-150°C, the temperature of the second temperature zone is preferably 150-160°C, the temperature of the third temperature zone is preferably 160-170°C, and the temperature of the fourth temperature zone is preferably 170-180°C; the screw speed of the twin-screw extruder is preferably 200-300 rpm, specifically 200 rpm, 250 rpm, or 300 rpm. In this invention, after extrusion, the process preferably further includes water-cutting granulation, drying, and screening.

[0031] The present invention also provides a flame-retardant composite material, comprising a polymer matrix and an additive; the additive is the flame-retardant functional filler described in the above technical solution or the flame-retardant functional filler prepared by the preparation method described in the above technical solution.

[0032] In this invention, the polymer matrix material preferably includes at least one selected from polyolefin, polyvinyl chloride, polyamide, and polyurethane; the polyolefin preferably includes polyethylene and / or polypropylene; the polypropylene is preferably homopolymer polypropylene, and the melt index of the homopolymer polypropylene is preferably 2.5 g / 10 min (230℃ / 2.16 kg). In this invention, the mass percentage of the additive in the flame-retardant composite material is preferably 20-50%, specifically 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0033] In this invention, the preferred method for preparing the flame-retardant composite material includes: sequentially mixing, extruding and granulating a polymer matrix and an additive to obtain the flame-retardant composite material.

[0034] In this invention, before mixing, it is preferable to dry the polymer matrix and sieve the additives; the drying temperature is preferably 90°C and the drying time is preferably 3 hours; drying removes the moisture adsorbed on the resin surface to avoid defects such as bubbles and shrinkage cavities during subsequent molding; the sieve mesh size used for sieving is preferably 100 mesh to ensure that the filler is evenly dispersed and free of agglomerated particles.

[0035] In this invention, the mixing is preferably carried out under stirring conditions, wherein the stirring temperature is preferably 60-80°C, the stirring speed is preferably 600-1000 rpm, and the stirring time is preferably 10-20 min. In this invention, during the mixing process, a processing aid is preferably added to improve melt flowability; the processing aid is preferably calcium stearate; the mass of the processing aid is preferably 0.5% of the polymer matrix mass.

[0036] In this invention, the extrusion is preferably performed using a twin-screw extruder, and the length-to-diameter ratio of the twin-screw extruder is preferably 32-38:1, specifically 32:1, 35:1, or 38:1. The twin-screw extruder preferably includes four temperature zones, specifically: a first temperature zone of 140-150°C, a second temperature zone of 150-160°C, a third temperature zone of 160-170°C, and a fourth temperature zone of 170-180°C. The screw speed is preferably 200-300 rpm, specifically 200 rpm, 250 rpm, or 300 rpm. Granulation is preferably water-cooled pelletizing. After granulation, the invention further preferably includes drying, with the drying temperature preferably at 80-100°C and the drying time preferably at 1-2 hours.

[0037] In this invention, when the flame-retardant composite material is tested, it is preferable to obtain the required test sample by injection molding the flame-retardant composite material; the injection molding temperature is preferably 170°C, the pressure is preferably 80MPa, and the holding time is preferably 15s.

[0038] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0039] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0040] Example 1 Flame-retardant functional filler, by weight, consists of the following raw materials: 65 parts of mineral-derived magnesium hydroxide, 10 parts of flame-retardant synergist (aluminum hydroxide and nano-montmorillonite in a mass ratio of 4:1), 5 parts of toughening agent (SEBS and POE in a mass ratio of 1.5:1), 3 parts of dispersant (stearic acid and polyethylene wax in a mass ratio of 2.5:1), 1.5 parts of γ-aminopropyltriethoxysilane, 1 part of color modifier (nano-titanium dioxide and fluorescent whitening agent OB-1 in a mass ratio of 6:1), and 0.5 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1). Preparation method: The mineral-derived magnesium hydroxide powder was dried at 110℃ for 3 hours, cooled, and then γ-aminopropyltriethoxysilane was added. The powder was then modified in a high-speed mixer at 90℃ and 1000rpm for 20 minutes to obtain modified mineral-derived magnesium hydroxide. Modified magnesium hydroxide from mineral processing, flame retardant synergist, toughening agent, dispersant, color modifier and antioxidant were added sequentially to a high-speed mixer and mixed at 70°C and 800 rpm for 15 minutes to obtain a mixture. The mixture is added to a twin-screw extruder with temperatures of 145℃, 155℃, 165℃ and 175℃ in each zone, and a screw speed of 250 rpm. After extrusion, the material is water-cooled, pelletized, air-dried and screened to obtain flame-retardant functional filler.

[0041] Example 2 Flame-retardant functional filler, by weight, consists of the following raw materials: 70 parts of mineral-derived magnesium hydroxide, 8 parts of flame-retardant synergist (aluminum hydroxide and nano-montmorillonite in a mass ratio of 3:1), 4 parts of toughening agent (SEBS and POE in a mass ratio of 2:1), 2 parts of dispersant (stearic acid and polyethylene wax in a mass ratio of 2:1), 2 parts of titanate coupling agent (KR-46B), 0.8 parts of color modifier (nano-titanium dioxide and fluorescent whitening agent OB-1 in a mass ratio of 5:1), and 0.4 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1). Preparation method: The mineral-derived magnesium hydroxide powder was dried at 115℃ for 2.5h, cooled, and then a titanate coupling agent was added. The powder was then modified in a high-speed mixer at 95℃ and 1100rpm for 25min to obtain modified mineral-derived magnesium hydroxide. Modified magnesium hydroxide from mineral processing, flame retardant synergist, toughening agent, dispersant, color modifier and antioxidant were added sequentially to a high-speed mixer and mixed at 65°C and 900 rpm for 12 minutes to obtain a mixture. The mixture is added to a twin-screw extruder with temperatures of 140℃, 150℃, 160℃ and 170℃ in each zone, and a screw speed of 280 rpm. After extrusion, the material is water-cooled, pelletized, air-dried and screened to obtain flame-retardant functional filler.

[0042] Comparative Example 1 The traditional single-mineral magnesium hydroxide filler masterbatch is composed of the following raw materials: 70 parts mineral magnesium hydroxide, 2 parts stearic acid, 1 part silane coupling agent (γ-aminopropyltriethoxysilane), and 0.3 parts antioxidant (the mass ratio of antioxidant 1010 and antioxidant 168 is 1:1). Add the raw materials to a high-speed mixer and mix at 70°C and 800 rpm for 15 minutes to obtain a mixture. The mixture is added to a twin-screw extruder with temperatures of 145℃, 155℃, 165℃ and 175℃ in each zone, and a screw speed of 250 rpm. After extrusion, the material is water-cooled, pelletized, air-dried and screened to obtain flame-retardant functional filler.

[0043] Example 3 Homopolymer polypropylene (melt index 2.5 g / 10 min, 230℃ / 2.16 kg) was used as the polymer matrix and dried at 90℃ for 3 h. The flame-retardant functional filler obtained in Example 1 was passed through a 100-mesh sieve. Polypropylene resin and flame-retardant functional filler (i.e., 60 parts of polypropylene and 40 parts of flame-retardant functional filler) were weighed at a mass ratio of 6:4 and added together into a high-speed mixer. At the same time, 0.5% of the polypropylene mass of processing aid calcium stearate was added. The mixing temperature was set to 70℃ and the speed was set to 800 rpm. The mixture was stirred continuously for 15 min to obtain a uniform mixture. The above mixture is added to a twin-screw extruder (length-to-diameter ratio 35:1). The temperatures of each zone of the twin-screw extruder are controlled sequentially as follows: zone 1 145℃, zone 2 155℃, zone 3 165℃, and zone 4 175℃. The screw speed is adjusted to 250 rpm. After melting, shearing, and thorough mixing, the mixture is extruded. The extrudate is water-cooled and pelletized. The resulting pellets are then dried at 90℃ for 1.5 hours. Impurities and unqualified pellets are removed by screening, and finally, flame-retardant composite material is obtained.

[0044] Example 4 Flame-retardant composite materials were prepared according to Example 3, wherein the flame-retardant functional filler of Example 1 was replaced with the flame-retardant functional filler of Example 2.

[0045] Comparative Example 2 Flame-retardant composite materials were prepared according to Example 3, wherein the flame-retardant functional filler of Example 1 was replaced with the flame-retardant functional filler of Comparative Example 1.

[0046] Performance testing The flame-retardant composite materials obtained in the examples and comparative examples were subjected to performance tests. Composite material particles are added to an injection molding machine, and the injection temperature is set to 170℃, the injection pressure to 80MPa, and the holding time to 15s. Standard tensile specimens and flame-retardant specimens are obtained by injection molding, which are used for subsequent performance tests of oxygen index, tensile strength, elongation at break, and hue.

[0047] Figure 1 This is a color comparison diagram of the filler of Example 1 (right) and the filler of Comparative Example 1 (left), demonstrating the whiteness advantage of the filler obtained by the present invention.

[0048] Figure 2The image shows a cross-sectional scanning electron microscope (SEM) image of the composite material obtained in Example 1, which shows that the mineral-based magnesium hydroxide is uniformly dispersed in the substrate resin.

[0049] The performance tests of the composite materials obtained in Examples 3-4 and Comparative Example 2 are shown in Table 1. Table 1. Test results of composite material properties

[0050] The test results show that the composite materials obtained in Examples 3-4 of this invention are significantly better than the comparative examples in terms of oxygen index, tensile strength, elongation at break and whiteness value. This proves that the present invention achieves synergistic optimization of flame retardant performance, mechanical properties and color, and meets the high-performance application requirements of polymer materials.

[0051] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A flame-retardant functional filler, characterized in that, The components include the following parts by mass: The composition includes 60-80 parts of magnesium hydroxide obtained from mining, 5-15 parts of flame retardant synergist, 3-8 parts of toughening agent, 1-5 parts of dispersant, 0.5-3 parts of coupling agent, 0.3-2 parts of color modifier, and 0.2-1 parts of antioxidant. The flame retardant synergist includes aluminum hydroxide and nano-montmorillonite; The toughening agents include SEBS and POE.

2. The flame-retardant functional filler according to claim 1, characterized by The mass ratio of aluminum hydroxide to nano-montmorillonite is 3~5:

1.

3. The flame retardant functional filler according to claim 1, characterized in that, The mass ratio of SEBS to POE is 1~2:

1.

4. The flame retardant functional filler according to claim 1, characterized by, The dispersant comprises stearic acid and polyethylene wax; the mass ratio of stearic acid to polyethylene wax is 2~3:

1.

5. The flame retardant functional filler according to claim 1, wherein The coupling agent includes at least one of silane coupling agents and titanate coupling agents; The silane coupling agent includes γ-aminopropyltriethoxysilane; The titanate coupling agent includes KR-46B coupling agent.

6. The flame retardant functional filler according to claim 1, wherein The hue modifier includes nano titanium dioxide and fluorescent whitening agent OB-1; The mass ratio of the nano-titanium dioxide to the fluorescent whitening agent OB-1 is 5~8:

1.

7. The flame-retardant functional filler according to claim 1, characterized in that, The antioxidants include antioxidant 1010 and antioxidant 168; the mass ratio of antioxidant 1010 to antioxidant 168 is 1:

1.

8. The method for producing a flame-retardant functional filler according to any one of claims 1 to 7, characterized by, Includes the following steps: Magnesium hydroxide obtained from mining is mixed with a coupling agent and then modified to obtain modified magnesium hydroxide obtained from mining. The modified mineral-derived magnesium hydroxide and the remaining components are mixed and then extruded to obtain the flame-retardant functional filler.

9. The preparation method according to claim 8, characterized in that, The modification treatment is carried out under stirring conditions, wherein the stirring temperature is 80~100℃, the stirring time is 15~30min, and the stirring speed is 800~1200rpm. The modified mineral magnesium hydroxide and the remaining components are mixed under stirring conditions, wherein the stirring temperature is 60~80℃, the stirring speed is 600~1000rpm, and the stirring time is 10~20min; The extrusion is carried out in a twin-screw extruder, which includes four temperature zones: the temperature of the first temperature zone is 140~150℃, the temperature of the second temperature zone is 150~160℃, the temperature of the third temperature zone is 160~170℃, and the temperature of the fourth temperature zone is 170~180℃. The screw speed of the twin-screw extruder is 200~300 rpm.

10. A flame-retardant composite material, characterized in that, Including polymer matrix and additives; The additive is the flame-retardant functional filler according to any one of claims 1 to 7 or the flame-retardant functional filler prepared by the preparation method according to claim 8 or 9; The polymer matrix material includes at least one of polyolefin, polyvinyl chloride, polyamide, and polyurethane; the polyolefin includes polyethylene and / or polypropylene; The additive has a mass percentage content of 20-50% in the flame-retardant composite material.

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