High-flame-retardant ABS composite material and preparation method thereof

Abstract

The invention discloses a high-flame-retardant ABS (Acrylonitrile Butadiene Styrene) composite material and a preparation method thereof, and belongs to the technical field of high polymer materials. The high-flame-retardant ABS composite material provided by the invention is prepared from the following raw materials in parts by mass: 70 parts of ABS, 8 to 10 parts of microencapsulated red phosphorus, 7 to 8 parts of self-made silicon dioxide coated aluminum hypophosphite, 5 to 7 parts of self-made modified zinc-cobalt-aluminum hydrotalcite, 5 to 7 parts of self-made SMA-GMA, 0.5 to 1.0 part of antioxidant and 0.5 to 1.0 part of ethylene bis stearamide. Compared with the prior art, the contradiction among flame retardant efficiency, mechanical property and stability is solved, and the high-end application requirements of new energy automobile battery pack shells and the like are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a highly flame-retardant ABS composite material and a preparation method thereof. Background Art

[0002] ABS resin, due to its excellent mechanical strength and processing properties, is widely used in electronic and electrical housings, automotive interiors, and other fields. With the upgrade of the EU RoHS directive and the improvement of the UL94 standard, electronic equipment housing materials must meet V-0 flame retardancy and low-smoke, non-toxic requirements. Traditional halogen-based flame-retardant ABS is facing elimination due to the release of toxic gases during combustion.

[0003] Existing halogen-free flame retardant systems (such as aluminum hydroxide / magnesium) require a filling content of more than 40wt% to achieve V-0 level, resulting in increased material density and a decrease in impact strength of more than 50%. Although the phosphorus-nitrogen synergistic system is environmentally friendly, it undergoes pre-decomposition during high-temperature processing, causing defects such as flow marks and silver streaks in composite injection molded parts.

[0004] The industry urgently needs a technical solution that can achieve UL94 V-0 rating at a low addition level of 25wt% while maintaining the original impact strength and stability of ABS. Failure to address the poor compatibility of flame retardants with resins and their high-temperature decomposition will hinder the promotion of high-end applications such as new energy vehicle battery pack casings. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly flame-retardant ABS composite material and a preparation method thereof, so as to solve the contradiction between the flame-retardant efficiency, mechanical properties and stability of the ABS composite material under low addition of flame retardant.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A highly flame-retardant ABS composite material, comprising the following raw materials in parts by weight: ABS 70 copies; 8-10 parts of microencapsulated red phosphorus; 7-8 parts of silicon dioxide-coated aluminum hypophosphite; 5-7 parts of modified zinc-cobalt-aluminum hydrotalcite; SMA-GMA 5-7 parts; 0.5-1.0 parts of antioxidant; 0.5-1.0 parts of ethylene bisstearamide.

[0007] Furthermore, the silica-coated aluminum hypophosphite is prepared by the following steps: Aluminum hypophosphite is immersed in an ethanol solution with a volume fraction of 25% to 30%, and then ethyl orthosilicate is added thereto with stirring. Ammonia water is used to adjust the pH of the system to 8.8 to 9.0. The system is then heated to 55 to 60°C and stirred at a constant temperature for 2 to 3 hours. After completion, the reaction is carried out, cooled, filtered, washed, and dried to obtain silica-coated aluminum hypophosphite.

[0008] Furthermore, the amount of ethyl orthosilicate used is 15% to 20% of the mass of aluminum hypophosphite.

[0009] Furthermore, the modified zinc-cobalt-aluminum hydrotalcite is prepared by the following steps: A1. Dissolve Zn(NO3)2, Co(NO3)2, and Al(NO3)3 in deionized water at a molar ratio of Zn:Co:Al=2:1:1 to obtain a salt solution; then mix 2.4 mol / L NaOH solution and 0.8 mol / L Na2CO3 solution at a volume ratio of 1:1 to obtain an alkaline solution; A2. The salt solution and the alkaline solution were simultaneously added dropwise to the reactor at a rate of 1.5 mL / min. The reactor was heated to 55-60°C under nitrogen protection and aged at this temperature for 24 hours. After completion, the reactor was cooled to room temperature, the precipitate was collected by centrifugation, and the precipitate was washed with deionized water to a pH of 7. The solid component was collected by filtration, dried, and then ground through a 100-mesh sieve to obtain zinc-cobalt-aluminum hydrotalcite. A3. Stearic acid and anhydrous ethanol were stirred and dissolved in a 60°C water bath in a mass ratio of 1:4 to obtain a modified solution. The modified solution was sprayed onto the surface of the zinc-cobalt-aluminum hydrotalcite. After completion, the solution was dried in a hot air circulation system at 55-60°C for 30 minutes. After completion, the solution was crushed and passed through a 100-mesh sieve to obtain a modified zinc-cobalt-aluminum hydrotalcite.

[0010] Furthermore, the total concentration of metal ions in the salt solution in A1 is 1.5 mol / L.

[0011] Furthermore, the usage ratio of the modified solution and zinc-cobalt-aluminum hydrotalcite in A3 is 0.1-1 mL:1 g.

[0012] Further, the SMA-GMA is prepared by the following steps: Polystyrene maleic anhydride copolymer was dissolved in xylene in a mass ratio of 7:3 and stirred at 80°C under nitrogen protection until completely dissolved. Monodisperse glycidyl methacrylate microspheres and dicumyl peroxide were then added thereto with stirring. After completion, the temperature was raised to 105-110°C for reaction for 3-4 hours. After completion, a reaction solution was obtained, which was then poured into excess acetone for precipitation. The solution was filtered, washed with anhydrous ethanol, and vacuum dried to obtain SMA-GMA.

[0013] Furthermore, the amount of the monodisperse glycidyl methacrylate microspheres is 15% of the mass of the polystyrene maleic anhydride copolymer; the particle size of the monodisperse glycidyl methacrylate microspheres is 0.1 μm; and the amount of dicumyl peroxide is 0.8% to 1.0% of the total mass of the polystyrene maleic anhydride copolymer and the monodisperse glycidyl methacrylate microspheres.

[0014] Furthermore, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: S1. Weigh the above raw materials in parts by mass, and stir the microcapsule red phosphorus, silica-coated aluminum hypophosphite, modified zinc-cobalt-aluminum hydrotalcite, and SMA-GMA at 80-100° C. for 10-30 min to obtain a premix; S2. Extruding the premix, ABS, antioxidant and ethylene bisstearamide in a twin-screw extruder to obtain a highly flame-retardant ABS composite material.

[0015] Furthermore, the particle size of the microcapsule red phosphorus is 25 to 30 μm; the mass fraction of red phosphorus in the microcapsule red phosphorus is 85%; and the antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0016] Beneficial effects of the present invention: This invention addresses the technical problem of existing ABS composites struggling to achieve a balanced balance of flame retardancy, mechanical properties, and stability at low flame retardant addition levels. This invention proposes a highly flame-retardant ABS composite solution based on a triple synergistic flame retardant system and a reactive compatibilizer. Testing has shown that the highly flame-retardant ABS composite prepared in this invention exhibits excellent flame retardancy, mechanical property retention, and stability. The following data analysis is combined with the following information: (1) Significantly improve flame retardant efficiency (achieve V-0 flame retardancy at low addition amount): Comparative Data: Examples 10-12, with a total flame retardant addition of approximately 25 wt% (e.g., Example 11: 10 parts microencapsulated red phosphorus, 8 parts SiO2-coated aluminum hypophosphite, and 6 parts modified zinc-cobalt-aluminum hydrotalcite, representing approximately 25.5 wt% of a 70-part ABS matrix), all achieved UL94 V-0 rating and LOI >33%. Comparative Example 1 (a traditional magnesium hydroxide system, approximately 30 wt% addition) achieved only UL94 V-1 and an LOI of 28.5%, demonstrating over 40% improvement in flame retardancy (a 37.5% reduction in addition yields superior performance).

[0017] Key mechanism: Microencapsulated red phosphorus: releases PO· free radicals during combustion to interrupt the chain reaction (gas phase flame retardant), providing basic flame retardancy; silica-coated aluminum hypophosphite: the coating delays decomposition (LOI drops to 30.2% when not coated in comparative example 2), catalyzes the formation of a dense carbon layer during combustion (condensed phase flame retardant), and isolates from hot oxygen; modified zinc-cobalt-aluminum hydrotalcite: zinc ions catalyze red phosphorus to form a cross-linked phosphate-carbon network (LOI drops to 29.8% when zinc-cobalt-aluminum hydrotalcite is deficient in comparative example 5), thereby enhancing the strength of the carbon layer.

[0018] Synergistic effect: The triple system is indispensable (when the zinc-cobalt-aluminum hydrotalcite is missing in comparative example 5, UL94 drops to V-1). A total addition of about 25wt% reaches the V-0 level, solving the problem that the traditional system requires 40wt%.

[0019] (2) Breaking through the bottleneck of mechanical performance degradation (impact strength increases): Data comparison: Example 11 impact strength 16.8 kJ / m 2 , Comparative Example 1 (9.5 kJ / m 2 ) increased by 77%, compared with the comparative example 3 (unmodified zinc-cobalt-aluminum hydrotalcite, 14.0 kJ / m 2 ) increased by 20%, compared with the comparative example 4 (no SMA-GMA, 14.5 kJ / m 2 ) increased by 16%. The tensile strength (47.0 MPa) was also significantly higher than that of Comparative Example 1 (38.0 MPa).

[0020] Key mechanism: SMA-GMA interface compatibilization: its carboxyl group forms an ionic bond with the hydroxyl group of the modified zinc-cobalt-aluminum hydrotalcite (-COO⁻Zn 2+ ), strengthening the interface bonding. When the SMA-GMA is missing in Example 4, the impact strength decreases by 14%, verifying that the chemical bond reduces stress concentration; Modified zinc-cobalt-aluminum hydrotalcite dispersion optimization: stearic acid modification improves dispersibility (when the comparative example 3 is not modified, the impact strength drops to 14.0 kJ / m 2 ) to avoid agglomeration and weakening of the matrix (tensile strength increased by 7.3% compared with comparative example 3).

[0021] Industry breakthrough: The impact strength of the traditional halogen-free system decreases by more than 50% (verified by Comparative Example 1), while the present invention increases it by more than 10%, resolving the contradiction between mechanical properties and flame retardancy.

[0022] (3) Significant improvement in stability (MFR fluctuation ≤ 5%): Data comparison: Examples 10-12 have MFR fluctuations of ≤4.2%, while Comparative Example 2 (uncoated aluminum hypophosphite) reaches as high as 18.5%, and Comparative Example 1 (conventional system) is 8.5%. Comparative Example 3 (unmodified zinc-cobalt-aluminum hydrotalcite, 6.0%) and Comparative Example 4 (no SMA-GMA, 5.5%) also exceed those of the present invention.

[0023] Key mechanism: Thermal delay effect of SiO2 coating: The coating layer shifts the decomposition peak of aluminum hypophosphite with the ABS processing temperature (190-220°C), avoiding pre-decomposition (the volatility of Comparative Example 2 surges to 18.5%); SMA-GMA auxiliary stabilization: enhances interfacial compatibility and reduces rheological fluctuations caused by flame retardant agglomeration (the volatility of Comparative Example 4 is 5.5% > 3.8% of Example 11).

[0024] Solve the industry's pain points: The traditional phosphorus-nitrogen system melt index fluctuation exceeds ±15%, while the present invention controls it within ±5%, eliminating injection molding defects (such as flow marks and silver streaks).

[0025] (4) The core role of the synergy mechanism: The triple flame retardant system coupling: microencapsulated red phosphorus (gas phase flame retardant) + SiO2 coated aluminum hypophosphite (carbon formation catalyst) + modified zinc cobalt aluminum hydrotalcite (dispersion and catalytic cross-linking) achieves high efficiency flame retardancy at low addition dosage.

[0026] The key role of reactive compatibilizers: SMA-GMA modifies zinc-cobalt-aluminum hydrotalcite and ABS matrix through ionic bond bridging, achieving "flame retardant-reinforcement" integration (impact strength increases).

[0027] Verification of the impact of component omissions: The absence of any component (coating layer, modification, SMA-GMA) in Examples 2 to 5 resulted in significant performance degradation (e.g., LOI decreased by a maximum of 4.2% and impact strength decreased by a maximum of 20%), demonstrating the necessity of a complete technical solution.

[0028] Summary: The present invention achieves UL94 V-0 flame retardancy (LOI>33%) at a low addition amount of about 25-30wt% through a synergistic flame retardant system of microencapsulated red phosphorus, silica-coated aluminum hypophosphite, and modified zinc-cobalt-aluminum hydrotalcite, combined with the interfacial compatibilization effect of SMA-GMA, and improves the impact strength to 16.2 kJ / m 2 , and controls the MFR fluctuation rate to ≤4.2%. Compared with traditional technologies, this invention solves the contradiction between flame retardancy, mechanical properties, and stability, meeting the needs of high-end applications such as new energy vehicle battery pack housings. DETAILED DESCRIPTION

[0029] Below in conjunction with the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, it is obvious that described embodiment is only a part of embodiment of the present invention, rather than whole embodiment. Based on the embodiment in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise all fall within the scope of protection of the present invention. Meanwhile, raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0030] Example 1

[0031] Preparation of silica-coated aluminum hypophosphite: Aluminum hypophosphite (Shanghai McLean) was immersed in an ethanol solution with a volume fraction of 25%, and then ethyl orthosilicate (Shandong Yuanjin New Materials, the amount is 15% of the mass of aluminum hypophosphite) was added thereto with stirring. After completion, the pH of the system was adjusted to 8.8 with ammonia water. After completion, the system was heated to 55°C and stirred at a constant temperature for 2 hours. After completion, the solid component was collected by cooling and filtration. The solid component was then washed with pure water and then placed at a constant temperature of 50°C for 12 hours to obtain silica-coated aluminum hypophosphite.

[0032] Example 2

[0033] Preparation of silica-coated aluminum hypophosphite: Aluminum hypophosphite (Shanghai McLean) was immersed in a 30% volume fraction ethanol solution, and then ethyl orthosilicate (Shandong Yuanjin New Materials, the amount was 18% of the mass of aluminum hypophosphite) was added thereto with stirring. After completion, the pH of the system was adjusted to 9.0 with ammonia water. After completion, the system was heated to 55°C and stirred at a constant temperature for 3 hours. After completion, the solid component was collected by cooling and filtration. The solid component was then washed with pure water and then placed at a constant temperature of 50°C for 12 hours to obtain silica-coated aluminum hypophosphite.

[0034] Example 3

[0035] Preparation of silica-coated aluminum hypophosphite: Aluminum hypophosphite (Shanghai McLean) was immersed in a 30% volume fraction ethanol solution, and then ethyl orthosilicate (Shandong Yuanjin New Materials, the amount was 20% of the mass of aluminum hypophosphite) was added thereto with stirring. After completion, the pH of the system was adjusted to 9.0 with ammonia water. After completion, the system was heated to 60°C and stirred at a constant temperature for 3 hours. After completion, the solid component was collected by cooling and filtration. The solid component was then washed with pure water and then placed at a constant temperature of 60°C for drying for 12 hours. After completion, silica-coated aluminum hypophosphite was obtained.

[0036] Example 4

[0037] Preparation of modified zinc-cobalt-aluminum hydrotalcite: A1. Prepare the solution: Dissolve Zn(NO3)2, Co(NO3)2, and Al(NO3)3 in deionized water at a molar ratio of Zn:Co:Al of 2:1:1 (total metal ion concentration is controlled to be 1.5 mol / L) to obtain a salt solution; then mix 2.4 mol / L NaOH solution and 0.8 mol / L Na2CO3 solution at a volume ratio of 1:1 to obtain an alkaline solution; A2. Preparation of zinc-cobalt-aluminum hydrotalcite: The salt solution and the alkaline solution were simultaneously added dropwise to a reactor at a rate of 1.5 mL / min. The reactor was heated to 55°C under nitrogen and aged at this temperature for 24 h. After cooling to room temperature, the precipitate was collected by centrifugation and washed with deionized water to a pH of 7. The solid component was collected by filtration and dried in an oven at 60°C for 12 h. After completion, the solid component was ground and passed through a 100-mesh sieve to obtain zinc-cobalt-aluminum hydrotalcite. A3, modification process: Stearic acid (Shanghai McLean, C 18 :30%, C 16 : 70%) and anhydrous ethanol at a ratio of 1:4 (mass ratio) were stirred and dissolved in a water bath at 60°C to obtain a modified solution, and the modified solution was sprayed onto the surface of the zinc-cobalt-aluminum hydrotalcite under high-speed stirring through an atomizing nozzle (aperture 0.5 mm) at a ratio of 0.1 mL (modified solution): 1 g (zinc-cobalt-aluminum hydrotalcite). After completion, the mixture was dried in a hot air circulation system at 55°C for 30 min and then crushed and passed through a 100-mesh sieve to obtain a modified zinc-cobalt-aluminum hydrotalcite.

[0038] Example 5

[0039] Preparation of modified zinc-cobalt-aluminum hydrotalcite: A1. Prepare the solution: Dissolve Zn(NO3)2, Co(NO3)2, and Al(NO3)3 in deionized water at a molar ratio of Zn:Co:Al of 2:1:1 (total metal ion concentration is controlled to be 1.5 mol / L) to obtain a salt solution; then mix 2.4 mol / L NaOH solution and 0.8 mol / L Na2CO3 solution at a volume ratio of 1:1 to obtain an alkaline solution; A2. Preparation of zinc-cobalt-aluminum hydrotalcite: The salt solution and the alkaline solution were simultaneously added dropwise to a reactor at a rate of 1.5 mL / min. The reactor was heated to 55°C under nitrogen and aged at this temperature for 24 h. After cooling to room temperature, the precipitate was collected by centrifugation and washed with deionized water to a pH of 7. The solid component was collected by filtration and dried in a 70°C oven for 12 h. After completion, the solid component was ground and passed through a 100-mesh sieve to obtain zinc-cobalt-aluminum hydrotalcite. A3, modification process: Stearic acid (Shanghai McLean, C 18 :30%, C 16 : 70%) and anhydrous ethanol at a ratio of 1:4 (mass ratio) were stirred and dissolved in a water bath at 60°C to obtain a modified solution, and the modified solution was sprayed onto the surface of the zinc-cobalt-aluminum hydrotalcite under high-speed stirring through an atomizing nozzle (aperture 0.5 mm) at a ratio of 0.5 mL (modified solution): 1 g (zinc-cobalt-aluminum hydrotalcite). After completion, the mixture was dried in a hot air circulation system at 55°C for 30 min and then crushed and passed through a 100-mesh sieve to obtain a modified zinc-cobalt-aluminum hydrotalcite.

[0040] Example 6

[0041] Preparation of modified zinc-cobalt-aluminum hydrotalcite: A1. Prepare the solution: Dissolve Zn(NO3)2, Co(NO3)2, and Al(NO3)3 in deionized water at a molar ratio of Zn:Co:Al of 2:1:1 (total metal ion concentration is controlled to be 1.5 mol / L) to obtain a salt solution; then mix 2.4 mol / L NaOH solution and 0.8 mol / L Na2CO3 solution at a volume ratio of 1:1 to obtain an alkaline solution; A2. Preparation of zinc-cobalt-aluminum hydrotalcite: The salt solution and the alkaline solution were simultaneously added dropwise to a reactor at a rate of 1.5 mL / min. The reactor was heated to 60°C under nitrogen and aged at this temperature for 24 h. After cooling to room temperature, the precipitate was collected by centrifugation and washed with deionized water to a pH of 7. The solid component was collected by filtration and dried in an oven at 80°C for 12 h. After completion, the solid component was ground and passed through a 100-mesh sieve to obtain zinc-cobalt-aluminum hydrotalcite. A3, modification process: Stearic acid (Shanghai McLean, C 18 :30%, C 16 : 70%) and anhydrous ethanol at a ratio of 1:4 (mass ratio) were stirred and dissolved in a water bath at 60°C to obtain a modified solution, and the modified solution was sprayed onto the surface of the zinc-cobalt-aluminum hydrotalcite under high-speed stirring through an atomizing nozzle (aperture 0.5 mm) at a ratio of 1 mL (modified solution): 1 g (zinc-cobalt-aluminum hydrotalcite). After completion, the mixture was dried in a hot air circulation system at 60°C for 30 min and then crushed and passed through a 100-mesh sieve to obtain a modified zinc-cobalt-aluminum hydrotalcite.

[0042] Example 7

[0043] Preparation of SMA-GMA: Polystyrene maleic anhydride copolymer (Shanghai McLean, SMA1000 resin, Mn≈2300) was dissolved in xylene (anhydrous grade) in a mass ratio of 7:3 and stirred at 80°C under nitrogen protection until completely dissolved. Monodisperse methacrylate glycidyl microspheres (15% of the mass of the polystyrene maleic anhydride copolymer, particle size 0.1 μm) and initiator diisopropyl peroxide (99%, 0.8% of the total mass of the polystyrene maleic anhydride copolymer and the monodisperse methacrylate glycidyl microspheres) were then added thereto with stirring. After completion, the temperature was raised to 105°C for reaction for 3 hours. After completion, the reaction solution was obtained, and then the reaction solution was poured into excess acetone for precipitation. After filtration, the precipitate was washed three times with anhydrous ethanol, and then dried in vacuo at 70°C for 12 hours to obtain white powder SMA-GMA.

[0044] Example 8

[0045] Preparation of SMA-GMA: Polystyrene maleic anhydride copolymer (Shanghai McLean, SMA1000 resin, Mn≈2300) was dissolved in xylene (anhydrous grade) in a mass ratio of 7:3 and stirred at 80°C under nitrogen protection until completely dissolved. Monodisperse methacrylate glycidyl microspheres (15% of the mass of the polystyrene maleic anhydride copolymer, particle size 0.1 μm) and initiator diisopropyl peroxide (99%, 1.0% of the total mass of the polystyrene maleic anhydride copolymer and the monodisperse methacrylate glycidyl microspheres) were then added thereto with stirring. After completion, the temperature was raised to 105°C for reaction for 4 hours. After completion, the reaction solution was obtained, and then the reaction solution was poured into excess acetone for precipitation. After filtration, the precipitate was washed three times with anhydrous ethanol and then dried in vacuo at 70°C for 12 hours to obtain white powder SMA-GMA.

[0046] Example 9

[0047] Preparation of SMA-GMA: Polystyrene maleic anhydride copolymer (Shanghai McLean, SMA1000 resin, Mn≈2300) was dissolved in xylene (anhydrous grade) in a mass ratio of 7:3 and stirred at 80°C under nitrogen protection until completely dissolved. Monodisperse methacrylate glycidyl microspheres (15% of the mass of the polystyrene maleic anhydride copolymer, particle size 0.1 μm) and initiator diisopropyl peroxide (99%, 1.0% of the total mass of the polystyrene maleic anhydride copolymer and the monodisperse methacrylate glycidyl microspheres) were then added thereto with stirring. After completion, the temperature was raised to 110°C for reaction for 4 hours. After completion, the reaction solution was obtained, and then the reaction solution was poured into excess acetone for precipitation. After filtration, the precipitate was washed three times with anhydrous ethanol and then dried in vacuo at 80°C for 12 hours to obtain white powder SMA-GMA.

[0048] Example 10

[0049] Preparation of highly flame-retardant ABS composite materials: First, the highly flame-retardant ABS composite material includes the following raw materials in parts by weight: ABS 70 copies; 8 parts of microencapsulated red phosphorus; 7 parts of the silica-coated aluminum hypophosphite prepared in Example 1; 5 parts of the modified zinc-cobalt-aluminum hydrotalcite prepared in Example 4; 5 parts of SMA-GMA prepared in Example 7; 0.5 parts of antioxidant; 0.5 parts of ethylene bisstearamide.

[0050] Then, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: S1. Premixing: Weigh the above raw materials in parts by mass, and stir microcapsule red phosphorus (25-30 μm, AMGARD CRP, red phosphorus mass fraction of 85%, Albright & Wilson, UK), silica-coated aluminum hypophosphite prepared in Example 1, modified zinc-cobalt-aluminum hydrotalcite prepared in Example 4, and SMA-GMA prepared in Example 7 at 80° C. for 10 min to obtain a premix; S2. Melt blending: The above premix was extruded with ABS (Chimei PA-757, Taiwan, China), an antioxidant (BASF 1010 / 168 (mass ratio 1:1)) and ethylene bisstearamide (EBS, Dezhou Hongchen Chemical) in a twin-screw extruder (temperature section: first section 190°C ~ second section 200°C ~ third section 210°C ~ fourth section 205°C ~ fifth section 200°C, rotation speed: 350 rpm, vacuum degree: -0.08 MPa) to obtain a highly flame-retardant ABS composite material.

[0051] Example 11

[0052] Preparation of highly flame-retardant ABS composite materials: First, the highly flame-retardant ABS composite material includes the following raw materials in parts by weight: ABS 70 copies; 10 parts of microencapsulated red phosphorus; 8 parts of the silica-coated aluminum hypophosphite prepared in Example 2; 6 parts of the modified zinc-cobalt-aluminum hydrotalcite prepared in Example 5; 6 parts of SMA-GMA prepared in Example 8; 1.0 part of antioxidant; 1.0 part of ethylene bisstearamide.

[0053] Then, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: S1. Premixing: Weigh the above raw materials according to parts by mass, and stir microcapsule red phosphorus (25-30 μm, AMGARD CRP, red phosphorus mass fraction of 85%, Albright & Wilson, UK), silica-coated aluminum hypophosphite prepared in Example 2, modified zinc-cobalt-aluminum hydrotalcite prepared in Example 5, and SMA-GMA prepared in Example 8 at 100° C. for 30 min to obtain a premix; S2. Melt blending: The above premix was extruded with ABS (Chimei PA-757, Taiwan, China), an antioxidant (BASF 1010 / 168 (mass ratio 1:1)) and ethylene bisstearamide (EBS, Dezhou Hongchen Chemical) in a twin-screw extruder (temperature section: first section 190°C ~ second section 200°C ~ third section 210°C ~ fourth section 205°C ~ fifth section 200°C, rotation speed: 350 rpm, vacuum degree: -0.08 MPa) to obtain a highly flame-retardant ABS composite material.

[0054] Example 12 Preparation of highly flame-retardant ABS composite materials: First, the highly flame-retardant ABS composite material includes the following raw materials in parts by weight: ABS 70 copies; 10 parts of microencapsulated red phosphorus; 8 parts of the silica-coated aluminum hypophosphite prepared in Example 3; 7 parts of the modified zinc-cobalt-aluminum hydrotalcite prepared in Example 6; 7 parts of SMA-GMA prepared in Example 9; 1.0 part of antioxidant; 1.0 part of ethylene bisstearamide.

[0055] Then, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: S1. Premixing: Weigh the above raw materials according to parts by mass, and stir microcapsule red phosphorus (25-30 μm, AMGARD CRP, red phosphorus mass fraction of 85%, Albright & Wilson, UK), silica-coated aluminum hypophosphite prepared in Example 3, modified zinc-cobalt-aluminum hydrotalcite prepared in Example 6, and SMA-GMA prepared in Example 9 at 100° C. for 30 min to obtain a premix; S2. Melt blending: The above premix was extruded with ABS (Chimei PA-757, Taiwan, China), an antioxidant (BASF 1010 / 168 (mass ratio 1:1)) and ethylene bisstearamide (EBS, Dezhou Hongchen Chemical) in a twin-screw extruder (temperature section: first section 190°C ~ second section 200°C ~ third section 210°C ~ fourth section 205°C ~ fifth section 200°C, rotation speed: 350 rpm, vacuum degree: -0.08 MPa) to obtain a highly flame-retardant ABS composite material.

[0056] Comparative Example 1 Comparative Example 1 is the control group of Example 11. The raw materials "microcapsule red phosphorus, silica-coated aluminum hypophosphite prepared in Example 2, modified zinc-cobalt-aluminum hydrotalcite prepared in Example 5, and SMA-GMA" in Example 11 are replaced with equal parts by mass of magnesium hydroxide. The remaining raw materials, raw material amounts, and preparation steps remain the same as in Example 11, and a highly flame-retardant ABS composite material is finally obtained, which is specifically as follows: Preparation of highly flame-retardant ABS composite materials: First, the highly flame-retardant ABS composite material includes the following raw materials in parts by weight: ABS 70 copies; 30 parts of magnesium hydroxide; 1.0 part of antioxidant; 1.0 part of ethylene bisstearamide.

[0057] Then, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: The above raw materials were weighed according to mass parts, and magnesium hydroxide (Shanghai McLean) was extruded with ABS (Chimei PA-757, Taiwan, China), an antioxidant (BASF 1010 / 168 (mass ratio 1:1)) and ethylene bisstearamide (EBS, Dezhou Hongchen Chemical) in a twin-screw extruder (temperature section: first section 190°C ~ second section 200°C ~ third section 210°C ~ fourth section 205°C ~ fifth section 200°C, rotation speed: 350 rpm, vacuum degree: -0.08 MPa) to obtain a highly flame-retardant ABS composite material.

[0058] Comparative Example 2 Comparative Example 2 is the control group of Example 11. The raw material "silicon dioxide-coated aluminum hypophosphite prepared in Example 2" in Example 11 is replaced by an equal mass portion of raw material aluminum hypophosphite (Shanghai McLean), that is, the silica coating process is cancelled, and the remaining raw materials, raw material amounts and preparation steps remain the same as in Example 11, and finally a highly flame-retardant ABS composite material is obtained.

[0059] Comparative Example 3 Comparative Example 3 is the control group of Example 11. The raw material "modified zinc-cobalt-aluminum hydrotalcite prepared in Example 5" in Example 11 is replaced by an equal mass portion of zinc-cobalt-aluminum hydrotalcite prepared by A2 in Example 5, that is, the modification process is cancelled. The remaining raw materials, raw material amounts and preparation steps remain the same as in Example 11, and finally a highly flame-retardant ABS composite material is obtained.

[0060] Comparative Example 4 Comparative Example 4 is the control group of Example 11. The raw material "SMA-GMA prepared in Example 8" in Example 11 is replaced by an equal mass portion of raw material polystyrene maleic anhydride copolymer (Shanghai McLean, SMA1000 resin, Mn≈2300), that is, the SMA-GMA reaction compatibilization process is cancelled, and the remaining raw materials, raw material amounts and preparation steps remain the same as in Example 11, and finally a highly flame retardant ABS composite material is obtained.

[0061] Comparative Example 5 Comparative Example 5 is a control group of Example 11. The raw materials "modified zinc-cobalt-aluminum hydrotalcite prepared in Example 5 and SMA-GMA prepared in Example 8" in Example 11 are removed, that is, a single flame retardant component is missing. The remaining raw materials, raw material amounts and preparation steps remain the same as in Example 11, and a highly flame retardant ABS composite material is finally obtained, which is as follows: Preparation of highly flame-retardant ABS composite materials: First, the highly flame-retardant ABS composite material includes the following raw materials in parts by weight: ABS 70 copies; 10 parts of microencapsulated red phosphorus; 8 parts of the silica-coated aluminum hypophosphite prepared in Example 2; 1.0 part of antioxidant; 1.0 part of ethylene bisstearamide.

[0062] Then, the preparation method of the highly flame-retardant ABS composite material comprises the following steps: S1. Premixing: Weigh the above raw materials according to parts by mass, and stir microcapsule red phosphorus (25-30 μm, AMGARD CRP, red phosphorus mass fraction of 85%, Albright & Wilson, UK) and the silica-coated aluminum hypophosphite prepared in Example 2 at 100° C. for 30 min to obtain a premix; S2. Melt blending: The above premix was extruded with ABS (Chimei PA-757, Taiwan, China), an antioxidant (BASF 1010 / 168 (mass ratio 1:1)) and ethylene bisstearamide (EBS, Dezhou Hongchen Chemical) in a twin-screw extruder (temperature section: first section 190°C ~ second section 200°C ~ third section 210°C ~ fourth section 205°C ~ fifth section 200°C, rotation speed: 350 rpm, vacuum degree: -0.08 MPa) to obtain a highly flame-retardant ABS composite material.

[0063] The performance test was performed on the highly flame-retardant ABS composite materials prepared in Examples 10 to 12 and Comparative Examples 1 to 5. The performance test process is as follows, and the test results are shown in Table 1: 1. Flame retardant properties: (1) UL94 vertical burning (GB / T 2408-2021): Sample size 125×13×3 mm, record the burning time and the ignition of cotton wool by dripping.

[0064] (2) Limiting oxygen index (LOI) (GB / T 2406.2-2009): Sample size 100 × 10 × 3 mm, ignited in nitrogen and oxygen mixture, and the self-extinguishing oxygen concentration was measured.

[0065] 2. Mechanical properties: (1) Simply supported beam impact strength (GB / T 1043.1-2008): specimen 80 × 10 × 4 mm, V-notch, impact velocity 2.9 m / s.

[0066] (2) Tensile strength (GB / T 1040.2-2006): dumbbell-shaped specimen, tensile rate 50 mm / min.

[0067] 3. Stability: (1) Melt flow rate (MFR) fluctuation (GB / T 3682-2018): Test conditions: 220℃ / 10kg, sample once every 30 minutes, test 5 times in a row, calculate the average value, and calculate the fluctuation rate according to the following formula: .

[0068] Table 1 Test results project Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 UL94(3mm) V-0 V-0 V-0 V-1 V-2 V-0 V-0 V-1 LOI(%) 33.5 34.0 33.8 28.5 30.2 31.5 32.0 29.8 <![CDATA[Impact strength (kJ / m 2 )]]> 16.2 16.8 16.5 9.5 13.0 14.0 14.5 12.2 Tensile strength (MPa) 46.3 47.0 46.8 38.0 42.5 43.8 44.2 41.0 MFR volatility (%) 4.2 3.8 4.0 8.5 18.5 6.0 5.5 7.2 According to the data analysis in Table 1: 1. Flame retardant performance analysis (UL94 / LOI): Examples 10 to 12 (containing microencapsulated red phosphorus + SiO2-coated aluminum hypophosphite + modified zinc-cobalt-aluminum hydrotalcite + SMA-GMA) all reached UL94 V-0 grade with LOI>33%, demonstrating that high-efficiency flame retardancy can be achieved at low addition amounts; Comparative Example 1 (using only magnesium hydroxide): UL94 V-1 grade, LOI 28.5%, verifying that traditional flame retardants require high filling amounts and have insufficient performance; Comparative Example 2 (uncoated aluminum hypophosphite): UL94 V-2 grade, LOI 30.2%, indicating that the SiO2 coating layer is crucial for thermal stability (avoiding pre-decomposition of aluminum hypophosphite); Comparative Example 5 (lacking modified zinc-cobalt-aluminum hydrotalcite + SMA-GMA): UL94 V-1 grade, LOI 29.8%, confirming that the catalytic carbonization effect of the modified zinc-cobalt-aluminum hydrotalcite and the SMA-GMA interface compatibilization are indispensable.

[0069] Impact of the lack of key components: Comparative Example 3 (unmodified zinc-cobalt-aluminum hydrotalcite): Although it reached the V-0 grade, the LOI dropped to 31.5% (lower than 34.0% in Example 11), indicating that stearic acid modification improved the dispersibility of zinc-cobalt-aluminum hydrotalcite and optimized the flame retardant efficiency; Comparative Example 4 (without SMA-GMA): The V-0 grade was maintained but the LOI was 32.0%, indicating that SMA-GMA had a small direct contribution to flame retardancy and mainly affected mechanical properties.

[0070] 2. Mechanical properties analysis (impact / tensile strength): Synergistic toughening of SMA-GMA and modified zinc-cobalt-aluminum hydrotalcite: Example 11 Impact strength 16.8 kJ / m 2 , significantly higher than: Comparative Example 3 (unmodified zinc-cobalt-aluminum hydrotalcite): 14.0 kJ / m 2 (17% decrease); Comparative Example 4 (no SMA-GMA): 14.5 kJ / m 2 (A decrease of 14%). Reason analysis: The carboxyl group of SMA-GMA forms an ionic bond with the hydroxyl group of zinc-cobalt-aluminum hydrotalcite, which enhances the interface bonding and reduces stress concentration.

[0071] Modified zinc-cobalt-aluminum hydrotalcite improves strength by 7.3% compared to Example 11 (tensile strength 47.0 MPa) and Comparative Example 3 (43.8 MPa), proving that stearic acid modification improves dispersibility and avoids agglomeration and weakening of the matrix. Comparative Example 1 (magnesium hydroxide system): impact strength is only 9.5 kJ / m 2 (a decrease of 44%), indicating the damage to mechanical properties caused by traditional flame retardants.

[0072] 3. Stability analysis (MFR volatility): Thermal stabilization mechanism of SiO2 coating layer The MFR fluctuation rate of Examples 10 to 12 is ≤4.2%, while the fluctuation rate of Comparative Example 2 (uncoated aluminum hypophosphite) reaches 18.5%, which proves that SiO2 coating delays the decomposition peak of aluminum hypophosphite and avoids melt fluctuation caused by pre-decomposition; Comparative Example 3 (unmodified zinc-cobalt-aluminum hydrotalcite): the fluctuation rate is 6.0%, indicating that the modification further improves the stability.

[0073] Auxiliary stabilization effect of SMA-GMA: Comparative Example 4 (without SMA-GMA): The fluctuation rate of 5.5% is still higher than that of Example 11 (3.8%), indicating that SMA-GMA reduces the rheological fluctuation caused by flame retardant agglomeration by enhancing the interfacial compatibility.

[0074] 4. Conclusion and Analysis: (1) Synergy of triple flame retardant system: microencapsulated red phosphorus (vapor phase flame retardant), SiO2 coated aluminum hypophosphite (carbon formation catalyst), modified zinc cobalt aluminum hydrotalcite (catalysis + dispersion) achieve V-0 flame retardancy at low addition amount (compared with traditional system); (2) The core value of interfacial compatibilization: SMA-GMA generates ionic bonds through carboxyl-hydroxyl reactions, which increases the impact strength by 10% (compared to the uncompatibilized system), breaking through the industry problem of decreased mechanical properties of flame-retardant composite materials; (3) Impact of component omission: The absence of any key component (such as SiO2 coating, zinc-cobalt-aluminum hydrotalcite modification, SMA-GMA) will lead to a significant decrease in flame retardancy, mechanical or processing properties, verifying the necessity of a complete technical solution.

[0075] It should be noted that, in this document, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0076] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A highly flame retardant ABS composite material, characterized in that: Including the following raw materials by weight: ABS 70 copies; 8-10 parts of microencapsulated red phosphorus; 7-8 parts of silicon dioxide-coated aluminum hypophosphite; 5-7 parts of modified zinc-cobalt-aluminum hydrotalcite; SMA-GMA 5-7 parts; 0.5-1.0 parts of antioxidant; 0.5-1.0 parts of ethylene bisstearamide.

2. A highly flame-retardant ABS composite material according to claim 1, characterized in that: The silica-coated aluminum hypophosphite is prepared by the following steps: immersing the aluminum hypophosphite in an ethanol solution with a volume fraction of 25% to 30%, adding ethyl orthosilicate thereto with stirring, adjusting the pH of the system to 8.8 to 9.0 with ammonia water, heating the system to 55 to 60° C., stirring at a constant temperature for 2 to 3 hours, and cooling, filtering, washing, and drying to obtain the silica-coated aluminum hypophosphite.

3. A highly flame-retardant ABS composite material according to claim 2, characterized in that: The amount of the ethyl orthosilicate used is 15% to 20% of the mass of the aluminum hypophosphite.

4. The highly flame-retardant ABS composite material according to claim 1, characterized in that: The modified zinc-cobalt-aluminum hydrotalcite is prepared by the following steps: A1. Dissolve Zn(NO3)2, Co(NO3)2, and Al(NO3)3 in deionized water at a molar ratio of Zn:Co:Al=2:1:1 to obtain a salt solution; then mix 2.4 mol / L NaOH solution and 0.8 mol / L Na2CO3 solution at a volume ratio of 1:1 to obtain an alkaline solution; A2. The salt solution and the alkaline solution were simultaneously added dropwise to the reactor at a rate of 1.5 mL / min. The reactor was heated to 55-60°C under nitrogen protection and aged at this temperature for 24 hours. After completion, the reactor was cooled to room temperature, the precipitate was collected by centrifugation, and the precipitate was washed with deionized water to a pH of 7. The solid component was collected by filtration, dried, and then ground through a 100-mesh sieve to obtain zinc-cobalt-aluminum hydrotalcite. A3. Stearic acid and anhydrous ethanol were stirred and dissolved in a 60°C water bath in a mass ratio of 1:4 to obtain a modified solution. The modified solution was sprayed onto the surface of the zinc-cobalt-aluminum hydrotalcite. After completion, the solution was dried in a hot air circulation system at 55-60°C for 30 minutes. After completion, the solution was crushed and passed through a 100-mesh sieve to obtain a modified zinc-cobalt-aluminum hydrotalcite.

5. The highly flame-retardant ABS composite material according to claim 4, characterized in that: The total concentration of metal ions in the salt solution in A1 is 1.5 mol / L.

6. The highly flame-retardant ABS composite material according to claim 4, characterized in that: The usage ratio of the modified solution and zinc-cobalt-aluminum hydrotalcite in A3 is 0.1-1 mL:1 g.

7. The highly flame-retardant ABS composite material according to claim 1, characterized in that: The SMA-GMA is prepared by the following steps: Polystyrene maleic anhydride copolymer was dissolved in xylene in a mass ratio of 7:3 and stirred at 80°C under nitrogen protection until completely dissolved. Monodisperse glycidyl methacrylate microspheres and dicumyl peroxide were then added thereto with stirring. After completion, the temperature was raised to 105-110°C for reaction for 3-4 hours. After completion, a reaction solution was obtained, which was then poured into excess acetone for precipitation. The solution was filtered, washed with anhydrous ethanol, and vacuum dried to obtain SMA-GMA.

8. The highly flame-retardant ABS composite material according to claim 7, characterized in that: The amount of the monodisperse glycidyl methacrylate microspheres is 15% of the mass of the polystyrene maleic anhydride copolymer; the particle size of the monodisperse glycidyl methacrylate microspheres is 0.1 μm; and the amount of the dicumyl peroxide is 0.8% to 1.0% of the total mass of the polystyrene maleic anhydride copolymer and the monodisperse glycidyl methacrylate microspheres.

9. A method for preparing a highly flame-retardant ABS composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Weigh the above raw materials in parts by mass, and stir the microcapsule red phosphorus, silica-coated aluminum hypophosphite, modified zinc-cobalt-aluminum hydrotalcite, and SMA-GMA at 80-100° C. for 10-30 min to obtain a premix; S2. Extruding the premix, ABS, antioxidant and ethylene bisstearamide in a twin-screw extruder to obtain a highly flame-retardant ABS composite material.

10. The method for preparing a highly flame-retardant ABS composite material according to claim 9, characterized in that: The particle size of the microcapsule red phosphorus is 25 to 30 μm; the mass fraction of red phosphorus in the microcapsule red phosphorus is 85%; and the antioxidant is prepared by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.