Flame-retardant reinforced PC / ABS injection molding material based on reclaimed materials and preparation method thereof

Abstract

The invention provides a flame-retardant reinforced PC / ABS injection molding material based on recycled materials and a preparation method thereof. The flame-retardant reinforced PC / ABS injection molding material comprises the following components in parts by weight: 60-80 parts of recycled PC / ABS base material; 8-15 parts of a phosphorus-nitrogen composite flame retardant; and 2-5 parts of a synergist. The recycled PC / ABS base material is used in a high proportion, and the reinforcing agent compounded by the acrylic acid modified polytetrafluoroethylene fiber and the nano kaolin and the compatilizer compounded by the styrene-acrylonitrile-glycidyl methacrylate and the polyphenyl ether-maleic anhydride graft polymer are combined, so that the performance degradation of the recycled material is repaired; the phosphorus-nitrogen composite flame retardant and the halloysite nanotube / talcum powder synergist are cooperated, so that low-addition-amount efficient halogen-free flame retardance is realized; the interface compatibility of PC and ABS is improved by compounding the compatilizer; according to the flame-retardant and environment-friendly recycled material and the preparation method thereof, ultrasonic cleaning, drying pretreatment and nitrogen protection melt blending processes are matched, flame retardance and enhancement performance are synergistically optimized, processing stability is considered, and the problems that the recycled material is low in utilization rate, insufficient in flame retardance and environment friendliness, poor in compatibility and insufficient in functional adaptability are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a flame retardant reinforced PC / ABS injection molding material based on recycled materials and a preparation method thereof. Background Art

[0002] PC / ABS alloy combines the high strength and heat resistance of polycarbonate (PC) with the toughness and easy processing of acrylonitrile-butadiene-styrene copolymer (ABS). Its comprehensive performance is adapted to the needs of multiple scenarios. It has excellent mechanical properties, can withstand long-term dynamic loads and impacts, has good dimensional stability, and is suitable for precision structural parts; it has good processability and can efficiently produce thin-walled, complex structural parts through injection molding, with a smooth surface after molding; its heat resistance can meet the temperature requirements of the surrounding areas of the car engine compartment and the heat dissipation area of ​​electronic equipment. Therefore, this alloy is widely used in the automotive field for interior parts (such as dashboards, center consoles), exterior parts (such as rearview mirror housings) and functional parts (such as sensor brackets), as well as notebook cases, smartphone mid-frames, 5G base station components, etc. in the electronics field.

[0003] 1. The recycling rate of recycled materials is low and their performance deteriorates significantly: Traditional recycling only involves crushing and melting, without repairing internal defects, resulting in molecular chain breakage and reduced cross-linking density. The tensile strength is 20-30% lower than that of virgin materials, and the notched impact strength is 30-40% lower. This makes it difficult to meet high-end needs and is often downgraded for use, resulting in a waste of resources.

[0004] Second, the flame retardant system is inefficient and questionable for environmental friendliness: Brominated flame retardants must be added at least 20% to meet standards, but are toxic and do not comply with environmental regulations. Halogen-free flame retardants must be added at least 25%, which is costly and degrades the mechanical and processing properties of the material.

[0005] 3. Poor compatibility between PC and ABS in recycled materials: loss of compatibilizer and mixing of impurities during the recycling process increase the interfacial tension between PC and ABS, leading to separation of the two phases and easy delamination and cracking of the finished product;

[0006] 4. Insufficient processing stability and functional adaptability: Residual moisture and small molecules in recycled materials can easily cause bubbles and silver streaks in finished products, resulting in a low pass rate. Furthermore, there is a contradiction between flame retardancy and reinforcement performance, making it difficult to simultaneously meet the requirements of UL94V-0 flame retardancy and tensile strength ≥60MPa.

[0007] To this end, a flame retardant reinforced PC / ABS injection molding material based on recycled materials and a preparation method thereof are proposed. Summary of the Invention

[0008] In view of this, the embodiments of the present invention hope to provide a flame retardant reinforced PC / ABS injection molding material based on recycled materials and a preparation method thereof, so as to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0009] To solve the above technical problems, a technical solution adopted in this application is: a flame retardant reinforced PC / ABS injection molding material based on recycled materials, comprising the following components in parts by weight:

[0010] Recycle 60-80 parts of PC / ABS base material;

[0011] 8-15 parts of phosphorus-nitrogen composite flame retardant;

[0012] 2-5 parts of a synergist, which is a compound of halloysite nanotubes and talc;

[0013] 3-7 parts of a reinforcing agent, which is a compound of acrylic acid-modified polytetrafluoroethylene fiber and nano-kaolin;

[0014] 5-10 parts of a compatibilizer, which is a compound of styrene-acrylonitrile-glycidyl methacrylate and polyphenylene ether-maleic anhydride graft polymer;

[0015] 1-3 parts of auxiliary additives.

[0016] As a further preferred embodiment of the present technical solution, the phosphorus-nitrogen composite flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3:1.

[0017] As a further preferred embodiment of the present technical solution, the mass ratio of the halloysite nanotubes to the talc in the synergist is 1:3.

[0018] As a further preferred embodiment of the present technical solution, the mass ratio of acrylic acid modified polytetrafluoroethylene fiber to nano-kaolin in the reinforcing agent is 2:1, and the reinforcing agent is surface hydroxylated.

[0019] As a further preferred embodiment of the present technical solution, the mass ratio of styrene-acrylonitrile-glycidyl methacrylate to polyphenylene ether-maleic anhydride graft polymer in the compatibilizer is 6:4.

[0020] As a further preferred embodiment of the present technical solution, the auxiliary additives include an antioxidant, a lubricant and an anti-dripping agent, wherein the antioxidant is a compound of hindered phenol 1010 and phosphite 168, the lubricant is molybdenum disulfide extreme pressure lithium grease, and the anti-dripping agent is polytetrafluoroethylene powder; the mass ratio of the antioxidant, lubricant and anti-dripping agent in the auxiliary additives is 2:1:1.

[0021] As a further preferred embodiment of the present technical solution, the recycled PC / ABS base material is derived from waste electronic and electrical appliance housings or automotive interior trims, and is pre-treated by crushing, ultrasonic cleaning, and drying to have a purity of ≥95% and a moisture content of ≤0.05%.

[0022] To solve the above technical problems, another technical solution adopted in this application is: a method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials, comprising the following steps:

[0023] Step 1: crush the recycled PC / ABS waste through a crusher and screen to obtain particles with a particle size of 3-5 mm;

[0024] Step 2: Place the particles in 50°C deionized water and ultrasonically clean them for 30 minutes to remove surface oil and impurities;

[0025] Step 3: Dry the washed particles at 80°C for 4 hours to obtain dried particles;

[0026] Step 4: premix the phosphorus-nitrogen composite flame retardant, synergist, reinforcing agent and part of the compatibilizer at 60° C. and 120 r / min for 5 min, and then melt-granulate through a twin-screw extruder at 220-240° C. and 300 r / min to obtain a premixed masterbatch;

[0027] Step 5: Add the dried particles, premixed masterbatch, remaining compatibilizer and auxiliary additives into a twin-screw extruder, melt-blend under nitrogen protection, and extrude into granules to obtain composite material granules;

[0028] Step 6: After drying the composite material pellets at 100° C. for 6 hours, injection molding is performed by an injection molding machine at 240-260° C. and a mold temperature of 80-100° C. to obtain a flame retardant reinforced PC / ABS injection molding material based on recycled materials.

[0029] As a further preferred embodiment of the present technical solution, in step 4, the partial compatibilizer is styrene-acrylonitrile-glycidyl methacrylate, which accounts for 50-60% of the total mass of the compatibilizer.

[0030] As a further preferred embodiment of the present technical solution, in step five, the remaining compatibilizer is a polyphenylene ether-maleic anhydride graft polymer; the ratio of the twin-screw extruder feed rate to the screw speed is 1:1.2, and the nitrogen flow rate is 2-3 L / min.

[0031] The embodiment of the present invention adopts the above technical solution, which has the following advantages:

[0032] 1. The present invention uses a high proportion of recycled PC / ABS base materials, and combines a reinforcing agent and a compound compatibilizer of acrylic modified polytetrafluoroethylene fiber and nano-kaolin to repair the molecular chain defects of the recycled materials and improve the mechanical properties, thus solving the problems of low recycling rate and significant performance degradation of recycled materials.

[0033] 2. The present invention achieves high flame retardancy at a low addition level of 8-15 parts through the synergistic effect of the phosphorus-nitrogen composite flame retardant and the halloysite nanotube / talc synergist, and is halogen-free and environmentally friendly, solving the problems of insufficient efficiency and questionable environmental friendliness of flame retardant systems.

[0034] 3. The present invention uses a composite compatibilizer of styrene-acrylonitrile-glycidyl methacrylate and polyphenylene ether-maleic anhydride graft polymer to specifically improve the interfacial compatibility between PC and ABS, reduce the two-phase separation caused by the recycling process, and solve the problem of poor compatibility between PC and ABS in recycled materials;

[0035] 4. The present invention controls the moisture content through ultrasonic cleaning and drying pretreatment, and reduces thermal degradation by melt blending under nitrogen protection. At the same time, the flame retardant and reinforcement systems are synergistically designed to take into account the requirements of UL94V-0 flame retardancy and tensile strength ≥60MPa, thereby solving the problems of insufficient processing stability and functional adaptability.

[0036] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 The figure is a schematic flow chart of a method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials according to the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0040] It should be clear that the following embodiments of the present disclosure are described through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other in the absence of conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0041] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0042] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0043] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.

[0044] Example 1

[0045] A flame retardant reinforced PC / ABS injection molding material based on recycled materials, comprising the following components in parts by weight:

[0046] Recycle 60-80 parts of PC / ABS base material; the recycled PC / ABS base material comes from waste electronic and electrical housings or automotive interior parts. It needs to be crushed, ultrasonically cleaned (50℃ deionized water, 30 minutes), and air-dried at 80℃ for 4 hours to ensure purity ≥95% and moisture content ≤0.05% before being used as the main base material of the material;

[0047] 8-15 parts of a phosphorus-nitrogen composite flame retardant; the phosphorus-nitrogen composite flame retardant is preferably a mixture of ammonium polyphosphate (APP) and melamine cyanurate (MCA) in a mass ratio of 3:1, and achieves high flame retardancy through the synergistic effect of condensed phase carbonization and gas phase flame retardancy;

[0048] 2-5 parts of a synergist; the synergist is a compound of halloysite nanotubes (HNTs) and talc in a mass ratio of 1:3, which promotes the densification of the carbon layer during the flame retardant process and improves the flexural strength of the material;

[0049] 3-7 parts of reinforcing agent; the reinforcing agent is compounded by acrylic modified polytetrafluoroethylene fiber (PTFE) and nano-kaolin in a mass ratio of 2:1, and is surface hydroxylated to enhance the interface bonding with the PC / ABS matrix and improve the mechanical properties of the material;

[0050] 5-10 parts of compatibilizer; the compatibilizer is a mixture of styrene-acrylonitrile-glycidyl methacrylate (SAN-GMA) and polyphenylene ether-maleic anhydride graft polymer (PPO-g-MAH) in a mass ratio of 6:4. It improves the compatibility of PC and ABS in the recycled material through reactive compatibilization and reduces the separation of the two phases;

[0051] 1-3 parts of auxiliary additives; the auxiliary additives include antioxidants, lubricants and anti-dripping agents, wherein the antioxidant is a compound of hindered phenol 1010 and phosphite 168, the lubricant is molybdenum disulfide extreme pressure lithium grease, and the anti-dripping agent is polytetrafluoroethylene powder. The mass ratio of the three is 2:1:1, which respectively play the roles of resisting thermal oxidative aging, improving processing fluidity and preventing melt dripping.

[0052] In one embodiment, specifically: the phosphorus-nitrogen composite flame retardant is prepared by mixing ammonium polyphosphate and melamine cyanurate in a mass ratio of 3:1;

[0053] Among them, ammonium polyphosphate, as a phosphorus-based flame retardant, can promote the formation of an expanded carbon layer at high temperatures, which plays a role in heat insulation and oxygen isolation; melamine cyanurate, as a nitrogen-based flame retardant, releases inert gases such as ammonia when heated, diluting combustible gases and inhibiting combustion reactions; when the two are compounded in a ratio of 3:1, the phosphorus-nitrogen synergistic effect can significantly improve the flame retardant efficiency, so that the flame retardant can achieve UL94V-0 flame retardancy at a low addition amount of 8-15 parts, without relying on toxic brominated flame retardants, complying with environmental protection regulations, and avoiding the problem of deterioration of the material's mechanical properties caused by high addition amounts of a single flame retardant.

[0054] In one embodiment, specifically: the mass ratio of halloysite nanotubes to talc in the synergist is 1:3;

[0055] Among them, halloysite nanotubes have a unique nanotubular structure and a large specific surface area. They can form a physical barrier network in the material, promote the uniform formation and stabilization of the carbon layer during the flame retardant process, and enhance the heat insulation and oxygen isolation effects; talcum powder, as a layered inorganic filler, can further densify the carbon layer and reduce the cracking of the carbon layer. At the same time, it improves the mechanical properties of the material (such as bending strength) through the filling effect; when the two are compounded in a ratio of 1:3, the nano effect of halloysite nanotubes can be used to enhance the flame retardant synergy, and the processing fluidity of the material can be balanced by the appropriate addition of talcum powder, avoiding the dispersion difficulty caused by excessive nano components.

[0056] In one embodiment, specifically: the mass ratio of acrylic acid modified polytetrafluoroethylene fiber to nano-kaolin in the reinforcing agent is 2:1, and the reinforcing agent is surface hydroxylated;

[0057] Among them, acrylic modified polytetrafluoroethylene fiber (PTFE fiber) has excellent toughness and impact resistance. As a continuous phase reinforcement, it can improve the tensile and impact resistance of the material. Nano-kaolin, as a nano-scale filler, can fill the internal defects of the matrix and enhance the rigidity and dimensional stability of the material. When the two are compounded in a 2:1 ratio, the fiber can form a mechanical support network and the nano-kaolin fills the gaps in the network, achieving a "toughness-rigidity" balance and avoiding performance imbalances caused by excessive amounts of a single component (such as excessive fibers affecting processing fluidity and excessive nanoparticles causing agglomeration).

[0058] The role of surface hydroxylation treatment is to strengthen the interface bonding between the reinforcing agent and the PC / ABS matrix: the hydroxyl group (-OH) can form hydrogen bonds or intermolecular forces with the ester group in the PC molecular chain and the polar group in the ABS, reducing the interface defects between the reinforcing agent and the matrix, improving the stress transfer efficiency, and thus more effectively exerting the reinforcing effect.

[0059] In one embodiment, specifically: the mass ratio of styrene-acrylonitrile-glycidyl methacrylate to polyphenylene ether-maleic anhydride graft polymer in the compatibilizer is 6:4;

[0060] Among them, the glycidyl methacrylate (GMA) in the SAN-GMA molecular chain contains epoxy groups, which can undergo a ring-opening reaction with the terminal hydroxyl groups in the PC molecular chain to form chemical bonds, thereby reducing the interfacial tension of the PC phase; the maleic anhydride (MAH) group in PPO-g-MAH can react with the double bonds of the butadiene phase in ABS, thereby enhancing the interfacial bonding with the ABS phase; when compounded in a 6:4 ratio, SAN-GMA is mainly responsible for improving the initial interfacial compatibility between PC and ABS, while PPO-g-MAH further strengthens the interfacial bonding strength. The two work together to effectively reduce the separation of the two phases caused by compatibilizer loss and impurity mixing during the recycling process, thereby avoiding delamination and cracking of the product.

[0061] In one embodiment, specifically: the auxiliary additives include an antioxidant, a lubricant, and an anti-dripping agent, wherein the antioxidant is a compound of hindered phenol 1010 and phosphite 168, the lubricant is molybdenum disulfide extreme pressure lithium grease, and the anti-dripping agent is polytetrafluoroethylene powder; the mass ratio of the antioxidant, lubricant, and anti-dripping agent in the auxiliary additives is 2:1:1;

[0062] The antioxidant is a compound of hindered phenol 1010 and phosphite 168. Hindered phenol 1010 is the primary antioxidant, capturing free radicals generated during material processing and use, inhibiting oxidation chain reactions. Phosphite 168 is a secondary antioxidant, decomposing hydroperoxides. The synergistic effect of the two effectively delays the thermal oxidative aging of recycled PC / ABS base materials during high-temperature processing (such as twin-screw extrusion and injection molding), reducing performance degradation caused by molecular chain breakage.

[0063] The lubricant used is molybdenum disulfide extreme pressure lithium grease, which has excellent lubricity and extreme pressure properties. It can reduce the melt viscosity of the material during twin-screw extrusion and injection molding, reduce friction between the material and the equipment, and improve processing fluidity. At the same time, it avoids processing stress concentration caused by impurities in recycled materials and reduces the risk of silver streaks and cracks in the product.

[0064] The anti-drip agent is a polytetrafluoroethylene (PTFE) powder that forms a fibrous network structure when the material burns, entangling the molten material and preventing dripping. Combined with a phosphorus-nitrogen composite flame retardant and a synergist, it further improves the material's flame retardancy (for example, helping it reach UL94V-0) and prevents dripping from causing secondary combustion.

[0065] The three are compounded in a mass ratio of 2:1:1. A higher proportion of antioxidants is used to ensure the stability of the recycled material during multiple processing, and appropriate amounts of lubricants and anti-dripping agents are used to optimize processability and flame retardant integrity respectively. There is no adverse interaction between the components, and the overall performance of the material is synergistically improved.

[0066] In one embodiment, specifically: the recycled PC / ABS base material is derived from scrap electronic and electrical appliance housings or automotive interior parts, and is pre-treated by crushing, ultrasonic cleaning, and drying to a purity of ≥95% and a moisture content of ≤0.05%. By removing impurities and controlling moisture, a foundation is laid for subsequent mixing with components such as flame retardants and reinforcing agents, thereby avoiding problems such as decreased mechanical properties of the material and reduced processing qualification rate due to insufficient purity or excessive moisture content of the recycled material. This is a key pre-treatment link in achieving high-value regeneration of recycled materials.

[0067] Example 2

[0068] Figure 1 Schematic diagram of a method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials according to an embodiment of the present application. Figure 1As shown, a method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials comprises the following steps:

[0069] Step 1: crush the recycled PC / ABS waste through a crusher and screen to obtain particles with a particle size of 3-5 mm;

[0070] Specifically, first, recycled PC / ABS scraps from electronic and electrical appliance housings or automotive interior parts are collected and manually sorted to remove non-PC / ABS impurities such as metal, glass, and other plastics;

[0071] Then, put the sorted pure waste into the crusher, set the crusher screen aperture to 3-5mm, start the equipment to perform the crushing operation, and control the crushing time within 10 minutes to crush the waste into irregular particles;

[0072] Then, after the crushing is completed, the material is screened through a vibrating screen to separate particles with a particle size within the range of 3-5mm, and materials with a particle size that is too large (>5mm) or too small (<3mm) are eliminated;

[0073] Finally, a laser particle size analyzer is used to detect the size distribution of the screened particles to ensure that the D90 of the particles is ≤ 5 mm (that is, the particle size of more than 90% of the particles does not exceed 5 mm) to meet the requirements of material mixing uniformity in subsequent processing.

[0074] Step 2: Place the particles in 50°C deionized water and ultrasonically clean them for 30 minutes to remove surface oil and impurities;

[0075] Specifically, first, prepare a KQ-500DE CNC ultrasonic cleaner (power 500W, frequency 40kHz), and add 50°C deionized water into the cleaning tank, with the amount of water being sufficient to completely immerse the particles to be cleaned;

[0076] Then, place the recycled PC / ABS particles with a particle size of 3-5 mm obtained by screening in step 1 into a cleaning basket, and then place the cleaning basket into the deionized water in the cleaning tank to ensure that the particles are completely immersed in the water;

[0077] Next, start the ultrasonic cleaner and set the cleaning time to 30 minutes. During the cleaning process, replace the 50°C deionized water every 10 minutes to enhance the removal of impurities such as surface oil and release agent residues.

[0078] Finally, after 30 minutes of cleaning, the particles are removed from the cleaning basket and prepared for subsequent drying pretreatment.

[0079] Step 3: Dry the washed particles at 80°C for 4 hours to obtain dried particles;

[0080] Specifically, first, prepare the blast drying oven, check the equipment operating status, and ensure that the temperature control accuracy meets the requirements;

[0081] Then, the recycled PC / ABS particles after ultrasonic cleaning in step 2 were evenly spread on the drying tray to avoid excessive accumulation of particles (thickness not exceeding 2 cm) to ensure uniform drying;

[0082] Next, place the tray containing the particles into the blast drying oven, close the door, set the drying temperature to 80°C, the drying time to 4 hours, and turn on the blast function to ensure sufficient circulation of hot air in the oven.

[0083] Finally, after drying, the particles were cooled to room temperature and the moisture content of the particles was tested using a Karl Fischer moisture meter to ensure that the moisture content was ≤ 0.05%, indicating that the dried particles were obtained.

[0084] Step 4: premix the phosphorus-nitrogen composite flame retardant, synergist, reinforcing agent and part of the compatibilizer at 60° C. and 120 r / min for 5 min, and then melt-granulate through a twin-screw extruder at 220-240° C. and 300 r / min to obtain a premixed masterbatch;

[0085] Specifically, first, weigh the phosphorus-nitrogen composite flame retardant (ammonium polyphosphate and melamine cyanurate in a 3:1 ratio), the synergist (halloysite nanotubes and talc in a 1:3 ratio), the reinforcing agent (acrylic acid-modified polytetrafluoroethylene fiber and nano-kaolin in a 2:1 ratio, surface hydroxylated), and part of the compatibilizer (styrene-acrylonitrile-glycidyl methacrylate, accounting for 50-60% of the total weight of the compatibilizer) according to the formula ratio, ensuring that each component is weighed accurately;

[0086] Then, add the weighed materials into the high-speed mixer, close the mixer cover, set the mixing temperature to 60°C, the stirring speed to 120r / min, start the equipment for premixing, and control the premixing time to 5min to ensure that the components are initially dispersed evenly;

[0087] After premixing, the mixed material was fed into the feeding port of the twin-screw extruder, and the extruder temperature profile was set as follows: zone 1 60°C, zone 2 180°C, zone 3 220°C, zone 4 240°C, zone 5 240°C, die head temperature 240°C, screw speed 300 r / min, feeding rate 10 kg / h, for melt blending and granulation;

[0088] Finally, the material after extrusion granulation is screened through a 20-mesh vibrating screen to remove oversized or adhered particles to obtain a premixed masterbatch with a size of 2-4 mm.

[0089] Step 5: Add the dried particles, premixed masterbatch, remaining compatibilizer and auxiliary additives into a twin-screw extruder, melt-blend under nitrogen protection, and extrude into granules to obtain composite material granules;

[0090] Specifically, first, the dried recycled PC / ABS particles obtained in step 3, the premixed masterbatch prepared in step 4, the remaining compatibilizer (polyphenylene ether-maleic anhydride graft polymer, accounting for 40-50% of the total mass of the compatibilizer), and the auxiliary additives (a compound of antioxidants 1010 and 168, molybdenum disulfide extreme pressure lithium grease, and polytetrafluoroethylene powder in a mass ratio of 2:1:1) are weighed according to the formula ratio, ensuring that the weighing error of each material is ≤0.1%;

[0091] Then, check the operating status of the twin-screw extruder and set the temperature distribution: zone 1 80℃, zone 2 200℃, zone 3 240℃, zone 4 240℃, zone 5 240℃, die head temperature 240℃, screw speed 350r / min, and feed rate according to the speed ratio of 1:1.2 (for example, when the speed is 350r / min, the feed rate is about 29kg / h);

[0092] Next, connect the nitrogen protection device and adjust the nitrogen flow rate to 2-3L / min (purity ≥99.99%) to ensure that nitrogen can continuously flow into the extruder barrel and remove the internal air;

[0093] Then, the weighed dry granules, premixed masterbatch, remaining compatibilizer and auxiliary additives are continuously added to the twin-screw extruder in proportion through the main feeding port, and the equipment is started for melt blending. The materials are fully mixed under screw shearing and nitrogen protection to avoid high-temperature oxidative degradation;

[0094] Finally, the blended melt is extruded through a die head and pelletized by an underwater pelletizing system to obtain composite material pellets with a size of 3-5 mm. After screening through a vibrating screen, the moisture content of the pellets is tested (needed to be ≤0.03%).

[0095] Step 6: After drying the composite material pellets at 100° C. for 6 hours, injection molding is performed by an injection molding machine at 240-260° C. and a mold temperature of 80-100° C. to obtain a flame retardant reinforced PC / ABS injection molding material based on recycled materials;

[0096] Specifically, first, prepare the same blast drying oven as in step 3, check the temperature control accuracy of the equipment to ensure that it can stably maintain 100°C; at the same time, evenly spread the composite material pellets (size 3-5mm) obtained in step 5 on the drying tray, avoiding excessive accumulation (thickness ≤ 2cm) to ensure uniform drying;

[0097] Then, place the tray containing the pellets into the drying oven, close the oven door, set the drying temperature to 100°C, the drying time to 6 hours, and turn on the blower function to ensure sufficient circulation of hot air in the oven; after drying, wait for the pellets to cool to room temperature, and use a KarlFischer moisture meter to test the moisture content to ensure that the moisture content is ≤0.02% and set aside;

[0098] Next, prepare the injection molding machine and check the operating status of the equipment barrel, mold and hydraulic system; set the injection molding parameters according to the characteristics of the pellets: barrel temperature zone control is 240-260℃ (zone 1 240℃, zone 2 250℃, zone 3 260℃, zone 4 260℃), mold temperature 80-100℃, holding pressure 80MPa, holding time 15 seconds, cooling time 20 seconds, ejection pressure 50MPa;

[0099] Then add the dried composite material pellets into the injection molding machine hopper, start the equipment for pre-plasticization, and make the pellets fully melt and plasticize in the barrel;

[0100] Finally, after the injection molding machine parameters stabilize, the molding program is started, and the molten material is injected into the mold cavity through the nozzle. After pressure maintenance and cooling and shaping, the product is pushed out of the mold through the ejection mechanism, thus obtaining a flame-retardant reinforced PC / ABS injection molding material based on recycled materials.

[0101] In one embodiment, specifically: in step 4, part of the compatibilizer is styrene-acrylonitrile-glycidyl methacrylate, accounting for 50-60% of the total mass of the compatibilizer; the core purpose of this design is to utilize the reactivity and dispersibility advantages of SAN-GMA to promote the uniform dispersion of functional components in the premixing stage: the glycidyl methacrylate (GMA) group contained in the SAN-GMA molecular chain has epoxy activity, which can interact with the polar groups in components such as the phosphorus-nitrogen composite flame retardant, synergist, and enhancer, thereby improving the dispersion uniformity of these functional components during the premixing process and avoiding subsequent processing defects caused by component agglomeration; at the same time, the 50-60% ratio is designed to leave room for an appropriate amount of remaining compatibilizer (polyphenylene ether-maleic anhydride grafted polymer, PPO-g-MAH) in the subsequent step 5, and achieve functional synergy through "step-by-step addition" - SAN-GMA focuses on promoting dispersion in the premixing stage, and PPO-g-MAH focuses on subsequent enhanced interfacial bonding with the recycled PC / ABS base material, thereby jointly improving the compatibility and mechanical properties of the material.

[0102] In one embodiment, specifically: in step five, the remaining compatibilizer is a polyphenylene ether-maleic anhydride grafted polymer; wherein the maleic anhydride group of the polyphenylene ether-maleic anhydride grafted polymer (PPO-g-MAH) can react with the butadiene phase of ABS in the recycled PC / ABS base material, strengthen the interfacial bonding with the matrix, and form a synergistic compatibilization effect with the premixed SAN-GMA in step four (focusing on reaction with the PC phase), further reducing the separation of the two phases and improving the mechanical properties of the material.

[0103] The twin-screw extruder feed rate to screw speed ratio was 1:1.2, and the nitrogen flow rate was 2-3 L / min;

[0104] Specifically, step five specifies that the ratio of the feeding rate to the screw speed of the twin-screw extruder is 1:1.2. This ratio design ensures that the material obtains sufficient shear and mixing time in the screw, avoids uneven mixing due to too fast feeding or excessive material retention and degradation due to too slow feeding, and ensures the uniformity of melt blending; and the nitrogen flow rate is controlled at 2-3L / min (purity ≥99.99%), which can effectively remove the air in the extruder, prevent the oxidative degradation of recycled materials and additives at high temperatures, reduce the generation of small molecular volatiles, and thus improve the performance stability of composite material pellets.

[0105] Example 3

[0106] Material components (parts by weight):

[0107] Recycled PC / ABS base material: 70 parts (derived from electronic and electrical appliance housing waste, with a purity of 96% and a moisture content of 0.04% after pretreatment);

[0108] Phosphorus-nitrogen composite flame retardant: 12 parts (9 parts of ammonium polyphosphate (APP) + 3 parts of melamine cyanurate (MCA), mass ratio 3:1);

[0109] Synergist: 3 parts (0.75 parts of halloysite nanotubes + 2.25 parts of talc, mass ratio 1:3);

[0110] Reinforcement: 5 parts (3.33 parts of acrylic acid-modified PTFE fiber + 1.67 parts of nano-kaolin, mass ratio 2:1, surface hydroxylated);

[0111] Compatibilizer: 8 parts (SAN-GMA 4.8 parts + PPO-g-MAH 3.2 parts, mass ratio 6:4);

[0112] Auxiliary additives: 2 parts (10101 parts of antioxidant + 1680.5 parts of antioxidant + 0.33 parts of lubricant + 0.17 parts of anti-dripping agent, mass ratio 2:1:1).

[0113] The specific preparation process is as follows:

[0114] Pretreatment of recycled materials: crush the waste materials into 3-5mm, ultrasonically clean them in deionized water at 50℃ for 30min, and air dry them at 80℃ for 4h to obtain dry particles;

[0115] Preparation of premixed masterbatch: The phosphorus-nitrogen composite flame retardant, synergist, reinforcing agent and part of the compatibilizer (SAN-GMA 4.8 parts) were premixed at 60°C and 120 rpm for 5 min, and melt-granulated through a twin-screw extruder (230°C, 300 rpm) to obtain the premixed masterbatch;

[0116] Blending and extrusion: dry granules, premixed masterbatch, remaining compatibilizer (3.2 parts of PPO-g-MAH) and auxiliary additives were added to a twin-screw extruder, melt-blended (240°C, 350 r / min, feed rate to speed ratio of 1:1.2) under nitrogen protection (flow rate 2.5 L / min), and extruded into granules;

[0117] Injection molding: The composite material pellets were dried at 100°C for 6 h, injection molded at 250°C, and the mold temperature was 90°C to obtain the finished product.

[0118] Example 4

[0119] Material components (parts by weight):

[0120] Recycled PC / ABS base material: 60 parts;

[0121] Phosphorus-nitrogen composite flame retardant: 15 parts (APP 11.25 parts + MCA 3.75 parts);

[0122] Synergist: 5 parts (1.25 parts of halloysite nanotubes + 3.75 parts of talc);

[0123] Reinforcement: 7 parts (4.67 parts of acrylic acid modified PTFE fiber + 2.33 parts of nano-kaolin);

[0124] Compatibilizer: 10 parts (6 parts SAN-GMA + 4 parts PPO-g-MAH);

[0125] Auxiliary additives: 3 parts (1.5 parts of antioxidant 1010 + 0.75 parts of antioxidant 168 + 0.5 parts of lubricant + 0.25 parts of anti-dripping agent).

[0126] The specific preparation process is the same as that of Example 3, except that the twin-screw extrusion temperature is adjusted to 240°C and the injection molding temperature of the injection molding machine is adjusted to 260°C during the preparation of the premixed masterbatch.

[0127] Example 5

[0128] Material components (parts by weight):

[0129] Recycled PC / ABS base material: 80 parts;

[0130] Phosphorus-nitrogen composite flame retardant: 8 parts (6 parts APP + 2 parts MCA);

[0131] Synergist: 2 parts (halloysite nanotubes 0.5 parts + talc 1.5 parts);

[0132] Reinforcement: 3 parts (2 parts of acrylic acid modified PTFE fiber + 1 part of nano kaolin);

[0133] Compatibilizer: 5 parts (3 parts SAN-GMA + 2 parts PPO-g-MAH);

[0134] Auxiliary additives: 1 part (0.5 parts of antioxidant 1010 + 0.25 parts of antioxidant 168 + 0.17 parts of lubricant + 0.08 parts of anti-dripping agent).

[0135] The specific preparation process is the same as that of Example 3, except that the twin-screw extrusion temperature is adjusted to 220°C and the injection molding temperature of the injection molding machine is adjusted to 240°C during the preparation of the premixed masterbatch.

[0136] Comparative Example

[0137] Materials were prepared using traditional recycling methods, as follows:

[0138] Material composition: 70 parts of recycled PC / ABS base material, 20 parts of brominated flame retardant (decabromodiphenyl ether), 5 parts of glass fiber, 5 parts of single compatibilizer (SAN-GMA), and 1 part of additive;

[0139] Preparation method: directly crush and dry, then mix with additives, and extrude with twin screws (230℃, 300r / min), without pre-mixed masterbatch and nitrogen protection.

[0140] The materials prepared in Example 3, Example 4, Example 5 and the comparative example were tested for performance, and the test results are shown in the following table:

[0141]

[0142] By analyzing the test results:

[0143] The materials prepared in Example 3, Example 4 and Example 5 all have a tensile strength of ≥60 MPa and a notched impact strength of ≥54 kJ / m 2 , which is significantly better than the comparative example (traditional recycling method), proving that the present invention effectively repairs the performance degradation of the recycled material by compounding the reinforcing agent and the compatibilizer;

[0144] The materials prepared in Examples 3, 4, and 5 all achieved a flame retardant rating of UL94V-0, and the amount of flame retardant added (8-15 parts) was much lower than that in the comparative example (20 parts of bromine-based), indicating that the synergistic effect of the phosphorus-nitrogen composite flame retardant and the synergist improved the flame retardant efficiency and was halogen-free and environmentally friendly.

[0145] The materials prepared in Example 3, Example 4 and Example 5 had a moisture content of ≤0.05% and a processing qualification rate of ≥96%, which was better than that of the comparative example, proving that the cleaning, drying and nitrogen protection processes improved processing stability;

[0146] Among them, Example 3 has the best comprehensive performance, which verifies that "70 parts of recycled base material + 12 parts of phosphorus-nitrogen flame retardant + compound system" is the best formula.

[0147] The above examples show that the present invention can effectively solve the performance and processing problems of traditional recycled materials and achieve high-value regeneration.

[0148] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similarities between the various embodiments can be referred to in conjunction with each other. For system-related embodiments, since they are generally similar to method-related embodiments, their description is relatively simple. For relevant details, refer to the description of the method-related embodiments.

[0149] The basic principles of the present disclosure have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this disclosure are merely illustrative and not restrictive, and should not be construed as necessarily possessed by each embodiment of the present disclosure. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, rather than as limitations. These details do not limit the present disclosure to necessarily being implemented using these specific details.

[0150] In the present disclosure, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. The block diagrams of the devices, devices, equipment, and systems involved in the present disclosure are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "having," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0151] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0152] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0153] Various changes, substitutions, and modifications may be made to the technology described herein without departing from the teachings defined by the appended claims. Moreover, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of things, means, methods, and actions described above. Currently existing or later developed processes, machines, manufactures, compositions of things, means, methods, or actions that perform substantially the same function or achieve substantially the same results as the corresponding aspects described herein may be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufactures, compositions of things, means, methods, or actions.

[0154] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0155] The above description has been provided for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A flame retardant reinforced PC / ABS injection molding material based on recycled materials, characterized in that: The composition comprises the following components in parts by weight: Recycle 60-80 parts of PC / ABS base material; 8-15 parts of phosphorus-nitrogen composite flame retardant; 2-5 parts of a synergist, which is a compound of halloysite nanotubes and talc; 3-7 parts of a reinforcing agent, which is a compound of acrylic acid-modified polytetrafluoroethylene fiber and nano-kaolin; 5-10 parts of a compatibilizer, which is a compound of styrene-acrylonitrile-glycidyl methacrylate and polyphenylene ether-maleic anhydride graft polymer; 1-3 parts of auxiliary additives.

2. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The phosphorus-nitrogen composite flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3:

1.

3. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The mass ratio of the halloysite nanotubes to the talc in the synergist is 1:

3.

4. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The mass ratio of acrylic acid modified polytetrafluoroethylene fiber to nano-kaolin in the reinforcing agent is 2:1, and the reinforcing agent is surface hydroxylated.

5. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The mass ratio of styrene-acrylonitrile-glycidyl methacrylate to polyphenylene ether-maleic anhydride graft polymer in the compatibilizer is 6:

4.

6. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The auxiliary additives include an antioxidant, a lubricant and an anti-dripping agent, wherein the antioxidant is a compound of hindered phenol 1010 and phosphite 168, the lubricant is molybdenum disulfide extreme pressure lithium grease, and the anti-dripping agent is polytetrafluoroethylene powder; the mass ratio of the antioxidant, lubricant and anti-dripping agent in the auxiliary additives is 2:1:

1.

7. The flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 1, characterized in that: The recycled PC / ABS base material comes from waste electronic and electrical appliance housings or automotive interior parts, and is pre-treated by crushing, ultrasonic cleaning, and drying to have a purity of ≥95% and a moisture content of ≤0.05%.

8. A method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials, applied to the flame retardant reinforced PC / ABS injection molding material based on recycled materials as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: crush the recycled PC / ABS waste through a crusher and screen to obtain particles with a particle size of 3-5 mm; Step 2: Place the particles in 50°C deionized water and ultrasonically clean them for 30 minutes to remove surface oil and impurities; Step 3: Dry the washed particles at 80°C for 4 hours to obtain dried particles; Step 4: premix the phosphorus-nitrogen composite flame retardant, synergist, reinforcing agent and part of the compatibilizer at 60° C. and 120 r / min for 5 min, and then melt-granulate through a twin-screw extruder at 220-240° C. and 300 r / min to obtain a premixed masterbatch; Step 5: Add the dried particles, premixed masterbatch, remaining compatibilizer and auxiliary additives into a twin-screw extruder, melt-blend under nitrogen protection, and extrude into granules to obtain composite material granules; Step 6: After drying the composite material pellets at 100° C. for 6 hours, injection molding is performed by an injection molding machine at 240-260° C. and a mold temperature of 80-100° C. to obtain a flame retardant reinforced PC / ABS injection molding material based on recycled materials.

9. The method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 8, characterized in that: In step 4, the partial compatibilizer is styrene-acrylonitrile-glycidyl methacrylate, accounting for 50-60% of the total mass of the compatibilizer.

10. The method for preparing a flame retardant reinforced PC / ABS injection molding material based on recycled materials according to claim 8, characterized in that: In step five, the remaining compatibilizer is a polyphenylene ether-maleic anhydride graft polymer; the ratio of the feeding rate to the screw speed of the twin-screw extruder is 1:1.2, and the nitrogen flow rate is 2-3 L / min.

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