Reinforced ABS composite material and preparation method thereof

Abstract

The invention discloses an enhanced ABS composite material and a preparation method thereof, and relates to the technical field of plastics, the enhanced ABS composite material comprises the following components by mass: high flow ABS, high impact ABS, modified short glass fiber, modified ground glass fiber, ABS-based CO2 foaming master batch, SEBS-g-MAH, modified nano talcum powder and an antistatic agent. The modified short glass fiber and the modified ground glass fiber are synergistically enhanced and are matched with the SEBS-g-MAH compatilizer to optimize interface bonding, so that the problems of limited nucleation effect and insufficient interface bonding strength of a single glass fiber are solved, the phenomena that a gas phase is enriched on the surface of the glass fiber and grows along the glass fiber are effectively inhibited, cell nucleation and growth are more uniform, and the glass fiber composite material is prepared. Meanwhile, the performance loss caused by foaming is made up through the synergistic enhancement effect of the glass fibers, the foam structure of the composite material is precisely regulated and controlled, and the mechanical property and the structural stability of the lightweight material are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of plastics technology, specifically to a reinforced ABS composite material and its preparation method. Background Technology

[0002] ABS is a copolymer made by grafting polybutadiene rubber with monomers styrene and acrylonitrile. It has advantages such as impact resistance, low temperature resistance, excellent insulation properties, good surface gloss, and easy painting and coloring. It is a widely used thermoplastic engineering plastic, mainly used in the automotive, machinery, aerospace, building materials, and electronics and electrical industries. However, as an engineering plastic with excellent comprehensive performance, ABS is much more expensive than commonly used plastics such as PP and PS, which leads to higher production costs.

[0003] Existing ABS foamed composite materials mostly employ a combination of single glass fiber reinforcement and single interface modification methods in a constant-temperature chemical injection foaming process. The interfacial bonding strength between glass fiber and ABS matrix is ​​insufficient, and the gas phase easily accumulates on the glass fiber surface and grows along it. At the same time, the release of foaming pressure can easily cause cell collapse and rupture. Antistatic modification can easily deteriorate the cell structure, ultimately resulting in an uneven cell structure and wide pore size distribution. After weight reduction, the mechanical properties and heat resistance are significantly reduced, and the dimensional stability is poor. It is impossible to balance antistatic properties and foaming properties, making it difficult to meet the requirements of high-precision and medium-high temperature working conditions. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an enhanced ABS composite material and its preparation method, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: by weight, it comprises the following components: 40-60 parts of high-flow ABS, 20-40 parts of high-impact ABS, 5-15 parts of modified short glass fiber, 2-8 parts of modified ground glass fiber, 2-4 parts of ABS-based CO2 foaming masterbatch, 2.5-7.5 parts of SEBS-g-MAH, 0.5-2 parts of modified nano talc, and 0.3-1 parts of antistatic agent; The short glass fiber has a diameter of 13μm and a length of 3mm, while the ground glass fiber has a diameter of 9-14μm and a length of 50-300μm. The mass content of maleic anhydride in the SEBS-g-MAH is 1.4%–2.0%; The main product of the decomposition of the foaming agent in the ABS-based CO2 foaming masterbatch is CO2. The modified nano-talc powder is stearic acid-coated nano-talc powder with a particle size of 50-100 nm. The antistatic agent is a polyquaternary ammonium salt type antistatic agent, specifically polyquaternary ammonium salt-7, and the effective solid content of polyquaternary ammonium salt-7 is ≥30%.

[0006] Preferably, the material is made from the following components by weight: 50 parts high-flow ABS, 30 parts high-impact ABS, 10 parts modified short glass fiber, 5 parts modified ground glass fiber, 3 parts ABS-based CO2 foaming masterbatch, 5 parts SEBS-g-MAH, 1 part modified nano talc, and 0.5 parts antistatic agent.

[0007] 3. The reinforced ABS composite material according to claim 1, characterized in that: the high-flow ABS is AF365F, with a melt flow rate of 75 g / 10 min and a density of 1.18 g / cm³. 3 ; The high-impact ABS is PA709, with a melt flow rate of 6 ml / 10 min and a density of 1.03 g / cm³. 3 .

[0008] Preferably, the modified short glass fiber is obtained by modifying short glass fiber with silane coupling agent KH550, and the short glass fiber has a diameter of 13μm and a length of 3mm; The modified ground glass fiber is obtained by modifying ground glass fiber with silane coupling agent KH550, and the ground glass fiber has a diameter of 9-14μm and a length of 50-300μm.

[0009] Preferably, the grafting amount of the silane coupling agent KH550 on the surfaces of the modified short glass fiber and the modified ground glass fiber is 0.8-1.2 wt%.

[0010] Preferably, the amount of stearic acid coated in the modified nano-talc powder is 3-5 wt%, and the stearic acid and nano-talc powder are combined through physical adsorption and chemical bonding to form a core-shell structure.

[0011] A method for preparing reinforced ABS composite material includes the following steps: S1. Prepare a modification solution using silane coupling agent KH550. Immerse short glass fibers and ground glass fibers in the modification solution for ultrasonic modification. After drying, obtain modified short glass fibers and modified ground glass fibers. S2. Dry and dehydrate the high-flow ABS, high-impact ABS, SEBS-g-MAH, modified nano talc powder and antistatic agent separately, and dry the ABS-based CO2 foaming masterbatch separately for later use. S3. Mix the pretreated high-flow ABS, high-impact ABS, SEBS-g-MAH and antistatic agent evenly to obtain a matrix premix. Add the matrix premix to a twin-screw extruder to melt, then add modified short glass fiber, modified ground glass fiber and modified nano talc powder to continue melting, blending and extruding. After water cooling and pelletizing, obtain reinforced ABS masterbatch. S4. Mix the reinforced ABS masterbatch and ABS-based CO2 foaming masterbatch evenly, add them to the injection molding machine, and use gradient temperature control and secondary mold opening foaming process for injection molding. After cooling and shaping, the reinforced ABS composite material is obtained.

[0012] Preferably, the modified liquid in step S1 is a mixture obtained by diluting silane coupling agent KH550 in anhydrous ethanol at a mass ratio of 1:50. The ultrasonic modification treatment has a power of 300-400W, a frequency of 40kHz, and a treatment time of 30-40min. The drying treatment is to dry at 120℃ to constant weight, and then keep dry at 100℃ for 2-3h.

[0013] Preferably, in step S2, the drying conditions for high-flow ABS, high-impact ABS and SEBS-g-MAH are vacuum drying at 80°C for 4-6 hours, the drying conditions for modified nano talc powder and antistatic agent are vacuum drying at 100°C for 2-3 hours, and the drying conditions for ABS-based CO2 foaming masterbatch are forced air drying at 60°C for 1-2 hours. In step S3, the matrix premix is ​​mixed in a high-speed mixer at a speed of 800-1000 r / min for 8-10 min, the melt blending temperature of the twin-screw extruder is 170-210℃, the main screw speed is 200-240 r / min, and the feed speed is 20-25 r / min.

[0014] Preferably, in step S4, the temperature of the barrel under gradient temperature control is 180-190℃ in zone one, 190-200℃ in zone two, and 200-210℃ in zone three, and the nozzle temperature is 205-210℃. The parameters for the secondary mold opening foaming process are: injection pressure 80-100MPa, holding time 5-8s, first mold opening distance 5-8mm, holding and releasing rate 5-8MPa / s, and second mold opening after releasing time 1-2s. The secondary mold opening distance is 10-15mm, the mold temperature is controlled at 60-70℃, the cooling and setting time is 10-15s, the length-to-diameter ratio of the injection molding machine screw is 25:1-30:1, and the screw speed is 150-200r / min.

[0015] This invention provides a reinforced ABS composite material and its preparation method. It has the following beneficial effects: (1) By using modified short glass fiber and modified ground glass fiber for synergistic reinforcement, and combined with SEBS-g-MAH compatibilizer to optimize interface bonding, the problem of limited nucleation effect of single glass fiber and insufficient interface bonding strength is solved. It effectively inhibits the enrichment of gas phase on the glass fiber surface and the phenomenon of growth along the glass fiber, making the nucleation and growth of the cell more uniform. At the same time, the synergistic reinforcement effect of glass fiber compensates for the performance loss caused by foaming. The precise control of the cell structure of composite material greatly improves the mechanical properties and structural stability of the material after lightweighting, and adapts to the molding and use requirements of high-precision parts.

[0016] (2) By introducing stearic acid-coated modified nano-talc powder, it can not only form additional nucleation points to help optimize the cell structure, but also rely on its own heat resistance to make up for the defect of the decrease in heat deformation temperature after ABS foaming. It can form a complementary performance with the glass fiber reinforced phase. At the same time, the modified nano-talc powder has good compatibility with the matrix and will not destroy the foaming system and interface bonding. It can achieve the simultaneous improvement of the cell performance and heat resistance of the composite material, break through the limitation of traditional ABS foam materials being difficult to apply under medium and high temperature conditions, and expand the application scenarios of the material.

[0017] (3) A polyquaternary ammonium salt antistatic agent with excellent compatibility with ABS matrix and foaming system is selected. The conflict between antistatic agent and foaming system is avoided in terms of component selection. At the same time, the injection foaming process with gradient temperature control and secondary mold opening is combined to ensure that the antistatic agent is evenly dispersed in the matrix without affecting the nucleation and growth of the cells. This solves the problem that it is difficult to balance antistatic performance and foaming performance in traditional modification. It achieves the synergistic combination of lightweight composite material, mechanical properties and antistatic properties, and makes the material suitable for the preparation of high-precision lightweight parts with electrostatic protection requirements. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the preparation method of the reinforced ABS composite material of the present invention; Figure 2 This is a line graph showing the cell diameter of the tested materials in the embodiments and comparative examples of the present invention. Figure 3 This is a line graph showing the cell density of the materials tested in the embodiments and comparative examples of the present invention. Figure 4 This is a line graph showing the pore size distribution coefficient of the test materials in the embodiments and comparative examples of the present invention; Figure 5 This is a line graph showing the weight loss rate of the materials tested in the embodiments and comparative examples of the present invention. Figure 6 This is a line graph showing the tensile strength of materials tested in the embodiments and comparative examples of the present invention. Figure 7 This is a line graph showing the tensile strength retention rate of the materials tested in the embodiments and comparative examples of the present invention. Figure 8 This is a line graph showing the notched impact strength of materials tested in the embodiments and comparative examples of the present invention. Figure 9 This is a line graph showing the heat distortion temperature of the materials tested in the embodiments and comparative examples of the present invention. Figure 10 This is a line graph showing the shrinkage rate of the test products of the embodiments and comparative examples of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 This invention provides an enhanced ABS composite material and its preparation method. To achieve the above objectives, this invention is implemented through the following technical solution: by mass parts, it comprises the following components: 40-60 parts of high-flow ABS, 20-40 parts of high-impact ABS, 5-15 parts of modified short glass fiber, 2-8 parts of modified ground glass fiber, 2-4 parts of ABS-based CO2 foaming masterbatch, 2.5-7.5 parts of SEBS-g-MAH, 0.5-2 parts of modified nano-talc powder, and 0.3-1 parts of antistatic agent; Short glass fibers have a diameter of 13μm and a length of 3mm, while ground glass fibers have a diameter of 9-14μm and a length of 50-300μm. The mass content of maleic anhydride in SEBS-g-MAH is 1.4%–2.0%; The main decomposition product of the foaming agent in ABS-based CO2 foaming masterbatch is CO2. The modified nano-talc powder is a nano-talc powder coated with stearic acid, with a particle size of 50-100nm. The antistatic agent is a polyquaternary ammonium salt type antistatic agent, specifically polyquaternary ammonium salt-7, and the effective solid content of polyquaternary ammonium salt-7 is ≥30%.

[0021] Matrix resin: High-flow ABS (model AF365F): Melt flow rate 75g / 10min (220℃ / 10kg), density 1.18g / cm³ 3 It has excellent processing fluidity, which can ensure the filling capacity of the melt and the uniform growth of bubbles during the foaming process; High-impact ABS (model PA709): Melt flow rate 6 ml / 10 min (220℃ / 10 kg), density 1.03 g / cm³ 3The high content of polybutadiene rubber phase gives the composite material excellent impact resistance, and when compounded with high-flow ABS, it can balance molding processability and mechanical toughness. Reinforcing phase glass fiber: Short glass fiber (SGF): with a diameter of 13μm and a length of 3mm, it has a moderate aspect ratio and can play a significant role in mechanical reinforcement. Ground glass fiber (MGF): with a diameter of 9-14μm and a length of 50-300μm, exhibiting a micro-sized distribution, it can serve as a nucleation point for foam cells to optimize the foaming structure; Modification treatment: Surface modification is carried out using silane coupling agent KH550 (purity ≥98%). Organic functional groups are formed on the glass fiber surface through "hydrolysis-condensation-grafting" reaction. The grafting amount is precisely controlled at 1.0wt% (determined by thermogravimetric analysis) to ensure the interfacial bonding force with the ABS matrix and avoid excessive aggregation of coupling agent. Functional additives: SEBS-g-MAH (model FG1901G): Maleic anhydride content 1.7% (determined by infrared spectroscopy), melt flow rate 22g / 10min (230℃ / 5kg), as a compatibilizer it can bridge glass fiber and ABS matrix and improve interfacial compatibility; Modified nano-talc powder: original particle size 50-100nm (transmission electron microscopy characterization), modified by coating with stearic acid (analytical grade), coating amount 4wt% (determined by potentiometric titration). Stearic acid molecules form a core-shell structure through physical adsorption and chemical bonding with hydroxyl groups, which improves the dispersibility with the matrix. Antistatic agent (polyquaternium-7, effective solid content 30%): cationic polymer structure, with excellent compatibility with ABS matrix and is not easy to migrate or precipitate; ABS-based CO2 foaming masterbatch: The main component of the foaming agent is a compound system of sodium bicarbonate and citric acid. The main decomposition product is CO2, and the decomposition temperature is 180-200℃, which matches the injection molding process temperature. The carrier is ABS resin to ensure compatibility with the matrix.

[0022] The product is made from the following components by weight: 50 parts high-flow ABS, 30 parts high-impact ABS, 10 parts modified short glass fiber, 5 parts modified ground glass fiber, 3 parts ABS-based CO2 foaming masterbatch, 5 parts SEBS-g-MAH, 1 part modified nano talc, and 0.5 parts antistatic agent.

[0023] The high-flow ABS is AF365F, with a melt flow rate of 75 g / 10 min and a density of 1.18 g / cm³. 3 ; The high-impact ABS is PA709, with a melt flow rate of 6 ml / 10 min and a density of 1.03 g / cm³. 3 .

[0024] The modified short glass fiber is prepared by modifying short glass fiber with silane coupling agent KH550. The short glass fiber has a diameter of 13μm and a length of 3mm. Modified ground glass fiber is prepared by modifying ground glass fiber with silane coupling agent KH550. The ground glass fiber has a diameter of 9-14μm and a length of 50-300μm.

[0025] The grafting amount of silane coupling agent KH550 on the surface of modified short glass fiber and modified ground glass fiber is 0.8-1.2wt%.

[0026] The coating amount of stearic acid in the modified nano-talc is 3-5 wt%. Stearic acid and nano-talc are combined through physical adsorption and chemical bonding to form a core-shell structure.

[0027] The preparation method of reinforced ABS composite material includes the following steps: S1. Prepare a modification solution using silane coupling agent KH550. Immerse short glass fibers and ground glass fibers in the modification solution for ultrasonic modification. After drying, obtain modified short glass fibers and modified ground glass fibers. S2. Dry and dehydrate the high-flow ABS, high-impact ABS, SEBS-g-MAH, modified nano talc powder and antistatic agent separately, and dry the ABS-based CO2 foaming masterbatch separately for later use. S3. Mix the pretreated high-flow ABS, high-impact ABS, SEBS-g-MAH and antistatic agent evenly to obtain a matrix premix. Add the matrix premix to a twin-screw extruder to melt, then add modified short glass fiber, modified ground glass fiber and modified nano talc powder to continue melting, blending and extruding. After water cooling and pelletizing, obtain reinforced ABS masterbatch. S4. Mix the reinforced ABS masterbatch and ABS-based CO2 foaming masterbatch evenly, add them to the injection molding machine, and use gradient temperature control and secondary mold opening foaming process for injection molding. After cooling and shaping, the reinforced ABS composite material is obtained.

[0028] In step S1, the modified solution is a mixture obtained by diluting silane coupling agent KH550 in anhydrous ethanol at a mass ratio of 1:50. The ultrasonic modification treatment has a power of 300-400W, a frequency of 40kHz, and a treatment time of 30-40min. The drying treatment involves drying at 120℃ to constant weight, followed by heat drying at 100℃ for 2-3h.

[0029] In step S2, the drying conditions for high-flow ABS, high-impact ABS and SEBS-g-MAH are vacuum drying at 80℃ for 4-6 hours, the drying conditions for modified nano talc powder and antistatic agent are vacuum drying at 100℃ for 2-3 hours, and the drying conditions for ABS-based CO2 foaming masterbatch are forced air drying at 60℃ for 1-2 hours. In step S3, the matrix premix is ​​mixed in a high-speed mixer at a speed of 800-1000 r / min for 8-10 min, the melt blending temperature of the twin-screw extruder is 170-210℃, the main screw speed is 200-240 r / min, and the feed speed is 20-25 r / min.

[0030] In step S4, the temperature of the barrel under gradient temperature control is 180-190℃ in zone 1, 190-200℃ in zone 2, and 200-210℃ in zone 3, and the nozzle temperature is 205-210℃. The parameters for the secondary mold opening foaming process are: injection pressure 80-100MPa, holding time 5-8s, first mold opening distance 5-8mm, holding and releasing rate 5-8MPa / s, and second mold opening after releasing time 1-2s. The secondary mold opening distance is 10-15mm, the mold temperature is controlled at 60-70℃, the cooling and setting time is 10-15s, the length-to-diameter ratio of the injection molding machine screw is 25:1-30:1, and the screw speed is 150-200r / min.

[0031] By overcoming the limitations of existing single ABS matrix, a blend of high-flow ABS and high-impact ABS in a 5:3 mass ratio is used. This approach utilizes the processing fluidity of high-flow ABS to ensure uniform melt filling and bubble distribution during foaming, while the rubber phase of high-impact ABS enhances the impact resistance of the composite material. This solves the technical challenge of the inability to achieve both fluidity and toughness in a single matrix.

[0032] The innovative approach employs a hybrid reinforcement of short glass fibers and ground glass fibers, creating a synergistic effect of macroscopic reinforcement and microscopic nucleation. Short glass fibers enhance the tensile strength and rigidity of the composite material due to their aspect ratio advantage, while ground glass fibers provide numerous cell nucleation sites with their micro-sized distribution. Combined with modification by the silane coupling agent KH550, the accumulation of gas phase on the glass fiber surface is effectively suppressed, promoting uniform nucleation and growth of bubbles in the melt. This solves the problems of uneven cell structure and limited improvement in mechanical properties caused by single glass fiber reinforcement.

[0033] Compatibilizer-coupling agent dual-interface modification: The maleic anhydride groups of SEBS-g-MAH react with the hydroxyl groups on the glass fiber surface and the polar groups of the ABS matrix, forming a "dual-interface bridge" with the silane coupling agent KH550, which greatly improves the interfacial bonding strength and avoids interfacial peeling during foaming. Multifunctional synergistic effect of nano-talc: It not only acts as an auxiliary nucleating agent to refine the pores, but also improves the heat resistance of composite materials with its layered structure. Stearic acid coating modification solves the industry pain point of easy agglomeration of nano-powders. Precise selection of antistatic agent: Polyquaternium-7 cationic antistatic agent is selected, which has excellent compatibility with ABS matrix. While achieving antistatic function, it does not affect melt strength and foaming performance, breaking through the technical bottleneck of conflict between traditional antistatic agents and foaming system. The modification process employs "ultrasonic-assisted and stepwise drying". Ultrasonic vibration promotes the penetration of coupling agent into the glass fiber surface, while stepwise drying removes residual solvent and moisture, ensuring the uniformity and stability of the modification. Compared with traditional immersion modification, the fluctuation of grafting amount on the glass fiber surface is reduced from ±0.3wt% to ±0.1wt%, and the interfacial bonding strength is increased by more than 25%. By using a segmented feeding method of "main feeding and side feeding", the matrix premix is ​​melted first, and then the glass fiber and nano talc are added. This avoids the length loss caused by excessive shearing of glass fiber in the high-temperature zone (the glass fiber length retention rate is increased from 70% to 90%), while preventing the agglomeration of nano powder and ensuring that each component is evenly dispersed. Gradient temperature control matches the melting and foaming characteristics of materials: the barrel temperature gradually increases from zone one to zone three to ensure uniform melt viscosity and avoid local overheating that causes premature decomposition of the foaming agent or local undercooling that affects bubble growth. Stable pressure release and secondary mold opening: The first mold opening releases some pressure, and the stable pressure release avoids the collapse of the bubble cell caused by a sudden drop in pressure. The secondary mold opening provides sufficient space for bubble cell growth. Compared with the traditional one-time mold opening process, the bubble cell density is increased by 40% and the bubble cell uniformity is increased by 35%.

[0034] Through synergistic optimization of components and processes, a five-fold synergistic improvement in "lightweight, high mechanical properties, heat resistance, antistatic properties, and dimensional stability" was achieved, balancing lightweight and mechanical properties: a weight reduction rate of 15.8% was achieved, while the tensile strength retention rate was 81.2% and the notched impact strength was 4.68 KJ / m. 2 This solves the problem of "reduced mechanical properties due to lightweighting" in traditional ABS foam materials; it achieves compatibility between function and foaming performance: the heat distortion temperature is increased to 88℃, and the surface resistivity is reduced to 8.5×10⁻⁶. 9 With an Ω-coated surface area and a shrinkage rate of 0.42%, it meets the demand for multifunctional lightweight materials in high-end fields such as automotive electronics and precision electrical appliances.

[0035] Example 1 The reinforced ABS composite material, by weight, is made of the following components: 50 parts of high-flow ABS (AF365F), 30 parts of high-impact ABS (PA709), 10 parts of modified short glass fiber, 5 parts of modified ground glass fiber, 3 parts of ABS-based CO2 foaming masterbatch, 5 parts of SEBS-g-MAH, 1 part of modified nano talc, and 0.5 parts of polyquaternary ammonium salt type antistatic agent; Preparation method of reinforced ABS composite material: A modification solution was prepared by diluting silane coupling agent KH550 in anhydrous ethanol at a mass ratio of 1:50. Short glass fibers (13 μm in diameter and 3 mm in length) and ground glass fibers (9-14 μm in diameter and 50-300 μm in length) were immersed in the modification solution and ultrasonically modified for 35 min at 350 W and 40 kHz. After drying at 120 °C to constant weight, they were dried at 100 °C for 2.5 h to obtain modified short glass fibers and modified ground glass fibers (KH550 grafting amount 1.0 wt%). High-flow ABS, high-impact ABS, and SEBS-g-MAH were vacuum dried at 80℃ for 5 hours; modified nano-talc powder (4wt% stearic acid coating, particle size 50-100nm) and antistatic agent were vacuum dried at 100℃ for 2.5 hours; and ABS-based CO2 foaming masterbatch was dried in a forced-air dryer at 60℃ for 1.5 hours for later use. Pretreated high-flow ABS, high-impact ABS, SEBS-g-MAH, and antistatic agent are added to a high-speed mixer and mixed at 900 r / min for 9 min to obtain a matrix premix. The premix is ​​then added to the first barrel of a twin-screw extruder for melting, followed by the addition of modified short glass fibers, modified ground glass fibers, and modified nano talc. The mixture is then melt-blended and extruded at 170-210℃ (main screw speed 220 r / min, feed speed 22 r / min). After water cooling and pelletizing, reinforced ABS masterbatch is obtained. The reinforced ABS masterbatch and ABS-based CO2 foaming masterbatch were mixed evenly and fed into an injection molding machine with a screw length-to-diameter ratio of 28:1. Gradient temperature control was used (zone 1 185℃, zone 2 195℃, zone 3 205℃, nozzle 208℃), injection pressure 90MPa, holding time 6s, first mold opening distance 6mm, pressure release at a rate of 6MPa / s for 1.5s, and then second mold opening (distance 12mm), mold temperature 65℃, and cooling and setting for 12s to obtain the reinforced ABS composite material.

[0036] Example 2 The reinforced ABS composite material, by weight, is made of the following components: 40 parts high-flow ABS, 40 parts high-impact ABS, 15 parts modified short glass fiber, 2 parts modified ground glass fiber, 2 parts ABS-based CO2 foaming masterbatch, 2.5 parts SEBS-g-MAH, 0.5 parts modified nano talc, and 0.3 parts polyquaternary ammonium salt type antistatic agent; Preparation method: Only the ultrasonic modification time of S1 was adjusted to 40 min, the mixing speed of S3 was 800 r / min (mixing for 10 min), the injection pressure of S4 was 80 MPa, the holding time was 8 s and the pressure release rate was 5 MPa / s, and the remaining steps were the same as in Example 1.

[0037] Example 3 The reinforced ABS composite material, by weight, is made of the following components: 60 parts high-flow ABS, 20 parts high-impact ABS, 5 parts modified short glass fiber, 8 parts modified ground glass fiber, 4 parts ABS-based CO2 foaming masterbatch, 7.5 parts SEBS-g-MAH, 2 parts modified nano talc, and 1 part polyquaternary ammonium salt type antistatic agent.

[0038] Preparation method: only adjust the ultrasonic modification time of S1 to 30 min, the mixing speed of S3 to 1000 r / min (mixing for 8 min), the injection pressure of S4 to 100 MPa, the holding time to 5 s and the pressure release rate to 8 MPa / s, and the remaining steps are the same as in Example 1.

[0039] Comparative Example 1 The difference from Example 1 is that the modified nano-talc powder is removed from the composition, while the remaining components and preparation process are completely the same as in Example 1.

[0040] Comparative Example 2 The difference from Example 1 is that the modified ground glass fiber is replaced with an equal mass of modified short glass fiber, with a glass fiber content of 15 parts. The remaining components and preparation process are completely the same as in Example 1.

[0041] Comparative Example 3 The difference from Example 1 is that short glass fibers and ground glass fibers are used directly, and KH550 ultrasonic modification treatment is not performed. The remaining components and preparation process are completely the same as in Example 1.

[0042] Comparative Example 4 The difference from Example 1 is that the antistatic agent of polyquaternium-7 is removed from the components and replaced with an equal mass of conventional antistatic agent. The remaining components and preparation process are completely the same as in Example 1.

[0043] Comparative Example 5 The difference from Example 1 is that the S4 injection molding foaming adopts a constant temperature of 200°C process, removes the pressure holding and releasing steps, and directly opens the mold for the second time after the first mold opening. The remaining components and preparation process are completely the same as those in Example 1.

[0044] Comparative Example 6 The difference from Example 1 is that it is prepared according to existing technology: 80 parts of high-flow ABS, 15 parts of short glass fiber, 5 parts of SEBS-g-MAH, and 3 parts of foaming masterbatch, and foamed in a constant temperature of 200℃ for a second time without high-impact ABS, ground glass fiber, modified nano talc powder, or antistatic agent.

[0045] Test content Cell structure testing: Scanning electron microscope (SEM) was used to observe the cell morphology of the core layer of each sample cross section. ImageJ software was used to statistically analyze the cell diameter, cell density and pore size distribution coefficient, and to analyze the effects of different components and processes on cell nucleation and growth. Weight reduction rate test: The density of solid composite material and foamed composite material was measured by electronic densitometer, and the weight reduction rate was calculated as "weight reduction rate = (solid density - foamed density) / solid density × 100%" to evaluate the lightweighting effect; Mechanical property testing: Tensile strength was tested using an electronic universal testing machine according to GB / T1040.2-2006 standard, and the tensile strength retention rate was calculated (strength of foamed sample / strength of solid sample × 100%). According to GB / T1843-2008 standard, the notched impact strength is tested using a cantilever beam impact testing machine; Heat resistance test: In accordance with GB / T1634.2-2004 standard, the heat distortion temperature was tested using a heat distortion Vicat softening point tester at a load of 1.82MPa and a heating rate of 2℃ / min to evaluate the change in heat resistance of the material after foaming.

[0046] Antistatic performance test: According to GB / T1410-2006 standard, the surface resistivity was measured using a high resistance meter at a test voltage of 500V to verify the effect of the antistatic agent. Dimensional stability test: After the standard injection-molded sample (100mm×10mm×4mm) is placed at room temperature for 24 hours, the dimensional change in the length direction is measured with a digital caliper, and the shrinkage rate of the product is calculated.

[0047] Test Results The table below shows the performance test results of reinforced ABS composite materials (refer to...). Figure 2-10 ) ; It can be seen from the above table: The pore diameters of the bubbles in Examples 1-3 are concentrated in the range of 35-38 μm, and the pore density is ≥5.32 × 10⁻⁶. 6 cells / cm 3 The pore size distribution coefficient is ≤0.19, and the pores are small and uniform. This is due to the synergistic nucleation effect of modified short glass fibers and ground glass fibers and the auxiliary nucleation effect of modified nano talc. The cell structure of Comparative Example 1 (unmodified nano talc), Comparative Example 3 (unmodified glass fiber), and Comparative Example 5 (constant temperature foaming) all showed significant deterioration, proving that the component combination and process design of the present invention can effectively regulate cell nucleation and growth. The weight reduction rate of the example reached 15.2%-17.6%, while the tensile strength retention rate was ≥79.8% and the notched impact strength was ≥4.52KJ / m. 2 This invention achieves a balance between lightweighting and mechanical properties. Compared with conventional materials, the weight reduction rate of Comparative Example 6 is only 13.3%, and the loss of mechanical properties is significant. This shows that the present invention effectively reduces the loss of mechanical properties while upgrading the lightweighting. The heat distortion temperature of the material in the example was increased to 85-90℃, which is better than that of Comparative Example 1 (76℃) and Comparative Example 6 (75℃), demonstrating the heat resistance enhancement effect of modified nano talc powder; The surface resistivity of the example decreased to 10. 9— 10 10 Ω, while Comparative Example 4 (traditional antistatic agent) and Comparative Example 6 had no effective antistatic effect, proving that polyquaternium-7 can achieve compatibility between antistatic and foaming properties; The shrinkage rate of the product in the example was ≤0.48%, which was much lower than that of the comparative example (0.62%-0.95%), indicating that the process and component design of the present invention can effectively suppress dimensional deformation after foaming and improve the dimensional accuracy of the product. The performance of Examples 1-3 is superior to that of the comparative examples. Among them, Example 1 (optimal ratio) has the best overall performance, which verifies the rationality and advancement of the synergistic design of the compound matrix, mixed glass fiber, functional components and special process of the present invention, and breaks through the performance bottleneck of existing ABS foam composite materials.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A reinforced ABS composite material, characterized in that: By weight, it comprises the following components: 40-60 parts high-flow ABS, 20-40 parts high-impact ABS, 5-15 parts modified short glass fiber, 2-8 parts modified ground glass fiber, 2-4 parts ABS-based CO2 foaming masterbatch, 2.5-7.5 parts SEBS-g-MAH, 0.5-2 parts modified nano talc, and 0.3-1 parts antistatic agent; The short glass fiber has a diameter of 13μm and a length of 3mm, while the ground glass fiber has a diameter of 9-14μm and a length of 50-300μm. The mass content of maleic anhydride in the SEBS-g-MAH is 1.4%–2.0%; The main product of the decomposition of the foaming agent in the ABS-based CO2 foaming masterbatch is CO2. The modified nano-talc powder is stearic acid-coated modified nano-talc powder with a particle size of 50-100 nm. The antistatic agent is a polyquaternary ammonium salt type antistatic agent, specifically polyquaternary ammonium salt-7, and the effective solid content of polyquaternary ammonium salt-7 is ≥30%.

2. The reinforced ABS composite material according to claim 1, characterized in that: By weight, it is made of the following components: 50 parts high-flow ABS, 30 parts high-impact ABS, 10 parts modified short glass fiber, 5 parts modified ground glass fiber, 3 parts ABS-based CO2 foaming masterbatch, 5 parts SEBS-g-MAH, 1 part modified nano talc, and 0.5 parts antistatic agent.

3. The reinforced ABS composite material according to claim 1, characterized in that: The high-flow ABS is AF365F, with a melt flow rate of 75 g / 10 min and a density of 1.18 g / cm³. 3 ; The high-impact ABS is PA709, with a melt flow rate of 6 ml / 10 min and a density of 1.03 g / cm³. 3 .

4. The reinforced ABS composite material according to claim 1, characterized in that: The modified short glass fiber is obtained by modifying short glass fiber with silane coupling agent KH550, and the short glass fiber has a diameter of 13μm and a length of 3mm; The modified ground glass fiber is obtained by modifying ground glass fiber with silane coupling agent KH550, and the ground glass fiber has a diameter of 9-14μm and a length of 50-300μm.

5. The reinforced ABS composite material according to claim 4, characterized in that: The grafting amount of the silane coupling agent KH550 on the surfaces of the modified short glass fiber and the modified ground glass fiber is 0.8-1.2 wt%.

6. The reinforced ABS composite material according to claim 1, characterized in that: The modified nano-talc powder contains 3-5 wt% stearic acid coating, and the stearic acid and nano-talc powder are combined through physical adsorption and chemical bonding to form a core-shell structure.

7. A method for preparing the reinforced ABS composite material as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Prepare a modification solution using silane coupling agent KH550. Immerse short glass fibers and ground glass fibers in the modification solution for ultrasonic modification. After drying, obtain modified short glass fibers and modified ground glass fibers. S2. Dry and dehydrate the high-flow ABS, high-impact ABS, SEBS-g-MAH, modified nano talc powder and antistatic agent separately, and dry the ABS-based CO2 foaming masterbatch separately for later use. S3. Mix the pretreated high-flow ABS, high-impact ABS, SEBS-g-MAH and antistatic agent evenly to obtain a matrix premix. Add the matrix premix to a twin-screw extruder to melt, then add modified short glass fiber, modified ground glass fiber and modified nano talc powder to continue melting, blending and extruding. After water cooling and pelletizing, obtain reinforced ABS masterbatch. S4. Mix the reinforced ABS masterbatch and ABS-based CO2 foaming masterbatch evenly, add them to the injection molding machine, and use gradient temperature control and secondary mold opening foaming process for injection molding. After cooling and shaping, the reinforced ABS composite material is obtained.

8. The method for preparing a reinforced ABS composite material according to claim 7, characterized in that, In step S1, the modified solution is a mixture obtained by diluting silane coupling agent KH550 in anhydrous ethanol at a mass ratio of 1:

50. The ultrasonic modification treatment has a power of 300-400W, a frequency of 40kHz, and a treatment time of 30-40min. The drying treatment involves drying at 120℃ to constant weight, followed by heat drying at 100℃ for 2-3h.

9. The method for preparing a reinforced ABS composite material according to claim 7, characterized in that: In step S2, the drying conditions for high-flow ABS, high-impact ABS and SEBS-g-MAH are vacuum drying at 80℃ for 4-6 hours, the drying conditions for modified nano talc powder and antistatic agent are vacuum drying at 100℃ for 2-3 hours, and the drying conditions for ABS-based CO2 foaming masterbatch are forced air drying at 60℃ for 1-2 hours. In step S3, the matrix premix is ​​mixed in a high-speed mixer at a speed of 800-1000 r / min for 8-10 min, the melt blending temperature of the twin-screw extruder is 170-210℃, the main screw speed is 200-240 r / min, and the feed speed is 20-25 r / min.

10. The method for preparing a reinforced ABS composite material according to claim 7, characterized in that: In step S4, the temperature of the barrel under gradient temperature control is 180-190℃ in zone 1, 190-200℃ in zone 2, and 200-210℃ in zone 3, and the nozzle temperature is 205-210℃. The parameters for the secondary mold opening foaming process are: injection pressure 80-100MPa, holding time 5-8s, first mold opening distance 5-8mm, holding and releasing rate 5-8MPa / s, and second mold opening after releasing time 1-2s. The secondary mold opening distance is 10-15mm, the mold temperature is controlled at 60-70℃, the cooling and setting time is 10-15s, the length-to-diameter ratio of the injection molding machine screw is 25:1-30:1, and the screw speed is 150-200r / min.

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