Weather-resistant heat-conducting ABS material and preparation method thereof

Abstract

The application provides a weather-resistant heat-conducting ABS material, which comprises an ABS protective layer, a BN / PMMA foaming compression layer and a heat-conducting connecting layer, the BN / PMMA foaming compression layer is located between the ABS protective layer and the heat-conducting connecting layer, the thickness of the heat-conducting connecting layer is 0.1-0.2 mm, and the thickness of the ABS protective layer is 0.5-1.0 mm; the ABS protective layer comprises ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride grafted ABS, lubricant EBS, dispersant polyethylene wax and antioxidant 1010; the BN / PMMA foaming compression layer comprises modified sheet BN, nano carbon fiber, nano silicon dioxide and PMMA resin; and the heat-conducting connecting layer comprises PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate and PMMA oligomer. The ABS material is developed through resin modification, structure design and process optimization, and is efficient in heat dissipation and weather-resistant.

Description

Technical Field

[0001] This invention relates to the field of functional polymer materials, specifically to a weather-resistant and thermally conductive ABS material and its preparation method. Background Technology

[0002] Due to its excellent mechanical properties, processability, and cost advantages, ABS resin has become the preferred choice for outdoor polymer structural materials. Currently, its outdoor applications and related research have reached a certain scale. The research status can be carried out from two dimensions: application scenario expansion and modification technology exploration. In terms of application scenarios, ABS resin has been widely used in many fields such as outdoor LED lamp housings, new energy outdoor energy storage equipment housings, outdoor communication base station housings, municipal public facilities (such as bus stop protective panels and street light covers), outdoor leisure products, and automotive exterior parts. With its good impact resistance and easy processing, it is gradually replacing some traditional outdoor metal, glass, and ordinary plastic materials, becoming one of the core choices for lightweight and low-cost outdoor structural materials.

[0003] Current industry research focuses on three main areas: weather resistance modification, thermal conductivity modification, and interfacial compatibility optimization of ABS resin. Among these, weather resistance modification is a research hotspot. Existing research mainly improves the weather resistance of ABS through two pathways: one is physical modification by adding weather-resistant additives, such as light stabilizers, antioxidants, and UV absorbers, to inhibit outdoor aging through the synergistic effect of different additives; the other is chemical modification, including monomer grafting modification, blending modification, and surface coating modification, attempting to improve the UV resistance and thermo-oxidative aging resistance of ABS resin at the molecular structure level. Meanwhile, with the increasing demand for heat dissipation in outdoor electronic devices, research on the thermal conductivity modification of ABS resin is also gradually increasing. This mainly involves adding thermally conductive fillers to construct a thermally conductive network, attempting to compensate for its inherent poor thermal conductivity. However, related research is still in the optimization stage and has not yet formed a mature industrialization technology.

[0004] Although research on the outdoor application of ABS resin has made some progress, its application technology still has many limitations, which seriously restricts its promotion and use in mid-to-high-end outdoor scenarios. First, the weather resistance modification effect is limited and lacks synergy. Physically compounded weather resistance additives are prone to migration and precipitation, leading to rapid degradation of weather resistance after long-term outdoor use, resulting in yellowing, chalking, and decreased mechanical properties. Chemical modification suffers from complex processes, high costs, and reduced toughness after modification; moreover, most modification schemes do not consider the synergistic improvement of weather resistance and other properties. Second, there is a conflict between thermal conductivity and weather resistance modification. Existing thermal conductivity modification fillers are mostly inorganic fillers, which have poor compatibility with ABS resin and are prone to agglomeration. This not only affects the density of the thermal conductivity network but also reduces the material's weather resistance and mechanical toughness. Simultaneously, some weather resistance additives hinder the dispersion of thermal conductivity fillers, further exacerbating the imbalance between thermal conductivity and weather resistance.

[0005] The aforementioned technical pain points not only restrict the outdoor application of ABS resin, but also prevent existing outdoor thermal conductive protective materials from simultaneously achieving weather resistance, high thermal conductivity, structural stability, and process feasibility. This makes it difficult to meet the stringent usage requirements of mid-to-high-end outdoor electronic equipment, municipal facilities, and other scenarios. The industry urgently needs to break through the existing technical bottlenecks. Summary of the Invention

[0006] Technical problem to be solved: The purpose of this invention is to provide a weather-resistant and thermally conductive ABS material and its preparation method. In response to the technical difficulties of low thermal conductivity and poor outdoor weather resistance of ABS, this invention develops a composite ABS material that is suitable for outdoor equipment and meets the core usage requirements of lightweight, efficient heat dissipation, weather resistance and durability through resin modification, structural design and process optimization.

[0007] Technical solution: A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer, the thickness of the thermally conductive bonding layer is 0.1~0.2mm, and the thickness of the ABS protective layer is 0.5~1.0mm; The ABS protective layer comprises the following components by weight: 80-88 parts ABS resin, 3-5 parts nano zinc oxide, 2-3 parts nano lanthanum oxide, 2-4 parts maleic anhydride-grafted ABS, 0.8-1.2 parts lubricant EBS, 0.6-0.8 parts dispersant polyethylene wax, and 0.6-1 parts antioxidant 1010. The BN / PMMA foamed compression layer comprises the following components by weight: 12-18 parts of modified sheet BN, 2-3 parts of nano-carbon fiber, 0.8-1.8 parts of nano-silica with a particle size of 15-25nm, and 70-80 parts of PMMA resin. The thermally conductive bonding layer comprises the following components in parts by weight: 90-100 parts PMMA resin, 3-6 parts nano-cubic boron nitride, 0.5-1.5 parts nano-cerium oxide, 0.6-1.1 parts butyl stearate, and 0.4-0.9 parts PMMA oligomer.

[0008] Preferably, the preparation method of the modified sheet-like BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat it to 75~80℃, stir at 400~500r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 3~5% of the mass of BN, and react at a constant temperature for 4~5h. After the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN; S12. KH-570 modified BN is redispersed in toluene, PMMA oligomer is added, the amount of which is 5-8% of the mass of BN, the temperature is raised to 85-90℃, benzoyl peroxide is added, the amount of which is 1-2% of the mass of PMMA oligomer, and the reaction is carried out at a constant temperature for 3-4 hours to obtain composite modified BN.

[0009] Preferably, the method for preparing the BN / PMMA foamed compression layer includes the following steps: S21. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying the granules after melt-blending and extrusion, they are injection molded to obtain sheet composite materials with a thickness of 0.5~1.5mm. S22. Place the sheet-like composite material into an autoclave and introduce critical carbon dioxide to foam it, thereby obtaining a BN / PMMA foamed compression layer.

[0010] The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.5~1.0mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.1~0.2mm. S3. The ABS protective layer, BN / PMMA foamed compression layer and thermally conductive bonding layer are laid in order from top to bottom, and then gradient hot pressing is performed in the mold. After hot pressing, curing treatment is performed to obtain weather-resistant and thermally conductive ABS material.

[0011] Preferably, the parameters for gradient hot pressing in S3 are as follows: First, at 165~170℃, the pressure is slowly increased to 6.0~7.0MPa at a rate of 0.6~0.8MPa / min, and held at the temperature and pressure for 5~6 minutes; then, the temperature is increased to 175~180℃, and the pressure is increased to 8.5~9.5MPa at a rate of 0.4~0.6MPa / min, and held at the temperature and pressure for 10~12 minutes; finally, the temperature is reduced to 130~135℃, the pressure is maintained at 8.5~9.5MPa, and held at the temperature and pressure for 4~5 minutes.

[0012] Preferably, the curing process in S3 is: curing at 85°C for 8~10 hours.

[0013] Preferably, the parameters for foaming with the critical carbon dioxide are: a saturation pressure of 2000~3200 psi, a temperature of 70~120℃, and a holding time of 30~40 min.

[0014] Beneficial effects: The ABS material of this invention has the following advantages: In this invention, the ABS material adopts a layered design, including an ABS protective layer, a BN / PMMA foamed compression layer, and a thermally conductive bonding layer. The ABS protective layer contains nano-zinc oxide and nano-lanthanum oxide, which work synergistically to provide highly efficient UV shielding, effectively blocking outdoor UV corrosion. It also incorporates antioxidant 1010 to inhibit thermo-oxidative aging and delay the breaking of material molecular chains. In the BN / PMMA foamed compression layer, modified sheet-like BN serves as the core thermally conductive filler, combined with carbon nanofibers. The carbon nanofibers fill the gaps between the sheet-like BN, forming a dense three-dimensional thermally conductive network, significantly improving thermal conductivity. An ultra-thin thermally conductive bonding layer is added to the inner side, improving the thermal conductivity connection efficiency between the intermediate layer and the user side, while further protecting the thermally conductive network of the intermediate layer and preventing concentrated heat corrosion on the user side. In this invention, flake-shaped h-BN is selected as the thermally conductive filler. It is modified with silane coupling agent KH-570 and polymethyl methacrylate oligomers to significantly improve the compatibility and dispersibility of BN with PMMA matrix, avoid agglomeration, and form uniformly dispersed cells in PMMA matrix during the foaming stage. At this time, the thermally conductive filler is mainly dispersed on the cell walls and has not formed a tight overlap. Subsequently, through gradient hot-pressing, the cells can be promoted to collapse in an orderly manner. The modified flake-shaped BN and carbon nanofibers that were originally dispersed on the cell walls are squeezed and oriented to move closer together, breaking the dispersed state and forming a continuous and dense three-dimensional thermally conductive network with a tight overlap. This reduces the gaps between the thermally conductive fillers and reduces the thermal resistance during heat conduction. At the same time, the compression process can strengthen the tightness of the bonding between the thermally conductive filler and PMMA matrix, avoid the gap between the filler and the matrix that would cause the thermal conduction path to break, and thus significantly improve the overall thermal conductivity. This invention employs gradient compression. First, the pressure is slowly increased at 165-170°C. This step aims to fix the pore structure of the intermediate CO2 foam layer, preventing sudden pore rupture during subsequent main compression. Simultaneously, it allows for initial compression of the intermediate layer preform, initial overlap of the thermally conductive filler, and initial adhesion between the non-foamed layers on both sides and the intermediate layer, initiating initial interface fusion without damaging the mechanical structure of the non-foamed layers. Then, the temperature is raised to 175-180°C for further compression. Under this compression condition, the CO2 foam pores in the intermediate layer collapse in an orderly manner, and the composite modified h-BN and nanofiber microfilaments are oriented and tightly overlapped, forming a dense three-dimensional thermally conductive network. Simultaneously, the intermediate layer and the inner connecting layer are tightly bonded through PMMA molecular chain entanglement, achieving deep fusion of the three-layer interface. The non-foamed layers on both sides maintain morphological stability. Finally, the temperature is lowered to 130-135°C to stabilize the dense thermally conductive network of the intermediate layer, preventing pore rebound and displacement of the thermally conductive filler. This also stabilizes the bonding state of the three-layer interface, eliminates internal stress generated during compression, and ensures a uniform and stable overall structure, balancing thermal conductivity and structural strength. Detailed Implementation

[0015] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: Example 1

[0016] A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer; The ABS protective layer comprises the following components by weight: 80 parts ABS resin (KF730), 3 parts nano zinc oxide, 2 parts nano lanthanum oxide, 2 parts maleic anhydride grafted ABS (Huawen® HW-102M), 0.8 parts lubricant EBS, 0.6 parts dispersant polyethylene wax, and 0.6 parts antioxidant 1010. The thermally conductive bonding layer comprises the following components in parts by weight: 90 parts PMMA resin (Arkema V920-100), 3 parts nano cubic boron nitride, 0.5 parts nano cerium oxide, 0.6 parts butyl stearate, and 0.4 parts PMMA oligomer (Altuglas BS203). The BN / PMMA foamed compression layer comprises the following components by weight: 12 parts modified sheet BN, 2 parts carbon nanofibers, 0.8 parts nano-silica with a particle size of 15-25 nm, and 70 parts PMMA resin (Arkema V920-100); wherein the preparation method of the modified sheet BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat it to 75℃, stir at 400r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 3% of the mass of BN, react at constant temperature for 5h, after the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN. S12. KH-570 modified BN was redispersed in toluene, PMMA oligomer (Altuglas BS203) was added at 5% of the mass of BN, the temperature was raised to 90℃, benzoyl peroxide was added at 2% of the mass of PMMA oligomer, and the reaction was carried out at a constant temperature for 3 hours to obtain composite modified BN. The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.68mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.15 mm. S3. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying the melt-blended extruded granules, they are injection molded to obtain sheet composite material with a thickness of 0.8 mm. The sheet composite material is placed in an autoclave and foamed by introducing critical carbon dioxide. The saturation pressure of foaming is set to 2000 psi, the temperature is 90 ℃, and the holding time is 40 min to obtain BN / PMMA foamed compression layer. S4. Lay the ABS protective layer, BN / PMMA foamed compression layer, and thermally conductive bonding layer in a top-to-bottom order, and then perform gradient hot pressing in the mold. First, at 165℃, slowly increase the pressure to 7.0MPa at a rate of 0.8MPa / min, and hold for 5 minutes. Then, increase the temperature to 180℃ and increase the pressure to 8.5MPa at a rate of 0.4MPa / min, and hold for 10 minutes. Finally, reduce the temperature to 130℃, maintain the pressure at 8.5MPa, and hold for 4 minutes. After hot pressing, cure at 85℃ for 10 hours to obtain weather-resistant and thermally conductive ABS material.

[0017] Example 2

[0018] A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer; The ABS protective layer comprises the following components by weight: 88 parts ABS resin, 5 parts nano zinc oxide, 3 parts nano lanthanum oxide, 4 parts maleic anhydride-grafted ABS (Huawen® HW-102M), 1.2 parts lubricant EBS, 0.8 parts dispersant polyethylene wax, and 1 part antioxidant 1010. The thermally conductive bonding layer comprises the following components in parts by weight: 100 parts PMMA resin (Arkema V920-100), 6 parts nano cubic boron nitride, 1.5 parts nano cerium oxide, 1.1 parts butyl stearate, and 0.9 parts PMMA oligomer (Altuglas BS203). The BN / PMMA foamed compression layer comprises the following components by weight: 18 parts modified sheet BN, 3 parts carbon nanofibers, 1.8 parts nano-silica with a particle size of 15-25 nm, and 80 parts PMMA resin (Arkema V920-100); wherein the preparation method of the modified sheet BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat it to 80℃, stir at 500r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 5% of the mass of BN, react at constant temperature for 4h, after the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN. S12. KH-570 modified BN was redispersed in toluene, and PMMA oligomer (Altuglas BS203) was added at 8% of the mass of BN. The temperature was raised to 85℃, and benzoyl peroxide was added at 1% of the mass of PMMA oligomer. The reaction was carried out at a constant temperature for 4 hours to obtain composite modified BN. The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.84mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.15 mm. S3. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying the granules after melt-blending and extrusion, they are injection molded to obtain sheet composite material with a thickness of 0.6 mm. The sheet composite material is placed in an autoclave and foamed by introducing critical carbon dioxide. The saturation pressure of foaming is set to 3200 psi, the temperature is 120 ℃, and the holding time is 30 min to obtain BN / PMMA foamed compression layer. S4. Lay the ABS protective layer, BN / PMMA foamed compression layer, and thermally conductive bonding layer in a top-to-bottom order, and then perform gradient hot pressing in the mold. First, at 170℃, slowly increase the pressure to 6.0MPa at a rate of 0.6MPa / min, and hold for 6 minutes. Then, increase the temperature to 175℃ and increase the pressure to 9.5MPa at a rate of 0.6MPa / min, and hold for 12 minutes. Finally, reduce the temperature to 135℃, maintain the pressure at 9.5MPa, and hold for 5 minutes. After hot pressing, cure at 85℃ for 8 hours to obtain weather-resistant and thermally conductive ABS material.

[0019] Example 3

[0020] A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer; The ABS protective layer comprises the following components by weight: 82 parts ABS resin, 3.5 parts nano zinc oxide, 2.2 parts nano lanthanum oxide, 2.5 parts maleic anhydride-grafted ABS (Huawen® HW-102M), 0.8 parts lubricant EBS, 0.65 parts dispersant polyethylene wax, and 0.7 parts antioxidant 1010. The thermally conductive bonding layer comprises the following components in parts by weight: 92 parts PMMA resin (Arkema V920-100), 4 parts nano cubic boron nitride, 0.8 parts nano cerium oxide, 0.8 parts butyl stearate, and 0.5 parts PMMA oligomer (Altuglas BS203). The BN / PMMA foamed compression layer comprises the following components by weight: 14 parts modified sheet BN, 2.5 parts carbon nanofibers, 1 part nano-silica with a particle size of 15-25 nm, and 74 parts PMMA resin (Arkema V920-100); wherein the preparation method of the modified sheet BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat to 75℃, stir at 450 r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 3.5% of the mass of BN, react at constant temperature for 5 h, after the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN; S12. KH-570 modified BN was redispersed in toluene, and PMMA oligomer (Altuglas BS203) was added at 6% of the mass of BN. The temperature was raised to 85℃, and benzoyl peroxide was added at 1.8% of the mass of PMMA oligomer. The reaction was carried out at a constant temperature for 3 hours to obtain composite modified BN. The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.7mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.14 mm. S3. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying, the melt-blended granules are injection molded to obtain a sheet composite material with a thickness of 0.55 mm. The sheet composite material is placed in an autoclave and foamed by introducing critical carbon dioxide. The saturation pressure of foaming is set to 2500 psi, the temperature is 110 ℃, and the holding time is 30 min to obtain a BN / PMMA foamed compression layer. S4. Lay the ABS protective layer, BN / PMMA foamed compression layer, and thermally conductive bonding layer in a top-to-bottom order, and then perform gradient hot pressing in the mold. First, at 165℃, slowly increase the pressure to 6.5MPa at a rate of 0.65MPa / min, and hold for 5 minutes. Then, increase the temperature to 175℃ and increase the pressure to 8.5MPa at a rate of 0.45MPa / min, and hold for 10 minutes. Finally, reduce the temperature to 130℃, maintain the pressure at 8.5MPa, and hold for 4 minutes. After hot pressing, cure at 85℃ for 10 hours to obtain weather-resistant and thermally conductive ABS material.

[0021] Example 4

[0022] A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer; The ABS protective layer comprises the following components by weight: 86 parts ABS resin, 4.5 parts nano zinc oxide, 2.5 parts nano lanthanum oxide, 3.5 parts maleic anhydride-grafted ABS (Huawen® HW-102M), 1.2 parts lubricant EBS, 0.75 parts dispersant polyethylene wax, and 0.9 parts antioxidant 1010. The thermally conductive bonding layer comprises the following components in parts by weight: 96 parts PMMA resin (Arkema V920-100), 5 parts nano cubic boron nitride, 1.2 parts nano cerium oxide, 1 part butyl stearate, and 0.8 parts PMMA oligomer (Altuglas BS203). The BN / PMMA foamed compression layer comprises the following components by weight: 16 parts modified sheet BN, 3 parts carbon nanofibers, 1.5 parts nano-silica with a particle size of 15-25 nm, and 78 parts PMMA resin (Arkema V920-100); wherein the preparation method of the modified sheet BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat to 80℃, stir at 500 r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 4.5% of the mass of BN, react at constant temperature for 4 h, after the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN; S12. KH-570 modified BN was redispersed in toluene, and PMMA oligomer (Altuglas BS203) was added at 7% of the mass of BN. The temperature was raised to 90℃, and benzoyl peroxide was added at 1.2% of the mass of PMMA oligomer. The reaction was carried out at a constant temperature for 4 hours to obtain composite modified BN. The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.8mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.16 mm. S3. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying the granules after melt-blending and extrusion, they are injection molded to obtain sheet composite material with a thickness of 0.68 mm. The sheet composite material is placed in an autoclave and foamed by introducing critical carbon dioxide. The saturation pressure of foaming is set to 3000 psi, the temperature is 105 ℃, and the holding time is 35 min to obtain BN / PMMA foamed compression layer. S4. Lay the ABS protective layer, BN / PMMA foamed compression layer, and thermally conductive bonding layer in a top-to-bottom order, and then perform gradient hot pressing in the mold. First, at 170℃, slowly increase the pressure to 7.0MPa at a rate of 0.75MPa / min, and hold for 6 minutes. Then, increase the temperature to 180℃ and increase the pressure to 9.5MPa at a rate of 0.55MPa / min, and hold for 12 minutes. Finally, reduce the temperature to 135℃, maintain the pressure at 9.5MPa, and hold for 5 minutes. After hot pressing, cure at 85℃ for 10 hours to obtain weather-resistant and thermally conductive ABS material.

[0023] Example 5

[0024] A weather-resistant and thermally conductive ABS material, the ABS material comprising an ABS protective layer, a BN / PMMA foamed compression layer and a thermally conductive bonding layer, wherein the BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer; The ABS protective layer comprises the following components by weight: 85 parts ABS resin, 4 parts nano zinc oxide, 2.3 parts nano lanthanum oxide, 3 parts maleic anhydride-grafted ABS (Huawen® HW-102M), 1 part lubricant EBS, 0.7 parts dispersant polyethylene wax, and 0.8 parts antioxidant 1010. The thermally conductive bonding layer comprises the following components in parts by weight: 95 parts PMMA resin (Arkema V920-100), 4.5 parts nano cubic boron nitride, 1 part nano cerium oxide, 0.9 parts butyl stearate, and 0.6 parts PMMA oligomer (Altuglas BS203). The BN / PMMA foamed compression layer comprises the following components by weight: 15 parts modified sheet BN, 2.8 parts carbon nanofibers, 1.4 parts nano-silica with a particle size of 15-25 nm, and 75 parts PMMA resin (Arkema V920-100); wherein the preparation method of the modified sheet BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat to 76℃, stir at 480 r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 4% of the mass of BN, and react at a constant temperature for 4.5 h. After the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN. S12. KH-570 modified BN was redispersed in toluene, and PMMA oligomer (Altuglas BS203) was added at a mass of 6.5% of BN. The temperature was raised to 85°C, and benzoyl peroxide was added at a mass of 1.5% of PMMA oligomer. The reaction was carried out at a constant temperature for 3.5 h to obtain composite modified BN. The above-mentioned method for preparing weather-resistant and thermally conductive ABS material includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.75mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.1 mm. S3. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying, the melt-blended granules are injection molded to obtain a sheet composite material with a thickness of 0.75 mm. The sheet composite material is placed in an autoclave and foamed by introducing critical carbon dioxide. The saturation pressure of foaming is set to 2600 psi, the temperature is 100 ℃, and the holding time is 35 min to obtain a BN / PMMA foamed compression layer. S4. Lay the ABS protective layer, BN / PMMA foamed compression layer, and thermally conductive bonding layer in a top-to-bottom order, and then perform gradient hot pressing in the mold. First, at 165℃, slowly increase the pressure to 6.5MPa at a rate of 0.7MPa / min, and hold for 5 minutes. Then, increase the temperature to 175℃ and increase the pressure to 9MPa at a rate of 0.5MPa / min, and hold for 10 minutes. Finally, reduce the temperature to 135℃, maintain the pressure at 9MPa, and hold for 4.5 minutes. After hot pressing, cure at 85℃ for 9 hours to obtain weather-resistant and thermally conductive ABS material.

[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 5 is that there is no thermally conductive bonding layer.

[0026] Comparative Example 2 The difference between Comparative Example 2 and Example 5 is that the BN / PMMA foamed compression layer is not foamed and compressed, but obtained by ordinary blending.

[0027] Comparative Example 3 The difference between Comparative Example 3 and Example 5 is that the BN / PMMA foamed compression layer does not contain carbon nanofibers.

[0028] Comparative Example 4 The difference between Comparative Example 4 and Example 5 is that the sheet-like h-BN is directly added to the BN / PMMA foaming compression layer without modification for foaming.

[0029] Comparative Example 5 The difference between Comparative Example 5 and Example 5 is that Comparative Example 5 does not use gradient hot pressing, but directly hot presses in one step.

[0030] Comparative Example 6 The difference between Comparative Example 6 and Example 5 is that Comparative Example 6 is not compressed after foaming.

[0031] Comparative Example 7 The difference between Comparative Example 7 and Example 5 is that nano-lanthanum oxide is not added to the ABS protective layer.

[0032] Performance testing: Tensile strength was tested according to GB / T 1040.1-2018 standard, with each sample tested three times and the average value taken. The ABS material was then subjected to UV aging tests in a UV aging chamber with a light intensity of 0.76 W·m⁻¹. -2 ·nm -1 The temperature was 50℃ and the time was 30 days. The tensile strength was tested. Each group of samples was tested 3 times and the average value was taken. The UV tensile strength retention rate W was calculated.

[0033] W = A / A0 × 100%; A0 is the initial tensile strength, and A is the tensile strength after UV aging.

[0034]

[0035] Thermal conductivity was tested according to GB / T 1410-2006 standard. ABS material was made into a circular sheet with a diameter of 80 mm and a thickness of 3 mm, and its thermal conductivity was tested using a thermal constant analyzer.

[0036]

[0037] As can be seen from the comparison of the above comparative examples and embodiments, whether it is the lack of gap filling effect of carbon nanofibers, the agglomeration caused by the lack of modification of h-BN, or the inability to achieve directional overlap of fillers by omitting the foaming-compression process, the thermally conductive fillers will eventually be dispersed and loose, the thermal conduction path will be broken, the thermal resistance will increase, and thus the thermal conductivity will decrease.

[0038] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A weather-resistant and thermally conductive ABS material, characterized in that: The ABS material includes an ABS protective layer, a BN / PMMA foamed compression layer, and a thermally conductive bonding layer. The BN / PMMA foamed compression layer is located between the ABS protective layer and the thermally conductive bonding layer. The thickness of the thermally conductive bonding layer is 0.1~0.2mm, and the thickness of the ABS protective layer is 0.5~1.0mm. The ABS protective layer comprises the following components by weight: 80-88 parts ABS resin, 3-5 parts nano zinc oxide, 2-3 parts nano lanthanum oxide, 2-4 parts maleic anhydride-grafted ABS, 0.8-1.2 parts lubricant EBS, 0.6-0.8 parts dispersant polyethylene wax, and 0.6-1 parts antioxidant 1010. The BN / PMMA foamed compression layer comprises the following components by weight: 12-18 parts of modified sheet BN, 2-3 parts of nano-carbon fiber, 0.8-1.8 parts of nano-silica with a particle size of 15-25nm, and 70-80 parts of PMMA resin. The thermally conductive bonding layer comprises the following components in parts by weight: 90-100 parts PMMA resin, 3-6 parts nano-cubic boron nitride, 0.5-1.5 parts nano-cerium oxide, 0.6-1.1 parts butyl stearate, and 0.4-0.9 parts PMMA oligomer.

2. The weather-resistant and thermally conductive ABS material according to claim 1, characterized in that: The method for preparing the modified sheet-like BN includes the following steps: S11. After washing and drying the flake h-BN, add it to toluene, heat it to 75~80℃, stir at 400~500r / min, slowly add silane coupling agent KH-570, the amount of KH-570 is 3~5% of the mass of BN, react at a constant temperature for 4~5h, after the reaction is completed, centrifuge, wash and dry to obtain KH-570 modified BN; S12. KH-570 modified BN is redispersed in toluene, PMMA oligomer is added, the amount of which is 5-8% of the mass of BN, the temperature is raised to 85-90℃, benzoyl peroxide is added, the amount of which is 1-2% of the mass of PMMA oligomer, and the reaction is carried out at a constant temperature for 3-4 hours to obtain composite modified BN.

3. The weather-resistant and thermally conductive ABS material according to claim 2, characterized in that: The method for preparing the BN / PMMA foamed compression layer includes the following steps: S21. PMMA matrix, carbon nanofibers, nano-silica and modified sheet BN are mixed in a weight ratio and then melt-blended and granulated using a twin-screw extruder. After drying the granules after melt-blending and extrusion, they are injection molded to obtain sheet composite materials with a thickness of 0.5~1.5mm. S22. Place the sheet-like composite material into an autoclave and introduce critical carbon dioxide to foam it, thereby obtaining a BN / PMMA foamed compression layer.

4. The method for preparing weather-resistant and thermally conductive ABS material according to claim 3, characterized in that, Includes the following steps: S1. ABS resin, nano zinc oxide, nano lanthanum oxide, maleic anhydride-grafted ABS, lubricant EBS, dispersant polyethylene wax, and antioxidant 1010 are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain outer layer particles. The outer layer particles are then added to a flat vulcanizing machine and hot-pressed at 180°C and 8MPa to prepare an ABS protective layer with a thickness of 0.5~1.0mm. S2. High PMMA resin, nano cubic boron nitride, nano cerium oxide, butyl stearate, and PMMA oligomer are mixed in a weight ratio and then added to a twin-screw extruder for melt blending and granulation to obtain inner layer particles; the inner layer particles are added to a casting machine and cast at 185°C to prepare a thermally conductive bonding layer with a thickness of 0.1~0.2mm. S3. The ABS protective layer, BN / PMMA foamed compression layer and thermally conductive bonding layer are laid in order from top to bottom, and then gradient hot pressing is performed in the mold. After hot pressing, curing treatment is performed to obtain weather-resistant and thermally conductive ABS material.

5. The method for preparing weather-resistant and thermally conductive ABS material according to claim 4, characterized in that: The parameters for gradient hot pressing in S3 are as follows: First, at 165~170℃, the pressure is slowly increased to 6.0~7.0MPa at a rate of 0.6~0.8MPa / min, and held at the temperature and pressure for 5~6 minutes; then, the temperature is increased to 175~180℃, and the pressure is increased to 8.5~9.5MPa at a rate of 0.4~0.6MPa / min, and held at the temperature and pressure for 10~12 minutes; finally, the temperature is reduced to 130~135℃, the pressure is maintained at 8.5~9.5MPa, and held at the temperature and pressure for 4~5 minutes.

6. The method for preparing the weather-resistant and thermally conductive ABS material according to claim 4, characterized in that: The curing process in S3 is as follows: heat preservation and curing at 85℃ for 8~10 hours.

7. The weather-resistant and thermally conductive ABS material according to claim 3, characterized in that: The parameters for foaming with the critical carbon dioxide are as follows: the saturation pressure for foaming is set to 2000~3200psi, the temperature is 70~120℃, and the holding time is 30~40min.

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