High-toughness and high-strength shading polycarbonate composite material and preparation method thereof

Abstract

The invention provides a high-toughness and high-strength shading polycarbonate composite material and a preparation method thereof. A modified shading master batch with a core-shell structure is added, and a core layer is selected from at least one of nano titanium dioxide, barium silicate and nano zinc oxide; the middle layer is a composite interface layer which coats the surface of the core layer and is composed of a hydroxamic acid ester functionalized silane coupling agent and poly (N-acetylglucosamine); and the shell layer is formed by a hyperbranched polyester-elastomer copolymer coated outside the middle layer. The material is simple in formula composition, the modified shading master batch of a core-shell structure is selected, and the high shading rate can be achieved by low addition of raw materials of the core layer; the middle layer utilizes a hydroxamic acid ester functionalized silane coupling agent and poly (N-acetylglucosamine) to form a reinforced interface layer, so that the compatibility with a PC matrix is improved, and stress mutation is reduced; and the outer layer is coated with the hyperbranched polyester-elastomer copolymer, so that a nanoscale energy absorption network is formed, and the balance between the mechanical property and the shading and diffuse reflection properties is realized.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a light-shielding polycarbonate composite material with high toughness and high strength. Background Art

[0002] Polycarbonate (PC) is a thermoplastic engineering plastic with excellent transparency, impact resistance, and dimensional stability. It is widely used in the automotive, electronics, construction, and medical fields. However, single-use polycarbonate materials have deficiencies in mechanical properties, light-blocking properties, and weather resistance in certain specific applications. Therefore, various modification methods are needed to meet the application requirements of different fields.

[0003] Currently, polycarbonate material modification is primarily carried out through alloying and inorganic filler addition. A common method for improving light-blocking performance is the addition of light-blocking fillers such as titanium dioxide and carbon black. For example, Chinese patent CN104356622A discloses a high-concentration PC reflective sheet masterbatch, its preparation method, and its application. The masterbatch comprises 30-40% PC resin, 50-60% inorganic particles, 4-10% dispersant, 1-2% flame retardant, and 1-3% light stabilizer. This technical solution improves light-blocking performance by adding a large amount of inorganic particles.

[0004] However, the above-mentioned existing technologies have the following defects: on the one hand, traditional light-shielding fillers such as titanium dioxide and zinc oxide are easy to agglomerate in the polycarbonate matrix and have poor dispersion, resulting in a decrease in the mechanical properties of the material; on the other hand, the addition of a large amount of light-shielding fillers to improve the light-shielding performance often leads to a significant decrease in the toughness of the material and an increase in the rigidity, making the material brittle and unable to meet the needs of certain applications that require both light-shielding and toughness.

[0005] Therefore, there is an urgent need to develop a polycarbonate composite material with a simple composition that can take into account both light-shielding performance and mechanical properties, so as to further broaden the scope of PC materials in vehicle applications. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a high-toughness and high-strength light-shielding polycarbonate composite material to solve the problem that the PC composite materials in the prior art are difficult to balance mechanical properties with light-shielding and diffuse reflection properties. At the same time, the present invention will also provide a method for preparing the high-toughness and high-strength light-shielding polycarbonate composite material.

[0007] To achieve the above-mentioned and other related purposes, the present invention provides the following technical solutions: In a first aspect of the present invention, a high-toughness and high-strength light-shielding polycarbonate composite material is provided, comprising the following components in parts by weight: 80-95 parts of polycarbonate; 5-20 parts of modified light-shielding masterbatch; Stabilizer 0.1-0.5 parts; Other additives 0.2-1 part.

[0008] As a preferred technical solution, the modified sunshade masterbatch has a core-shell structure, which includes a core layer, an intermediate layer and an outer shell layer in sequence; the core layer is selected from at least one of nano-titanium dioxide, barium silicate, and nano-zinc oxide; the intermediate layer is a composite interface layer coated on the surface of the core layer, composed of an isohydroxamate functionalized silane coupling agent and poly N-acetylglucosamine; the outer shell is composed of a hyperbranched polyester-elastomer copolymer coated on the outside of the intermediate layer.

[0009] Furthermore, the core layer is a double light-shielding system composed of a main material and an auxiliary material, wherein the main material is selected from nano-titanium dioxide, and the auxiliary material is selected from barium silicate or nano-zinc oxide. The particle size of nano-titanium dioxide is 15-30nm, the particle size of barium silicate is 50-80nm, and the particle size of nano-zinc oxide is 30-40nm.

[0010] Furthermore, in the interlayer, a hydroxamate-functionalized silane coupling agent accounts for 1.2-3.8% of the core layer's mass, while poly (N-acetylglucosamine) accounts for 0.4-1.2% of the core layer's mass. The hydroxamate groups form a stable five-membered ring chelate structure with the metal oxide surface. Combined with poly (N-acetylglucosamine), the bonding energy reaches 180-220 kJ / mol, significantly higher than that of traditional silane coupling agents (80-120 kJ / mol), inhibiting nanoparticle aggregation. Furthermore, the hydroxyl and amino groups of poly (N-acetylglucosamine) form hydrogen bonds with the ester groups of PC, creating a gradient modulus interface between the light-shielding masterbatch and the PC matrix, mitigating stress fluctuations caused by modulus differences between the two phases.

[0011] Furthermore, the hydroxamate functionalized silane coupling agent is preferably γ-hydroxamate propyltrimethoxysilane (KH-560).

[0012] Furthermore, the molecular weight of the hyperbranched polyester-elastomer copolymer is 8000-12000, and the degree of branching is 0.35-0.45.

[0013] Furthermore, the hyperbranched polyester-elastomer copolymer is selected from a block copolymer of a hydroxyl-terminated hyperbranched polyester and a polyurethane elastomer.

[0014] Furthermore, the thickness of the outer shell layer is preferably 3-5 nm.

[0015] As a preferred technical solution, the modified light-shielding masterbatch is obtained by the following preparation method: (1) Mixing nano-titanium dioxide and barium silicate or nano-zinc oxide in proportion and performing ultrasonic dispersion treatment to obtain uniformly dispersed nano-mixed particles; (2) dissolving a hydroxamate functionalized silane coupling agent and poly (N-acetylglucosamine) in a solvent in proportion, adding nano-hybrid particles to the mixed solution for reaction, washing, centrifuging, and drying to obtain modified nano-particles coated with an intermediate layer; (3) The modified nanoparticles are coated and granulated with the hyperbranched polyester-elastomer copolymer in a molten state to form a modified light-shielding masterbatch with a core-shell structure.

[0016] Furthermore, in step (2), the solvent is selected from at least one of water, ethanol, toluene, isopropanol, dimethyl sulfoxide, and acetic acid aqueous solution.

[0017] Furthermore, in step (2), the reaction temperature is 60-80°C and the reaction time is 2-4h.

[0018] Furthermore, in step (2), after the reaction is completed, the product is washed with anhydrous ethanol three times, centrifuged at 8000-10000 rpm, and then vacuum dried at 80-100° C. for 6-12 hours.

[0019] Furthermore, in step (3), the temperature of the melt coating granulation is 180-220°C and the time is 10-15 minutes.

[0020] Furthermore, in step (3), the mass ratio of the modified nanoparticles to the hyperbranched polyester-elastomer copolymer is 10:1-15:1.

[0021] As a preferred technical solution, the polycarbonate is selected from at least one of low-viscosity and medium-viscosity polycarbonates.

[0022] Furthermore, the polycarbonate has a melt index range of 1-50 g / 10 min and a molecular weight range of 20,000-30,000.

[0023] As a preferred technical solution, the stabilizer is a hindered phenol compound or a mixture containing hindered phenol compounds. Under the action of the hindered phenol compound or the mixture, the weathering stability of the polycarbonate can be significantly improved, extending the long-term service life of such polycarbonate materials.

[0024] As a preferred technical solution, the other auxiliary agents include at least one of antioxidants, light stabilizers, and color powders.

[0025] As a preferred technical solution, the high-toughness and high-strength light-shielding polycarbonate composite material further includes a compatibilizer, which is selected from methyl methacrylate-butadiene-styrene copolymer and has a weight portion of 0.5-2 parts.

[0026] A second aspect of the present invention provides a method for preparing a light-shielding polycarbonate composite material with high toughness and high strength, comprising the following steps: S1. Weigh each component according to weight ratio; S2. Blending the weighed components in a high-speed mixer to obtain a premix; S3, adding the premixed components into the reactor, introducing supercritical CO2, stirring and maintaining a certain temperature and pressure for auxiliary dispersion to obtain a mixture; S4. Feed the dispersed mixture from the main feed material into a twin-screw extruder, preheat for 3-5 minutes, and then extrude and granulate to obtain the high-toughness and high-strength light-shielding polycarbonate composite material.

[0027] Furthermore, in step S2, the blending time is 10-15 minutes.

[0028] Furthermore, in step S3, the pressure is 20-25 MPa and the temperature is 60-65°C.

[0029] Furthermore, in step S3, the amount of CO2 used is 3-5 wt% of the total mass of the premix.

[0030] Furthermore, in step S4, the temperature of each zone of the screw is 220° C.-260° C., and the screw speed is 200-600 rpm.

[0031] As described above, the high-toughness and high-strength light-shielding polycarbonate composite material of the present invention and the preparation method thereof have the following beneficial effects: This invention utilizes a modified core-shell structured sunblock masterbatch. Its core layer is a combination of nano-titanium dioxide and auxiliary materials, achieving high light-blocking efficiency with minimal additives. The intermediate layer is modified with a hydroxamate-functionalized silane coupling agent and poly (N-acetylglucosamine) to form a reinforced interface, improving compatibility with the PC matrix and reducing stress fluctuations caused by modulus differences between the two phases. The outer layer is coated with a hyperbranched polyester-elastomer copolymer, forming a nanoscale energy-absorbing network. This thin layer design does not reduce overall rigidity. This core-shell structure absorbs energy and redistributes stress during impact, while maintaining overall rigidity under static conditions, addressing the brittleness issue associated with traditional sunblock fillers.

[0032] 2. The material formula provided by the present invention has a relatively simple composition structure. While ensuring the comprehensive performance advantages, it achieves a balance between mechanical properties and light-shielding and diffuse reflection properties. The entire system achieves a synergistic effect of stress dispersion and energy absorption through a multi-level structural design. It has good notch impact resistance at room temperature and low temperature, with less rigidity reduction, and controllable cost, which has a greater market competitive advantage.

[0033] 3. The present invention combines supercritical CO2-assisted dispersion with high-shear twin-screw extrusion during the processing process. The penetration effect of supercritical CO2 can achieve uniform dispersion of each component; and supercritical CO2 can reduce the melt viscosity, promote the entanglement of poly N-acetylglucosamine and PC molecular chains, and enhance the interfacial bonding between components.

[0034] 4. The additional addition of a compatibilizer in the present invention is beneficial to improving the brittle defect of PC composite materials and achieving a better balance between various properties of such materials by improving the impact resistance at room temperature and low temperature.

[0035] 5. The polycarbonate composite material of this invention achieves a 25-30% increase in notched impact strength while only reducing rigidity by 3-4%, and a light-blocking efficiency exceeding 95%. The core-shell structure absorbs energy and redistributes stress during impact, while maintaining overall rigidity under static conditions, thus eliminating the brittleness issue associated with traditional light-blocking fillers. DETAILED DESCRIPTION

[0036] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0037] Example 1 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material, comprising the following components in parts by weight: 90 parts of polycarbonate; 10 parts of modified light-shielding masterbatch; 0.3 parts of stabilizer; 0.5 parts of other additives; and 1 part of compatibilizer.

[0038] In the high-toughness and high-strength light-shielding polycarbonate composite material, the polycarbonate is selected from medium-viscosity polycarbonate with a melt index of 25g / 10min and a molecular weight of 25,000. The compatibilizer is selected from methyl methacrylate-butadiene-styrene copolymer.

[0039] The modified sunscreen masterbatch has a core-shell structure, consisting of a core layer, an intermediate layer, and an outer shell layer. The core layer is a dual-shielding system composed of nano-titanium dioxide as the primary ingredient and barium silicate as the secondary ingredient, with the mass ratio of nano-titanium dioxide to barium silicate being 3:1. The intermediate layer is a composite interface layer coated on the surface of the core layer, composed of a hydroxamate-functionalized silane coupling agent and poly (N-acetylglucosamine). The hydroxamate-functionalized silane coupling agent accounts for 2.5wt% of the core layer mass, and the poly (N-acetylglucosamine) accounts for 0.8wt% of the core layer mass. The outer shell layer is composed of a hyperbranched polyester-elastomer copolymer coated on the outer surface of the intermediate layer. This hyperbranched polyester-elastomer copolymer is a block copolymer of a hydroxyl-terminated hyperbranched polyester and a polyurethane elastomer, with a molecular weight of 10,000 and a degree of branching of 0.4.

[0040] The preparation method of modified light-shielding masterbatch is as follows: (1) Preparation of core layer: Nano-titanium dioxide and barium silicate were mixed in a mass ratio of 3:1, added to deionized water, and ultrasonically dispersed in an ultrasonic processor for 30 minutes to obtain a uniformly dispersed nano-hybrid particle suspension; (2) Intermediate layer coating: Dissolve isohydroxamate functionalized silane coupling agent and poly N-acetylglucosamine in an ethanol / water mixed solvent (volume ratio 7:3, added with 1% acetic acid) at a mass ratio of 3:1, slowly add the nanohybrid particle suspension obtained in S1 to the mixed solution, stir and react at 60°C for 3 hours, then wash with ethanol three times, centrifuge and vacuum dry at 80°C for 12 hours to obtain modified nanoparticles coated with the intermediate layer; (3) Shell coating: The modified nanoparticles obtained in S2 were mixed with the hyperbranched polyester-elastomer copolymer at a mass ratio of 10:1, melt-mixed in a twin-screw extruder at a temperature of 200°C and a speed of 80 rpm for 10 minutes, and then cooled and pelletized to form a modified light-shielding masterbatch with a core-shell structure.

[0041] The preparation method of the high-toughness and high-strength light-shielding polycarbonate composite material is as follows: S1. Weigh each component according to the above weight ratio; S2, mixing polycarbonate, modified light-shielding masterbatch, stabilizer, compatibilizer and other additives according to the above ratio to obtain a premix; S3. The premix is ​​melt-mixed and extruded in a twin-screw extruder at a temperature of 260° C. and a rotation speed of 100 rpm, and pelletized after cooling in a cooling water tank to obtain a light-shielding polycarbonate composite material with high toughness and high strength.

[0042] Performance tests show that the high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has excellent mechanical properties and light-shielding properties. Among them, the tensile strength reaches 75MPa, the flexural strength reaches 95MPa, and the impact strength reaches 65kJ / m 2 , with a light transmittance of less than 0.5%. This excellent overall performance is primarily attributed to the core-shell structure of the modified sunblock masterbatch. The dual sunblocking system in the core layer provides excellent light-shielding performance; the intermediate layer's hydroxamate-functionalized silane coupling agent and poly (N-acetylglucosamine) composite interface layer enhances interfacial compatibility between the core and shell layers; and the hyperbranched polyester-elastomer copolymer in the shell layer not only increases the material's toughness but also improves the compatibility of the modified sunblock masterbatch with the polycarbonate matrix.

[0043] Example 2 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 1, the only difference is that the amount of the modified light-shielding masterbatch is changed to 5 parts.

[0044] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a light transmittance of about 1.2%, a tensile strength of 78 MPa, and an impact strength of 60 kJ / m 2 .

[0045] Example 3 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 1, the only difference is that the amount of the modified light-shielding masterbatch is changed to 20 parts.

[0046] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a light transmittance of less than 0.1%, a tensile strength of 70 MPa, and an impact strength of 68 kJ / m 2 .

[0047] Conclusion: By comparing the test results of Examples 1-3, it is shown that with the increase of the content of modified light-shielding masterbatch, the light-shielding performance and toughness of the material are improved, but the tensile strength is slightly reduced.

[0048] Example 4 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 1, the only difference is that the hydroxamate functionalized silane coupling agent accounts for 1.5 wt % of the core layer mass, and the poly N-acetylglucosamine accounts for 0.5 wt % of the core layer mass.

[0049] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 72 MPa and an impact strength of 62 kJ / m 2 .

[0050] Example 5 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 1, the only difference is that the hydroxamate-functionalized silane coupling agent accounts for 3.5 wt % of the core layer mass, and the poly N-acetylglucosamine accounts for 1.0 wt % of the core layer mass.

[0051] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 73 MPa and an impact strength of 67 kJ / m 2 .

[0052] Example 6 This embodiment provides a light-shielding polycarbonate composite material with high toughness and high strength. Compared with Example 1, the only difference is that the molecular weight of the hyperbranched polyester-elastomer copolymer is 8500 and the degree of branching is 0.38.

[0053] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 74 MPa and an impact strength of 63 kJ / m 2 .

[0054] Example 7 This embodiment provides a light-shielding polycarbonate composite material with high toughness and high strength. Compared with Example 1, the only difference is that the molecular weight of the hyperbranched polyester-elastomer copolymer is 11,500 and the degree of branching is 0.43.

[0055] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 72 MPa and an impact strength of 66 kJ / m 2 .

[0056] Example 8 This embodiment provides a method for preparing a light-shielding polycarbonate composite material with high toughness and high strength. The method adopts supercritical CO2-assisted dispersion technology to improve the dispersion uniformity and performance of the composite material.

[0057] The preparation method specifically comprises the following steps: S1. According to the composition ratio of the high-toughness, high-strength light-shielding polycarbonate composite material described in Example 1, weigh 90 parts of polycarbonate, 10 parts of modified light-shielding masterbatch, 0.3 parts of stabilizer, 0.5 parts of other additives, and 1 part of compatibilizer. The types of polycarbonate, modified light-shielding masterbatch, stabilizer, compatibilizer, and other additives are the same as those in Example 1.

[0058] S2. Put the components weighed in S1 into a high-speed mixer and mix them at a speed of 1500 rpm for 5 minutes to ensure that the components are preliminarily mixed and uniform, thereby obtaining a premix.

[0059] S3. Add the premix obtained in S2 to a high-pressure reactor, seal the reactor, and introduce supercritical CO2, with the amount of CO2 being 4wt% of the total mass of the premix; under the conditions of a pressure of 22MPa and a temperature of 63°C, stir at a speed of 200rpm for 30 minutes to allow the supercritical CO2 to fully penetrate into the premix, assist in dispersing the modified light-shielding masterbatch, and obtain a mixture.

[0060] S4. Feed the dispersed mixture from the main feed material into a twin-screw extruder, preheat for 4 minutes, and then extrude and granulate to obtain a high-toughness and high-strength light-shielding polycarbonate composite material: The mixture obtained in S3 was fed into a twin-screw extruder from the main feed port, preheated at 260°C for 4 minutes, and then extruded at a screw speed of 100 rpm. After cooling in a water tank, it was pelletized to obtain a high-toughness and high-strength light-shielding polycarbonate composite material.

[0061] Performance tests show that the high-toughness and high-strength light-shielding polycarbonate composite material prepared by the preparation method of this embodiment has a tensile strength increased by about 5% to 78.5 MPa and an impact strength increased by about 8% to 70 kJ / m compared with Example 1.2 The light transmittance dropped to below 0.3%. This is primarily attributed to the application of supercritical CO2-assisted dispersion technology. Supercritical CO2 can penetrate the polymer matrix, reduce the system viscosity, promote the uniform dispersion of the modified light-shielding masterbatch in the polycarbonate matrix, reduce agglomeration, and thus improve the overall performance of the material.

[0062] Example 9 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 8, the only difference is that the amount of the modified light-shielding masterbatch is changed to 5 parts.

[0063] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 81 MPa and an impact strength of 65 kJ / m 2 , the transmittance is about 0.9%.

[0064] Example 10 This embodiment provides a high-toughness and high-strength light-shielding polycarbonate composite material. Compared with Example 8, the only difference is that the amount of the modified light-shielding masterbatch is changed to 20 parts.

[0065] The high-toughness and high-strength light-shielding polycarbonate composite material prepared in this embodiment has a tensile strength of 74 MPa and an impact strength of 73 kJ / m 2 , the transmittance is less than 0.08%.

[0066] In summary, the present invention boasts a simple material formulation. It utilizes a modified light-blocking masterbatch with a core-shell structure, achieving high light-blocking efficiency with minimal raw material additions in the core layer. The intermediate layer utilizes a hydroxamate-functionalized silane coupling agent and poly (N-acetylglucosamine) to form a reinforced interface, improving compatibility with the PC matrix and reducing stress mutations. The outer layer is coated with a hyperbranched polyester-elastomer copolymer, forming a nanoscale energy-absorbing network that achieves a balance between mechanical properties and light-blocking and diffuse reflective properties. Therefore, the present invention effectively overcomes the shortcomings of existing technologies and possesses high industrial value.

[0067] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A high-toughness and high-strength light-shielding polycarbonate composite material, characterized in that: The composition comprises the following components in parts by weight: 80-95 parts of polycarbonate; 5-20 parts of modified light-shielding masterbatch; Stabilizer 0.1-0.5 parts; Other additives 0.2-1 part; The modified light-shielding masterbatch has a core-shell structure, which includes a core layer, an intermediate layer and an outer shell layer in sequence; the core layer is selected from at least one of nano-titanium dioxide, barium silicate and nano-zinc oxide; the intermediate layer is a composite interface layer coated on the surface of the core layer and composed of an isohydroxamate functionalized silane coupling agent and poly N-acetylglucosamine; the outer shell layer is composed of a hyperbranched polyester-elastomer copolymer coated on the outside of the intermediate layer.

2. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 1, characterized in that: The core layer is a double light-shielding system composed of a main material and auxiliary materials, wherein the main material is selected from nano titanium dioxide, and the auxiliary material is selected from barium silicate or nano zinc oxide.

3. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 1, characterized in that: In the middle layer, the hydroxamate functionalized silane coupling agent accounts for 1.2-3.8 wt % of the core layer mass; and the poly N-acetylglucosamine accounts for 0.4-1.2 wt % of the core layer mass.

4. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 1, characterized in that: The molecular weight of the hyperbranched polyester-elastomer copolymer is 8000-12000, and the branching degree is 0.35-0.

45.

5. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 4, characterized in that: The hyperbranched polyester-elastomer copolymer is selected from a block copolymer of a hydroxyl-terminated hyperbranched polyester and a polyurethane elastomer.

6. The high-toughness and high-strength light-shielding polycarbonate composite material according to any one of claims 1 to 5, characterized in that: The modified light-shielding masterbatch is obtained by the following preparation method: (1) Mixing nano-titanium dioxide and barium silicate or nano-zinc oxide in proportion and performing ultrasonic dispersion treatment to obtain uniformly dispersed nano-mixed particles; (2) dissolving a hydroxamate functionalized silane coupling agent and poly (N-acetylglucosamine) in a solvent in proportion, adding nano-hybrid particles to the mixed solution for reaction, washing, centrifuging, and drying to obtain modified nano-particles coated with an intermediate layer; (3) The modified nanoparticles are coated and granulated with the hyperbranched polyester-elastomer copolymer in a molten state to form a modified light-shielding masterbatch with a core-shell structure.

7. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 1, characterized in that: The polycarbonate is selected from at least one of low-viscosity and medium-viscosity polycarbonates; the polycarbonate has a melt index range of 1-50 g / 10 min and a molecular weight range of 20,000-30,000.

8. The high-toughness and high-strength light-shielding polycarbonate composite material according to claim 1, characterized in that: The high-toughness and high-strength light-shielding polycarbonate composite material further comprises a compatibilizer, which is selected from methyl methacrylate-butadiene-styrene copolymer and has a weight portion of 0.5-2 parts.

9. A method for preparing the high-toughness and high-strength light-shielding polycarbonate composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Weigh each component according to weight ratio; S2. Blending the weighed components in a high-speed mixer to obtain a premix; S3, adding the premixed components into the reactor, introducing supercritical CO2, stirring and maintaining a certain temperature and pressure for auxiliary dispersion to obtain a mixture; S4. Feed the dispersed mixture from the main feed material into a twin-screw extruder, preheat for 3-5 minutes, and then extrude and granulate to obtain the high-toughness and high-strength light-shielding polycarbonate composite material.

10. The preparation method according to claim 9, characterized in that In step S3, the pressure is 20-25 MPa, the temperature is 60-65°C, and the amount of CO2 used is 3-5 wt% of the total mass of the premix.