Flame-retardant anti-ultraviolet aging PC-ABS composition and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a flame-retardant anti-ultraviolet aging PC-ABS composition and a preparation method thereof. The flame-retardant anti-ultraviolet aging PC-ABS composition is prepared from the following raw materials in parts by weight: 65 to 72 parts of PC resin, 25 to 30 parts of ABS resin, 12 to 15 parts of a composite flame retardant, 2 to 3 parts of an anti-ultraviolet agent, 8 to 12 parts of modified nano titanium dioxide, 4 to 6 parts of a toughening agent, 0.2 to 0.4 part of an anti-dripping agent and 0.2 to 0.5 part of an antioxidant, the composite flame retardant is composed of aluminum diethylphosphinate and cresyl diphenyl phosphate. Through precise design of a molecular structure and multi-scale interface regulation and control, the flame retardance, the ultraviolet aging resistance and the mechanical property are synchronously improved, and the limitation that in the prior art, the flame retardance, the ultraviolet aging resistance and the mechanical property are considered to be unmatched is broken through.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a flame-retardant and UV-resistant PC-ABS composition and a preparation method thereof. Background Art

[0002] PC-ABS composites are an important engineering plastic alloy that combines the excellent properties of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS). They offer excellent molding flow, low-temperature impact resistance, and a high heat distortion temperature. Consequently, they are widely used in a wide range of applications, including household appliances, office equipment, communications equipment, photographic equipment, medical devices, construction and lighting, as well as aerospace, computers, and optical fiber. In recent years, with the rapid development of industries like automotive and home appliances, PC-ABS composites have placed higher performance demands on them, demanding not only superior flexural and tensile properties but also flame retardancy and light aging resistance. Summary of the Invention

[0003] This application aims to address the shortcomings of current technologies by providing a flame-retardant and UV-resistant PC-ABS composition and its preparation method. By adding a composite flame retardant, an anti-UV agent, and modified nano-titanium dioxide, this application significantly improves the flame retardancy, UV-resistant properties, and mechanical properties of the flame-retardant and UV-resistant PC-ABS composition.

[0004] In the first aspect, the present application provides a flame retardant and UV-resistant PC-ABS composition, which adopts the following technical scheme: a flame retardant and UV-resistant PC-ABS composition, comprising the following raw materials in parts by weight: 65-72 parts of PC resin, 25-30 parts of ABS resin, 12-15 parts of composite flame retardant, 2-3 parts of anti-ultraviolet agent, 8-12 parts of modified nano titanium dioxide, 4-6 parts of toughening agent, 0.2-0.4 parts of anti-drip agent, and 0.2-0.5 parts of antioxidant, wherein the composite flame retardant is composed of diethyl aluminum phosphinate and cresyl diphenyl phosphate.

[0005] By adopting the above technical solutions, PC resin provides high strength, heat resistance and dimensional stability. ABS resin improves processing fluidity and impact resistance. Composite flame retardant: aluminum diethylphosphinate (gas phase flame retardant) + cresyl diphenyl phosphate (condensed phase flame retardant) work synergistically to improve flame retardant properties. Anti-ultraviolet agent: a high molecular weight benzotriazole derivative with both UV absorption and anti-migration properties. The modified nano-titanium dioxide surface is grafted with a hyperbranched polymer to improve dispersibility and enhance flame retardant / anti-ultraviolet properties. Toughening agents optimize the impact resistance of materials. Anti-drip agents inhibit burning droplets. Antioxidants prevent oxidative degradation during processing and use. In short, this application achieves a synergistic improvement in flame retardancy, anti-ultraviolet and mechanical properties through molecular design and interface regulation. While maintaining the inherent processing performance of PC / ABS, it significantly expands the application boundaries of the material in harsh environments.

[0006] Preferably, the weight ratio of the aluminum diethylphosphinate to cresyl diphenyl phosphate is 4:3-4.

[0007] By adopting the above technical solution, aluminum diethylphosphinate (ADP) decomposes upon heating to produce AlPO4 and PO· free radicals, quenching the combustion chain reaction. It also promotes charring, forming a dense ceramic barrier that rapidly suppresses flame propagation. Cresyl diphenyl phosphate (CDP) promotes dehydration and charring, reducing the release of combustible gases. Synergistic mechanism: 1. Complementary in the flame retardant stage: ADP rapidly decomposes in the initial stages of combustion (300-400°C), lowering the system temperature through an endothermic reaction (heat absorption > 350 J / g), and releasing PO· free radicals to interrupt the gas-phase combustion chain reaction. CDP promotes polymer cross-linking and charring at high temperatures (> 400°C), forming an expanded char layer (thickness > 100 μm) that isolates oxygen and heat transfer. 2. Product interaction is enhanced: Al2O3 produced by ADP decomposition reacts with phosphate esters produced by CDP decomposition to form a more thermally stable AlPO4-Si-OC composite ceramic layer (temperature resistance > 800°C). The benzene ring structure of CDP provides a carbon source, forming a metal-organic hybrid carbon layer with the metal ions of ADP, significantly improving the density of the carbon layer. 3. Performance balance effect, the rigid inorganic particles of ADP and the flexible organic molecules of CDP form a "rigid and flexible" structure, which improves the flame retardant performance while maintaining excellent mechanical properties. In short, by precisely controlling the ratio of ADP to CDP, this solution achieves synergistic flame retardancy and material performance optimization. This design breaks through the bottleneck of traditional phosphorus-based flame retardants that are difficult to achieve both efficiency and mechanical properties, and provides a reliable solution for the application of PC / ABS in harsh environments. Preferably, the preparation method of the anti-ultraviolet agent comprises the following steps: S31. Add 100 parts of deionized water, 25 parts of urotropine, 10 parts of p-aminophenol, and 8 parts of glacial acetic acid to a reaction kettle in order by weight, stir and dissolve, raise the temperature to 78-82°C, react for 3-4 hours, cool to room temperature, separate the layers, separate the aqueous layer, and wash with deionized water three times to obtain intermediate A; S32. To the reactor, 300 parts of N,N-dimethylformamide, 80 parts of intermediate A, 50 parts of glycidyl methacrylate, 20 parts of styrene, 1 part of catalyst C-94, and 0.7 parts of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid were added in order by weight under nitrogen protection. The temperature was raised to 105-100° C. and the reaction was carried out for 6-7 hours. The temperature was then lowered to room temperature, 400 parts of deionized water were added and stirred evenly, and the mixture was centrifuged. The mixture was washed with anhydrous ethanol three times and dried under vacuum at 75° C. for 12 hours to obtain intermediate B. S33. According to parts by weight, N,N-dimethylformamide, 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate, intermediate B and sodium hydroxide are added to a stirred reactor in sequence, and refluxed for 16-20 hours. During the reaction, acetone is added, and then deionized water is added and dispersed at high speed for 1-2 hours. Finally, the mixture is rotary evaporated at 55°C to obtain an anti-ultraviolet agent.

[0008] By adopting the above technical solution, intermediate A is first prepared from methenamine and p-aminophenol. Intermediate A is then graft-copolymerized with glycidyl methacrylate and styrene to prepare intermediate B. Finally, intermediate B is reacted with 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate to produce an anti-UV agent. The prepared anti-UV agent contains styrene-grafted groups and epoxy groups provided by glycidyl methacrylate, which makes it highly compatible with PC and ABS, solving the problem of poor mixing uniformity of traditional benzotriazole-based UV absorbers. By combining it with intermediate B, a high-molecular-weight polymer containing benzotriazole is obtained, which not only has the ability to absorb UV rays but also prevents its migration and volatilization, significantly improving the anti-UV aging properties of the PC-ABS composition. Multi-component synergistic enhancement mechanism: 1. Synergy with the PC / ABS matrix, the branched polymer chain of the UV inhibitor forms an interpenetrating network structure with PC / ABS, thereby enhancing the interfacial bonding strength. Dynamic thermal stability: the epoxy group reacts with the carboxyl group of the PC end at the processing temperature to generate cross-linking points and increase the cross-linking density. 2. Synergy with modified nano-TiO2, spectral complementarity: TiO2 scatters UVA (320-400nm) + the UV inhibitor absorbs UVB (280-320nm) to achieve full-band protection. Synergistic quenching of free radicals: under ultraviolet excitation, the hydroxyl groups on the TiO2 surface and the UV inhibitor synergistically capture free radicals. 3. Synergy with the composite flame retardant, the decomposition temperature of the UV inhibitor is higher than the activation temperature of the flame retardant, thereby avoiding the destruction of the flame retardant performance. Carbon layer reinforcement: the aromatic carbon residue produced by the decomposition of the UV agent forms a multi-layer dense carbon layer with the ADP / CDP flame retardant system. In summary, this UV inhibitor breaks through the three major bottlenecks of traditional technology through precise molecular structure design and multi-scale interface regulation: 1. Solve the problem of poor long-term effectiveness caused by the easy migration of small molecule UV absorbers; 2. Overcome the defect of poor compatibility between inorganic nanoparticles and organic matrices; 3. Achieve synergistic improvement of flame retardant, UV resistance and mechanical properties.

[0009] Preferably, in step S33, the weight ratio of N,N-dimethylformamide, 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate, intermediate B and sodium hydroxide is 300:(80-90):(50-60):(1.2-1.5).

[0010] Preferably, the preparation method of the modified nano-titanium dioxide comprises the following steps: S51. According to parts by weight, 20 parts of nano-titanium dioxide were soaked in 200 parts of a 3% mass concentration of a silane coupling agent KH602 solution, stirred for 2-3 hours, then condensed and refluxed at 80°C, filtered, washed, and dried at 110°C for 12 hours to obtain silane-modified nano-titanium dioxide; S52. Mix N,N-dimethylformamide, hexachlorocyclotriphosphazene, and p-phenylenediamine in parts by weight, stir until dissolved, and obtain a mixed solution. Add triethylamine to the mixed solution, stir at a constant temperature of 75° C. for 12 h, continue the reaction, cool, wash, and dry at 55° C. for 8 h to obtain a hexachlorocyclotriphosphazene polymer. S53. Mix silane-modified nano-titanium dioxide, N,N-dimethylformamide, hexachlorocyclotriphosphazene polymer and triethylamine in parts by weight, reflux for 10-12 hours under nitrogen protection, cool, filter, wash and dry to obtain modified nano-titanium dioxide.

[0011] By adopting the above technical scheme, S51 (silanization modification) involves treating with a 3% KH602 solution, condensing and refluxing the silane coupling agent at 80°C, and then hydrolyzing the silane coupling agent to condense with the surface hydroxyl groups of TiO2 to form -Si-O-Ti bonds, reducing surface polarity and thus reducing the possibility of nano-titanium dioxide agglomeration. S52 (hyperbranched polymer synthesis) involves polycondensing hexachlorocyclotriphosphazene with p-phenylenediamine, catalyzed by triethylamine, and undergoing a nucleophilic substitution reaction to form a three-dimensional hyperbranched structure, retaining highly reactive amino groups (-NH2) at the ends. S53 (grafting and compounding) involves a nitrogen-protected reflux reaction, where triethylamine promotes the reaction of the amino groups of the grafted hyperbranched polymer with the residual silanol groups on the surface of the silane-modified TiO2, forming a covalent bond. In summary, the nano-titanium dioxide is modified by the silane coupling agent, which can hydrogen bond with the nano-titanium dioxide, reducing the surface polarity of the nano-titanium dioxide and thus reducing the possibility of nano-titanium dioxide agglomeration, thereby obtaining silane-modified nano-titanium dioxide. Hexachlorocyclotriphosphazene polymers undergo nucleophilic substitution with p-phenylenediamine to form hyperbranched polymers. These polymers are grafted onto silane-modified nano-titanium dioxide, creating an inert, rough, flame-retardant layer on the nano-titanium dioxide surface, effectively enhancing its flame retardancy. The hyperbranched polymers possess a three-dimensional structure, resistant molecular chains, and highly reactive end groups, forming a reactive interface between the polymer and the composite. This further enhances the compatibility between the nano-titanium dioxide and the composite, synergistically improving the composite's wear resistance, UV aging resistance, and flame retardancy.

[0012] Preferably, in step S52, the weight ratio of N,N-dimethylformamide, hexachlorocyclotriphosphazene, p-phenylenediamine and triethylamine is 100:2.52:4.82:4.52.

[0013] Preferably, in step S53, the weight ratio of the silane-modified nano-titanium dioxide, N,N-dimethylformamide, hexachlorocyclotriphosphazene polymer and triethylamine is 10:180-220:3.5:1.8.

[0014] Preferably, the antioxidant consists of antioxidant 1010 and antioxidant 1076 in a weight ratio of 2:1.

[0015] Preferably, the toughening agent is styrene-ethylene / butylene-styrene block copolymer; and the anti-drip agent is polytetrafluoroethylene powder.

[0016] In a second aspect, the present application provides a method for preparing a flame retardant and UV-resistant PC-ABS composition, which adopts the following technical solution: A method for preparing a flame-retardant and UV-resistant PC-ABS composition, using the raw materials of the flame-retardant and UV-resistant PC-ABS composition, comprises the following steps: The components are mixed in proportion, melt-blended at 240-255° C. through a twin-screw extruder, and extruded into granules to obtain a flame-retardant and UV-resistant PC-ABS composition.

[0017] In summary, the beneficial technical effects of this application are: 1. Highly effective flame retardant performance Oxygen index (LOI) 37-40%, passed UL94V-0 certification, burning without dripping.

[0018] The composite flame retardant (aluminum diethylphosphinate + cresyl diphenyl phosphate) works synergistically to form a dense heat-insulating carbon layer.

[0019] 2. Anti-UV aging: The anti-UV agent and modified nano-TiO2 significantly enhance the anti-UV aging and mechanical properties of the flame-retardant and anti-UV aging PC-ABS composite. After 1000 hours of UV aging, the tensile strength retention rate is ≥90%.

[0020] 3. Mechanical properties Notched impact strength ≥55kJ / m 2 , tensile strength ≥78MPa. Modified nano-TiO2 enhances interface bonding, and the epoxy group of the UV-resistant agent improves compatibility. DETAILED DESCRIPTION

[0021] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0022] In the following examples and preparation examples, 1 part means 100 g.

[0023] Preparation Example 1 The preparation method of the anti-ultraviolet agent comprises the following steps: S31. Add 100 parts of deionized water, 25 parts of urotropine, 10 parts of p-aminophenol, and 8 parts of glacial acetic acid to a reactor in order by weight, stir and dissolve, raise the temperature to 79° C., react for 3.4 hours, cool to room temperature, separate the layers, separate the aqueous layer, and wash with deionized water three times to obtain intermediate A; S32. To the reactor, 300 parts of N,N-dimethylformamide, 80 parts of intermediate A, 50 parts of glycidyl methacrylate, 20 parts of styrene, 1 part of catalyst C-94, and 0.7 parts of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid were added in order by weight. Under nitrogen protection, the temperature was raised to 107°C and the reaction was carried out for 6.7 hours. The temperature was then cooled to room temperature, 400 parts of deionized water were added and stirred evenly, the mixture was centrifuged, and the mixture was washed three times with anhydrous ethanol. The mixture was dried under vacuum at 75°C for 12 hours to obtain intermediate B. S33. According to parts by weight, 300 parts of N,N-dimethylformamide, 85 parts of 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate, 55 parts of intermediate B and 1.35 parts of sodium hydroxide were added to a stirred reactor in sequence and refluxed for 18 hours. During the reaction, 25 parts of acetone were added, and then 160 parts of deionized water were added and dispersed at high speed for 1.2 hours. Finally, the mixture was rotary evaporated at 55°C to obtain an anti-ultraviolet agent.

[0024] Preparation Example 2 The preparation method of modified nano titanium dioxide comprises the following steps: S51. According to parts by weight, 20 parts of nano-titanium dioxide with an average particle size of 80 nanometers were soaked in 200 parts of a 3% mass concentration of a silane coupling agent KH602 solution, stirred for 3 hours, then condensed and refluxed at 80°C, filtered, washed, and dried at 110°C for 12 hours to obtain silane-modified nano-titanium dioxide; S52. Mix 100 parts of N,N-dimethylformamide, 2.52 parts of hexachlorocyclotriphosphazene, and 4.82 parts of p-phenylenediamine in parts by weight, and stir until dissolved to obtain a mixed solution. Add 4.52 parts of triethylamine to the mixed solution, stir at a constant temperature of 75° C. for 12 hours, continue the reaction, cool, wash, and dry at 55° C. for 8 hours to obtain a hexachlorocyclotriphosphazene polymer. S53. Mix 10 parts of silane-modified nano-titanium dioxide, 210 parts of N,N-dimethylformamide, 3.5 parts of hexachlorocyclotriphosphazene polymer and 1.8 parts of triethylamine in parts by weight, reflux under nitrogen protection for 10-12 hours, cool, filter, wash and dry to obtain modified nano-titanium dioxide.

[0025] Example 1 A flame-retardant and UV-resistant PC-ABS composition comprises the following raw materials in parts by weight: 65 parts of PC resin, 25 parts of ABS resin, 12 parts of a composite flame retardant, 2 parts of an anti-ultraviolet agent, 8 parts of modified nano-titanium dioxide, 4 parts of a styrene-ethylene / butylene-styrene block copolymer, 0.2 parts of polytetrafluoroethylene powder, and 0.2 parts of an antioxidant, wherein the composite flame retardant comprises aluminum diethylphosphinate and cresyl diphenyl phosphate in a weight ratio of 4:3, and the antioxidant comprises antioxidant 1010 and antioxidant 1076 in a weight ratio of 2:1. The raw materials of the flame retardant and UV-resistant PC-ABS composition include the following steps: The components are mixed in proportion, melt-blended at 240° C. through a twin-screw extruder, and extruded into granules to obtain a flame-retardant and UV-resistant PC-ABS composition.

[0026] Example 2 A flame-retardant and UV-resistant PC-ABS composition comprises the following raw materials in parts by weight: 72 parts of PC resin, 30 parts of ABS resin, 15 parts of a composite flame retardant, 3 parts of an anti-ultraviolet agent, 12 parts of modified nano-titanium dioxide, 6 parts of a styrene-ethylene / butylene-styrene block copolymer, 0.4 parts of polytetrafluoroethylene powder, and 0.5 parts of an antioxidant, wherein the composite flame retardant comprises aluminum diethylphosphinate and cresyl diphenyl phosphate in a weight ratio of 4:4, and the antioxidant comprises antioxidant 1010 and antioxidant 1076 in a weight ratio of 2:1. The raw materials of the flame retardant and UV-resistant PC-ABS composition include the following steps: The components are mixed in proportion, melt-blended at 255° C. through a twin-screw extruder, and extruded into granules to obtain a flame-retardant and UV-resistant PC-ABS composition.

[0027] Example 3 A flame-retardant and UV-resistant PC-ABS composition comprises the following raw materials in parts by weight: 69 parts of PC resin, 27 parts of ABS resin, 14 parts of a composite flame retardant, 2.5 parts of an anti-ultraviolet agent, 10 parts of modified nano-titanium dioxide, 5 parts of a styrene-ethylene / butylene-styrene block copolymer, 0.3 parts of polytetrafluoroethylene powder, and 0.4 parts of an antioxidant, wherein the composite flame retardant comprises aluminum diethylphosphinate and cresyl diphenyl phosphate in a weight ratio of 4:3.5, and the antioxidant comprises antioxidant 1010 and antioxidant 1076 in a weight ratio of 2:1. The raw materials of the flame retardant and UV-resistant PC-ABS composition include the following steps: The components are mixed in proportion, melt-blended at 250° C. through a twin-screw extruder, and extruded into granules to obtain a flame-retardant and UV-resistant PC-ABS composition.

[0028] Comparative Example 1 The same as Example 3, except that unmodified nano-titanium dioxide is used in equal parts by weight instead of modified nano-titanium dioxide.

[0029] Comparative Example 2 The same as Example 3, except that an equal weight portion of ultraviolet absorber UV-531 (CAS No.: 1843-05-6) is used instead of the anti-ultraviolet agent.

[0030] Comparative Example 3 The same as Example 3, except that no anti-ultraviolet agent was added.

[0031] Comparative Example 4 The same as Example 3, except that the composite flame retardant is aluminum diethylphosphinate.

[0032] Comparative Example 5 The same as Example 3, except that the composite flame retardant is cresyl diphenyl phosphate.

[0033] Performance Testing The flame retardant and UV-resistant PC-ABS compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were sampled, and standard test strips were made and performance tests were performed. The results are shown in Table 1.

[0034] The tensile strength test method was in accordance with ASTM D-638. The specimen dimensions were 120 mm in length, 10 mm in width, and 4 mm in thickness. The tensile rate in the experiment was set at 50 mm / min. The flexural strength test method was in accordance with ASTM D-790, with the specimen dimensions being 80 mm in length, 10 mm in width, and 4 mm in thickness, the travel rate being set at 2 mm / min, and the span being 52 cm.

[0035] The notched impact strength test method is in accordance with ASTM D-256 standard, with specimen dimensions of 62.5 mm in length, 12.7 mm in width, 4 mm in thickness, notch depth of 2.54 mm, and impact load of 5.5 J. UV aging resistance test: Specimens measuring 120 mm in length, 10 mm in width, and 4 mm in thickness were exposed to UV light from a 1000W high-pressure mercury lamp in an aging chamber at 80°C for 1000 hours. After aging, tensile strength was tested according to ASTM D-638, and the tensile strength retention was calculated. Flame retardant performance (limiting oxygen index): According to the GB / T2406.2-2009 standard test, the limiting oxygen index of the sample is measured using an oxygen index meter. The sample size is 100mm*6.5mm*1.6mm.

[0036] Table 1 Performance test Analyzing the data in Table 1, we can see that: 1) The flame retardant and UV-resistant PC-ABS compositions prepared in Examples 1 to 3 significantly improve the flame retardancy, UV-resistant properties, and mechanical properties of the flame retardant and UV-resistant PC-ABS compositions by adding a composite flame retardant, an anti-UV agent, and modified nano-titanium dioxide. The oxygen index (LOI) is ≥37%, and the notched impact strength is ≥55 kJ / m 2 , tensile strength ≥78MPa, after 1000h UV aging, tensile strength retention rate ≥90%.

[0037] 2) A comparative analysis of the flame-retardant, UV-resistant PC-ABS compositions prepared in Example 3 and Comparative Example 1 shows that the modified nano-titanium dioxide prepared in this application is modified by a silane coupling agent. The silane coupling agent can hydrogen bond with the nano-titanium dioxide, reducing the surface polarity of the nano-titanium dioxide, thereby reducing the possibility of nano-titanium dioxide agglomeration, resulting in silane-modified nano-titanium dioxide. Hexachlorocyclotriphosphazene polymer undergoes nucleophilic substitution with p-phenylenediamine to form a hyperbranched polymer. The hyperbranched polymer is grafted onto the silane-modified nano-titanium dioxide, forming an inert and rough flame-retardant layer on the surface of the nano-titanium dioxide, effectively improving flame retardancy. The hyperbranched polymer has a three-dimensional structure, a molecular chain that is not easily entangled, and a highly reactive end group, which forms a reactive interface between the hyperbranched polymer and the composition, thereby further improving the compatibility between the nano-titanium dioxide and the composition, and synergistically improving the composition's UV-resistant and flame-retardant properties.

[0038] 3) A comparative analysis of the properties of the flame-retardant and UV-resistant PC-ABS compositions prepared in Example 3 and Comparative Examples 2-3 shows that the UV-resistant agent prepared in the present application contains styrene-grafted groups and epoxy groups provided by glycidyl methacrylate, which makes the prepared UV-resistant agent have good compatibility with PC and ABS, solving the problem of poor mixing uniformity of traditional benzotriazole UV absorbers; by combining with intermediate B, a high molecular weight polymer with a benzotriazole structure is obtained, which has the ability to absorb UV rays while preventing its migration and volatilization problems, significantly improving the UV-resistant aging performance of the PC-ABS composition.

[0039] 4) A comparative analysis of the properties of the flame-retardant and UV-resistant PC-ABS compositions prepared in Example 3 and Comparative Examples 4-5 shows that the composite flame retardant is composed of aluminum diethylphosphinate and cresyl diphenyl phosphate in a weight ratio of 4:3.5. The combined effect of aluminum diethylphosphinate and cresyl diphenyl phosphate improves the flame retardant properties while maintaining excellent mechanical properties.

[0040] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the above embodiments provide a detailed description of the present application, relevant technical personnel should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents. Any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of the claims of the present application.

Claims

1. A flame retardant and UV-resistant PC-ABS composition, characterized in that: The invention comprises the following raw materials in parts by weight: 65-72 parts of PC resin, 25-30 parts of ABS resin, 12-15 parts of composite flame retardant, 2-3 parts of anti-ultraviolet agent, 8-12 parts of modified nano titanium dioxide, 4-6 parts of toughening agent, 0.2-0.4 parts of anti-drip agent and 0.2-0.5 parts of antioxidant, wherein the composite flame retardant is composed of aluminum diethylphosphinate and cresyl diphenyl phosphate.

2. The flame retardant and UV-resistant PC-ABS composition according to claim 1, characterized in that: The weight ratio of the aluminum diethylphosphinate to cresyl diphenyl phosphate is 4:3-4.

3. The flame retardant and UV-resistant PC-ABS composition according to claim 1, characterized in that: The preparation method of the anti-ultraviolet agent comprises the following steps: S31. Add 100 parts of deionized water, 25 parts of urotropine, 10 parts of p-aminophenol, and 8 parts of glacial acetic acid to a reaction kettle in order by weight, stir and dissolve, raise the temperature to 78-82°C, react for 3-4 hours, cool to room temperature, separate the layers, separate the aqueous layer, and wash with deionized water three times to obtain intermediate A; S32. To the reactor, 300 parts of N,N-dimethylformamide, 80 parts of intermediate A, 50 parts of glycidyl methacrylate, 20 parts of styrene, 1 part of catalyst C-94, and 0.7 parts of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid were added in order by weight under nitrogen protection. The temperature was raised to 105-100° C. and the reaction was carried out for 6-7 hours. The temperature was then lowered to room temperature, 400 parts of deionized water were added and stirred evenly, and the mixture was centrifuged. The mixture was washed with anhydrous ethanol three times and dried under vacuum at 75° C. for 12 hours to obtain intermediate B. S33. According to parts by weight, N,N-dimethylformamide, 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate, intermediate B and sodium hydroxide are added to a stirred reactor in sequence, and refluxed for 16-20 hours. During the reaction, acetone is added, and then deionized water is added and dispersed at high speed for 1-2 hours. Finally, the mixture is rotary evaporated at 55°C to obtain an anti-ultraviolet agent.

4. The flame retardant and UV-resistant PC-ABS composition according to claim 3, characterized in that: In step S33, the weight ratio of N,N-dimethylformamide, 6-(4,7-bis(4-(tert-butyl)phenyl)-2H-benzo[D][1,2,3]triazol-2-yl)hexyl 2-hydroxyacetate, intermediate B and sodium hydroxide is 300:(80-90):(50-60):(1.2-1.5).

5. The flame retardant and UV-resistant PC-ABS composition according to claim 1, characterized in that: The preparation method of the modified nano titanium dioxide comprises the following steps: S51. According to parts by weight, 20 parts of nano-titanium dioxide were soaked in 200 parts of a 3% mass concentration of a silane coupling agent KH602 solution, stirred for 2-3 hours, then condensed and refluxed at 80°C, filtered, washed, and dried at 110°C for 12 hours to obtain silane-modified nano-titanium dioxide; S52. Mix N,N-dimethylformamide, hexachlorocyclotriphosphazene, and p-phenylenediamine in parts by weight, stir until dissolved, and obtain a mixed solution. Add triethylamine to the mixed solution, stir at a constant temperature of 75° C. for 12 h, continue the reaction, cool, wash, and dry at 55° C. for 8 h to obtain a hexachlorocyclotriphosphazene polymer. S53. Mix silane-modified nano-titanium dioxide, N,N-dimethylformamide, hexachlorocyclotriphosphazene polymer and triethylamine in parts by weight, reflux for 10-12 hours under nitrogen protection, cool, filter, wash and dry to obtain modified nano-titanium dioxide.

6. The flame retardant and UV-resistant PC-ABS composition according to claim 5, characterized in that: In step S52, the weight ratio of N,N-dimethylformamide, hexachlorocyclotriphosphazene, p-phenylenediamine and triethylamine is 100:2.52:4.82:4.

52.

7. The flame retardant and UV-resistant PC-ABS composition according to claim 5, characterized in that: In step S53, the weight ratio of the silane-modified nano-titanium dioxide, N,N-dimethylformamide, hexachlorocyclotriphosphazene polymer and triethylamine is 10:180-220:3.5:1.

8.

8. The flame retardant and UV-resistant PC-ABS composition according to claim 1, characterized in that: The antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a weight ratio of 2:

1.

9. The flame retardant and UV-resistant PC-ABS composition according to claim 1, characterized in that: The toughening agent is styrene-ethylene / butylene-styrene block copolymer; the anti-drip agent is polytetrafluoroethylene powder.

10. A method for preparing the flame retardant and UV-resistant PC-ABS composition according to any one of claims 1 to 9, characterized in that: The following steps are involved: The components are mixed in proportion, melt-blended at 240-255° C. through a twin-screw extruder, and extruded into granules to obtain a flame-retardant and UV-resistant PC-ABS composition.

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