High-strength weather-resistant PC-ABS alloy and preparation method thereof

Abstract

The invention discloses a high-strength and weather-resistant PC-ABS alloy material and a preparation process thereof.The prepared PC-ABS composite material is simple in process, the antibacterial effect of the PC-ABS composite material is improved through a chitosan derivative, meanwhile, the original tensile strength and bending performance of the PC-ABS composite material are kept, the PC-ABS composite material has excellent mechanical performance, a specific stabilizer compounding system is adopted, and the PC-ABS composite material is environmentally friendly and low in cost. And a coating system is established and is uniformly dispersed in the PC-ABS composite material, so that the weather aging resistance and the yellowing resistance are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ABS materials, and particularly relates to a high-strength and weather-resistant PC-ABS alloy and a preparation method thereof. Background Art

[0002] ABS material is short for Acrylonitrile-Butadiene-Styrene plastic, and its chemical name is acrylonitrile-butadiene-styrene copolymer. ABS plastic is a terpolymer of acrylonitrile, butadiene and styrene, which combines the respective advantages of the three monomers and becomes an engineering plastic with excellent comprehensive properties. ABS is a light yellow granular or bead-shaped opaque resin, non-toxic, odorless, with low water absorption, and has good comprehensive physical and mechanical properties, such as excellent electrical properties, wear resistance, dimensional stability, chemical resistance and surface gloss, etc., and is easy to process and form. The disadvantages are poor weather resistance, poor heat resistance, and flammability.

[0003] Polycarbonate (PC) is a kind of thermoplastic engineering plastic. Its molecular chain contains both a benzene ring structure with relatively large rigidity and an ether bond with relatively strong chain flexibility. This special molecular chain structure makes polycarbonate have relatively high strength and heat resistance on the one hand, and relatively high toughness on the other hand. PC is an amorphous polymer with high transparency, good gloss, excellent dimensional stability, and low molding shrinkage. Without any modification, PC itself can reach the UL 94V–2 flame retardant grade (3.2mm). Because of these excellent properties, PC is widely used in optical lighting, household appliance shells, power tool shells, electronic appliances, automotive interiors, bumpers, etc. However, the processing fluidity of PC is poor, and the internal stress is not easy to release during molding processing, which easily causes stress concentration and makes the product crack. Therefore, acrylonitrile-butadiene-styrene plastic (ABS) is generally added to PC to make PC-ABS alloy to improve the fluidity and stress cracking resistance of the material.

[0004] As a typical representative of high-performance engineering plastics, polycarbonate / acrylonitrile-butadiene-styrene copolymer (PC-ABS) alloy realizes the balance of mechanical properties and processing efficiency through the synergistic effect of the rigidity and heat resistance of polycarbonate (PC) and the processing fluidity and impact resistance of acrylonitrile-butadiene-styrene (ABS). Through the synergistic effect of PC and ABS, the alloy shows high impact resistance at both normal temperature and low temperature, and at the same time has high rigidity, which can meet the mechanical requirements of complex structural parts; compared with pure ABS, the Vicat softening point of PC-ABS alloy can be increased to above 110°C, which is suitable for high-temperature working conditions;

[0005] PC-ABS alloys have been widely used in lightweight components such as automotive instrument panels, center control panels, and headlight covers, electronic consumer products such as mobile phone / laptop computer casings and charger plugs, and medical device casings, etc., fully meeting the industry's requirements for lightweight and highly durable materials. However, PC-ABS alloys have problems such as insufficient chemical resistance and limited anti-yellowing ability. When in long-term contact with grease, alcohol solvents, or extremely humid and hot environments, stress cracking or surface swelling is likely to occur, resulting in attenuation of mechanical properties; under ultraviolet irradiation or high-temperature oxidation conditions, the material is prone to photoaging and thermo-oxidative aging, causing significant yellowing phenomena, which affect the appearance quality and long-term use stability. This defect limits its further application in scenarios such as outdoor lighting equipment and high-weather-resistant automotive exterior parts. Current technologies mostly modify by adding antioxidants, ultraviolet absorbers, or surface coating processes, but it is easy to cause problems such as decreased compatibility, increased cost, or deteriorated processing performance. Therefore, developing a PC-ABS alloy with both high chemical resistance, anti-yellowing property, and balanced mechanical properties has become a key direction that the industry urgently needs to break through.

[0006] Therefore, those skilled in the art urgently need to develop high-strength and weather-resistant PC-ABS alloys to improve their anti-yellowing ability and safety reliability. Summary of the Invention

[0007] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provides a high-strength and weather-resistant PC-ABS alloy and its preparation method. This material realizes efficient anti-aging and anti-yellowing while having excellent impact resistance and antibacterial properties.

[0008] Specifically, the present invention is realized through the following technologies:

[0009] A high-strength and weather-resistant PC-ABS alloy material, the alloy material comprises the following components in parts by weight: 30-50% by weight of PC, 40-60% by weight of ABS, 5-15% by weight of chitosan or its derivatives, 1-2% by weight of stabilizer, 1-10% by weight of toughening agent, 1-2% by weight of lubricant.

[0010] Preferably, the chitosan or its derivatives are selected from one or more of chitosan, hydroxypropyl chitosan, 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan, O-carboxymethyl chitosan, N-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-alkylated chitosan, O-alkylated chitosan, N-dodecylated chitosan, N-hexadecylated chitosan, hydroxypropyl trimethyl ammonium chloride chitosan.

[0011] Preferably, the chitosan or its derivative is selected from one or more of 3-O-acetyl-6-O-stearoyl-N-phthaloylchitosan, 3-O-acetyl-6-O-palmitoyl-N-phthaloylchitosan, and 3-O-acetyl-6-O-valeryl-N-phthaloylchitosan.

[0012] Preferably, the chitosan or its derivative is 3-O-acetyl-6-O-valeryl-N-phthaloylchitosan.

[0013] Preferably, the stabilizer is a compound system of 2,5-di-tert-butylhydroquinone and deoxycholic acid; the mass ratio of 2,5-di-tert-butylhydroquinone to deoxycholic acid is 1:0.1 - 1.

[0014] In a preferred embodiment, the stabilizer and the chitosan or its derivative form a coating material.

[0015] Preferably, the toughening agent is selected from one or a combination of polyethylene, polypropylene, high rubber content ABS powder, SBS, SEBS, POE, MBS, ACR, ethylene-propylene rubber, and nitrile rubber, and further preferably one or a combination of POE, SEBS, and ethylene-propylene rubber.

[0016] Preferably, the lubricant is selected from one or a combination of vinyl bisstearamide, zinc stearate, magnesium stearate, oleamide, and stearamide; and further preferably vinyl bisstearamide.

[0017] On the other hand, the present invention provides a method for preparing the above PC-ABS alloy material, which includes the following steps:

[0018] Step 1: Weigh the prescribed amount of the stabilizer and ultrasonically disperse it in deionized water. Dissolve the prescribed amount of the chitosan or its derivative in dilute hydrochloric acid, and slowly add the solution of the chitosan or its derivative to the deionized water in which the stabilizer is dispersed while stirring. Control the temperature and continuously stir and react; after the reaction is completed, add an alkali solution dropwise, continuously stir, filter the slurry, wash the product with deionized water, and dry it in a vacuum drying oven to obtain a coating material.

[0019] Step 2: Weigh the prescribed amounts of ABS, PC, toughening agent, and lubricant and put them into a high-speed mixer, and stir and mix at room temperature; add the coating material obtained in Step 1 and continue to stir and mix to obtain a uniform mixture.

[0020] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder, cool it, and pelletize it to obtain a PC-ABS composite material.

[0021] In a preferred embodiment, the method for preparing the PC-ABS composite material specifically includes the following steps:

[0022] Step 1: Weigh the prescribed amount of stabilizer and ultrasonically disperse it in an appropriate amount of deionized water. Dissolve the prescribed amount of chitosan or its derivative in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer is dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and dry it in a vacuum at 80 °C for 12 hours to obtain the coating material.

[0023] Step 2: Weigh the prescribed amounts of ABS, PC, toughening agent, and lubricant and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0024] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C. The screw rotation speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0025] Advantages of the present invention:

[0026] Compared with the prior art, the process for preparing the PC-ABS composite material of the present application is simple. By adding a specific amount of chitosan derivative to PC-ABS, its antibacterial effect is greatly improved, the antibacterial ability is uniform, and at the same time, it does not affect the original impact resistance of the PC-ABS resin, maintaining its original tensile strength and bending properties, and having excellent mechanical properties. In addition, the compounding system of the specific stabilizer 2,5-di-tert-butylhydroquinone and deoxycholic acid, and the establishment of a coating system uniformly dispersed in the PC-ABS composite material significantly improve the weathering aging and anti-yellowing ability. Detailed implementation manners

[0027] The present invention will be further illustrated by the following examples. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0028] In the specific implementation manner, refer to the components to prepare the PC-ABS composite material. The preparation method includes: ultrasonically disperse the stabilizer in deionized water, dissolve chitosan or its derivative in dilute hydrochloric acid, slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer is dispersed while stirring to prepare the coating material. After mixing ABS, PC, toughening agent, and lubricant in a high-speed mixer, add the coating material evenly. The mixture is melt and co-extruded through a twin-screw extruder to obtain the PC-ABS composite material. Specific examples are listed in detail as follows.

[0029] Example 1

[0030] Component

[0031]

[0032] The specific preparation process is as follows:

[0033] Step 1: Weigh the prescribed amount of stabilizer 2,5-di-tert-butylhydroquinone and deoxycholic acid, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan to the deionized water in which the stabilizer is dispersed. Heat to 80°C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and dry it in vacuum at 80°C for 12 hours to obtain the coating material.

[0034] Step 2: Weigh the prescribed amount of ABS, PC, POE, ethylene-propylene rubber, and vinyl bis-stearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0035] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is: the first section is 220 - 230°C, the second section is 235 - 240°C, the third section is 240 - 245°C, the fourth section is 245 - 250°C, and the die head is 235 - 240°C. The screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0036] Example 2

[0037] Component

[0038]

[0039] The specific preparation process is as follows:

[0040] Step 1: Weigh the prescribed amount of stabilizers 2,5-di-tert-butylhydroquinone and deoxycholic acid, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan to the deionized water in which the stabilizers are dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0041] Step 2: Weigh the prescribed amount of ABS, PC, SEBS, and vinyl bisstearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0042] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C. The screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0043] Example 3

[0044] Components

[0045]

[0046]

[0047] The specific preparation process is as follows:

[0048] Step 1: Weigh the prescribed amount of stabilizers 2,5-di-tert-butylhydroquinone and deoxycholic acid, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan to the deionized water in which the stabilizers are dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0049] Step 2: Weigh the prescribed amount of ABS, PC, ABS high rubber powder, and vinyl bisstearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0050] Step 3: Extrude the obtained mixture by melt blending through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0051] Example 4

[0052] Component

[0053]

[0054] The specific preparation process is as follows:

[0055] Step 1: Weigh the prescribed amount of stabilizer 2,5-di-tert-butylhydroquinone and deoxycholic acid, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan to the deionized water in which the stabilizer is dispersed, and heat to 80 °C and stir for 10 hours for reaction; after the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min, filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0056] Step 2: Weigh the prescribed amounts of ABS, PC, POE, ethylene-propylene rubber, and magnesium stearate, and put them into a high-speed mixer, and stir and mix at room temperature for 20 min; add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0057] Step 3: Extrude the obtained mixture by melt blending through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0058] Example 5

[0059] Component

[0060]

[0061] The specific preparation process is as follows:

[0062] Step 1: Weigh the prescribed amount of the stabilizer 2,5-di-tert-butylhydroquinone and deoxycholic acid, and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan to the deionized water in which the stabilizer is dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0063] Step 2: Weigh the prescribed amounts of ABS, PC, POE, and vinyl bisstearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0064] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperatures of the extruder are as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C. The screw rotation speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0065] Comparative Example 1

[0066] Component

[0067]

[0068] The specific preparation process is as follows:

[0069] Step 1: Weigh the prescribed amount of the stabilizer 2,5-di-tert-butylhydroquinone and ultrasonically disperse it in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan in an appropriate amount of dilute hydrochloric acid. While stirring, slowly add the solution of 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan to the deionized water in which the stabilizer is dispersed. Heat to 80 °C and stir for 10 hours for reaction. After the reaction is completed, while stirring, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutrality. After adding, stir for 30 min. Filter the slurry, wash the product with deionized water, and vacuum dry at 80 °C for 12 hours to obtain the coating material.

[0070] Step 2: Weigh the prescribed amounts of ABS, PC, POE, ethylene-propylene rubber, and vinyl bisstearamide, and put them into a high-speed mixer. Stir and mix at room temperature for 20 min. Add the coating material obtained in Step 1 and continue to stir and mix for 20 min to obtain a uniform mixture.

[0071] Step 3: Extrude the obtained mixture by melt blending through a twin-screw extruder. The temperatures of the extruder are as follows: the first stage is 220 - 230 °C, the second stage is 235 - 240 °C, the third stage is 240 - 245 °C, the fourth stage is 245 - 250 °C, and the head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0072] Comparative Example 2

[0073] Component

[0074]

[0075]

[0076] The specific preparation process is as follows:

[0077] Step 1: Weigh the prescribed amounts of ABS, PC, 2,5-di-tert-butylhydroquinone, deoxycholic acid, POE, ethylene-propylene rubber, and vinyl bisstearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min to obtain a uniform mixture.

[0078] Step 2: Extrude the obtained mixture by melt blending through a twin-screw extruder. The temperatures of the extruder are as follows: the first stage is 220 - 230 °C, the second stage is 235 - 240 °C, the third stage is 240 - 245 °C, the fourth stage is 245 - 250 °C, and the head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0079] Comparative Example 3

[0080] Component

[0081]

[0082] The specific preparation process is as follows:

[0083] Step 1: Weigh the prescribed amount of the stabilizer bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate and 2,6-di-tert-butyl-p-cresol and ultrasonically disperse them in an appropriate amount of deionized water. Dissolve the prescribed amount of 3-O-acetyl-6-O-valeryl-N-phthaloylchitosan in an appropriate amount of dilute hydrochloric acid. Slowly add the solution of 3-O-acetyl-6-O-valeryl-N-phthaloylchitosan to the deionized water in which the stabilizer is dispersed while stirring, and heat to 80 °C and stir for 10 hours for reaction; after the reaction is completed, slowly add an appropriate amount of sodium hydroxide solution to adjust to neutral while stirring. After adding, stir for 30 min, filter the slurry, wash the product with deionized water, and dry it under vacuum at 80 °C for 12 hours to obtain the coating material.

[0084] Step 2: Weigh the prescribed amounts of ABS, PC, POE, ethylene-propylene rubber, and vinyl bis-stearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min; add the coating material from Step 1 and continue to stir and mix for 20 min to obtain a homogeneous mixture.

[0085] Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0086] Comparative Example 4

[0087] Components

[0088]

[0089] The specific preparation process is as follows:

[0090] Step 1: Weigh the prescribed amounts of ABS, PC, 2-(4,6-diphenyl-1,3,5-triazin-2)-5-n-hexyloxyphenol, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, SEBS, and vinyl bis-stearamide and put them into a high-speed mixer. Stir and mix at room temperature for 20 min to obtain a homogeneous mixture.

[0091] Step 2: Melt and co-extrude the obtained mixture through a twin-screw extruder. The temperature of the extruder is as follows: the first section is 220 - 230 °C, the second section is 235 - 240 °C, the third section is 240 - 245 °C, the fourth section is 245 - 250 °C, and the die head is 235 - 240 °C; the screw speed of the extruder is 300 - 500 r / min. Cool and pelletize to obtain the PC-ABS composite material.

[0092] Accelerated aging experiment:

[0093] Use the specification of ASTM G154-23 for accelerated aging test for testing.

[0094] Sample preparation: Take the PC-ABS composite materials of Examples 1 - 5 and Comparative Examples 1 - 4 to make weather-resistant test pieces of 70×45×30 mm.

[0095] Light source and irradiance: Select a UVB-313 fluorescent ultraviolet lamp (main wavelength 313 nm, simulating short-wave ultraviolet for accelerating degradation) as the light source, and control the irradiation intensity at 0.6 - 0.7 W / m 2 / nm (Calibration lamp tube, meeting the requirements of ASTM G154).

[0096] Temperature and cycle parameters: During the light exposure stage, the temperature is 60 °C (blackboard temperature or test chamber air temperature), with 4 hours of continuous UV irradiation; during the non-illuminated stage, the temperature is 50 °C (turn off the UV lamp and maintain the temperature to simulate the night environment), and keep it for 4 hours; each 8-hour period is a complete cycle (4h light exposure + 4h non-illuminated).

[0097] Sampling and testing: Fix the PC-ABS spline (or other materials) on the specimen holder, avoiding blocking the light source, and conduct color difference tests every 100 hours for a total of 600 hours. (1. The ΔE value represents the overall difference in material color change, calculated based on the changes in L* (lightness), a* (red-green axis), and b* (yellow-blue axis) in the CIE Lab color space. ΔL* is the change in lightness (L* value after aging - initial L* value), Δa* is the change in the red-green axis (a* value after aging - initial a* value), Δb* is the change in the yellow-blue axis (b* value after aging - initial b* value). ΔE < 1 indicates that the human eye can hardly detect the color difference, 1 ≤ ΔE < 3 indicates a slight difference that requires professional instruments to identify, and ΔE ≥ 3 indicates an obvious visible color change; 2. The ΔY1 yellowness index represents the change in yellowness degree before and after aging. The simplified formula is ΔY1 ≈ 100×(1.28×Δa* - 1.06×Δb*). ΔY1 > 5 indicates significant yellowing, and ΔY1 < 2 indicates an acceptable degree of yellowing).

[0098] Tensile strength test: Refer to the standard of GB / T 1040.1-2018, use a universal testing machine to test the tensile strength at a testing rate of 50 mm / min. Test the tensile strength before accelerated aging, after 300 hours of accelerated aging, and after 600 hours of accelerated aging respectively.

[0099] Table 1 Results of accelerated light resistance and yellowing test

[0100]

[0101] Table 2 Results of tensile strength test

[0102]

[0103] The above results show that adding specific stabilizers to the PC-ABS of the present invention improves its excellent mechanical properties. Adding chitosan or its derivatives can greatly improve the antibacterial effect. The stabilizer and chitosan or its derivatives establish a coating system and are uniformly dispersed in the PC-ABS composite material, significantly enhancing the weather aging and yellowing resistance ability.

[0104] It should be noted here that the embodiments of the present invention are only used to illustrate the present invention, rather than to limit the present invention. Therefore, any simple improvement to the present invention under the premise of the method of the present invention falls within the scope of protection required by the present invention.

Claims

1. A high-strength and weather-resistant PC-ABS alloy material, characterized in that, The alloy material comprises the following components in parts by weight: 30-50 parts by weight of PC, 40-60 parts by weight of ABS, 5-15 parts by weight of chitosan or its derivative, 1-2 parts by weight of stabilizer, 1-10 parts by weight of toughening agent, and 1-2 parts by weight of lubricant.

2. The PC-ABS alloy material according to claim 1, wherein The chitosan or its derivative is selected from one or more of chitosan, hydroxypropyl chitosan, 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan (CTS18), 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan (CTS16), 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan (CTS5), O-carboxymethyl chitosan, N-carboxymethyl chitosan, N,O-carboxymethyl chitosan, N-alkylated chitosan, O-alkylated chitosan, N-dodecylated chitosan, N-hexadecylated chitosan, and hydroxypropyl trimethyl ammonium chloride chitosan.

3. The PC-ABS alloy material according to claim 1, wherein, The chitosan or its derivative is selected from one or more of 3-O-acetyl-6-O-stearoyl-N-phthaloyl chitosan, 3-O-acetyl-6-O-palmitoyl-N-phthaloyl chitosan, and 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan.

4. The PC-ABS alloy material according to claim 1, wherein The chitosan or its derivative is selected from 3-O-acetyl-6-O-valeryl-N-phthaloyl chitosan.

5. The PC-ABS alloy material according to claim 1, characterized in that, The stabilizer is a compound system of 2,5-di-tert-butylhydroquinone and deoxycholic acid.

6. The PC-ABS alloy material according to claim 5, wherein, The mass ratio of 2,5-di-tert-butylhydroquinone to deoxycholic acid is 1:0.1-1.

7. The PC-ABS alloy material according to claim 1, wherein The stabilizer and the chitosan or its derivative form a coating material.

8. The PC-ABS alloy material according to claim 1, wherein, The toughening agent is selected from one or a combination of polyethylene, polypropylene, ABS high rubber powder, SBS, SEBS, POE, MBS, ACR, ethylene-propylene rubber, and nitrile rubber; further preferably, it is selected from one or a combination of POE, SEBS, and ethylene-propylene rubber.

9. The PC-ABS alloy material according to claim 6, characterized in that The lubricant is selected from one or a combination of vinyl bisstearamide, zinc stearate, magnesium stearate, oleic acid amide, and stearamide.

10. The PC-ABS alloy material according to claim 1, characterized in that, The specific steps of its preparation method include: Step 1: Weigh the prescribed amount of stabilizer and ultrasonically disperse it in deionized water. Dissolve the prescribed amount of chitosan or its derivative in dilute hydrochloric acid, and slowly add the solution of chitosan or its derivative to the deionized water in which the stabilizer is dispersed while stirring. Control the temperature and continuously stir and react; after the reaction is completed, add an alkali solution dropwise, continue stirring, filter the slurry, wash the product with deionized water, and dry it in a vacuum drying oven to obtain a coating material. Step 2: Weigh the prescribed amounts of ABS, PC, toughening agent, and lubricant and put them into a high-speed mixer, and stir and mix them at room temperature; add the coating material obtained in Step 1 and continue to stir and mix to obtain a uniform mixture. Step 3: Melt and co-extrude the obtained mixture through a twin-screw extruder, cool it, and pelletize it to obtain a PC-ABS composite material.

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