Carbon black nanosuspension-based pet masterbatch and method for preparing the same

Abstract

This invention discloses a PET masterbatch based on carbon black nano-slurry and its preparation method, relating to the field of PET technology. The PET masterbatch comprises the following raw material components: by mass, 50-70 parts polyethylene terephthalate, 10-20 parts carbon black nano-slurry, 8-15 parts modified styrene-acrylate copolymer, and 1-3 parts antioxidant. The preparation steps include: mixing the carbon black nano-slurry with polyethylene terephthalate, modified styrene-acrylate copolymer, and antioxidant, and then loading the mixture into a twin-screw extruder for extrusion granulation to obtain the PET masterbatch. This invention uses carbon black pre-dispersion in the liquid phase to form a stable dispersed nano-slurry, which is then blended with PET powder to improve the dispersion of carbon black in the resin material, thereby improving the UV shielding performance of the PET masterbatch. The modified styrene-acrylate copolymer provides good impact resistance and a good balance of toughness.

Description

Technical Field

[0001] This invention relates to the field of PET technology, specifically to a PET masterbatch based on carbon black nano-slurry and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) is widely used in outdoor products, such as outdoor textile fabrics, due to its excellent mechanical properties, chemical resistance, and processability. However, PET molecular chains are prone to photo-oxidative degradation under long-term exposure to ultraviolet light, leading to yellowing, surface cracking, and a sharp decline in mechanical properties, which severely shortens the service life of outdoor products. To enhance the UV shielding ability of PET, inorganic UV shielding materials are often added in industry. Among them, carbon black, as a highly efficient light shielding agent and black colorant, significantly improves the UV aging resistance and weather resistance of PET, protecting the material from photodegradation. However, adding it directly to PET can lead to uneven dispersion due to agglomeration, affecting the subsequent UV shielding performance. Furthermore, carbon black agglomerates can become stress concentration points in PET, which can lead to a decline in mechanical properties in severe cases. Therefore, developing a PET masterbatch based on carbon black nano-slurry is of great significance for significantly improving the UV shielding performance and mechanical toughness of PET masterbatch. Summary of the Invention

[0003] The purpose of this invention is to provide a PET masterbatch based on carbon black nano-slurry and its preparation method, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing PET masterbatch based on carbon black nano-slurry includes the following preparation steps: mixing carbon black nano-slurry with polyethylene terephthalate, modified styrene-acrylate copolymer and antioxidant, and then loading the mixture into a twin-screw extruder for extrusion granulation to obtain PET masterbatch; Preferably, the PET masterbatch comprises the following raw material components: by weight, 50-70 parts polyethylene terephthalate, 10-20 parts carbon black nano-slurry, 8-15 parts modified styrene-acrylate copolymer, and 1-3 parts antioxidant.

[0005] Preferably, the carbon black nano-slurry comprises the following raw material components: by weight, 8-15 parts nano carbon black, 5-12 parts nano hybrid powder, 10-25 parts dispersant, and 55-70 parts propylene glycol methyl ether acetate. Preferably, the preparation steps of the nano-hybrid powder are as follows: mix nano-titanium dioxide, nano-carbon black, diethylene glycol monobutyl ether, grinding aid, methanol and deionized water, add grinding balls and grind for 6-8 hours, filter, dry and calcine to obtain nano-hybrid powder; More preferably, the calcination process parameters are as follows: in nitrogen, heat to 400-450°C at a heating rate of 2-5°C / min, then introduce ammonia to remove the nitrogen, and then heat to 800-850°C at a heating rate of 3-5°C / min, and hold for 4-8 hours. More preferably, the mass ratio of nano-titanium dioxide to nano-carbon black is (1-4):1; Preferably, the preparation steps of the dispersing agent are as follows: under a nitrogen atmosphere, adipic acid, phthalic anhydride, diethylene glycol, hexanediol and n-hexanoic acid are mixed in xylene, a catalyst is added, the temperature is raised to 180-190℃ and reacted for 12-14h, and water is removed. After the reaction is completed, the terminal hydroxyl polyester is obtained by vacuum distillation; the terminal hydroxyl polyester is placed in a mixed solvent of xylene and butyl acetate, kept at 45-50℃ and then poured into a mixed solution of toluene diisocyanate and toluene, kept at the temperature for 2-3h, then polyetheramine is added, kept at the temperature for 3-4h, and the dispersing agent is obtained. Preferably, the molar ratio of adipic acid, phthalic anhydride, diethylene glycol, hexanediol and hexanoic acid is 8:4:(8-12):(1-5):1; Preferably, the mass ratio of hydroxyl-terminated polyester, toluene diisocyanate, and polyetheramine is (1-3):(0.05-0.20):1; More preferably, the polyetheramine has an average number-average molecular weight of 1000-3000; The modified styrene-acrylate copolymer is obtained by copolymerizing styrene, glycidyl methacrylate and methyl methacrylate, and then melt-blending it with γ-aminopropyltriethoxysilane and polyethylene terephthalate.

[0006] Preferably, the preparation steps of the modified styrene-acrylate copolymer are as follows: Styrene, glycidyl methacrylate, and methyl methacrylate are mixed under a nitrogen atmosphere, azobisisobutyronitrile is added, the mixture is heated to 75-80℃ and stirred for 3-5 hours, methanol is added, the mixture is filtered, washed, and dried to obtain the styrene-acrylate copolymer; the styrene-acrylate copolymer is mixed with γ-aminopropyltriethoxysilane, melt-blended at 180-190℃ for 10-15 minutes, polyethylene terephthalate is added, and the mixture is heated to 280-290℃ and stirred for 10-15 minutes to obtain the modified styrene-acrylate copolymer; Preferably, the mass ratio of styrene, glycidyl methacrylate, and methyl methacrylate in the styrene-acrylate copolymer is (7-8):(0.5-1.5):(1-1.5). Preferably, the mass ratio of styrene-acrylate copolymer to γ-aminopropyltriethoxysilane and polyethylene terephthalate is 100:(0.5-0.8):(20-30). Preferably, the extrusion granulation process parameters are as follows: the temperature of the extruder's feed zone is 240-260℃, the temperature of die zone one is 250-260℃, the temperature of die zone two is 260-275℃, the temperature of die zone three is 270-280℃, the temperature of die zone four is 265-275℃, the temperature of die zone five is 255-260℃, the temperature of the discharge zone is 240-250℃, and the screw speed is 200-300 r / min, granulation yields PET masterbatch.

[0007] A PET masterbatch based on carbon black nano-slurry was prepared according to the above preparation method.

[0008] Compared with the prior art, the beneficial effects achieved by the present invention are: 1. This invention pre-disperses carbon black in a liquid phase to form a stable nano-slurry, which is then blended with PET powder to improve the dispersion of carbon black in resin materials. The carbon black nano-slurry is further supplemented with nano-hybrid powder. This nano-hybrid powder is formed by wet milling titanium dioxide and carbon black, relying on π-π stacking and hydrogen bonding to create a continuous carbon black coating layer on the TiO2 surface. Nitriding further improves the UV shielding performance of carbon black in PET materials. The dispersing agent uses a polyester backbone, with adipic acid and hexanediol as solvation chains to provide soft segments. Diethylene glycol is further introduced to improve its flexibility, enhance the spreading of the dispersing agent in the slurry, and increase the dispersion stability of the slurry. Furthermore, by grafting isocyanate groups with polyetheramines of different number-average molecular weights, a balance between steric hindrance and reactivity is achieved, anchoring the nano-carbon black and nano-hybrid powder on the surface and further preventing agglomeration. 2. The PET masterbatch prepared in this invention introduces a modified styrene-acrylate copolymer. After copolymerization of styrene, glycidyl methacrylate, and methyl methacrylate, it is mixed with a low content of γ-aminopropyltriethoxysilane. While retaining most of the epoxy groups, ethoxy groups are introduced to bond the PET powder. The retained epoxy groups can further react with the dispersing aids in the aforementioned carbon black nano-dispersion slurry during melt blending, forming appropriate crosslinks with PET to create a three-dimensional network structure that absorbs impact energy and achieves a balance between rigidity and toughness. In addition, it further anchors carbon black and other nano-powders, improves the dispersion uniformity of carbon black and other nano-powders in PET, and further enhances the ultraviolet light shielding performance. Detailed Implementation

[0009] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include: The nano-titanium dioxide has a particle size of 100-300nm, the nano-carbon black has a particle size of <100nm, the grinding aid is a TDL series grinding aid, the PET powder is CR-8816, and the antioxidant is 1010; In Example 1, the average Mn of the polyetheramine was 2000; in Example 2, the average Mn of the polyetheramine was 1000; and in Example 3, the average Mn of the polyetheramine was 3000. In the following examples, parts refer to parts by weight, and all raw materials mentioned above and others not mentioned are commercially available.

[0011] Example 1: This example provides a method for preparing PET masterbatch based on carbon black nano-slurry, including the following preparation steps: Step 1: By weight, mix 7.5 parts of nano titanium dioxide, 3 parts of nano carbon black, 2 parts of diethylene glycol monobutyl ether, 1 part of grinding aid, 2 parts of methanol and 80 parts of deionized water, add grinding balls and grind for 6 hours, filter and dry, then heat to 400°C in nitrogen at a heating rate of 5°C / min, then introduce ammonia to remove the nitrogen, and heat to 800°C at a heating rate of 3°C / min and hold for 6 hours to obtain nano-hybrid powder; then take 12 parts of nano carbon black, 8 parts of nano-hybrid powder, 18 parts of dispersant and 62 parts of propylene glycol methyl ether acetate and mix and stir for 8 hours to obtain carbon black nano slurry; Step 2: By weight, mix 15 parts of carbon black nano-slurry with 60 parts of polyethylene terephthalate, 12 parts of modified styrene-acrylate copolymer, and 3 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 220 r / min, and the extruder temperature as follows: feed zone 240℃, die zone 1 250℃, die zone 2 260℃, die zone 3 275℃, die zone 4 270℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 9.15 parts diethylene glycol, 3 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 180℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 45℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at this temperature for 2 hours, 10 parts polyetheramine are added and the reaction is kept at this temperature for 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 75℃ and stirred for 4 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 0.1 parts of γ-aminopropyltriethoxysilane, melt-blended at 180℃ for 10 minutes, 4 parts of polyethylene terephthalate are added and the mixture is heated to 280℃ and stirred for 10 minutes to obtain the modified styrene-acrylate copolymer.

[0012] Example 2: This example provides a method for preparing PET masterbatch based on carbon black nano-slurry, including the following preparation steps: Step 1: By weight, mix 10 parts of nano titanium dioxide, 3 parts of nano carbon black, 2 parts of diethylene glycol monobutyl ether, 1 part of grinding aid, 2 parts of methanol and 80 parts of deionized water, add grinding balls and grind for 8 hours, filter and dry, then heat to 420°C in nitrogen at a heating rate of 3°C / min, then introduce ammonia to remove the nitrogen, and heat to 820°C at a heating rate of 5°C / min, and hold for 6 hours to obtain nano-hybrid powder; then take 15 parts of nano carbon black, 8 parts of nano-hybrid powder, 22 parts of dispersant and 55 parts of propylene glycol methyl ether acetate and mix and stir for 8 hours to obtain carbon black nano slurry; Step 2: By weight, mix 18 parts of carbon black nano-slurry with 55 parts of polyethylene terephthalate, 12 parts of modified styrene-acrylate copolymer, and 2 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 250 r / min, and the extruder temperature as follows: feed zone 245℃, die zone 1 255℃, die zone 2 265℃, die zone 3 270℃, die zone 4 265℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 8.8 parts diethylene glycol, 4 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 180℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 50℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at this temperature for 2 hours, 10 parts polyetheramine are added and the reaction is kept at this temperature for 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 80℃ and stirred for 4 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 0.16 parts of γ-aminopropyltriethoxysilane, melt-blended at 190℃ for 10 minutes, 6 parts of polyethylene terephthalate are added and the mixture is heated to 280℃ and stirred for 15 minutes to obtain the modified styrene-acrylate copolymer.

[0013] Example 3: This example provides a method for preparing PET masterbatch based on carbon black nano-slurry, including the following preparation steps: Step 1: By weight, mix 4 parts nano titanium dioxide, 3 parts nano carbon black, 2 parts diethylene glycol monobutyl ether, 1 part grinding aid, 2 parts methanol and 80 parts deionized water, add grinding balls and grind for 6 hours, filter and dry, then heat to 450°C in nitrogen at a heating rate of 3°C / min, then introduce ammonia to remove the nitrogen, and heat to 850°C at a heating rate of 5°C / min and hold for 6 hours to obtain nano-hybrid powder; then take 9 parts nano carbon black, 6 parts nano-hybrid powder, 15 parts dispersant and 70 parts propylene glycol methyl ether acetate and mix and stir for 6 hours to obtain carbon black nano slurry; Step 2: By weight, mix 12 parts of carbon black nano-slurry with 68 parts of polyethylene terephthalate, 10 parts of modified styrene-acrylate copolymer, and 3 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 250 r / min, and the extruder temperature as follows: feed zone 240℃, die zone 1 250℃, die zone 2 270℃, die zone 3 280℃, die zone 4 270℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 9.15 parts diethylene glycol, 3 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 190℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 50℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at 3 hours, 10 parts polyetheramine are added and the reaction is kept at 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 80℃ and stirred for 5 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 0.1 parts of γ-aminopropyltriethoxysilane, melt-blended at 185℃ for 12 minutes, 6 parts of polyethylene terephthalate are added and the mixture is heated to 280℃ and stirred for 15 minutes to obtain the modified styrene-acrylate copolymer.

[0014] Comparative Example 1: As a control experiment for Example 1, the difference is that the nano-hybrid powder was replaced with nano-carbon black, and the carbon black nano-slurry included 20 parts of nano-carbon black but did not include the nano-hybrid powder; the preparation steps included: Step 1: By weight, take 20 parts of nano carbon black, 18 parts of dispersant and 62 parts of propylene glycol methyl ether acetate and mix and stir for 8 hours to obtain carbon black nano slurry; Step 2: By weight, mix 15 parts of carbon black nano-slurry with 60 parts of polyethylene terephthalate, 12 parts of modified styrene-acrylate copolymer, and 3 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 220 r / min, and the extruder temperature as follows: feed zone 240℃, die zone 1 250℃, die zone 2 260℃, die zone 3 275℃, die zone 4 270℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 9.15 parts diethylene glycol, 3 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 180℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 45℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at this temperature for 2 hours, 10 parts polyetheramine are added and the reaction is kept at this temperature for 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 75℃ and stirred for 4 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 0.1 parts of γ-aminopropyltriethoxysilane, melt-blended at 180℃ for 10 minutes, 4 parts of polyethylene terephthalate are added and the mixture is heated to 280℃ and stirred for 10 minutes to obtain the modified styrene-acrylate copolymer.

[0015] Comparative Example 2: As a control experiment of Example 1, the difference is that diethylene glycol was replaced with an equimolar amount of hexanediol, i.e., the molar ratio of adipic acid, phthalic anhydride, diethylene glycol, hexanediol and n-hexanoic acid was 8:4:0:13:1; including the following preparation steps: Step 1: By weight, mix 6 parts of nano titanium dioxide, 3 parts of nano carbon black, 2 parts of diethylene glycol monobutyl ether, 1 part of grinding aid, 2 parts of methanol and 80 parts of deionized water, add grinding balls and grind for 6 hours, filter and dry, then heat to 400°C in nitrogen at a heating rate of 5°C / min, then introduce ammonia to remove the nitrogen, and heat to 800°C at a heating rate of 3°C / min and hold for 6 hours to obtain nano-hybrid powder; then take 12 parts of nano carbon black, 8 parts of nano-hybrid powder, 18 parts of dispersant and 62 parts of propylene glycol methyl ether acetate and mix and stir for 8 hours to obtain carbon black nano slurry; Step 2: By weight, mix 15 parts of carbon black nano-slurry with 60 parts of polyethylene terephthalate, 12 parts of modified styrene-acrylate copolymer, and 3 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 220 r / min, and the extruder temperature as follows: feed zone 240℃, die zone 1 250℃, die zone 2 260℃, die zone 3 275℃, die zone 4 270℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 13.2 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 180℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 45℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at this temperature for 2 hours, 10 parts polyetheramine are added and the reaction is kept at this temperature for 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 75℃ and stirred for 4 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 0.1 parts of γ-aminopropyltriethoxysilane, melt-blended at 180℃ for 10 minutes, 4 parts of polyethylene terephthalate are added and the mixture is heated to 280℃ and stirred for 10 minutes to obtain the modified styrene-acrylate copolymer.

[0016] Comparative Example 3: As a control experiment for Example 1, the difference is that γ-aminopropyltriethoxysilane was not added to the modified styrene-acrylate copolymer; the preparation steps included: Step 1: By weight, mix 6 parts of nano titanium dioxide, 3 parts of nano carbon black, 2 parts of diethylene glycol monobutyl ether, 1 part of grinding aid, 2 parts of methanol and 80 parts of deionized water, add grinding balls and grind for 6 hours, filter and dry, then heat to 400°C in nitrogen at a heating rate of 5°C / min, then introduce ammonia to remove the nitrogen, and heat to 800°C at a heating rate of 3°C / min and hold for 6 hours to obtain nano-hybrid powder; then take 12 parts of nano carbon black, 8 parts of nano-hybrid powder, 18 parts of dispersant and 62 parts of propylene glycol methyl ether acetate and mix and stir for 8 hours to obtain carbon black nano slurry; Step 2: By weight, mix 15 parts of carbon black nano-slurry with 60 parts of polyethylene terephthalate, 12 parts of styrene-acrylate copolymer, and 3 parts of antioxidant, and then load the mixture into a twin-screw extruder. Set the screw speed to 220 r / min, and the extruder temperature as follows: feed zone 240℃, die zone 1 250℃, die zone 2 260℃, die zone 3 275℃, die zone 4 270℃, die zone 5 260℃, and discharge zone 250℃. Extrusion granulation yields cylindrical PET masterbatch with a height of 2 mm. The dispersant preparation steps are as follows: Under a nitrogen atmosphere, 10 parts adipic acid, 5.1 parts phthalic anhydride, 9.15 parts diethylene glycol, 3 parts hexanediol and 1 part n-hexanoic acid are mixed and placed in 6 parts xylene. 0.02 parts tetrabutyl titanate are added, the temperature is raised to 180℃ and reacted for 12 hours, and water is removed. After the reaction is completed, the hydroxyl-terminated polyester is obtained by vacuum distillation. 10 parts of the hydroxyl-terminated polyester are placed in a mixed solvent of 25 parts xylene and 25 parts butyl acetate. After being kept at 45℃, it is poured into a mixed solution of 0.6 parts toluene diisocyanate and 20 parts toluene. After being kept at this temperature for 2 hours, 10 parts polyetheramine are added and the reaction is kept at this temperature for 3 hours to obtain the dispersant. The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, 17.5 parts of styrene, 3.75 parts of glycidyl methacrylate and 3.75 parts of methyl methacrylate are mixed, 0.02 parts of azobisisobutyronitrile are added, the mixture is heated to 75℃ and stirred for 4 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; 20 parts of the styrene-acrylate copolymer are mixed with 4 parts of polyethylene terephthalate and heated to 280℃ and stirred for 10 minutes to obtain the modified styrene-acrylate copolymer.

[0017] Performance testing: 1. Place the PET masterbatch on a flat vulcanizing machine and press it into sheets. The temperature of the upper and lower plates is 280℃, the pressure is 15MPa, and the vulcanization time is 3min to make a sheet of 50mm×50mm×3mm. The transmittance of the sheet is tested by an ultraviolet spectrophotometer. The ultraviolet spectral region is 200-380nm. 2. Place the PET masterbatch in an injection molding machine to obtain a tensile specimen of 20mm×4mm×2mm. After 24 hours, clamp it with a universal testing machine and test the elongation at break at a tensile rate of 10mm / min. 3. Place the PET masterbatch in the injection molding machine to obtain an 80mm×10mm×3mm impact test specimen with a V-notch depth of 2mm. After 24 hours, set aside for use. Use a simple beam impact testing machine to perform impact tests on the specimen according to GB / T16420. The pendulum energy is 2J, and the notched impact strength is tested. Table 1

[0018] Conclusion: As can be seen from the data in the table above, Example 1 achieves superior overall performance compared to the other examples. Comparative Example 1, as a control experiment of Example 1, did not add nano-hybrid powder, resulting in a significant reduction in UV shielding effect. The change in the composition of the nano-slurry also affected the mechanical properties, with elongation at break and impact strength decreasing accordingly. Comparative Example 2 adjusted the composition of the dispersing aid. Hexanediol is rigid and lacks the flexibility provided by diethylene glycol, affecting the dispersion effect of the nano-slurry. The transmittance increased, but the toughness and impact strength decreased as the nano-slurry dispersion worsened, and the performance also decreased accordingly. Comparative Example 3 did not add KH550, which reduced the chemical anchoring between the modified styrene-acrylate copolymer and PET, and also had a significant impact on the nano-slurry, resulting in a decrease in both UV shielding performance and mechanical strength.

[0019] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing PET masterbatch based on carbon black nano-slurry, characterized in that, The preparation process includes the following steps: carbon black nano-slurry is mixed with polyethylene terephthalate, modified styrene-acrylate copolymer, and antioxidant, and then loaded into a twin-screw extruder for extrusion granulation to obtain PET masterbatch; the modified styrene-acrylate copolymer is obtained by copolymerizing styrene, glycidyl methacrylate and methyl methacrylate, and then melt-blending it with γ-aminopropyltriethoxysilane and polyethylene terephthalate; The PET masterbatch comprises the following raw material components: by weight, 50-70 parts polyethylene terephthalate, 10-20 parts carbon black nano-slurry, 8-15 parts modified styrene-acrylate copolymer, and 1-3 parts antioxidant; the carbon black nano-slurry comprises the following raw material components: by weight, 8-15 parts nano carbon black, 5-12 parts nano hybrid powder, 10-25 parts dispersant, and 55-70 parts propylene glycol methyl ether acetate; The dispersing agent is prepared as follows: under a nitrogen atmosphere, adipic acid, phthalic anhydride, diethylene glycol, hexanediol and n-hexanoic acid are mixed and placed in xylene, a catalyst is added, the temperature is raised to 180-190℃ and reacted for 12-14 hours, and water is removed. After the reaction is completed, the terminal hydroxyl polyester is obtained by vacuum distillation. The terminal hydroxyl polyester is placed in a mixed solvent of xylene and butyl acetate, kept at 45-50℃ and then poured into a mixed solution of toluene diisocyanate and toluene. After keeping the temperature for 2-3 hours, polyetheramine is added and kept at the temperature for 3-4 hours to obtain the dispersing agent.

2. The method for preparing PET masterbatch based on carbon black nano-slurry according to claim 1, characterized in that, The preparation steps of the nano-hybrid powder are as follows: nano-titanium dioxide, nano-carbon black, diethylene glycol monobutyl ether, grinding aid, methanol and deionized water are mixed, and then ground with grinding balls for 6-8 hours. After filtration, drying and calcination, the nano-hybrid powder is obtained. The calcination process parameters are as follows: in nitrogen, the temperature is heated to 400-450℃ at a heating rate of 2-5℃ / min, then ammonia is introduced to remove the nitrogen, and then the temperature is heated to 800-850℃ at a heating rate of 3-5℃ / min and held for 4-8 hours. The mass ratio of nano-titanium dioxide to nano-carbon black is (1-4):

1.

3. The method for preparing PET masterbatch based on carbon black nano-slurry according to claim 1, characterized in that, The molar ratio of adipic acid, phthalic anhydride, diethylene glycol, hexanediol and hexanoic acid is 8:4:(8-12):(1-5):1; the mass ratio of the terminal hydroxyl polyester, toluene diisocyanate and polyetheramine is (1-3):(0.05-0.20):1; the average number-average molecular weight of the polyetheramine is 1000-3000.

4. The method for preparing PET masterbatch based on carbon black nano-slurry according to claim 1, characterized in that, The preparation steps of the modified styrene-acrylate copolymer are as follows: Under a nitrogen atmosphere, styrene, glycidyl methacrylate and methyl methacrylate are mixed, azobisisobutyronitrile is added, the mixture is heated to 75-80℃ and stirred for 3-5 hours, methanol is added, the mixture is filtered, washed and dried to obtain the styrene-acrylate copolymer; the styrene-acrylate copolymer is mixed with γ-aminopropyltriethoxysilane, melt-blended at 180-190℃ for 10-15 minutes, polyethylene terephthalate is added and the mixture is heated to 280-290℃ and stirred for 10-15 minutes to obtain the modified styrene-acrylate copolymer.

5. The method for preparing PET masterbatch based on carbon black nano-slurry according to claim 4, characterized in that, The mass ratio of styrene, glycidyl methacrylate, and methyl methacrylate in the styrene-acrylate copolymer is (7-8):(0.5-1.5):(1-1.5); the mass ratio of the styrene-acrylate copolymer to γ-aminopropyltriethoxysilane and polyethylene terephthalate is 100:(0.5-0.8):(20-30).

6. The method for preparing PET masterbatch based on carbon black nano-slurry according to claim 1, characterized in that, The extrusion granulation process parameters are as follows: the temperature of the feed zone of the extruder is 240-260℃, the temperature of the first die zone is 250-260℃, the temperature of the second die zone is 260-275℃, the temperature of the third die zone is 270-280℃, the temperature of the fourth die zone is 265-275℃, the temperature of the fifth die zone is 255-260℃, the temperature of the discharge zone is 240-250℃, and the screw speed is 200-300 r / min, granulation yields PET masterbatch.

7. A PET masterbatch based on carbon black nano-slurry, characterized in that, Prepared by the preparation method according to any one of claims 1-6.

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