Uvioresistant pet color masterbatch and preparation method thereof

Abstract

The application discloses an anti-ultraviolet PET color master batch and a preparation method thereof, and relates to the technical field of PET. The method comprises the following steps: S1, an anti-ultraviolet agent containing an unsaturated double bond and thiosalicylic acid are subjected to ultraviolet click reaction, and then reacted with m-dihydroxybenzene to obtain an anti-ultraviolet enhancer; S2, the anti-ultraviolet agent containing the unsaturated double bond and a mercapto-based silane coupling agent are subjected to ultraviolet click reaction, and then the mixed filler is modified to obtain an anti-ultraviolet filler; and S3, raw materials of the anti-ultraviolet PET color master batch are uniformly mixed, and then added into a double-screw extruder, melted, blended, extruded and granulated to obtain the anti-ultraviolet PET color master batch. The anti-ultraviolet PET color master batch comprises the following raw materials: according to mass percentage, 5-15wt% of the anti-ultraviolet filler, 5-10wt% of the anti-ultraviolet enhancer, 0-10wt% of color powder, 2-4wt% of a dispersing agent, and the rest is PET carrier, and the total is 100wt%.

Description

Technical Field

[0001] This invention relates to the field of PET technology, specifically to a UV-resistant PET masterbatch and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) is widely used in packaging, fiber, and engineering plastics due to its excellent mechanical properties, transparency, and processability. However, PET products are prone to photo-oxidation under long-term ultraviolet radiation (especially in the 280-400nm band), leading to chain breakage, yellowing, and a sharp decline in mechanical properties, which severely limits its application life in outdoor building materials, automotive exteriors, and other applications.

[0003] In summary, to solve the above problems, this invention will prepare a UV-resistant PET masterbatch, which is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a UV-resistant PET masterbatch and its preparation method to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for preparing a UV-resistant PET masterbatch includes the following steps:

[0007] S1: An anti-UV agent containing unsaturated double bonds reacts with thiosalicylic acid in an ultraviolet-sensitive click reaction, and then reacts with resorcinol to obtain an anti-UV enhancer.

[0008] S2: After the UV-resistant agent containing unsaturated double bonds and the mercapto silane coupling agent undergo a UV-click reaction, the mixed filler is then modified to obtain the UV-resistant filler.

[0009] S3: Add the raw materials of UV-resistant PET masterbatch into a mixer and mix them evenly to obtain a mixture; add the mixture into a twin-screw extruder, melt-blend, and extrude and granulate to obtain UV-resistant PET masterbatch.

[0010] Furthermore, the UV-resistant PET masterbatch comprises the following raw materials: by mass percentage, 5-15 wt% UV-resistant filler, 5-10 wt% UV-resistant reinforcing agent, 0-10 wt% color powder, 2-4 wt% dispersant, and the remainder is PET carrier, totaling 100 wt%.

[0011] Furthermore, the method for preparing the UV stabilizer containing unsaturated double bonds is as follows: under nitrogen protection, 4-methylacrylamidosalicylic acid and zinc chloride are added to chlorobenzene, stirred and mixed evenly, and heated to 110~130℃. Then, resorcinol is added while stirring, and the reaction is carried out at a constant temperature for 1~6 hours. After the reaction is completed, the UV stabilizer containing unsaturated double bonds is obtained by filtration and vacuum distillation.

[0012] Furthermore, the mass ratio of 4-methylacrylamidosalicylic acid and resorcinol is 1:(0.5~0.6).

[0013] Furthermore, the amount of zinc chloride added is 1 to 10% of the amount of reactants added.

[0014] Further, the preparation method of the UV-resistant enhancer is as follows: (1) Under nitrogen protection, the UV-resistant agent containing unsaturated double bonds, thiosalicylic acid, and photoinitiator are added to isopropanol, stirred and mixed evenly, and then subjected to a reaction at 100~120mW / cm 2 (1) After a 1-2 hour reaction with ultraviolet light, a carboxyl-containing UV inhibitor was obtained by vacuum distillation. (2) Under nitrogen protection, the carboxyl-containing UV inhibitor and zinc chloride were added to chlorobenzene, stirred and mixed evenly, and heated to 110-130°C. Resorcinol was then added and the mixture was kept at a constant temperature for 1-6 hours. The reaction was then stopped, and the UV inhibitor was obtained by filtration and vacuum distillation.

[0015] Furthermore, the mass ratio of the UV stabilizer containing unsaturated double bonds, thiosalicylic acid, and photoinitiator is (0.8~1.2):1:(0.1~0.2).

[0016] Furthermore, the mass ratio of the carboxyl-containing UV stabilizer and resorcinol is 1:(0.5~0.6).

[0017] Furthermore, the amount of zinc chloride added is 1 to 10% of the amount of reactants added.

[0018] Further, the preparation method of the UV-resistant filler is as follows: (1) Under nitrogen protection, an UV-resistant agent containing unsaturated double bonds, a mercapto silane coupling agent, and a photoinitiator are added to isopropanol, stirred and mixed evenly, and then subjected to a reaction at 100~120mW / cm 2 (1) The UV light-induced reaction was carried out for 1-2 hours, and the UV-resistant silane coupling agent was obtained by vacuum distillation; (2) The UV-resistant silane coupling agent, deionized water, and anhydrous ethanol were mixed at a mass ratio of (0.04-0.06):1:4, and acetic acid was added to adjust the pH of the solution to 4-6. The mixture was stirred for 10-30 minutes to obtain the UV-resistant silane hydrolysate; (3) The mixed filler was added to the UV-resistant silane hydrolysate and stirred for 1-3 hours. After filtration and drying, the UV-resistant filler was obtained.

[0019] Furthermore, the mass ratio of the UV stabilizer containing unsaturated double bonds, the mercapto silane coupling agent, and the photoinitiator is (0.8~1.2):1:(0.1~0.2).

[0020] Furthermore, the mercapto-based silane coupling agent includes, but is not limited to, any one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

[0021] Furthermore, the amount of the UV-resistant silane coupling agent added is 5-10% of the mass of the mixed filler.

[0022] Furthermore, the mixed filler is obtained by mixing cerium oxide-coated zinc oxide nanoparticles and nano-titanium dioxide in a mass ratio of 1:1.

[0023] Further, the preparation method of the cerium oxide-coated zinc oxide nanoparticles is as follows: (1) Polyvinylpyrrolidone and nano zinc oxide are added to a 75wt% ethanol aqueous solution and ultrasonically dispersed for 10~30min to obtain a dispersion; (2) 0.1~0.5mol / L cerium nitrate solution is added to the dispersion and stirred to mix evenly to obtain a mixture A; (3) At 40~50℃, 0.1~0.5mol / L sodium bicarbonate solution is slowly added dropwise to the mixture A while stirring. After the addition is completed, the reaction is continued to be stirred for 1~3h. After centrifugation and filtration, the precipitate is collected, washed and dried, and finally sintered at 400~500℃ for 1~5h to obtain cerium oxide-coated zinc oxide nanoparticles.

[0024] Furthermore, the mass ratio of polyvinylpyrrolidone and nano zinc oxide is (1~2):5.

[0025] Furthermore, the particle size of the nano zinc oxide is 5~20nm.

[0026] Furthermore, the ratio of the nano zinc oxide to cerium nitrate is (10~30)g:0.01mol.

[0027] Furthermore, the volume ratio of the cerium nitrate solution to the sodium bicarbonate solution is 1:1.

[0028] Furthermore, the nano-titanium dioxide is rutile nano-titanium dioxide with a particle size of 50~100nm.

[0029] Furthermore, the pigment includes, but is not limited to, one or more combinations of anthraquinone dyes, diazo dyes, or naphthyl ketone dyes.

[0030] Furthermore, the dispersant is polyester wax.

[0031] Furthermore, the melt blending temperature is 255~270℃, and the screw speed of the twin-screw extruder is 100~300r / min.

[0032] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0033] (1) In this invention, zinc chloride is used as a catalyst to react 4-methylacrylamidosalicylic acid with resorcinol via a Friedel-Crafs reaction to obtain an anti-UV agent containing both unsaturated double bonds and a benzophenone structure; then, it undergoes an ultraviolet click reaction with thiosalicylic acid to obtain an anti-UV agent containing a carboxyl group; then, in the same manner, the anti-UV agent containing a carboxyl group undergoes a Friedel-Crafs reaction with resorcinol to obtain an anti-UV enhancer. The anti-UV enhancer contains a benzophenone structure, which can improve the anti-UV performance of PET. The mechanism of action of the benzophenone-type anti-UV agent is that the oxygen on the carbonyl group in the benzophenone structure can form an intramolecular hydrogen bond with the hydrogen on the adjacent hydroxyl group, thereby forming a chelate ring. When it absorbs ultraviolet energy, it can promote the breaking of the hydrogen bond, open the chelate ring, and convert ultraviolet energy into heat energy for release. The number of adjacent hydroxyl groups on the carbonyl group in the benzophenone structure determines its absorption capacity and range of ultraviolet light. If there is only one hydroxyl group, it mainly absorbs ultraviolet light in the 290-380 nm range, and its ultraviolet absorption capacity is relatively weak. However, if it contains two hydroxyl groups, it can absorb ultraviolet light in the 380-400 nm range, and its ultraviolet absorption capacity is stronger. The ultraviolet-resistant enhancer prepared in this invention contains both benzophenone structures with one adjacent hydroxyl group and benzophenone structures with two adjacent hydroxyl groups. The combination of these two structures greatly enhances the ultraviolet resistance of PET masterbatch.

[0034] (2) In this invention, nano-zinc oxide and nano-titanium dioxide are introduced into the PET masterbatch as fillers. Both have the ability to block ultraviolet rays. Nano-zinc oxide mainly acts on long-wave ultraviolet rays, while nano-titanium dioxide acts on medium and short-wave ultraviolet rays. The two work together to enhance the UV resistance of the PET masterbatch. Furthermore, the introduction of fillers enhances the PET masterbatch, ensuring the mechanical properties of the subsequent PET products. However, considering that zinc oxide has high photocatalytic activity and is unstable, posing a significant threat of degradation to the prepared PET products, this invention uses cerium oxide to coat the zinc oxide. After coating, not only is the photocatalytic activity of nano-zinc oxide reduced, but its dispersibility is also enhanced. In addition, cerium oxide also has certain UV resistance properties, which can further enhance the UV resistance of the PET masterbatch in synergy with nano-zinc oxide and nano-titanium dioxide. Similarly, titanium dioxide also has certain photocatalytic activity, but it is relatively stable. Therefore, in this invention, only rutile titanium dioxide is selected, which has lower photocatalytic activity compared to other types of titanium dioxide. The synergistic effect of cerium oxide-coated zinc oxide nanoparticles and rutile nano-titanium dioxide can greatly enhance the UV resistance of PET masterbatches.

[0035] (3) Considering the poor dispersibility of cerium oxide-coated zinc oxide nanoparticles and rutile nano-titanium dioxide in PET, the design further employs silane coupling agents to modify the mixed fillers, thereby enhancing the dispersion compatibility of the mixed fillers. However, in order to further enhance the UV resistance of the PET masterbatch, the present invention further employs an UV-resistant agent containing unsaturated double bonds and a mercapto-based silane coupling agent to conduct a UV-click reaction, thereby preparing a UV-resistant silane coupling agent with certain UV resistance properties. This agent is then used to modify the mixed fillers, which not only enhances the dispersion compatibility of the mixed fillers but also enhances the UV resistance of the PET masterbatch.

[0036] In summary, the present invention achieves excellent UV resistance in PET masterbatch through the synergistic effect of UV-resistant fillers and UV-resistant enhancers. Detailed Implementation

[0037] 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.

[0038] 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:

[0039] In the following examples, the PET carrier, grade: FR530, item number: HH2011RKTRNZ, was purchased from Dongguan Shenghao Plastic Raw Materials Co., Ltd.

[0040] 4-Methylacrylamide salicylic acid, purity 98%, CAS No.: 50512-48-6, purchased from Shanghai Youhe Biotechnology Co., Ltd.

[0041] Resorcinol, purity 99%, thiosalicylic acid, purity 97%, CAS No.: 147-93-3, photoinitiator AIBN, purity 99%, cerium nitrate, purity 99%, 3-mercaptopropyltrimethoxysilane, purity 99%, purchased from Merck Reagent Co., Ltd.

[0042] Nano zinc oxide, particle size: 10nm, product number: YM-ZnO, purchased from Yumu (Ningbo) New Materials Co., Ltd.

[0043] Rutile nano-titanium dioxide, particle size: 100nm, item number: 1317-80-2; and anatase nano-titanium dioxide, particle size: 100nm, item number: 1317-70-0, were both purchased from Hubei Yongkuo Technology Co., Ltd.

[0044] Anthraquinone dye KN-R, model: KN-R, purchased from Jiangsu World Chemical Co., Ltd.

[0045] Polyester wax 691, model: CERALENE® 691, purchased from Busan Ong Kai Co., Ltd.; 100g per serving.

[0046] S1: Preparation of UV-resistant enhancer:

[0047] S11: Under nitrogen protection, 10 parts of 4-methacrylamide salicylic acid and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the mixture was kept at a constant temperature for 4 hours. The reaction was then stopped, and the product was filtered and distilled under reduced pressure to obtain an anti-UV agent containing unsaturated double bonds.

[0048] S12: (1) Under nitrogen protection, 10 parts of an anti-UV agent containing unsaturated double bonds, 10 parts of thiosalicylic acid, and 1.5 parts of photoinitiator AIBN were added to 40 parts of isopropanol, stirred and mixed evenly, and then subjected to 110mW / cm 2 (1) After the UV light intensity was activated for 1.5 h, the UV anti-oxidant containing carboxyl groups was obtained by vacuum distillation; (2) Under nitrogen protection, 10 parts of the UV anti-oxidant containing carboxyl groups and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the reaction was kept at a constant temperature for 4 h. The reaction was then stopped, filtered and vacuum distilled to obtain the UV anti-oxidant enhancer.

[0049] S2: Preparation of UV-resistant fillers:

[0050] S21: Under nitrogen protection, 2 parts of an anti-UV agent containing unsaturated double bonds, 2 parts of 3-mercaptopropyltrimethoxysilane, and 0.3 parts of photoinitiator AIBN were added to 10 parts of isopropanol and stirred until homogeneous. The mixture was then subjected to a 110 mW / cm² temperature range. 2 The UV light-induced click reaction was carried out for 1.5 hours, followed by vacuum distillation to obtain an anti-UV silane coupling agent.

[0051] S22: (1) Add 3 parts of polyvinylpyrrolidone and 10 parts of nano zinc oxide to 40 parts of 75wt% ethanol aqueous solution, and ultrasonically disperse for 30 min to obtain a dispersion; (2) Add 1.25L of 0.4mol / L cerium nitrate solution to the dispersion, stir and mix evenly to obtain mixture A; (3) At 45℃, slowly add 1.25L of 0.4mol / L sodium bicarbonate solution to mixture A, stirring while adding. After the addition is complete, continue stirring and reacting for 3 h. After centrifugation and filtration, collect the precipitate, wash and dry it, and finally sinter at 450℃ for 3 h to obtain cerium oxide-coated zinc oxide nanoparticles;

[0052] S23: Mix 10 parts of cerium oxide-coated zinc oxide nanoparticles and 10 parts of rutile nano-titanium dioxide evenly to obtain a mixed filler;

[0053] S24: (1) Add 1.5 parts of anti-UV silane coupling agent, 30 parts of deionized water, and 120 parts of anhydrous ethanol to a container, mix evenly, and add acetic acid to adjust the pH of the solution to 5.5. Stir and mix for 30 minutes to obtain anti-UV silane hydrolysate; (2) Add 20 parts of mixed filler to the anti-UV silane hydrolysate, mix and stir for 3 hours, filter and dry to obtain anti-UV filler;

[0054] S3: Add 78.5 parts of PET carrier, 10 parts of UV-resistant filler, 7.5 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0055] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 78.5 wt% PET carrier, 10 wt% UV-resistant filler, 7.5 wt% UV-resistant enhancer, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0056] Example 2: Example 2 is based on Example 1, but with the following adjustment: the amount of raw materials used in the UV-resistant PET masterbatch remains unchanged. Specifically:

[0057] S3: Add 86 parts of PET carrier, 5 parts of UV-resistant filler, 5 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0058] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 86 wt% PET carrier, 5 wt% UV-resistant filler, 5 wt% UV-resistant reinforcing agent, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0059] Example 3: Example 3 is based on Example 1, but with the following adjustment: the amount of raw materials used in the UV-resistant PET masterbatch remains unchanged. Specifically:

[0060] S3: Add 71 parts of PET carrier, 15 parts of UV-resistant filler, 10 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0061] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 71 wt% PET carrier, 15 wt% UV-resistant filler, 10 wt% UV-resistant reinforcing agent, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0062] The following is a control experiment based on Example 1, with comparative examples 1 to 4, as detailed below:

[0063] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustment: 3-mercaptopropyltrimethoxysilane modification is not performed; instead, 3-aminopropyltrimethoxysilane is used to modify the mixed filler. Other processes remain unchanged. Specifically:

[0064] S1: Preparation of UV-resistant enhancer:

[0065] S11: Under nitrogen protection, 10 parts of 4-methacrylamide salicylic acid and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the mixture was kept at a constant temperature for 4 hours. The reaction was then stopped, and the product was filtered and distilled under reduced pressure to obtain an anti-UV agent containing unsaturated double bonds.

[0066] S12: (1) Under nitrogen protection, 10 parts of an anti-UV agent containing unsaturated double bonds, 10 parts of thiosalicylic acid, and 1.5 parts of photoinitiator AIBN were added to 40 parts of isopropanol, stirred and mixed evenly, and then subjected to 110mW / cm 2 (1) After the UV light intensity was activated for 1.5 h, the UV anti-oxidant containing carboxyl groups was obtained by vacuum distillation; (2) Under nitrogen protection, 10 parts of the UV anti-oxidant containing carboxyl groups and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the reaction was kept at a constant temperature for 4 h. The reaction was then stopped, filtered and vacuum distilled to obtain the UV anti-oxidant enhancer.

[0067] S2: Preparation of UV-resistant fillers:

[0068] S21: (1) Add 3 parts of polyvinylpyrrolidone and 10 parts of nano zinc oxide to 40 parts of 75wt% ethanol aqueous solution, and ultrasonically disperse for 30 min to obtain a dispersion; (2) Add 1.25L of 0.4mol / L cerium nitrate solution to the dispersion, stir and mix evenly to obtain mixture A; (3) At 45℃, slowly add 1.25L of 0.4mol / L sodium bicarbonate solution to mixture A, stirring while adding. After the addition is complete, continue stirring and reacting for 3 h. After centrifugation and filtration, collect the precipitate, wash and dry it, and finally sinter at 450℃ for 3 h to obtain cerium oxide-coated zinc oxide nanoparticles;

[0069] S22: Mix 10 parts of cerium oxide-coated zinc oxide nanoparticles and 10 parts of rutile nano-titanium dioxide evenly to obtain a mixed filler;

[0070] S23: (1) Add 1.5 parts of 3-aminopropyltrimethoxysilane, 30 parts of deionized water, and 120 parts of anhydrous ethanol to a container, mix evenly, and add acetic acid to adjust the pH of the solution to 5.5. Stir and mix for 30 min to obtain silane hydrolysate; (2) Add 20 parts of mixed filler to silane hydrolysate, mix and stir for 3 h, filter and dry to obtain UV-resistant filler;

[0071] S3: Add 78.5 parts of PET carrier, 10 parts of UV-resistant filler, 7.5 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0072] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 78.5 wt% PET carrier, 10 wt% UV-resistant filler, 7.5 wt% UV-resistant enhancer, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0073] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustments: no coating treatment of nano-zinc oxide and the use of anatase nano-titanium dioxide, while other processes remain unchanged. Specifically:

[0074] S1: Preparation of UV-resistant enhancer:

[0075] S11: Under nitrogen protection, 10 parts of 4-methacrylamide salicylic acid and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the mixture was kept at a constant temperature for 4 hours. The reaction was then stopped, and the product was filtered and distilled under reduced pressure to obtain an anti-UV agent containing unsaturated double bonds.

[0076] S12: (1) Under nitrogen protection, 10 parts of an anti-UV agent containing unsaturated double bonds, 10 parts of thiosalicylic acid, and 1.5 parts of photoinitiator AIBN were added to 40 parts of isopropanol, stirred and mixed evenly, and then subjected to 110mW / cm 2 (1) After the UV light intensity was activated for 1.5 h, the UV anti-oxidant containing carboxyl groups was obtained by vacuum distillation; (2) Under nitrogen protection, 10 parts of the UV anti-oxidant containing carboxyl groups and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the reaction was kept at a constant temperature for 4 h. The reaction was then stopped, filtered and vacuum distilled to obtain the UV anti-oxidant enhancer.

[0077] S2: Preparation of UV-resistant fillers:

[0078] S21: Under nitrogen protection, 2 parts of an anti-UV agent containing unsaturated double bonds, 2 parts of 3-mercaptopropyltrimethoxysilane, and 0.3 parts of photoinitiator AIBN were added to 10 parts of isopropanol and stirred until homogeneous. The mixture was then subjected to a 110 mW / cm² temperature range. 2 The UV light-induced click reaction was carried out for 1.5 hours, followed by vacuum distillation to obtain an anti-UV silane coupling agent.

[0079] S22: Mix 10 parts of nano zinc oxide and 10 parts of anatase nano titanium dioxide evenly to obtain a mixed filler;

[0080] S23: (1) Add 1.5 parts of anti-UV silane coupling agent, 30 parts of deionized water, and 120 parts of anhydrous ethanol to a container, mix evenly, and add acetic acid to adjust the pH of the solution to 5.5. Stir and mix for 30 minutes to obtain anti-UV silane hydrolysate; (2) Add 20 parts of mixed filler to the anti-UV silane hydrolysate, mix and stir for 3 hours, filter and dry to obtain anti-UV filler;

[0081] S3: Add 78.5 parts of PET carrier, 10 parts of UV-resistant filler, 7.5 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0082] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 78.5 wt% PET carrier, 10 wt% UV-resistant filler, 7.5 wt% UV-resistant enhancer, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0083] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustment: no UV-resistant filler is added, while other processes remain unchanged. Specifically:

[0084] S1: Preparation of UV-resistant enhancer:

[0085] S11: Under nitrogen protection, 10 parts of 4-methacrylamide salicylic acid and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the mixture was kept at a constant temperature for 4 hours. The reaction was then stopped, and the product was filtered and distilled under reduced pressure to obtain an anti-UV agent containing unsaturated double bonds.

[0086] S12: (1) Under nitrogen protection, 10 parts of an anti-UV agent containing unsaturated double bonds, 10 parts of thiosalicylic acid, and 1.5 parts of photoinitiator AIBN were added to 40 parts of isopropanol, stirred and mixed evenly, and then subjected to 110mW / cm 2 (1) After the UV light intensity was activated for 1.5 h, the UV anti-oxidant containing carboxyl groups was obtained by vacuum distillation; (2) Under nitrogen protection, 10 parts of the UV anti-oxidant containing carboxyl groups and 0.78 parts of zinc chloride were added to 40 parts of chlorobenzene, stirred and mixed evenly, and heated to 120°C. Then, 5.5 parts of resorcinol were added and the reaction was kept at a constant temperature for 4 h. The reaction was then stopped, filtered and vacuum distilled to obtain the UV anti-oxidant enhancer.

[0087] S2: Add 88.5 parts of PET carrier, 7.5 parts of UV-resistant reinforcing agent, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0088] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 88.5 wt% PET carrier, 7.5 wt% UV-resistant enhancer, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0089] Comparative Example 4: Comparative Example 4 is based on Example 1, with the following adjustment: no UV-enhancing agent is added, while other processes remain unchanged. Specifically:

[0090] S1: Preparation of UV-resistant fillers:

[0091] S11: Under nitrogen protection, 2 parts of an anti-UV agent containing unsaturated double bonds, 2 parts of 3-mercaptopropyltrimethoxysilane, and 0.3 parts of photoinitiator AIBN were added to 10 parts of isopropanol and stirred until homogeneous. The mixture was then subjected to a 110 mW / cm² temperature range. 2 The UV light-induced click reaction was carried out for 1.5 hours, followed by vacuum distillation to obtain an anti-UV silane coupling agent.

[0092] S12: (1) Add 3 parts of polyvinylpyrrolidone and 10 parts of nano zinc oxide to 40 parts of 75wt% ethanol aqueous solution, and ultrasonically disperse for 30 min to obtain a dispersion; (2) Add 1.25L of 0.4mol / L cerium nitrate solution to the dispersion, stir and mix evenly to obtain mixture A; (3) At 45℃, slowly add 1.25L of 0.4mol / L sodium bicarbonate solution to mixture A, stirring while adding. After the addition is complete, continue stirring and reacting for 3 h. After centrifugation and filtration, collect the precipitate, wash and dry it, and finally sinter at 450℃ for 3 h to obtain cerium oxide-coated zinc oxide nanoparticles;

[0093] S13: Mix 10 parts of cerium oxide-coated zinc oxide nanoparticles and 10 parts of rutile nano-titanium dioxide evenly to obtain a mixed filler;

[0094] S14: (1) Add 1.5 parts of anti-UV silane coupling agent, 30 parts of deionized water, and 120 parts of anhydrous ethanol to a container, mix evenly, and add acetic acid to adjust the pH of the solution to 5.5. Stir and mix for 30 min to obtain anti-UV silane hydrolysate; (2) Add 20 parts of mixed filler to the anti-UV silane hydrolysate, mix and stir for 3 h, filter and dry to obtain anti-UV filler;

[0095] S2: Add 86 parts of PET carrier, 10 parts of UV-resistant filler, 1 part of anthraquinone dye KN-R, and 3 parts of polyester wax 691 into a mixer and mix evenly to obtain a mixture. Add the mixture into a twin-screw extruder and melt-blend at 260±5℃, controlling the screw speed at 200r / min. Extrude and granulate to obtain UV-resistant PET masterbatch.

[0096] The UV-resistant PET masterbatch includes the following raw materials: by mass percentage, 86 wt% PET carrier, 10 wt% UV-resistant filler, 1 wt% anthraquinone dye KN-R, and 3 wt% polyester wax 691.

[0097] Performance testing: The UV-resistant PET masterbatches prepared in Examples 1-3 and Comparative Examples 1-4 were heated and melted with PET chips, with the amount of UV-resistant PET masterbatch added being 10% of the mass of the PET chips. The films were then processed into 0.1 mm thick PET films using a blow molding machine. Finally, tensile properties and UV resistance were tested. The specific testing methods are as follows:

[0098] (1) Tensile properties: Tensile properties were tested according to GB / T 1040.3-2006.

[0099] (2) UV resistance test: At room temperature, the PET film was placed in a 200W mercury light source irradiation accelerated aging chamber for 360 hours, and then taken out and subjected to tensile performance test.

[0100] The results of the above tests are shown in Table 1 below:

[0101] Table 1

[0102]

[0103] Results Analysis: As shown in Table 1, comparing Examples 1-3, Example 1 exhibits the least performance degradation before and after aging, making it the optimal example. Further comparison of Examples 1 and 2 reveals that although excessive addition of UV-resistant fillers reduces the dispersibility of the fillers in the PET masterbatch, leading to a decrease in the relevant mechanical properties of the PET masterbatch, its UV resistance is significantly improved. Further comparison of Examples 1 and 3 shows that when the amount of UV-resistant fillers further increases, agglomeration may occur in the PET masterbatch, resulting in a significant decrease in the mechanical properties of the prepared PET film. However, due to the large amount of UV-resistant fillers and UV-resistant reinforcing agents, its UV resistance remains relatively excellent, thus the tensile strength decreases more slowly. Agglomeration increases the brittleness of PET during aging, leading to a significant decrease in elongation at break. Comparing Example 1 and Comparative Example 1 shows that the use of UV-resistant coupling agents to modify the mixed fillers reduces the UV resistance of the PET masterbatch, resulting in more severe aging of related properties. Comparing Example 1 and Comparative Example 2, it can be seen that the use of cerium oxide to coat nano-zinc oxide and the selection of rutile titanium dioxide significantly improve the UV aging resistance of PET film. Comparing Example 1 and Comparative Examples 3-4, it can be seen that UV-resistant fillers and UV-resistant reinforcing agents have a significant impact on the UV resistance of PET masterbatches; only through their synergistic effect can a UV-resistant PET masterbatch with excellent overall performance be prepared.

[0104] 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 a UV-resistant PET masterbatch, characterized in that: Includes the following steps: S1: After the UV-resistant agent containing unsaturated double bonds and thiosalicylic acid undergo a UV-click reaction, it then undergoes a Friedel-Crafs reaction with resorcinol to obtain a UV-resistant enhancer. S2: After the UV-resistant agent containing unsaturated double bonds and the mercapto silane coupling agent undergo a UV-click reaction, the mixed filler is then modified to obtain the UV-resistant filler. S3: After mixing the raw materials of UV-resistant PET masterbatch, add them to a twin-screw extruder, melt-blend, extrude and granulate to obtain UV-resistant PET masterbatch; The UV-resistant PET masterbatch comprises the following raw materials: by mass percentage, 5-15 wt% UV-resistant filler, 5-10 wt% UV-resistant reinforcing agent, 0-10 wt% color powder, 2-4 wt% dispersant, and the remainder is PET carrier, totaling 100 wt%. The method for preparing the UV stabilizer containing unsaturated double bonds is as follows: under nitrogen protection, 4-methylacrylamidosalic acid and zinc chloride are added to chlorobenzene, stirred and mixed evenly, and heated to 110~130℃. Then, resorcinol is added while stirring, and the reaction is carried out at a constant temperature for 1~6 hours. After the reaction is completed, the UV stabilizer containing unsaturated double bonds is obtained by filtration and vacuum distillation. The mass ratio of 4-methylacrylamidosalicylic acid and resorcinol is 1:(0.5~0.6). The amount of zinc chloride added is 1-10% of the amount of reactants added. The mixed filler is obtained by mixing cerium oxide-coated zinc oxide nanoparticles and nano-titanium dioxide in a mass ratio of 1:

1.

2. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The method for preparing the UV-protective agent is as follows: (1) Under nitrogen protection, an anti-UV agent containing unsaturated double bonds, thiosalicylic acid, and a photoinitiator are added to isopropanol and stirred until homogeneous. The mixture is then subjected to a nitrogen atmosphere of 100-120 mW / cm². 2 The UV light-induced reaction was carried out for 1-2 hours, followed by vacuum distillation to obtain a carboxyl-containing UV inhibitor. (2) Under nitrogen protection, add carboxyl-containing UV stabilizer and zinc chloride to chlorobenzene, stir and mix evenly, heat to 110~130℃, then stir and add resorcinol, react at constant temperature for 1~6h, stop the reaction, filter and distill under reduced pressure to obtain UV stabilizer; The mass ratio of the UV stabilizer containing unsaturated double bonds, thiosalicylic acid, and photoinitiator is (0.8~1.2):1:(0.1~0.2). The mass ratio of the carboxyl-containing UV stabilizer and resorcinol is 1:(0.5~0.6); The amount of zinc chloride added is 1-10% of the amount of reactants added.

3. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The method for preparing the UV-resistant filler is as follows: (1) Under nitrogen protection, an anti-UV agent containing unsaturated double bonds, a mercapto silane coupling agent, and a photoinitiator are added to isopropanol and stirred until homogeneous. The mixture is then subjected to a nitrogen atmosphere of 100-120 mW / cm². 2 The UV light-induced reaction was carried out for 1-2 hours, followed by vacuum distillation to obtain an anti-UV silane coupling agent. (2) Mix the UV-resistant silane coupling agent, deionized water, and anhydrous ethanol at a mass ratio of (0.04~0.06):1:4, and add acetic acid to adjust the pH of the solution to 4~6. Stir and mix for 10~30 min to obtain the UV-resistant silane hydrolysate. (3) Add the mixed filler to the anti-UV silane hydrolysate, mix and stir for 1-3 hours, filter and dry to obtain the anti-UV filler; The mass ratio of the UV stabilizer containing unsaturated double bonds, the mercapto silane coupling agent, and the photoinitiator is (0.8~1.2):1:(0.1~0.2). The amount of the UV-resistant silane coupling agent added is 5-10% of the mass of the mixed filler.

4. The method for preparing a UV-resistant PET masterbatch according to claim 3, characterized in that: The mercaptosilane coupling agent includes any one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

5. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The preparation method of the cerium oxide-coated zinc oxide nanoparticles is as follows: (1) Add polyvinylpyrrolidone and nano zinc oxide to a 75wt% ethanol aqueous solution and ultrasonically disperse for 10~30min to obtain a dispersion; (2) Add 0.1~0.5mol / L cerium nitrate solution to the dispersion, stir and mix evenly to obtain mixture A; (3) At 40~50℃, slowly add 0.1~0.5mol / L sodium bicarbonate solution to mixture A while stirring. After the addition is complete, continue stirring for 1~3h. After centrifugation and filtration, collect the precipitate, wash and dry it, and finally sinter it at 400~500℃ for 1~5h to obtain cerium oxide coated zinc oxide nanoparticles. The mass ratio of polyvinylpyrrolidone and nano zinc oxide is (1~2):5; The particle size of the nano zinc oxide is 5~20nm; The ratio of nano-zinc oxide to cerium nitrate is (10~30)g:0.01mol; The volume ratio of the cerium nitrate solution to the sodium bicarbonate solution is 1:

1. The nano-titanium dioxide is rutile titanium dioxide with a particle size of 50~100nm.

6. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The pigment includes one or more of anthraquinone dyes, diazo dyes, and naphthyl ketone dyes.

7. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The dispersant is polyester wax.

8. The method for preparing a UV-resistant PET masterbatch according to claim 1, characterized in that: The melt blending temperature is 255~270℃, and the screw speed of the twin-screw extruder is 100~300r / min.

9. The UV-resistant PET masterbatch prepared by the method of any one of claims 1 to 8.

Images