A moisture-heat-resistant UV-blocking polyester masterbatch and its preparation method

Abstract

The present invention belongs to the technical field of polyester masterbatch, and specifically relates to a moisture-resistant and heat-resistant UV-blocking polyester masterbatch and a preparation method thereof. The masterbatch comprises the following raw materials in parts by weight: 85-90 parts of polyethylene terephthalate, 10-15 parts of an anti-ultraviolet agent, 3-5 parts of an epoxy-terminated polyether, and 1-3 parts of a lubricant. The anti-ultraviolet agent is prepared by modifying a nano-light-shielding agent with a carboxylate coupling agent at a mass ratio of 3-5:100 to obtain a modified intermediate, and the modified intermediate is then grafted with a hydroxybenzophenone derivative at a mass ratio of 100:5-8 to obtain a modified intermediate; the nano-light-shielding agent is selected from one or a combination of two or more of nano-zinc oxide, nano-titanium dioxide, nano-cerium oxide, nano-tin antimony oxide, and nano-carbon black. The dispersion effect of the anti-ultraviolet agent in the masterbatch is improved, thereby improving UV blocking and light transmittance; at the same time, the anti-ultraviolet agent undergoes ester exchange with PET during the screw extrusion process to enhance the interaction with PET, avoid migration in a moist and hot environment, and make the UV shielding performance lasting and stable.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester masterbatches, and particularly relates to a moisture-heat-resistant ultraviolet-blocking polyester masterbatch and a preparation method thereof. Background Art

[0002] The primary purpose of food packaging is to protect food from light, moisture, oxygen, and microbial contamination during storage, transportation, and shelf life, thereby preventing adverse changes in food odor, color, and quality. These changes not only shorten the shelf life of food but can also pose a health risk to consumers. Light, especially ultraviolet (UV) radiation, is particularly impactful. UV rays can trigger chemical reactions in photosensitive substances in food, causing color fading, odor changes, and even the production of harmful substances. Furthermore, the penetration of moisture and oxygen accelerates oxidation and spoilage, while microbial contamination can cause food spoilage, further compromising food safety and quality.

[0003] To extend the shelf life of food, modern food packaging materials must possess excellent barrier properties, effectively blocking the intrusion of ultraviolet rays, oxygen, water vapor, and microorganisms. Furthermore, as consumers increasingly demand transparency, cleanliness, safety, and environmental friendliness, food packaging materials must also be transparent, non-toxic, odorless, easy to process, impact-resistant, and recyclable. Polyester materials, particularly polyethylene terephthalate (PET), are widely used in food packaging due to their high transparency, excellent mechanical properties, good chemical stability, easy processing and molding, and recyclability. For example, patent CN118181921A discloses a high-strength, high-barrier, heat-sealable BOPET film and its preparation method. The dual-layer composite film structure, consisting of a surface layer and a substrate layer, utilizes physical co-extrusion and chemical bonding to achieve a stable and high-strength composite. The functional PET masterbatch used in the surface layer improves overall mechanical properties and UV barrier properties, reducing the likelihood of UV-induced damage to the substrate material. The substrate material ensures the overall heat sealability of the film and also enhances the barrier and mechanical properties of the BOPET film. Graphene oxide is incorporated into both the surface layer and the substrate layer, improving their compatibility and stability. Patent CN107418159A discloses a BOPET UV-shielding masterbatch and its manufacturing method, comprising the following raw materials in parts by weight: 70-90 parts polyethylene terephthalate, 1-5 parts dispersant, 5-20 parts colorant, 10-20 parts nano-UV absorber, and 5-10 parts meta-aramid fiber.

[0004] All of the above technologies utilize inorganic UV-blocking agents and other agents co-extruded with base resins to produce masterbatches, thereby imparting excellent UV-blocking properties to the product. However, in actual applications, it is difficult to avoid hot and humid environments. Humidity and heat increase the mobility of inorganic particles, causing them to gradually deviate from their originally stable distribution within the resin matrix. This significantly degrades the material's UV-blocking performance, making it impossible to maintain its initial high UV-blocking performance.

[0005] Therefore, it is necessary to develop a polyester masterbatch that can give polyester materials high UV blocking and high light transmittance to meet the needs of food packaging for long-term preservation, high quality and clear display. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a UV-blocking polyester masterbatch and a preparation method thereof. The UV-blocking agent in the masterbatch raw material is a nano-light-shielding agent with a hydroxybenzophenone derivative grafted onto its surface via an ester group. This grafting modification of the nano-light-shielding agent can not only improve the dispersion effect of the UV-blocking agent in the masterbatch, improving UV blocking and light transmittance, but also undergo ester exchange with PET during the extrusion process to enhance interaction with PET, avoid migration in hot and humid environments, and ensure long-lasting and stable UV-shielding performance. To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] A moisture-heat-resistant UV-blocking polyester masterbatch comprises the following raw materials in parts by weight: 85-90 parts of polyethylene terephthalate, 10-15 parts of an anti-ultraviolet agent, 3-5 parts of epoxy-terminated polyether, and 1-3 parts of a lubricant. The anti-ultraviolet agent is prepared by modifying a nano-light-shielding agent with a carboxylate coupling agent at a mass ratio of 3-5:100 to obtain a modified intermediate, which is then grafted with a hydroxybenzophenone derivative at a mass ratio of 100:5-8. The nano-light-shielding agent is selected from one or a combination of two or more of nano-zinc oxide, nano-titanium dioxide, nano-cerium oxide, nano-antimony tin oxide, and nano-carbon black.

[0008] The hydroxybenzophenone derivative is selected from one or a combination of two or more of 3'-(1-hydroxyethyl)benzophenone and 4-(hydroxymethyl)phenyl ketone.

[0009] The carboxylate coupling agent is selected from one or a combination of two or more of 3-triethoxysilylethyl propionate, 4-triethoxysilylmethyl butyrate, and 2-(3-(triethoxysilyl)propyl)diethyl malonate.

[0010] The average particle size of the nano light shielding agent is 20-50 nm.

[0011] The anti-ultraviolet agent is prepared by a method comprising the following steps:

[0012] 1) Prepare an alcoholysis solution of a carboxylate coupling agent, disperse the nano-light shielding agent into the alcoholysis solution, and react to obtain a modified intermediate;

[0013] 2) Dispersing the modified intermediate in an organic solvent, adding a hydroxybenzophenone derivative and a catalyst, mixing evenly, and heating to reflux to react to obtain an anti-ultraviolet agent.

[0014] In step 1), the alcoholysis solution is prepared by mixing ethanol and water in a mass ratio of 90-95:5-10 to form an alcohol / water solution. The pH is adjusted to 4.5-5.5, and a carboxylate coupling agent is added, mixed, and allowed to stand for 5-10 minutes to obtain an alcoholysis solution. The concentration of the carboxylate coupling agent in the alcoholysis solution is 1-2 wt%. The dispersion step is performed by ultrasonic dispersion at a power of 200-300 W and a frequency of 50-80 kHz for 10-30 minutes. The reaction step is performed at a stirring speed of 500-800 rpm and a temperature of 40-60°C for 0.5-1 hour. After the reaction, centrifugation, washing, and drying are sequentially performed. The washing step is performed by washing with water 1-3 times. The drying step is performed at 100-120°C for 5-15 minutes.

[0015] In step 2), the dispersion step comprises ultrasonic dispersion at a power of 200-300 W and a frequency of 50-80 kHz for 10-30 minutes. The organic solvent is selected from one or a combination of two or more of chloroform, ethyl acetate, benzene, toluene, xylene, and dichloromethane, preferably a mixed solvent of ethyl acetate and toluene in a volume ratio of 3-5:1. The catalyst is selected from one of tetrabutyl titanate, p-toluenesulfonic acid, and sodium formate. The catalyst is used in an amount of 1-1.5 wt% of the hydroxybenzophenone derivative. The reaction time is 10-18 hours. Byproducts are evaporated during the reaction, and after completion, the reaction step comprises cooling to room temperature, centrifugation, washing, and drying. The washing step comprises alternating washing with water and ethanol for 1-3 times. The drying step comprises drying at 100-120°C for 5-15 minutes.

[0016] During the screw extrusion process, under the action of shear and heat, an ester exchange reaction occurs between PET and the UV inhibitor. Although this is beneficial to improving the moisture and heat resistance of the masterbatch or the composite material prepared using the masterbatch, a small amount of low molecular weight polyester will also be produced due to the ester exchange, resulting in an increase in the free volume of the masterbatch or the composite material prepared using the masterbatch, and an increase in the water vapor transmission rate. An appropriate amount of epoxy-terminated polyether reacts with the terminal carboxyl or hydroxyl group of PET through its active epoxy group, which can not only reduce the low molecular weight polyester, but also fill the free volume gaps through the flexible polyethylene glycol chain segment, effectively controlling the increase in water vapor transmission rate while maintaining the UV barrier durability.

[0017] The epoxy-terminated polyether has a number average molecular weight of 380-500 g / mol and is specifically selected from one or a combination of polyethylene glycol diglycidyl ether and poly(propylene glycol) diglycidyl ether.

[0018] The intrinsic viscosity of the polyethylene terephthalate is 0.75-0.82 dL / g.

[0019] The lubricant is selected from one or a combination of two or more of silicone powder, diethylene stearamide, zinc stearate, calcium stearate, polyethylene wax, and erucamide.

[0020] The present invention also provides a method for preparing the above-mentioned moisture-heat-resistant UV-blocking polyester masterbatch, comprising the following steps:

[0021] Polyethylene terephthalate, an anti-ultraviolet agent, an epoxy-terminated polyether and a lubricant are mixed evenly, and the mixture is extruded and granulated to obtain a UV-blocking polyester masterbatch.

[0022] The granulation process parameters are as follows: carried out in a twin-screw extruder, the screw speed is 210-240r / min, the temperature of zone 1 of the twin-screw extruder is 190℃-200℃, the temperature of zone 2 is 200℃-210℃, the temperature of zone 3 is 225℃-235℃, the temperature of zone 4 is 255℃-260℃, the temperature of zone 5 is 260℃-265℃, the temperature of zone 6 is 265℃-270℃, and the head temperature is 255-260℃.

[0023] The present invention also provides a PET bottle, the raw materials of which include the above-mentioned moisture-heat-resistant UV-blocking masterbatch; the moisture-heat-resistant UV-blocking masterbatch accounts for 3-5wt% of the PET bottle raw materials.

[0024] The PET bottle is obtained by blending PET bottle raw materials and injection molding it into a bottle embryo, and then performing longitudinal stretching and transverse stretching at the same time and blowing.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The anti-ultraviolet agent in the masterbatch raw material of the present invention is a nano-light shielding agent with a hydroxybenzophenone derivative grafted on the surface through an ester group. The modified nano-light shielding agent can improve the dispersion effect of the anti-ultraviolet agent in the masterbatch, improve UV blocking and light transmittance; at the same time, the anti-ultraviolet agent undergoes ester exchange with PET during the screw extrusion process to enhance the interaction with PET, avoid migration in a humid and hot environment, and make the UV shielding performance lasting and stable.

[0027] Second, the present invention utilizes the reaction between the active epoxy groups of the epoxy-terminated polyether and the terminal carboxyl or hydroxyl groups of PET to reduce the low molecular weight polyester produced by the transesterification between the UV inhibitor and PET. At the same time, the free volume voids are filled with flexible polyol chain segments, thereby overcoming the high water vapor transmission rate problem caused by the low molecular weight polyester while maintaining the UV barrier durability. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiment, but is not limited to the content on the specification sheets. Unless otherwise specified, "parts" described in the embodiments of the present invention are all parts by weight. All reagents used are commercially available reagents in this area.

[0029] Polypropylene glycol diglycidyl ether Mn-380, number average molecular weight 380, product number 406732, was purchased from Sigma-Aldrich.

[0030] Polyethylene glycol diglycidyl ether Mn-500, number average molecular weight 500, product number 475696, was purchased from Sigma-Aldrich.

[0031] Rutile nano-titanium dioxide with an average particle size of 20 nm and a brand name of TTP-R60S was purchased from Jiangsu Tianxing New Materials Co., Ltd.

[0032] 4-(Hydroxymethyl)phenyl ketone was purchased from Anaiji Chemical, product number JX450107.

[0033] 3'-(1-Hydroxyethyl)benzophenone (CAS No. 67173-18-6) was purchased from Shenzhen Hengfeng Wanda Pharmaceutical Technology Co., Ltd.

[0034] Polyethylene terephthalate, with an intrinsic viscosity of 0.8 dL / g, was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0035] Example 1

[0036] 1) Ethanol and water were prepared into an alcohol / water solution in a mass ratio of 90:10, the pH was adjusted to 5.5, ethyl 3-triethoxysilyl propionate was added, mixed, and allowed to stand for 10 minutes to obtain an alcoholysis solution, wherein the concentration of ethyl 3-triethoxysilyl propionate in the alcoholysis solution was 1 wt %. 100 kg of nano-titanium dioxide TTP-R60S was ultrasonically dispersed into 500 kg of the alcoholysis solution at a power of 200 W, a frequency of 50 kHz, and a time of 20 minutes. The mixture was stirred at a speed of 800 r / min and a temperature of 60° C. for 0.5 hours. After the reaction, the mixture was centrifuged, the centrifuged solid was washed three times with water, and dried at 100° C. for 15 minutes to obtain a modified intermediate.

[0037] 2) 10 kg of the modified intermediate was ultrasonically dispersed into 200 kg of a mixed solvent of ethyl acetate and toluene in a volume ratio of 5:1 under the conditions of 200 W power, 50 kHz frequency, and 20 min. 0.8 kg of 4-(hydroxymethyl)phenyl ketone and 8 g of p-toluenesulfonic acid were added and mixed. The mixture was heated to reflux and reacted while distilling off the by-products. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, and the centrifuged solid was washed alternately with ethanol and water three times, and dried at 100°C for 15 min to obtain an anti-ultraviolet agent.

[0038] 3) Mix 8.5 kg of polyethylene terephthalate, 1.5 kg of UV inhibitor, 0.5 kg of polyethylene glycol diglycidyl ether (product number 475696), and 0.3 kg of zinc stearate in a high-speed mixer and granulate to obtain moisture-heat-resistant UV-blocking polyester masterbatch.

[0039] The granulation was carried out in a twin-screw extruder: the screw speed was 210 r / min, the temperature of zone 1 was 190°C, the temperature of zone 2 was 200°C, the temperature of zone 3 was 225°C, the temperature of zone 4 was 255°C, the temperature of zone 5 was 260°C, the temperature of zone 6 was 265°C, and the head temperature was 260°C.

[0040] 4) 94 kg of polyethylene terephthalate, 5 kg of UV-blocking polyester masterbatch, and 1 part of diethylene glycol stearamide were weighed and mixed uniformly in a high-speed mixer to obtain a blended PET bottle raw material. The blended PET bottle was then injection molded into a preform using an injection molding machine. The preform was then stretched longitudinally and transversely using a stretch-blow molding machine, and finally inflated with compressed air to obtain a PET bottle.

[0041] Example 2

[0042] The rest is the same as Example 1, except that in step 2), the amount of 4-(hydroxymethyl)phenyl ketone used is 0.5 kg, and the amount of catalyst p-toluenesulfonic acid used is 5 g.

[0043] Example 3

[0044] The rest is the same as Example 1, except that in step 4), the amount of UV-blocking polyester masterbatch used is 3 kg, and the amount of polyethylene terephthalate used is 96 kg.

[0045] Example 4

[0046] The rest is the same as Example 1, except that in step 3), the amount of anti-ultraviolet agent used is 1 kg.

[0047] Example 5

[0048] The rest is the same as Example 1, except that in step 3), the amount of polyethylene glycol diglycidyl ether used is 0.3 kg.

[0049] Example 6

[0050] The rest is the same as Example 1, except that in step 3), an equal mass of polypropylene glycol diglycidyl ether (product number 406732) is used instead of polyethylene glycol diglycidyl ether (product number 475696).

[0051] Example 7

[0052] The rest is the same as Example 1, except that in step 2), 4-(hydroxymethyl)phenyl ketone is replaced by 3'-(1-hydroxyethyl)benzophenone of equal mass.

[0053] Example 8

[0054] 1) Ethanol and water were prepared into an alcohol / water solution in a mass ratio of 90:10, the pH was adjusted to 5.5, ethyl 3-triethoxysilyl propionate was added, mixed evenly, and allowed to stand for 10 minutes to obtain an alcoholysis solution, wherein the concentration of ethyl 3-triethoxysilyl propionate in the alcoholysis solution was 1 wt %. 100 kg of nano-titanium dioxide TTP-R60S was ultrasonically dispersed into 300 kg of the alcoholysis solution at a power of 200 W, a frequency of 50 kHz, and a time of 20 minutes. The mixture was reacted at a stirring speed of 800 r / min and 60° C. for 0.5 hours. After the reaction, the mixture was centrifuged, washed three times with water, and dried at 100° C. for 15 minutes to obtain a modified intermediate.

[0055] 2) 10 kg of the modified intermediate was ultrasonically dispersed into 200 kg of a mixed solvent of ethyl acetate and toluene in a volume ratio of 5:1 under the conditions of 200 W power, 50 kHz frequency, and 20 min. 0.8 kg of 4-(hydroxymethyl)phenyl ketone and 8 g of p-toluenesulfonic acid were added and mixed. The mixture was heated to reflux and reacted while distilling off the by-products. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, and the centrifuged solid was washed alternately with ethanol and water three times, and dried at 100°C for 15 min to obtain an anti-ultraviolet agent.

[0056] 3) Mix 9 kg of polyethylene terephthalate, 1.5 kg of UV inhibitor, 0.3 kg of polyethylene glycol diglycidyl ether (product number 475696), and 0.3 kg of zinc stearate in a high-speed mixer and granulate to obtain moisture-heat-resistant UV-blocking polyester masterbatch.

[0057] The granulation was carried out in a twin-screw extruder: the screw speed was 210 r / min, the temperature of zone 1 was 190°C, the temperature of zone 2 was 200°C, the temperature of zone 3 was 225°C, the temperature of zone 4 was 255°C, the temperature of zone 5 was 260°C, the temperature of zone 6 was 265°C, and the head temperature was 260°C.

[0058] 4) Weigh 96 kg of polyethylene terephthalate, 3 kg of UV-blocking polyester masterbatch, and 1 part of diethylene stearamide and mix them evenly in a high-speed mixer to obtain a blended PET bottle raw material. The blended PET bottle is then injection molded into a preform using an injection molding machine. The preform is then stretched longitudinally and transversely using a stretch-blow molding machine, and finally inflated with compressed air to obtain a PET bottle.

[0059] Comparative Example 1

[0060] 1) 8.5 kg of polyethylene terephthalate, 1.5 kg of a blend of nano-titanium dioxide TTP-R60S and 4-(hydroxymethyl)phenyl ketone at a mass ratio of 100:8, 0.5 kg of polyethylene glycol diglycidyl ether (product number 475696), and 0.3 kg of zinc stearate were mixed in a high-speed mixer and granulated to obtain a moisture-heat-resistant UV-blocking polyester masterbatch.

[0061] The granulation was carried out in a twin-screw extruder: the screw speed was 210 r / min, the temperature of zone 1 was 190°C, the temperature of zone 2 was 200°C, the temperature of zone 3 was 225°C, the temperature of zone 4 was 255°C, the temperature of zone 5 was 260°C, the temperature of zone 6 was 265°C, and the head temperature was 260°C.

[0062] 2) 94 kg of polyethylene terephthalate, 5 kg of UV-blocking polyester masterbatch, and 1 part of diethylene glycol stearamide were weighed and mixed uniformly in a high-speed mixer to obtain a blended PET bottle raw material. The blended PET bottle was then injection molded into a preform using an injection molding machine. The preform was then stretched longitudinally and transversely using a stretch-blow molding machine, and finally inflated with compressed air to obtain a PET bottle.

[0063] Comparative Example 2

[0064] The rest is the same as Example 1, except that in step 3), polyethylene glycol diglycidyl ether is not added.

[0065] Comparative Example 3

[0066] The rest is the same as Example 1, except that there is no step of grafting 4-(hydroxymethyl)phenyl ketone, i.e., step 2).

[0067] 1) Ethanol and water are prepared into an alcohol / water solution in a mass ratio of 90:10, the pH is adjusted to 5.5, 1 wt% of ethyl 3-triethoxysilyl propionate in the alcohol / water solution is added, mixed, and allowed to stand for 10 minutes, 100 kg of nano-titanium dioxide TTP-R60S is ultrasonically dispersed into 500 kg of hydrolyzate at a power of 800 W, a frequency of 50 kHz, and a time of 20 minutes, and the mixture is reacted at a stirring speed of 800 r / min and 60° C. for 0.5 hours. After the reaction is completed, the mixture is centrifuged, the centrifuged solid is washed with water three times, and dried at 100° C. for 15 minutes to obtain modified titanium dioxide, i.e., an anti-ultraviolet agent;

[0068] 2) Mix 8.5 kg of polyethylene terephthalate, 1.5 kg of UV inhibitor, 0.5 kg of polyethylene glycol diglycidyl ether (product number 475696), and 0.3 kg of zinc stearate in a high-speed mixer and granulate to obtain UV-blocking polyester masterbatch.

[0069] The granulation was carried out in a twin-screw extruder: the screw speed was 210 r / min, the temperature of zone 1 was 190°C, the temperature of zone 2 was 200°C, the temperature of zone 3 was 225°C, the temperature of zone 4 was 255°C, the temperature of zone 5 was 260°C, the temperature of zone 6 was 265°C, and the head temperature was 260°C.

[0070] 3) Weigh 94 kg of polyethylene terephthalate, 5 kg of UV-blocking polyester masterbatch, and 1 part of diethylene stearamide and mix them evenly in a high-speed mixer to obtain a blended PET bottle raw material. The blended PET bottle is then injection molded into a preform using an injection molding machine. The preform is then stretched longitudinally and transversely using a stretch-blow molding machine, and finally inflated with compressed air to obtain a PET bottle.

[0071] UV / Visible Light Transmittance: Average UV and visible light transmittance was measured using a UV-8000 UV-Visible photometer from Shanghai Yuanxi Instrument Co., Ltd., covering the UV spectral range of 200-380 nm and the visible spectral range of 380-780 nm. Samples were produced by injection molding the blended PET bottle raw material prepared in step 4) of the above Examples and Comparative Examples on an injection molding machine. The barrel temperatures were set at 245°C, 250°C, 260°C, 265°C, 272°C, and 270°C. The sample dimensions were 100 mm x 20 mm x 3 mm.

[0072] Humidity and heat aging: Maintain at 50℃ / 90% RH for 7 days, re-measure the above UV transmittance, and calculate the increase rate of UV transmittance.

[0073] Water vapor transmission rate: refer to the standard GB / T 26253-2010 Plastic film and sheeting - Determination of water vapor transmission rate, the sample is 0.3mm sheet.

[0074] Table 1 Performance test results

[0075] .

[0076] As can be seen from Table 1, when the content of the UV blocking masterbatch is 5wt%, it can block more than 98.9% of UV rays, and the visible light transmittance is more than 91%, and the water vapor transmittance is less than 1.5g / m 2 · After 24 hours, the UV transmittance did not increase significantly after damp heat aging. From Examples 1 and 2 and Comparative Example 3, it can be seen that nano-sodium dioxide and 4-(hydroxymethyl)phenyl ketone have a synergistic effect of reducing UV transmittance.

[0077] The above detailed description is a specific description of one feasible embodiment of the present invention. This embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not depart from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A moisture-heat-resistant UV-blocking polyester masterbatch, characterized in that: The invention comprises the following raw materials in parts by weight: 85-90 parts of polyethylene terephthalate, 10-15 parts of an anti-ultraviolet agent, 3-5 parts of epoxy-terminated polyether, and 1-3 parts of a lubricant. The anti-ultraviolet agent is prepared by modifying a nano light-shielding agent with a carboxylate coupling agent at a mass ratio of 3-5:100 to obtain a modified intermediate, and then grafting the modified intermediate with a hydroxybenzophenone derivative at a mass ratio of 100:5-8. The nano light-shielding agent is selected from one or a combination of two or more of nano zinc oxide, nano titanium dioxide, nano cerium oxide, nano antimony tin oxide, and nano carbon black. The hydroxybenzophenone derivative is selected from one or a combination of two or more of 3'-(1-hydroxyethyl)benzophenone and 4-(hydroxymethyl)phenyl ketone; The carboxylate coupling agent is selected from one or a combination of two or more of 3-triethoxysilylethyl propionate, 4-triethoxysilylmethyl butyrate, and 2-(3-(triethoxysilyl)propyl)diethyl malonate; The preparation steps of the anti-ultraviolet agent include: 1) preparing an alcoholysis solution of a carboxylic acid ester coupling agent, dispersing a nano light shielding agent in the alcoholysis solution, and reacting to obtain a modified intermediate; the alcoholysis solution is prepared by preparing ethanol and water in a mass ratio of 90-95:5-10 to prepare an alcohol-water solution, and adjusting the pH to 4.5-5.

5.

2. The heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to claim 1, characterized in that: The average particle size of the nano light shielding agent is 20-50 nm.

3. The heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to claim 1, characterized in that: The preparation steps of the anti-ultraviolet agent also include: 2) Dispersing the modified intermediate in an organic solvent, adding a hydroxybenzophenone derivative and a catalyst, mixing evenly, and heating to reflux to react to obtain an anti-ultraviolet agent.

4. The heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to claim 1, characterized in that: In step 1), the concentration of the carboxylate coupling agent in the alcoholysis solution is 1-2 wt %.

5. The heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to claim 3, characterized in that: In step 2), the catalyst is selected from one of tetrabutyl titanate, p-toluenesulfonic acid, and sodium formate; the amount of the catalyst used is 1-1.5 wt % of the hydroxybenzophenone derivative; and the reaction time is 10-18 h.

6. The heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to claim 1, characterized in that: The epoxy-terminated polyether has a number average molecular weight of 380-500 g / mol and is selected from one or a combination of polyethylene glycol diglycidyl ether and poly(propylene glycol) diglycidyl ether; and the intrinsic viscosity of the polyethylene terephthalate is 0.75-0.82 dL / g.

7. The method for preparing the heat-resistant and moisture-resistant UV-blocking polyester masterbatch according to any one of claims 1 to 6, characterized in that: The steps include: Polyethylene terephthalate, an anti-ultraviolet agent, an epoxy-terminated polyether and a lubricant are mixed evenly, and the mixture is extruded and granulated to obtain a UV-blocking polyester masterbatch.

8. A PET bottle, characterized in that: The raw materials include the moisture-heat-resistant ultraviolet blocking masterbatch according to any one of claims 1 to 6; the moisture-heat-resistant ultraviolet blocking masterbatch accounts for 3-5wt% of the PET bottle raw materials.