Antistatic biaxially oriented polyester film and preparation method thereof

Abstract

The invention discloses an antistatic biaxially oriented polyester film and a preparation method thereof, and belongs to the technical field of polyester film preparation. The antistatic biaxially oriented polyester film is prepared from the following components in parts by weight: 32 to 46 parts of polyethylene glycol terephthalate, 10 to 12 parts of an antioxidant, 6 to 11 parts of a composite antistatic agent and 3 to 8 parts of a modified reinforcing agent, the composite antistatic agent is prepared from 1-allylimidazole, 2-bromopentane, potassium hexafluorophosphate, p-divinylbenzene, (3-acrylamidopropyl) trimethyl ammonium chloride, 2-phenyl-1-propylene and 2-hydroxyethyl acrylate, and the modified reinforcing agent is prepared from 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate. The polyester film prepared by the method has excellent antistatic property and mechanical property.

Description

Technical Field

[0001] The present invention belongs to the technical field of thin film preparation, and particularly relates to an antistatic biaxially oriented polyester film and a preparation method thereof. Background Art

[0002] Due to its advantages such as good product performance, high production efficiency, and stable quality, the biaxial stretching technology has become one of the most important advanced processes in thin film manufacturing. As an outstanding representative of this technology, the biaxially oriented polyester film has gradually occupied an important position in many fields by virtue of its high strength, high transparency, high toughness, and low shrinkage.

[0003] The antistatic biaxially oriented polyester film is a high-grade film made from bright material through drying, melting, extrusion, casting, and biaxial stretching. It has good mechanical properties, good rigidity, high strength, the tensile strength is 3 times that of PC polycarbonate film and PA nylon film, and the impact strength is 3 - 5 times that of BOPP film. It has excellent abrasion resistance, fold resistance, pinhole resistance, and tear resistance. The excellent physical and chemical properties make the biaxially oriented polyester film have broad application potential in many fields such as food packaging, electronic products, and medical supplies.

[0004] Patent CN113478936B discloses an antistatic biaxially oriented polyester film, which is composed of an upper surface layer, a core layer, and a lower surface layer. The upper surface layer and the lower surface layer are made of the following raw materials by mass percentage: 20 - 30% of antistatic PET chips and 70 - 80% of anti-sticking masterbatch. The core layer is made of the following raw materials by mass percentage: 94 - 98% of PET chips and 2 - 6% of vinyl ionomer nucleating agent; the antistatic PET chips are prepared by mixing PET resin and polymethacrylic acid and then melt-extruding. The prepared antistatic polyester film not only has excellent antistatic properties but also has high mechanical properties, optical properties, and thermal stability. However, there is still room for improvement in the antistatic properties and mechanical properties of the polyester film prepared by this method. Summary of the Invention

[0005] The purpose of the present invention is to provide an antistatic biaxially oriented polyester film and a preparation method thereof to solve the technical problems of poor antistatic properties and mechanical properties of polyester films in the prior art.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: The present invention provides an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 32-46 parts of polyethylene terephthalate, 10-12 parts of antioxidant, 6-11 parts of composite antistatic agent, and 3-8 parts of modified reinforcing agent. Among them, the composite antistatic agent is prepared from 1-allylimidazole, 2-bromopentane, potassium hexafluorophosphate, p-divinylbenzene, (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propene, and 2-hydroxyethyl acrylate, and the modified reinforcing agent is prepared from 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate, and butyl methacrylate.

[0007] Preferably, the preparation method of the composite antistatic agent includes the following steps: Q1: Add 1-allylimidazole and 2-bromopentane into a container, heat and react in an oil bath. After the reaction is completed, wash and dry to obtain Compound 1. Add Compound 1, potassium hexafluorophosphate, and methanol into a container, and react in an oil bath. After the reaction is completed, rotary evaporate and dry, wash and dry to obtain Compound 2; Q2: Add Compound 2, p-divinylbenzene, and azobisisobutyronitrile into a container, then add a mixed solution of anhydrous ethanol, ethyl acetate, and distilled water, and reflux and react in an oil bath under nitrogen protection. After the reaction is completed, filter, wash and dry to obtain Compound 3; Q3: Under a nitrogen atmosphere, add (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propene, 2-hydroxyethyl acrylate, and anhydrous ethanol into a container, stir and react at room temperature, then add azobisisobutyronitrile, raise the temperature to react. After the reaction is completed, cool down, rotary evaporate, concentrate, precipitate, and dry to obtain Compound 4; Q4: Add Compound 3 and Compound 4 into a container filled with anhydrous ethanol, stir and react under a nitrogen atmosphere. After the reaction is completed, dry to obtain the composite antistatic agent.

[0008] In the above process, first, using 1-allylimidazole and 2-bromopentane as raw materials, under the condition of heating in an oil bath, a nucleophilic substitution reaction occurs between the two to obtain Compound 1. Then, Compound 1 reacts with potassium hexafluorophosphate in methanol to undergo a substitution reaction to obtain Compound 2. Subsequently, Compound 2 and p-divinylbenzene undergo a copolymerization reaction under the condition of azobisisobutyronitrile as an initiator to obtain Compound 3. Then, using (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propene, and 2-hydroxyethyl acrylate as raw materials, under the condition of azobisisobutyronitrile as an initiator, a copolymerization reaction occurs to prepare Compound 4. Subsequently, Compound 3 and Compound 4 are mixed to prepare the composite antistatic agent. Among them, the synthesis reaction formula of Compound 3 is as follows:

[0009] The results of mass spectrometry analysis of Compound 1 were as follows: m / z: 258.07 (100.0%), 260.07 (97.4%), 261.07 (12.3%), 259.08 (12.1%); The results of mass spectrometry analysis of Compound 2 were as follows: m / z: 324.12 (100.0%), 325.12 (12.6%); The synthesis reaction formula of Compound 4 is as follows:

[0010] Preferably, in Q1, the molar ratio of 1-allylimidazole to 2-bromopentane is (0.8 - 1.2):(0.9 - 1.3), the reaction temperature under oil bath heating is 70 - 75 °C, the reaction time is 20 - 24 h, the molar ratio of Compound 1 to potassium hexafluorophosphate is (0.9 - 1.2):(1 - 1.5), the reaction temperature under oil bath is 25 - 28 °C, the reaction time is 10 - 12 h, and it is washed with ultrapure water, and the drying temperature is 50 - 60 °C, and the time is 10 - 12 h.

[0011] Preferably, in Q2, the molar ratio of Compound 2, divinylbenzene, and 2,2'-azobis(2-methylpropionitrile) is (0.9 - 1.1):(0.7 - 0.75):(0.45 - 0.55), the reaction temperature under oil bath reflux is 70 - 75 °C, the time is 20 - 24 h, and it is washed with absolute ethanol and ultrapure water, and the drying temperature is 50 - 55 °C, and the time is 10 - 12 h.

[0012] Preferably, in Q3, the molar ratio of (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propene, and 2-hydroxyethyl acrylate is (1 - 1.2):(0.5 - 0.55):(0.5 - 0.58), the stirring speed is 200 - 300 rpm, the reaction temperature for heating is 70 - 80 °C, the reaction time is 6 - 8 h, and it is added to toluene for precipitation, and the drying temperature is 80 - 85 °C, and the time is 20 - 24 h; In Q4, the dosage ratio of Compound 3 to Compound 4 is (9 - 16) g:(10 - 15) g, and the stirring reaction time is 18 - 24 h.

[0013] Preferably, the preparation method of the modified reinforcing agent includes the following steps: S1: Add 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate, and butyl methacrylate to a container containing a mixed solution of ethyl acetate and butanone, and stir for reaction; S2: Add azodiisovaleronitrile dissolved in ethyl acetate to the container, after introducing nitrogen, seal it, heat and oscillate for reaction, and after the reaction is completed, cool to obtain the modified reinforcing agent.

[0014] In the above process, 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate are used as raw materials, and a polymerization reaction occurs under the condition of azodiisopentanenitrile as a catalyst to prepare a modified reinforcing agent. The synthesis reaction formula of the modified reinforcing agent is as follows:

[0015] Preferably, in S1, the molar ratio of 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate is (0.8 - 0.85):(0.12 - 0.15):(0.02 - 0.05), and the stirring reaction time is 3 - 5 h; in S2, the nitrogen introduction time is 10 - 20 min, the heating and oscillation reaction temperature is 60 - 70 °C, and the time is 20 - 24 h.

[0016] Preferably, a method for preparing an antistatic biaxially oriented polyester film includes the following steps: Step 1: Heat and melt polyethylene terephthalate, then add an antioxidant, a composite antistatic agent and a modified reinforcing agent, and filter to obtain a melt mixture; Step 2: Extrude the melt mixture, perform longitudinal stretching and then transverse stretching, and then perform heat setting treatment, winding, and slitting to obtain an antistatic biaxially oriented polyester film.

[0017] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: 1. First, the present invention uses 1-allylimidazole, 2-bromopentane, potassium hexafluorophosphate, p-divinylbenzene, (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propene and 2-hydroxyethyl acrylate as raw materials to prepare a composite antistatic agent. Subsequently, 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate are used as raw materials to prepare a modified reinforcing agent. Adding the composite antistatic agent and the modified reinforcing agent to the preparation process of the polyester film at the same time can effectively improve the antistatic property and mechanical properties of the film.

[0018] 2. The antistatic agent prepared in the present invention is applied to the polyester film, which can effectively improve the antistatic performance of the film. Compounds 3 and 4 contained in the composite antistatic agent form a continuous conductive channel, enabling the static charges in the polyester film to be quickly conducted to other parts or the external environment. At the same time, the positive and negative ions contained therein can neutralize each other, further reducing the static potential. The polar groups (such as hydroxyl groups and quaternary ammonium salt groups) contained in the composite antistatic agent can improve the wettability of the surface of the polyester film, which helps the film surface to adsorb more moisture or other polar molecules in the air, forming a thin conductive layer, thereby promoting the dispersion and dissipation of charges, reducing the generation and accumulation of static electricity. At the same time, when static charges are generated on the surface of the polyester film, the polar groups in the composite antistatic agent can attract and disperse these charges, preventing them from concentrating in a certain local area, which helps to reduce the static potential and the possibility of static discharge. Moreover, compounds 3 and 4 can exert a synergistic effect to enhance the antistatic performance of the film.

[0019] 3. The modified reinforcing agent prepared in the present invention is added to the preparation process of the polyester film, which can effectively improve the mechanical properties of the film. The hydroxyl groups contained in the modified reinforcing agent can interact with the functional groups in the polyester film to form hydrogen bonds, thereby improving the compatibility between the modified reinforcing agent and the polyester film. The increased compatibility can enable the modified reinforcing agent to be uniformly dispersed in the polyester film, avoiding the generation of interfacial defects. At the same time, in the polyester film, the modified reinforcing agent is uniformly dispersed in polyethylene terephthalate. When it is subjected to external forces, it can absorb and dissipate energy, thereby preventing the propagation of cracks. Moreover, the existence of hydrogen bonds can enable stress to be more effectively transmitted and dispersed in the interfacial layer, thereby improving the mechanical properties of the film. Detailed implementation mode

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0021] Example 1: This example discloses a preparation method of a composite antistatic agent, including the following steps: Q1: Add 1.08 g of 1-allylimidazole and 1.661 g of 2-bromopentane into a container, heat and react in an oil bath at 70 °C for 24 h. After the reaction is completed, wash and dry to obtain Compound 1. Add 2.72 g of Compound 1, 2.3 g of potassium hexafluorophosphate and 30 mL of methanol into a container, react in an oil bath at 28 °C for 12 h. After the reaction is completed, rotary evaporate and dry, wash with ultrapure water, and dry at 60 °C for 12 h to obtain Compound 2; Q2: Add 3.249 g of Compound 2, 0.943 g of p-divinylbenzene, and 0.82 g of azobisisobutyronitrile into a container, then add a mixed solution of 5 mL of absolute ethanol, 25 mL of ethyl acetate, and 5 mL of distilled water. Under nitrogen protection, reflux the reaction in an oil bath at 75 °C for 24 h. After the reaction is completed, filter, wash with absolute ethanol and ultrapure water, and dry at 55 °C for 12 h to obtain Compound 3; Q3: Under a nitrogen atmosphere, add 2.27 g of (3-acrylamidopropyl) trimethylammonium chloride, 0.623 g of 2-phenyl-1-propene, 0.641 g of 2-hydroxyethyl acrylate, and 120 mL of absolute ethanol into a container. Stir the reaction at 300 rpm at room temperature, then add 0.04 g of azobisisobutyronitrile, and raise the temperature to 78 °C for 8 h. After the reaction is completed, cool down, perform rotary evaporation and concentration, add it to toluene for precipitation, and dry at 85 °C for 24 h to obtain Compound 4; Q4: Add 12.5 g of Compound 3 and 12.5 g of Compound 4 into a container filled with absolute ethanol. Under a nitrogen atmosphere, stir the reaction for 24 h. After the reaction is completed, dry to obtain a composite antistatic agent.

[0022] This example discloses a preparation method of a modified enhancer, including the following steps: S1: Add 16.24 g of 2-ethylhexyl methacrylate, 1.91 g of 4-hydroxybutyl acrylate, and 0.55 g of butyl methacrylate into a container containing a mixed solution of 8 mL of ethyl acetate and 4 mL of methyl ethyl ketone, and stir the reaction for 5 h; S2: Add 0.2 g of azodiisopentanenitrile dissolved in 10 mL of ethyl acetate into the container. After introducing nitrogen for 15 min, seal it and heat and oscillate the reaction at 65 °C for 24 h. After the reaction is completed, cool down to obtain a modified enhancer.

[0023] This example discloses an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 39 parts of polyethylene terephthalate, 11 parts of antioxidant, 8.5 parts of composite antistatic agent, and 5.5 parts of modified enhancer.

[0024] This example discloses a preparation method of an antistatic biaxially oriented polyester film, including the following steps: Step 1: Heat and melt polyethylene terephthalate, then add antioxidant, composite antistatic agent, and modified enhancer, and filter to obtain a melt mixture; Step 2: Extrude the melt mixture, perform longitudinal stretching and then transverse stretching, then perform heat setting treatment, wind up, and slit to obtain an antistatic biaxially oriented polyester film.

[0025] Example 2: This example discloses a preparation method of a composite antistatic agent, including the following steps: Q1: Add 0.864 g of 1 - allylimidazole and 1.359 g of 2 - bromopentane into a container, heat - react at 70 °C in an oil bath for 24 h. After the reaction is completed, wash and dry to obtain Compound 1. Then add 2.331 g of Compound 1, 1.84 g of potassium hexafluorophosphate, and 30 mL of methanol into a container, react at 28 °C in an oil bath for 12 h. After the reaction is completed, rotary - evaporate to dryness, wash with ultrapure water, and dry at 60 °C for 12 h to obtain Compound 2; Q2: Add 2.924 g of Compound 2, 0.91 g of p - divinylbenzene, and 0.738 g of azobisisobutyronitrile into a container, then add a mixed solution of 5 mL of absolute ethanol, 25 mL of ethyl acetate, and 5 mL of distilled water. Under nitrogen protection, reflux and react at 75 °C in an oil bath for 24 h. After the reaction is completed, filter, wash with absolute ethanol and ultrapure water, and dry at 55 °C for 12 h to obtain Compound 3; Q3: Under a nitrogen atmosphere, add 2.067 g of (3 - acrylamidopropyl) trimethylammonium chloride, 0.59 g of 2 - phenyl - 1 - propene, 0.58 g of 2 - hydroxyethyl acrylate, and 120 mL of absolute ethanol into a container, stir - react at 300 rpm at room temperature, then add 0.04 g of azobisisobutyronitrile, raise the temperature to 78 °C and react for 8 h. After the reaction is completed, cool down, rotary - evaporate, concentrate, add it to toluene for precipitation, and dry at 85 °C for 24 h to obtain Compound 4; Q4: Add 9 g of Compound 3 and 10 g of Compound 4 into a container filled with absolute ethanol. Under a nitrogen atmosphere, stir - react for 24 h. After the reaction is completed, dry to obtain the composite antistatic agent.

[0026] This example discloses a preparation method of a modified enhancer, which includes the following steps: S1: Add 15.84 g of 2 - ethylhexyl methacrylate, 1.728 g of 4 - hydroxybutyl acrylate, and 0.284 g of butyl methacrylate into a container containing a mixed solution of 8 mL of ethyl acetate and 4 mL of methyl ethyl ketone, and stir - react for 5 h; S2: Add 0.2 g of azodiisopentanenitrile dissolved in 10 mL of ethyl acetate into the container. After introducing nitrogen for 15 min, seal it and heat - oscillate at 65 °C for 24 h. After the reaction is completed, cool down to obtain the modified enhancer.

[0027] This example discloses an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 32 parts of polyethylene terephthalate, 10 parts of antioxidant, 6 parts of composite antistatic agent, and 3 parts of modified enhancer.

[0028] This example discloses a preparation method of an antistatic biaxially oriented polyester film, which includes the following steps: Step 1: Heat and melt polyethylene terephthalate, then add an antioxidant, a composite antistatic agent, and a modification enhancer, and filter to obtain a melt mixture; Step 2: Extrude the melt mixture, perform longitudinal stretching, then transverse stretching, and then perform heat setting treatment, wind up, and slit to obtain an antistatic biaxially stretched polyester film.

[0029] Example 3: This example discloses a preparation method of a composite antistatic agent, including the following steps: Q1: Add 1.296 g of 1-allylimidazole and 1.963 g of 2-bromopentane to a container, heat and react in an oil bath at 70 °C for 24 h. After the reaction, wash and dry to obtain Compound 1. Add 3.108 g of Compound 1, 2.76 g of potassium hexafluorophosphate, and 30 mL of methanol to a container, react in an oil bath at 28 °C for 12 h. After the reaction, perform rotary evaporation and drying, wash with ultrapure water, and dry at 60 °C for 12 h to obtain Compound 2; Q2: Add 3.574 g of Compound 2, 0.975 g of p-divinylbenzene, and 0.902 g of azobisisobutyronitrile to a container, then add a mixed solution of 5 mL of absolute ethanol, 25 mL of ethyl acetate, and 5 mL of distilled water. Under nitrogen protection, reflux and react in an oil bath at 75 °C for 24 h. After the reaction, filter, wash with absolute ethanol and ultrapure water, and dry at 55 °C for 12 h to obtain Compound 3; Q3: Under a nitrogen atmosphere, add 2.48 g of (3-acrylamidopropyl)trimethylammonium chloride, 0.649 g of 2-phenyl-1-propene, 0.673 g of 2-hydroxyethyl acrylate, and 120 mL of absolute ethanol to a container, stir and react at 300 rpm at room temperature, then add 0.04 g of azobisisobutyronitrile, raise the temperature to 78 °C and react for 8 h. After the reaction, cool down, perform rotary evaporation and concentration, add to toluene for precipitation, and dry at 85 °C for 24 h to obtain Compound 4; Q4: Add 16 g of Compound 3 and 15 g of Compound 4 to a container filled with absolute ethanol, stir and react for 24 h under a nitrogen atmosphere. After the reaction, dry to obtain the composite antistatic agent.

[0030] This example discloses a preparation method of a modification enhancer, including the following steps: S1: Add 16.83 g of 2-ethylhexyl methacrylate, 2.16 g of 4-hydroxybutyl acrylate, and 0.71 g of butyl methacrylate to a container containing a mixed solution of 8 mL of ethyl acetate and 4 mL of methyl ethyl ketone, and stir and react for 5 h; S2: Add 0.2 g of azodiisopentanenitrile dissolved in 10 mL of ethyl acetate to the container, introduce nitrogen for 15 min, then seal, heat and oscillate at 65 °C for 24 h. After the reaction, cool to obtain the modification enhancer.

[0031] This embodiment discloses an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 46 parts of polyethylene terephthalate, 12 parts of antioxidant, 11 parts of composite antistatic agent, and 8 parts of modified reinforcing agent.

[0032] This embodiment discloses a preparation method of an antistatic biaxially oriented polyester film, which includes the following steps: Step 1: Heat and melt polyethylene terephthalate, then add antioxidant, composite antistatic agent and modified reinforcing agent, and filter to obtain a melt mixture. Step 2: Extrude the melt mixture, conduct longitudinal stretching, then transverse stretching, then conduct heat setting treatment, wind up, and slit to obtain an antistatic biaxially oriented polyester film.

[0033] Example 4: This embodiment discloses a preparation method of a composite antistatic agent, which includes the following steps: Q1: Add 0.973 g of 1-allylimidazole and 1.455 g of 2-bromopentane into a container, heat and react in an oil bath at 70 °C for 24 h. After the reaction, wash and dry to obtain Compound 1. Add 2.573 g of Compound 1, 2.01 g of potassium hexafluorophosphate and 30 mL of methanol into a container, react in an oil bath at 28 °C for 12 h. After the reaction, rotary evaporate and dry, wash with ultrapure water, and dry at 60 °C for 12 h to obtain Compound 2. Q2: Add 3.151 g of Compound 2, 0.933 g of p-divinylbenzene and 0.783 g of azobisisobutyronitrile into a container, then add a mixed solution of 5 mL of absolute ethanol, 25 mL of ethyl acetate and 5 mL of distilled water, and reflux and react in an oil bath at 75 °C for 24 h under nitrogen protection. After the reaction, filter, wash with absolute ethanol and ultrapure water, and dry at 55 °C for 12 h to obtain Compound 3. Q3: Under a nitrogen atmosphere, add 2.113 g of (3-acrylamidopropyl)trimethylammonium chloride, 0.611 g of 2-phenyl-1-propene, 0.593 g of 2-hydroxyethyl acrylate and 120 mL of absolute ethanol into a container, stir and react at 300 rpm at room temperature, then add 0.04 g of azobisisobutyronitrile, raise the temperature to 78 °C and react for 8 h. After the reaction, cool down, rotary evaporate and concentrate, add it to toluene for precipitation, and dry at 85 °C for 24 h to obtain Compound 4. Q4: Add 11 g of Compound 3 and 11 g of Compound 4 into a container filled with absolute ethanol, stir and react for 24 h under a nitrogen atmosphere. After the reaction, dry to obtain a composite antistatic agent.

[0034] This embodiment discloses a preparation method of a modified reinforcing agent, which includes the following steps: S1: Add 16.01 g of 2-ethylhexyl methacrylate, 1.83 g of 4-hydroxybutyl acrylate, and 0.377 g of butyl methacrylate into a container filled with a mixed solution of 8 mL of ethyl acetate and 4 mL of methyl ethyl ketone, and stir and react for 5 h; S2: Add 0.2 g of azodiisovaleronitrile dissolved in 10 mL of ethyl acetate into the container. After purging with nitrogen for 15 min, seal it and heat and shake it at 65 °C for 24 h. After the reaction is completed, cool it to obtain a modified enhancer.

[0035] This example discloses an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 35 parts of polyethylene terephthalate, 11.5 parts of antioxidant, 7 parts of composite antistatic agent, and 4 parts of modified enhancer.

[0036] This example discloses a preparation method of an antistatic biaxially oriented polyester film, which includes the following steps: Step 1: Heat and melt polyethylene terephthalate, then add an antioxidant, a composite antistatic agent, and a modified enhancer, and filter to obtain a melt mixture; Step 2: Extrude the melt mixture, conduct longitudinal stretching and then transverse stretching, and then conduct heat setting treatment, winding, and slitting to obtain an antistatic biaxially oriented polyester film.

[0037] Example 5: This example discloses a preparation method of a composite antistatic agent, which includes the following steps: Q1: Add 1.151 g of 1-allylimidazole and 1.783 g of 2-bromopentane into a container, and react at 70 °C in an oil bath for 24 h. After the reaction is completed, wash and dry to obtain Compound 1. Add 2.951 g of Compound 1, 2.53 g of potassium hexafluorophosphate, and 30 mL of methanol into the container, and react at 28 °C in an oil bath for 12 h. After the reaction is completed, rotary evaporate and dry, wash with ultrapure water, and dry at 60 °C for 12 h to obtain Compound 2; Q2: Add 3.354 g of Compound 2, 0.958 g of p-divinylbenzene, and 0.851 g of azodiisobutyronitrile into a container, then add a mixed solution of 5 mL of absolute ethanol, 25 mL of ethyl acetate, and 5 mL of distilled water. Under nitrogen protection, reflux and react at 75 °C in an oil bath for 24 h. After the reaction is completed, filter, wash with absolute ethanol and ultrapure water, and dry at 55 °C for 12 h to obtain Compound 3; Q3: Under a nitrogen atmosphere, 2.375 g of (3-acrylamidopropyl) trimethylammonium chloride, 0.638 g of 2-phenyl-1-propene, 0.668 g of 2-hydroxyethyl acrylate and 120 mL of absolute ethanol were added to a container, stirred at 300 rpm at room temperature, and then 0.04 g of azobisisobutyronitrile was added. The temperature was raised to 78 °C and the reaction was carried out for 8 h. After the reaction was completed, the temperature was lowered, rotary evaporation was carried out, and the mixture was concentrated. Then it was added to toluene for precipitation and dried at 85 °C for 24 h to obtain Compound 4; Q4: 14 g of Compound 3 and 14 g of Compound 4 were added to a container containing absolute ethanol. Under a nitrogen atmosphere, the mixture was stirred and reacted for 24 h. After the reaction was completed, it was dried to obtain a composite antistatic agent.

[0038] This example discloses a preparation method of a modified reinforcing agent, which includes the following steps: S1: 16.54 g of 2-ethylhexyl methacrylate, 2.07 g of 4-hydroxybutyl acrylate and 0.68 g of butyl methacrylate were added to a container containing a mixed solution of 8 mL of ethyl acetate and 4 mL of methyl ethyl ketone, and stirred and reacted for 5 h; S2: 0.2 g of azodiisopentyl nitrile dissolved in 10 mL of ethyl acetate was added to the container. After nitrogen was introduced for 15 min, it was sealed and heated and oscillated at 65 °C for 24 h. After the reaction was completed, it was cooled to obtain a modified reinforcing agent.

[0039] This example discloses an antistatic biaxially oriented polyester film, which is composed of the following components in parts by weight: 42 parts of polyethylene terephthalate, 10.5 parts of antioxidant, 10 parts of composite antistatic agent, and 7 parts of modified reinforcing agent.

[0040] This example discloses a preparation method of an antistatic biaxially oriented polyester film, which includes the following steps: Step 1: Polyethylene terephthalate was heated and melted, and then an antioxidant, a composite antistatic agent and a modified reinforcing agent were added, and filtered to obtain a melt mixture; Step 2: The melt mixture was extruded, longitudinally stretched and then transversely stretched, and then heat-set, wound up and slit to obtain an antistatic biaxially oriented polyester film.

[0041] Comparative Example 1: Compared with Example 1, in the preparation of the composite antistatic agent in Comparative Example 1, 1-allylimidazole was not added, and other conditions remained unchanged.

[0042] Comparative Example 2: Compared with Example 1, in the preparation of the modified reinforcing agent in Comparative Example 2, 2-ethylhexyl methacrylate was not added, and other conditions remained unchanged.

[0043] Comparative Example 3: Compared with Example 1, in the process of preparing the antistatic biaxially oriented polyester film, the composite antistatic agent was not added in Comparative Example 3, and other conditions remained unchanged.

[0044] Comparative Example 4: Compared with Example 1, in the process of preparing the antistatic biaxially oriented polyester film, the modified reinforcing agent was not added in Comparative Example 4, and other conditions remained unchanged.

[0045] Experimental Example: The antistatic biaxially oriented polyester films prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to performance tests. The surface resistance of the samples was tested according to GB / T 33398-2016, and the tensile strength of the samples was tested according to GB / T 16958-2008. The test results are shown in Table 1: Table 1 Project Surface Resistance / Ω Tensile Strength / MPa Example 1 <![CDATA[2.4×10 8 > 278 Example 2 <![CDATA[2.7×10 8 > 273 Example 3 <![CDATA[2.8×10 8 > 274 Example 4 <![CDATA[2.5×10 8 > 271 Example 5 <![CDATA[2.6×10 8 > 273 Comparative Example 1 <![CDATA[1.4×10 9 > 271 Comparative Example 2 <![CDATA[2.8×10 8 > 251 Comparative Example 3 <![CDATA[1.7×10 9 > 271 Comparative Example 4 <![CDATA[2.9×10 8 > 248 As can be seen from the test results in Table 1, the antistatic biaxially oriented polyester films prepared in Examples 1-5 of the present invention have excellent antistatic performance and mechanical properties. By comparing Comparative Example 1 with Examples 1-5, it can be seen that adding 1-allylimidazole can effectively improve the antistatic performance of the antistatic biaxially oriented polyester film; by comparing Comparative Example 2 with Examples 1-5, it can be seen that adding 2-ethylhexyl methacrylate can effectively improve the mechanical properties of the antistatic biaxially oriented polyester film; by comparing Comparative Example 3 with Examples 1-5, it can be seen that adding the composite antistatic agent can effectively improve the antistatic performance of the antistatic biaxially oriented polyester film; by comparing Comparative Example 4 with Examples 1-5, it can be seen that adding the modified reinforcing agent can effectively improve the mechanical properties of the antistatic biaxially oriented polyester film.

[0046] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

[0047] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An antistatic biaxially oriented polyester film, characterized in that: The invention is composed of the following components in parts by weight: 32-46 parts of polyethylene terephthalate, 10-12 parts of antioxidant, 6-11 parts of composite antistatic agent and 3-8 parts of modifying and reinforcing agent, wherein the composite antistatic agent is prepared from 1-allylimidazole, 2-bromopentane, potassium hexafluorophosphate, p-divinylbenzene, (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propylene and 2-hydroxyethyl acrylate, and the modifying and reinforcing agent is prepared from 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate.

2. The antistatic biaxially oriented polyester film according to claim 1, characterized in that: The preparation method of the composite antistatic agent comprises the following steps: Q1: 1-allylimidazole and 2-bromopentane were added to a container, heated in an oil bath for reaction, washed and dried after the reaction to obtain compound 1, compound 1, potassium hexafluorophosphate and methanol were added to a container, reacted in an oil bath, and after the reaction, rotary dried, washed and dried to obtain compound 2; Q2: Compound 2, p-divinylbenzene and azobisisobutyronitrile are added to a container, and then a mixed solution of anhydrous ethanol, ethyl acetate and distilled water is added, and the mixture is refluxed in an oil bath under nitrogen protection. After the reaction is completed, the mixture is filtered, washed and dried to obtain compound 3; Q3: Under a nitrogen atmosphere, (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propylene, 2-hydroxyethyl acrylate and anhydrous ethanol were added to a container, stirred at room temperature for reaction, and then azobisisobutyronitrile was added, and the temperature was raised for reaction. After the reaction was completed, the temperature was lowered, rotary evaporated, concentrated, precipitated, and dried to obtain compound 4; Q4: Add compound 3 and compound 4 into a container filled with anhydrous ethanol, stir and react under a nitrogen atmosphere, and after the reaction is completed, dry to obtain a composite antistatic agent.

3. The antistatic biaxially oriented polyester film according to claim 2, characterized in that: In the Q1, the molar ratio of 1-allylimidazole and 2-bromopentane is (0.8-1.2): (0.9-1.3), the oil bath heating reaction temperature is 70-75°C, and the reaction time is 20-24h. The molar ratio of compound 1 and potassium hexafluorophosphate is (0.9-1.2): (1-1.5), the oil bath reaction temperature is 25-28°C, and the reaction time is 10-12h. Washing is performed with ultrapure water, and the drying temperature is 50-60°C for 10-12h.

4. The antistatic biaxially oriented polyester film according to claim 2, characterized in that: In Q2, the molar ratio of compound 2, p-divinylbenzene and azobisisobutyronitrile is (0.9-1.1): (0.7-0.75): (0.45-0.55), the oil bath reflux reaction temperature is 70-75°C, the time is 20-24h, and the washing is carried out with anhydrous ethanol and ultrapure water. The drying temperature is 50-55°C and the time is 10-12h.

5. The antistatic biaxially oriented polyester film according to claim 2, characterized in that: In the Q3, the molar ratio of (3-acrylamidopropyl)trimethylammonium chloride, 2-phenyl-1-propylene and 2-hydroxyethyl acrylate is (1-1.2): (0.5-0.55): (0.5-0.58), the stirring speed is 200-300 rpm, the heating reaction temperature is 70-80°C, the reaction time is 6-8h, and it is added to toluene for precipitation. The drying temperature is 80-85°C and the time is 20-24h. In the Q4, the amount ratio of compound 3 to compound 4 is (9-16) g: (10-15) g, and the stirring reaction time is 18-24h.

6. The antistatic biaxially oriented polyester film according to claim 1, characterized in that: The preparation method of the modified enhancer comprises the following steps: S1: adding 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate into a container containing a mixed solution of ethyl acetate and butanone, and stirring to react; S2: Add azobisisovaleronitrile dissolved in ethyl acetate into a container, introduce nitrogen, seal the container, heat and shake to react, and after the reaction is completed, cool the container to obtain a modified enhancer.

7. The antistatic biaxially oriented polyester film according to claim 6, characterized in that: In the S1, the molar ratio of 2-ethylhexyl methacrylate, 4-hydroxybutyl acrylate and butyl methacrylate is (0.8-0.85):(0.12-0.15):(0.02-0.05), and the stirring reaction time is 3-5 hours. In the S2, the nitrogen is introduced for 10-20 minutes, and the heating and shaking reaction temperature is 60-70°C for 20-24 hours.

8. A method for preparing an antistatic biaxially oriented polyester film according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: heating and melting polyethylene terephthalate, then adding an antioxidant, a composite antistatic agent and a modifier and enhancer, filtering, and obtaining a melt mixture; Step 2: Extruding the melt mixture, stretching it longitudinally and then transversely, and then heat-setting it, winding it, and slitting it to obtain an antistatic biaxially stretched polyester film.

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