High-temperature-resistant polyester film and preparation system thereof

Abstract

The utility model discloses a high-temperature-resistant polyester film which can be of a single-layer structure or a three-layer structure, the thickness of the polyester film of the single-layer structure ranges from 50 micrometers to 250 micrometers, and the breadth of the polyester film of the single-layer structure ranges from 1500 mm to 5000 mm. The polyester film with the three-layer structure comprises a surface layer A, a core layer B and a bottom layer C, the layer A and the layer C are arranged on the two sides of the layer B respectively, the total thickness of the polyester film with the three-layer structure is 50-250 microns, the thicknesses of the layer A and the layer C are 10-25 microns, and the thickness of the layer B is 30-200 microns; and the breadth of the polyester film with the three-layer structure is 1500 to 5000 mm. The utility model further provides a preparation system special for preparing the high-temperature-resistant polyester film with the single-layer or three-layer structure. The polyester film with a single-layer or three-layer structure prepared by the special preparation system has excellent high-temperature resistance, and can be applied to the application fields of electronics and electrics, automobiles, packaging, machinery, medical instruments, optics and the like.

Description

Technical Field

[0001] This application relates to a high-temperature resistant polyester film and its preparation system. Background Art

[0002] High-temperature resistant polyester films (such as polyethylene terephthalate, PET films) have a series of excellent properties. For example, high-temperature resistant polyester films can still maintain stable physical properties in high-temperature environments, have high tensile strength and tear resistance, a hard surface, good impact resistance, and are suitable for applications that require resistance to mechanical stress. They have excellent electrical insulation properties and are widely used as insulation materials in the electrical and electronic fields. They have good chemical corrosion resistance and can resist the erosion of various chemical substances, including oils, acid-base solutions, etc. They have low hygroscopicity and can maintain good mechanical strength and electrical properties in humid environments. They have high transparency, making them widely used in optical devices and packaging materials. Their surfaces are easy to coat, print, metallize, etc. to improve their functionality and added value. High-temperature resistant polyester films can be widely used in the electronic and electrical fields as electrical insulation materials, widely used in the insulation layers of motors, transformers, and capacitors. They can also be used to make flexible printed circuit boards (FPCs), insulation layers for cables and wires. High-temperature resistant polyester films are often used for high-temperature packaging of foods, pharmaceuticals, etc., especially in packaging applications that require high strength and corrosion resistance. High-temperature resistant polyester films can be used as important components in optical devices such as backlight films for liquid crystal displays (LCDs) and protective films for solar panels. Due to their high transparency and excellent surface treatment properties, high-temperature resistant polyester films are used for printed labels, advertising decorations, and protective layers for cards, etc. High-temperature resistant polyester films are also used in the aerospace and automotive industries as heat insulation and insulation materials in high-temperature environments. Due to their unique comprehensive properties, high-temperature resistant polyester films have a wide range of applications in various fields, especially in situations that require high strength, heat resistance, and corrosion resistance.

[0003] There are various different high-temperature resistant polyester films and their preparation application examples recorded in the prior art. For example, CN109054311B discloses a high-temperature resistant polyester film and its preparation method. CN 117024806 B discloses a preparation method of a high-temperature resistant enhanced PET release film.

[0004] In existing polyester films, the high temperature resistance performance is usually improved by adding modified materials. Although the modification process can reduce the agglomeration of the modified materials and improve their dispersibility, good dispersibility does not mean that the modified materials can be evenly distributed in the melt. Especially when the addition amount of the modified components is small, due to the poor fluidity of the melt, it takes a long time of heating and stirring to evenly disperse a small amount of modified materials in the molten polyester. However, the long-time high-temperature stirring will reduce the crystallinity of the polyester, making it difficult to produce products with uniform quality in the process.

[0005] In addition, the existing technology lacks a preparation system dedicated to preparing high-temperature resistant polyester films. Summary of the Invention

[0006] The technical problem to be solved by this application is to provide a high-temperature resistant polyester film and its preparation system to reduce or avoid the problems mentioned above.

[0007] To solve the above technical problems, this application proposes a preparation system for a high-temperature resistant polyester film, including an input pipeline for PET chips for ordinary films and a first mixing bin. The input end of the first mixing bin is respectively connected to the output end of the input pipeline for PET chips for ordinary films and the output end of a high-temperature resistant PET functional masterbatch preparation device; the output end of the first mixing bin is connected to a first twin-screw extruder; the output end of the first twin-screw extruder inputs the prepared thick sheet into a film pulling mechanism; the output end of the film pulling mechanism is further connected to a cooling and shaping device, and the output end of the cooling and shaping device is connected to a winding and slitting mechanism; a flow control valve is further provided in the input pipeline for PET chips for ordinary films.

[0008] This application also proposes another preparation system for a high-temperature resistant polyester film, including an input pipeline for PET chips for ordinary films, a first mixing bin and a second mixing bin. The output end of the input pipeline for PET chips for ordinary films is respectively connected to the first mixing bin and the second mixing bin, and the input end of the first mixing bin is further connected to a high-temperature resistant PET functional masterbatch preparation device; the output end of the first mixing bin is respectively connected to a first twin-screw extruder and a third twin-screw extruder; the output end of the second mixing bin is connected to a second twin-screw extruder; the output ends of the first twin-screw extruder and the third twin-screw extruder input the prepared A-layer thick sheet and C-layer thick sheet as the surface layer and the bottom layer into the film pulling mechanism, and the output end of the second twin-screw extruder inputs the prepared B-layer thick sheet as the core layer into the film pulling mechanism; the output end of the film pulling mechanism is further connected to a cooling and shaping device, and the output end of the cooling and shaping device is connected to a winding and slitting mechanism; a flow control valve is further provided in the pipeline connecting the input pipeline for PET chips for ordinary films to the first mixing bin.

[0009] Preferably, the high-temperature resistant PET masterbatch preparation device includes an esterification tank and a polycondensation tank; the esterification tank has a first inlet, a second inlet, a third inlet, and a fourth inlet connected to a first auxiliary material tank; the polycondensation tank has a fifth inlet connected to the outlet of the esterification tank, a sixth inlet connected to a second auxiliary material tank, and a seventh inlet; the outlet of the polycondensation tank is connected to at least one extruder, the outlet of the extruder is connected to a pelletizer, and the outlet of the pelletizer is connected to a vacuum drying tank.

[0010] Preferably, the first auxiliary material tank for preparing solution A is provided with three inlets and a stirrer for stirring solution A; the second auxiliary material tank for preparing solution B is provided with four inlets; the second auxiliary material tank is provided with a water bath heating jacket and a stirrer for stirring solution B.

[0011] The present application also provides a high-temperature resistant polyester film prepared by the foregoing preparation system, which is a polyester film with a single-layer structure. The thickness of the single-layer structure polyester film is 50 - 250 μm, and the width of the single-layer structure polyester film is 1500 - 5000 mm.

[0012] The present application also provides another high-temperature resistant polyester film prepared by the foregoing preparation system, which is a three-layer co-extrusion structure, including an A-layer surface layer, a B-layer core layer, and a C-layer bottom layer. The A layer and the C layer are respectively arranged on both sides of the B layer. The total thickness of the three-layer structure polyester film is 50 - 250 μm, the thickness of the A layer and the C layer is 10 - 25 μm, and the thickness of the B layer is 30 - 200 μm; the width of the three-layer structure polyester film is 1500 - 5000 mm.

[0013] The single-layer or three-layer structure polyester film prepared by the special preparation system of the present application has excellent high-temperature resistance and can be applied to application fields such as electronics and electrical appliances, automobiles, packaging, machinery, medical devices, and optics. Description of the Drawings

[0014] The following drawings are only intended to illustrate and explain the present application schematically and do not limit the scope of the present application.

[0015] Figure 1 It shows a schematic cross-sectional structure diagram of the high-temperature resistant polyester film of a specific embodiment of the present application.

[0016] Figure 2 It shows a schematic cross-sectional structure diagram of the high-temperature resistant polyester film of another specific embodiment of the present application.

[0017] Figure 3 It shows a preparation system that can be used to prepare Figure 1 the single-layer structure high-temperature resistant polyester film shown.

[0018] Figure 4 shows a preparation system for a high-temperature resistant polyester film with a three-layer structure as shown Figure 2

[0019] Figure 5 Shown is a schematic structural diagram of a PET functional masterbatch preparation device according to the present application Detailed implementation manners

[0020] For a clearer understanding of the technical features, objectives, and effects of the present application, the detailed implementation manners of the present application are now described with reference to the accompanying drawings. Among them, the same components are denoted by the same reference numerals

[0021] The present application provides a high-temperature resistant polyester film, as shown in Figure 1 and 2 Figure 1 Shown is a schematic cross-sectional structure diagram of a high-temperature resistant polyester film according to a specific embodiment of the present application Figure 2 Shown is a schematic cross-sectional structure diagram of a high-temperature resistant polyester film according to another specific embodiment of the present application

[0022] In Figure 1 the specific embodiment shown, the high-temperature resistant polyester film is a single-layer polyester film, and the thickness of the single-layer polyester film is preferably 50 - 250 μm. The width of the single-layer polyester film is 1500 - 5000 mm

[0023] In Figure 2 the specific embodiment shown, the high-temperature resistant polyester film is a three-layer co-extrusion structure, including an A-layer surface layer, a B-layer core layer, and a C-layer bottom layer. The A-layer and the C-layer are respectively disposed on both sides of the B-layer; the total thickness of the three-layer polyester film is preferably 50 - 250 μm, the thickness of the A-layer and the C-layer is 10 - 25 μm, and the thickness of the B-layer is 30 - 200 μm. The width of the three-layer polyester film is 1500 - 5000 mm

[0024] Among them Figure 1 the single-layer polyester film shown is made of 70wt% - 100wt% of high-temperature resistant PET functional masterbatch and ordinary film-grade PET Figure 2 In the three-layer polyester film shown, both the A-layer and the C-layer are made of 70wt% - 100wt% of high-temperature resistant PET functional masterbatch and ordinary film-grade PET, and the B-layer is made of ordinary film-grade PET

[0025] Furthermore, the present application also provides a high-temperature resistant PET functional masterbatch for a high-temperature resistant polyester film with a structure as shown in Figure 1 and Figure 2

[0026] ​​​In a specific embodiment, the high-temperature resistant PET functional masterbatch is prepared from the following raw materials in parts by weight: 50 - 100 parts by weight of terephthalic acid, 20 - 45 parts by weight of ethylene glycol, 5 - 10 parts by weight of dimethyl 2,6-naphthalenedicarboxylate, 0.02 - 0.04 parts by weight of acetic anhydride, 0.03 - 0.05 parts by weight of acetone, 0.005 - 0.01 parts by weight of antimony trioxide, 0.01 - 0.03 parts by weight of triethyl phosphate, 0.01 - 0.03 parts by weight of sodium dodecylbenzenesulfonate, 0.05 - 0.10 parts by weight of 2-hydroxy-4-(3-triethoxysilylpropoxy) benzophenone, 0.10 - 0.15 parts by weight of ethanol, and 0.01 - 0.03 parts by weight of cellulose acetate. Among them, the cellulose acetate is a commercially available powder with an acetyl content of 37% - 40%.

[0027] Furthermore, the present application also proposes preparation systems for high-temperature resistant polyester films that can be respectively used for Figure 1 and Figure 2 the structures shown, as shown in Figure 3 and Figure 4 respectively; among them, Figure 3 shows a preparation system for a high-temperature resistant polyester film with a single-layer structure that can be used to prepare Figure 1 the structure shown, Figure 4 shows a preparation system for a high-temperature resistant polyester film with a three-layer structure that can be used to prepare Figure 2 the structure shown.

[0028] As Figure 3 shown, the preparation system for the high-temperature resistant polyester film in this embodiment includes an input pipeline 500 for PET chips for ordinary films and a first mixing bin 501. The input end of the first mixing bin 501 is respectively connected to the output end of the input pipeline 500 for PET chips for ordinary films and the output end of the high-temperature resistant PET functional masterbatch preparation device 1000; the output end of the first mixing bin 501 is connected to a first twin-screw extruder 503; the output end of the first twin-screw extruder 503 inputs the prepared thick sheet into the film drawing mechanism 400. The output end of the film drawing mechanism 400 is further connected to a cooling and shaping device 401, and the output end of the cooling and shaping device 401 is connected to a winding and slitting mechanism 402.

[0029] Figure 3 When the preparation system shown works, the PET chips for ordinary films are input into the first mixing bin 501 through the input pipeline 500 for PET chips for ordinary films, and at the same time, the high-temperature resistant PET functional masterbatch prepared by the high-temperature resistant PET functional masterbatch preparation device 1000 is input into the first mixing bin 501.

[0030] To control the input amount of PET chips for ordinary films into the first mixing bin 501 in order to obtain a high-temperature resistant polyester film with desired properties, a flow control valve 510 is further provided in the input pipeline 500 of PET chips for ordinary films. For example, by controlling the flow control valve 510, the weight of PET chips for ordinary films input into the first mixing bin 501 can be controlled to account for 0-30% of the total mass. When it is necessary to prepare a high-temperature resistant polyester film entirely made of high-temperature resistant PET functional masterbatch, the flow control valve 510 can be closed, and no PET chips for ordinary films will be input into the first mixing bin 501.

[0031] After the raw materials in the first mixing bin 501 are uniformly mixed, they are further input into the first twin-screw extruder 503. The raw materials are melt co-extruded by the first twin-screw extruder 503, and thick sheets are formed through the die head of the first twin-screw extruder 503, and then input into the film stretching mechanism 400.

[0032] The film stretching mechanism 400 stretches the input thick sheets horizontally and vertically, and then inputs them into the cooling and shaping mechanism 401 for cooling and shaping. Finally, they are input into the winding and slitting mechanism 402 to obtain Figure 1 the polyester film with the single-layer structure shown.

[0033] As Figure 4 shown, the preparation system for high-temperature resistant polyester film in this embodiment includes an input pipeline 500 of PET chips for ordinary films, a first mixing bin 501, and a second mixing bin 502. The output end of the input pipeline 500 of PET chips for ordinary films is respectively connected to the first mixing bin 501 and the second mixing bin 502. The input end of the first mixing bin 501 is further connected to the high-temperature resistant PET functional masterbatch preparation device 1000; the output end of the first mixing bin 501 is respectively connected to the first twin-screw extruder 503 and the third twin-screw extruder 504; the output end of the second mixing bin 502 is connected to the second twin-screw extruder 505; the output ends of the first twin-screw extruder 503 and the third twin-screw extruder 504 input the prepared A-layer thick sheets and C-layer thick sheets as the surface layer and the bottom layer into the film stretching mechanism 400, and the output end of the second twin-screw extruder 505 inputs the prepared B-layer thick sheets as the core layer into the film stretching mechanism 400. The output end of the film stretching mechanism 400 is further connected to the cooling and shaping device 401, and the output end of the cooling and shaping device 401 is connected to the winding and slitting mechanism 402.

[0034] Figure 4 When the shown preparation system works, the PET chips for ordinary films are respectively input into the first mixing bin 501 and the second mixing bin 502 through the input pipeline 500 of PET chips for ordinary films. At the same time, the prepared functional masterbatch chips are input into the first mixing bin 501 through the PET functional masterbatch preparation device 1000 according to the addition amount of 70wt%-100wt% of the total mass of the core layer.

[0035] Similar to the Figure 3 illustrated embodiment, in order to control the input amount of PET chips for ordinary films input into the first mixing bin 501, a flow control valve 510 is further provided in the pipeline connecting the side of the first mixing bin 501 to the PET chip input pipeline 500 for ordinary films. Similarly, by controlling the flow control valve 510, the weight of the PET chips for ordinary films input into the first mixing bin 501 can be controlled to account for 0 - 30% of the total mass. If necessary, the flow control valve 510 can be closed to stop inputting PET chips for ordinary films into the first mixing bin 501.

[0036] The materials in the first mixing bin 501 are respectively prepared into A - layer thick sheets and C - layer thick sheets through the first twin - screw extruder 503 and the third twin - screw extruder 504, and the materials in the second mixing bin 502 are prepared into B - layer thick sheets through the second twin - screw extruder 505. The A - layer thick sheets, B - layer thick sheets, and C - layer thick sheets are respectively input into the film stretching mechanism 400.

[0037] The film stretching mechanism 400 performs transverse and longitudinal stretching on the input three - layer thick sheets, then inputs them into the cooling and shaping mechanism 401 for cooling and shaping, and finally inputs them into the winding and slitting mechanism 402 to prepare and obtain Figure 2 the polyester film with the three - layer structure as

[0038] Furthermore, the preparation system of the present application may further include a PET functional masterbatch preparation device 1000 for preparing high - temperature - resistant PET functional masterbatch, as Figure 5 shown, which shows the structural schematic diagram of the PET functional masterbatch preparation device according to a specific embodiment of the present application.

[0039] As Figure 5 shown, the PET functional masterbatch preparation device 1000 of the present application includes an esterification tank 100 and a polycondensation tank 200.

[0040] The esterification tank 100 has a first inlet 101 for inputting terephthalic acid, a second inlet 102 for inputting ethylene glycol, a third inlet 103 for inputting dimethyl 2,6 - naphthalenedicarboxylate, and a fourth inlet 104 connecting to the first auxiliary material tank 300. Among them, the first auxiliary material tank 300 for preparing solution A is provided with three inlets respectively corresponding to inputting acetic anhydride, acetone, and antimony trioxide.

[0041] The polycondensation tank 200 has a fifth inlet 205 connecting to the outlet of the esterification tank 100, a sixth inlet 206 connecting to the outlet of the second auxiliary material tank 301, and a seventh inlet 207 for triethyl phosphate. Among them, the second auxiliary material tank 301 for preparing the B solution is provided with four inlets respectively corresponding to input sodium dodecylbenzenesulfonate, 2-hydroxy-4-(3-triethoxysilylpropoxy) benzophenone, ethanol, and cellulose acetate.

[0042] Further, the outlet of the polycondensation tank 200 is connected to at least one extruder 600, the outlet of the extruder 600 is connected to a pelletizer 700, and the outlet of the pelletizer 700 is connected to a vacuum drying tank 800.

[0043] The following refers to Figure 5 Further details the preparation method of the high-temperature resistant PET functional masterbatch of the present application.

[0044] Through the three inlets of the first auxiliary material tank 300, 0.02 - 0.04 parts by weight of acetic anhydride and 0.03 - 0.05 parts by weight of acetone are respectively input into the first auxiliary material tank 300 and uniformly mixed. Then, 0.005 - 0.01 parts by weight of antimony trioxide is added to the first auxiliary material tank 300 and uniformly mixed and reacted for more than 30 minutes to prepare the A solution for standby.

[0045] Through the four inlets of the second auxiliary material tank 301, 0.01 - 0.03 parts by weight of sodium dodecylbenzenesulfonate, 0.05 - 0.10 parts by weight of 2-hydroxy-4-(3-triethoxysilylpropoxy) benzophenone, 0.10 - 0.15 parts by weight of ethanol, and 0.01 - 0.03 parts by weight of cellulose acetate are respectively input into the second auxiliary material tank 301 and uniformly mixed, heated to 50 - 60 °C, and left standing for hydrolysis for more than 1 hour to prepare the B solution for standby. Correspondingly, the second auxiliary material tank 301 is provided with a water bath heating jacket 3011 for heating.

[0046] Through the first inlet 101 of the esterification tank 100, 50 - 100 parts by weight of terephthalic acid is input into the esterification tank 100, 20 - 45 parts by weight of ethylene glycol is input through the second inlet 102, 5 - 10 parts by weight of dimethyl 2,6-naphthalenedicarboxylate is input through the third inlet 103, and the A solution prepared in the first auxiliary material tank 300 is stirred evenly and then added to the esterification tank 100 for reaction. The reaction temperature is 180 - 260 °C, the gauge pressure is 0.2 - 0.3 Mpa. When the water output reaches 1200 ml, the pressure is released to atmospheric pressure, and the reaction product is filtered and then input into the polycondensation tank 200 through the fifth inlet 205. Correspondingly, the first auxiliary material tank 300 is provided with a stirrer 3012 for stirring the A solution.

[0047] Then, the B solution prepared in the second auxiliary material tank 301 is stirred evenly and added to the polycondensation tank 200 through the sixth inlet 206. And 0.01 - 0.03 parts by weight of triethyl phosphate is added to the polycondensation tank 200 through the seventh inlet 207. Stir at normal pressure for 30 - 60 minutes, and react at a temperature of 230 - 280 °C and a pressure below 100 Pa for 3 - 5 hours. Correspondingly, the second auxiliary material tank 301 is also provided with a stirrer 3012 for stirring the B solution.

[0048] The reaction product in the polycondensation tank 200 is input into the extruder 600 and extruded, and then made into slices by the granulator 700. The made slices are input into the vacuum drying tank 800 for drying reaction for more than 10 hours to obtain the high-temperature resistant PET functional masterbatch of the present application. Among them, the drying temperature of the vacuum drying tank 800 is 230 - 250 °C and the pressure is below 100 Pa.

[0049] Among them, a partial suspension containing antimony acetate can be formed in the A solution, which can be fully dispersed in the system during the esterification process, can serve as a catalyst for multi-system esterification, and can improve the high-temperature resistance of the subsequent polymerization product. In the B solution, 2-hydroxy-4-(3-triethoxysilylpropoxy)benzophenone can be hydrolyzed to obtain silanol in the alkaline environment composed of sodium dodecylbenzenesulfonate and ethanol, and polymerized into a polysiloxane chain, and then dispersed into the emulsion formed by cellulose acetate to form a grid-like dispersion system. During the polycondensation reaction process, the dispersed polysiloxane chains can firmly connect PET and PEN, so that the high-temperature resistance of the functional masterbatch is greatly improved. A small amount of unhydrolyzed 2-hydroxy-4-(3-triethoxysilylpropoxy)benzophenone can still play the function of ultraviolet protection, further improving the anti-aging performance of the functional masterbatch.

[0050] Example 1

[0051] 0.02 parts by weight of acetic anhydride and 0.03 parts by weight of acetone are uniformly mixed, and then 0.005 parts by weight of antimony dioxide is added and uniformly mixed and reacted for 30 minutes to prepare the A solution for standby.

[0052] 0.01 parts by weight of sodium dodecylbenzenesulfonate, 0.05 parts by weight of 2-hydroxy-4-(3-triethoxysilylpropoxy)benzophenone, 0.10 parts by weight of ethanol and 0.01 parts by weight of cellulose acetate are uniformly mixed, heated to 50 °C, and left standing for hydrolysis for 1 hour to prepare the B solution for standby.

[0053] 50 parts by weight of terephthalic acid, 20 parts by weight of ethylene glycol, and 5 parts by weight of dimethyl 2,6-naphthalenedicarboxylate are added to the esterification tank and uniformly mixed, and then the A solution is stirred evenly and added to the esterification tank for reaction. The reaction temperature is 180 °C and the gauge pressure is 0.2 Mpa. When the water output reaches 1200 ml, the pressure is released to normal pressure, and the reaction product is filtered and then input into the polycondensation tank.

[0054] Then, solution B was stirred evenly and added to the polycondensation tank. 0.01 part by weight of triethyl phosphate was added to the polycondensation tank, and it was stirred at atmospheric pressure for 30 minutes. The reaction was carried out at a temperature of 230 °C and a pressure of 100 Pa for 3 hours. The reaction product in the polycondensation tank was extruded and sliced.

[0055] The sliced products were put into a vacuum drying tank for drying reaction for 10 hours to obtain the high-temperature resistant PET functional masterbatch of the present application. Among them, the drying temperature of the vacuum drying tank was 230 degrees Celsius and the pressure was 100 Pa.

[0056] The prepared high-temperature resistant PET functional masterbatch was mixed with ordinary film-use PET slices at 70 wt%, 85 wt%, and 100 wt% of the total mass of the film layer respectively, and was made into a polyester film with a single-layer structure through melt extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, and winding and slitting. The width of the obtained film was 1500 mm and the thickness was 30 μm.

[0057] The performance parameters of the three single-layer structure polyester films prepared in Example 1 were measured. Among them, the tensile strengths at 25 °C were 285 MPa, 293 MPa, and 297 MPa respectively; the transverse thermal shrinkage rates at 120 °C for 30 minutes were all less than 0.01%; the transverse thermal shrinkage rates at 200 °C for 30 minutes were 0.06%, 0.05%, and 0.04% respectively; the light transmittance rates were 93.1%, 93.2%, and 93.3% respectively; the tensile strengths at 300 °C were 167 MPa, 170 MPa, and 174 MPa respectively.

[0058] Example 2

[0059] 0.03 part by weight of acetic anhydride and 0.04 part by weight of acetone were uniformly mixed, and then 0.008 part by weight of antimony dioxide was added and uniformly mixed and reacted for 40 minutes to prepare solution A for standby.

[0060] 0.02 part by weight of sodium dodecylbenzenesulfonate, 0.08 part by weight of 2-hydroxy-4-(3-triethoxysilylpropoxy) benzophenone, 0.12 part by weight of ethanol, and 0.02 part by weight of cellulose acetate were uniformly mixed and heated to 55 °C, and left standing for hydrolysis for 1.5 hours to prepare solution B for standby.

[0061] 80 parts by weight of terephthalic acid, 35 parts by weight of ethylene glycol, and 8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate were added to the esterification tank and uniformly mixed. Then, solution A was stirred evenly and added to the esterification tank for reaction. The reaction temperature was 220 degrees Celsius and the gauge pressure was 0.25 Mpa. When the water output reached 1200 ml, the pressure was released to atmospheric pressure, and the reaction product was filtered and then input into the polycondensation tank.

[0062] Then, after stirring the solution B evenly, add it to the polycondensation tank, and add 0.02 parts by weight of triethyl phosphate to the polycondensation tank. Stir at normal pressure for 45 minutes, and react at a temperature of 255 °C and a pressure of 90 Pa for 4 hours. Extrude and slice the reaction product in the polycondensation tank.

[0063] Input the sliced product into a vacuum drying tank for drying and reacting for 11 hours to obtain the high-temperature resistant PET functional masterbatch of the present application. Among them, the drying temperature of the vacuum drying tank is 240 °C and the pressure is 90 Pa.

[0064] Mix the prepared high-temperature resistant PET functional masterbatch with ordinary film PET slices at 70 wt%, 85 wt%, and 100 wt% of the total mass of the film layer respectively, and through melt extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, winding and slitting, make a polyester film with a single-layer structure. The width of the made film is 3000 mm and the thickness is 100 μm.

[0065] Measure the performance parameters of the three single-layer structure polyester films prepared in Example 2. Among them, the tensile strength at 25 °C is 287 MPa, 297 MPa, and 301 MPa respectively; the transverse thermal shrinkage rate at 120 °C for 30 minutes is less than 0.01%; the transverse thermal shrinkage rate at 200 °C for 30 minutes is 0.05%, 0.04%, and 0.03% respectively; the light transmittance is 92.7%, 92.8%, and 92.9% respectively; the tensile strength at 300 °C is 177 MPa, 176 MPa, and 179 MPa respectively.

[0066] Example 3

[0067] Uniformly mix 0.04 parts by weight of acetic anhydride and 0.05 parts by weight of acetone, and then add 0.003 parts by weight of antimony dioxide and mix evenly for reaction for 50 minutes to prepare solution A for standby.

[0068] Uniformly mix 0.03 parts by weight of sodium dodecylbenzenesulfonate, 0.10 parts by weight of 2-hydroxy-4-(3-triethoxysilylpropoxy) benzophenone, 0.15 parts by weight of ethanol, and 0.03 parts by weight of cellulose acetate, heat to 60 °C, and stand for hydrolysis for 2 hours to prepare solution B for standby.

[0069] Add 100 parts by weight of terephthalic acid, 45 parts by weight of ethylene glycol, and 10 parts by weight of dimethyl 2,6-naphthalenedicarboxylate to the esterification tank and mix evenly, and then add solution A after stirring evenly to the esterification tank for reaction. The reaction temperature is 260 °C and the gauge pressure is 0.3 Mpa. When the water output reaches 1200 ml, relieve the pressure to normal pressure, filter the reaction product and input it into the polycondensation tank.

[0070] Then, after stirring the solution B evenly, it is added to the polycondensation tank, and 0.03 parts by weight of triethyl phosphate is added to the polycondensation tank. Stir at normal pressure for 60 minutes, and react at a temperature of 280 °C and a pressure of 80 Pa for 5 hours. The reaction product in the polycondensation tank is extruded and sliced.

[0071] The sliced products are input into a vacuum drying tank for drying reaction for 12 hours to obtain the high-temperature resistant PET functional masterbatch of the present application. Among them, the drying temperature of the vacuum drying tank is 250 °C and the pressure is 80 Pa.

[0072] The prepared high-temperature resistant PET functional masterbatch is mixed with ordinary film PET slices according to 70 wt%, 85 wt%, and 100 wt% of the total mass of the film layer respectively, and is melt-extruded, die-cast into sheets, stretched horizontally and vertically, cooled and shaped, and wound and slit to make a polyester film with a single-layer structure. The width of the film made is 5000 mm and the thickness is 250 μm.

[0073] Measure the performance parameters of the three single-layer structure polyester films prepared in Example 3. Among them, the tensile strengths at 25 °C are 301 MPa, 302 MPa, and 305 MPa respectively; the transverse thermal shrinkage rates at 120 °C for 30 minutes are all less than 0.01%; the transverse thermal shrinkage rates at 200 °C for 30 minutes are 0.02%, 0.01%, and 0.03% respectively; the light transmittance rates are 94.2%, 94.3%, and 94.1% respectively; the tensile strengths at 300 °C are 171 MPa, 177 MPa, and 183 MPa respectively.

[0074] Refer to the preparation process parameters of Examples 1-3 respectively, adjust the ratio of some raw materials, and conduct comparative experiments respectively.

[0075] Comparative Example 1

[0076] Refer to the preparation process parameters of Example 1 to make the functional masterbatch. During the preparation process, solution A is not used, and 0.005 parts by weight of antimony acetate is used to replace it in the step of adding solution A. 2-Hydroxy-4-(3-triethoxysilylpropoxy) benzophenone is not added when preparing solution B. The remaining process parameters and parts by weight of raw materials are the same as those in Example 1.

[0077] Similar to Example 1, the prepared functional masterbatch is mixed with ordinary film PET slices according to 70 wt%, 85 wt%, and 100 wt% of the total mass of the film layer respectively, and is melt-extruded, die-cast into sheets, stretched horizontally and vertically, cooled and shaped, and wound and slit to make a polyester film with a single-layer structure.

[0078] Measure the performance parameters of the three single-layer polyester films prepared in Comparative Example 1. Among them, the tensile strengths at 25 °C are 288 MPa, 209 MPa, and 213 MPa respectively; the transverse thermal shrinkage rates at 120 °C for 30 minutes are 6.7%, 6.6%, and 6.5% respectively; the transverse thermal shrinkage rates at 200 °C for 30 minutes are 10.3%, 10.0%, and 9.8% respectively; the light transmittance rates are 82.3%, 82.4%, and 82.1% respectively; the tensile strengths at 300 °C are 12 MPa, 13 MPa, and 15 MPa respectively.

[0079] Comparative Example 2

[0080] Prepare the functional masterbatch with reference to the preparation process parameters of Example 2. During the preparation process, do not use Solution A, and replace it with 0.008 parts by weight of antimony acetate in the step of adding Solution A. When preparing Solution B, do not add 2-hydroxy-4-(3-triethoxysilylpropoxy)benzophenone, nor add cellulose acetate. The remaining process parameters and parts by weight of raw materials are the same as those in Example 2.

[0081] Similar to Example 2, mix the prepared functional masterbatch with ordinary film PET chips at 70 wt%, 85 wt%, and 100 wt% of the total film layer mass respectively, and then through melt extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, winding and slitting, to make single-layer polyester films.

[0082] Measure the performance parameters of the three single-layer polyester films prepared in Comparative Example 2. Among them, the tensile strengths at 25 °C are 219 MPa, 218 MPa, and 221 MPa respectively; the transverse thermal shrinkage rates at 120 °C for 30 minutes are 2.5%, 2.8%, and 2.7% respectively; the transverse thermal shrinkage rates at 200 °C for 30 minutes are 3.3%, 3.4%, and 3.8% respectively; the light transmittance rates are 87.8%, 87.3%, and 87.2% respectively; the tensile strengths at 300 °C are 42 MPa, 43 MPa, and 45 MPa respectively.

[0083] Comparative Example 3

[0084] Prepare the functional masterbatch with reference to the preparation process parameters of Example 3. During the preparation process, do not use Solution A, and replace it with 0.01 parts by weight of antimony acetate in the step of adding Solution A. When preparing Solution B, do not add 2-hydroxy-4-(3-triethoxysilylpropoxy)benzophenone, nor add sodium dodecylbenzenesulfonate. The remaining process parameters and parts by weight of raw materials are the same as those in Example 3.

[0085] Similar to Example 3, mix the prepared functional masterbatch with ordinary film PET chips at 70 wt%, 85 wt%, and 100 wt% of the total film layer mass respectively, and then through melt extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, winding and slitting, to make single-layer polyester films.

[0086] Measure the performance parameters of the three single-layer polyester films prepared in Comparative Example 3. Among them, the tensile strengths at 25 °C are 188 MPa, 191 MPa, and 195 MPa respectively; the transverse thermal shrinkage rates at 120 °C for 30 minutes are 5.5%, 5.2%, and 4.6% respectively; the transverse thermal shrinkage rates at 200 °C for 30 minutes are 7.9%, 7.7%, and 7.6% respectively; the light transmittance rates are 83.2%, 83.3%, and 83.0% respectively; the tensile strengths at 300 °C are 20 MPa, 22 MPa, and 24 MPa respectively.

[0087] Based on the experimental data, the inventor analyzed and believed that in this application, due to the adoption of an optimized esterification dispersion catalytic system and the addition of a grid-like polysiloxane chain at the beginning stage of polycondensation with relatively small molecular chains, it can be relatively easily dispersed into the masterbatch without affecting the crystallinity of the polyester, thereby obtaining excellent high-temperature resistance performance. Further experiments showed that Examples 1-3 did not show obvious shrinkage after being baked at 300 °C for 30 minutes. And in the accelerated aging experiment, the average number of color spots of Examples 1-3 in 6 months was much less than that of Comparative Examples 1-3 (less than 10%), indicating that the polyester film of this application has excellent anti-aging performance and also shows excellent corrosion resistance performance, with stable quality.

[0088] Based on the functional masterbatches prepared in Examples 1-3 respectively, prepare three-layer polyester films.

[0089] Example 4

[0090] Slice the functional masterbatch prepared in Example 1 and uniformly mix it with PET polyester chips for ordinary films at an addition amount of 70 wt% of the total surface layer mass as the surface layer raw material; use PET chips for ordinary films as the core layer raw material, and through melt co-extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, and winding and slitting, make a three-layer ABC polyester film.

[0091] The thickness of layer A of the prepared polyester film is 10 μm, the thickness of layer B is 30 μm, the thickness of layer C is 10 μm, the total thickness is 50 μm, and the width is 1500 mm.

[0092] Example 5

[0093] Slice the functional masterbatch prepared in Example 2 and uniformly mix it with PET polyester chips for ordinary films at an addition amount of 85 wt% of the total surface layer mass as the surface layer raw material; use PET chips for ordinary films as the core layer raw material, and through melt co-extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, and winding and slitting, make a three-layer ABC polyester film.

[0094] The thickness of layer A of the produced polyester film is 20 μm, the thickness of layer B is 110 μm, the thickness of layer C is 20 μm, the total thickness is 150 μm, and the width is 3000 mm.

[0095] Example 6

[0096] The functional masterbatch chips prepared in Example 3 were used as the surface layer raw materials at an addition amount of 100 wt% of the total surface layer mass, and ordinary film PET chips were used as the core layer raw materials. A polyester film with a three-layer structure of ABC was made through melt co-extrusion, die casting, transverse and longitudinal stretching, cooling and shaping, and winding and slitting.

[0097] The thickness of layer A of the produced polyester film is 25 μm, the thickness of layer B is 200 μm, the thickness of layer C is 25 μm, the total thickness is 250 μm, and the width is 5000 mm.

[0098] Comparative Examples 4-6

[0099] Based on the functional masterbatches of Comparative Examples 1-3, polyester films with a three-layer structure of Comparative Examples 4-6 were prepared correspondingly using the same technical parameters as in Examples 4-6.

[0100] The performance parameters of the polyester films with a three-layer structure of Examples 4-6 and Comparative Examples 4-6 were tested, as shown in the following table.

[0101]

[0102] Through the comparison of experimental data, the polyester film with a three-layer structure of the present application, when using the optimized functional masterbatch, significantly has more excellent high-temperature resistance compared with polyester films made of other functional masterbatches or raw materials of components, and can be applied to prepare high-molecular products in industries such as high-temperature resistance, high mechanical strength, and chemical corrosion resistance in application fields such as electronics and electrical, automotive, packaging, machinery, medical devices, and optics.

[0103] Those skilled in the art should understand that although the present application is described in the manner of multiple embodiments, not every embodiment contains only one independent technical solution. Such narration in the specification is only for clarity. Those skilled in the art should understand the specification as a whole and consider the technical solutions involved in each embodiment as ways that can be combined with each other to form different embodiments to understand the protection scope of the present application.

[0104] The above are only illustrative specific embodiments of the present application and are not intended to limit the scope of the present application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the present application shall fall within the protection scope of the present application.

Claims

1. A preparation system for a high-temperature resistant polyester film, characterized in that, The preparation system includes an input pipeline for PET chips for ordinary films and a first mixing bin. The input end of the first mixing bin is respectively connected to the output end of the input pipeline for PET chips for ordinary films and the output end of the preparation device for high-temperature resistant PET functional masterbatch; the output end of the first mixing bin is connected to a first twin-screw extruder; the output end of the first twin-screw extruder inputs the prepared thick sheet into a film pulling mechanism; the output end of the film pulling mechanism is further connected to a cooling and shaping device, and the output end of the cooling and shaping device is connected to a winding and slitting mechanism; a flow control valve is further arranged in the input pipeline for PET chips for ordinary films.

2. A preparation system for a high-temperature resistant polyester film, characterized in that, The preparation system includes an input pipeline for PET chips for ordinary films, a first mixing bin and a second mixing bin. The output end of the input pipeline for PET chips for ordinary films is respectively connected to the first mixing bin and the second mixing bin, and the input end of the first mixing bin is further connected to the preparation device for high-temperature resistant PET functional masterbatch; the output end of the first mixing bin is respectively connected to a first twin-screw extruder and a third twin-screw extruder; the output end of the second mixing bin is connected to a second twin-screw extruder; the output ends of the first twin-screw extruder and the third twin-screw extruder input the prepared A-layer thick sheet and C-layer thick sheet as the surface layer and the bottom layer into the film pulling mechanism, and the output end of the second twin-screw extruder inputs the prepared B-layer thick sheet as the core layer into the film pulling mechanism; the output end of the film pulling mechanism is further connected to a cooling and shaping device, and the output end of the cooling and shaping device is connected to a winding and slitting mechanism; a flow control valve is further arranged in the pipeline connecting the input pipeline for PET chips for ordinary films to one side of the first mixing bin.

3. The preparation system according to claim 1 or 2, characterized in that, The preparation device for high-temperature resistant PET functional masterbatch includes an esterification tank and a polycondensation tank; the esterification tank has a first inlet, a second inlet, a third inlet and a fourth inlet connected to a first auxiliary material tank; the polycondensation tank has a fifth inlet connected to the outlet of the esterification tank, a sixth inlet connected to a second auxiliary material tank and a seventh inlet; the outlet of the polycondensation tank is connected to at least one extruder, the outlet of the extruder is connected to a pelletizer, and the outlet of the pelletizer is connected to a vacuum drying tank.

4. The preparation system according to claim 3, characterized in that, The first auxiliary material tank for preparing solution A is provided with three inlets and a stirrer for stirring solution A; the second auxiliary material tank for preparing solution B is provided with four inlets; the second auxiliary material tank is provided with a water bath heating jacket and a stirrer for stirring solution B.

5. A high-temperature resistant polyester film prepared by the preparation system according to claim 1, which is a single-layer polyester film, characterized in that, The thickness of the single-layer polyester film is 50 - 250 μm, and the width of the single-layer polyester film is 1500 - 5000 mm.

6. A high-temperature resistant polyester film prepared by the preparation system according to claim 2, which is a three-layer co-extrusion structure, including an A-layer surface layer, a B-layer core layer, and a C-layer bottom layer. The A layer and the C layer are respectively arranged on both sides of the B layer, and is characterized in that, The total thickness of the three-layer polyester film is 50 - 250 μm, the thickness of the A layer and the C layer is 10 - 25 μm, and the thickness of the B layer is 30 - 200 μm; the width of the three-layer polyester film is 1500 - 5000 mm.

Images