A method for improving the adhesion of polyester film to ethylene-vinyl acetate copolymer adhesive film

Abstract

The application discloses a preparation method for improving the adhesion of a polyester film and an ethylene-vinyl acetate copolymer adhesive film, and comprises the following steps: preparing a PET copolymer polyester resin, taking ethylene glycol (EG), terephthalic acid (PTA), a third monomer glycerol monoacetate or glycerol monopropionate or glycerol monobutyrate as raw materials, and reacting according to a certain proportion; in the reaction process, the third monomer is copolymerized into the main chain of the polyester molecule, the regularity of the polyester structure is reduced, the content of the amorphous part of the polyester is increased, and the infiltration of the EVA adhesive film is facilitated; meanwhile, the third monomer is copolymerized into the polyester molecular chain, the chain segment structure is similar to the EVA structure, the adhesion of the PET copolymer polyester film and the EVA adhesive film is improved, the 180-degree interlayer peeling strength of the PET copolymer polyester film and the EVA adhesive film can reach 92 N / cm at most, which is much higher than the 180-degree interlayer peeling strength of 30 N / cm of the unmodified PET homopolymer polyester film and the EVA adhesive film.

Description

Technical Field

[0001] This invention belongs to the field of organic polymer compound preparation, specifically relating to a method for improving the adhesion between polyester film and ethylene-vinyl acetate copolymer film. Background Technology

[0002] PET polyester film is widely used in the photovoltaic industry due to its excellent physical and chemical properties. However, because PET polyester film has a rigid molecular chain, high crystallinity, and few polar groups, its surface energy and surface tension are low. This results in a lack of long-term strong adhesion when laminated with photovoltaic EVA film. Although corona treatment of the PET polyester film can improve its surface properties and increase the number of polar groups, the surface roughness after corona treatment is low (12.3 nm). This thickness is insufficient for strong adhesion when laminated with EVA film, leading to delamination of the EVA film during long-term outdoor use. Currently, to improve the long-term adhesion between photovoltaic PET polyester film and EVA film, researchers have been studying surface modification techniques for PET film. The main technique involves coating the film surface with fluoroolefin-vinyl ether copolymer (FEVE) resin. While FEVE resin coating significantly improves the long-term adhesion between PET polyester film and EVA film, the production process of coating fluorocarbon resin uses organic solvents, causing environmental pollution and posing health risks to workers on-site. In addition, PET polyester films coated with fluorocarbon resin will produce a large amount of toxic gas when they catch fire, causing serious environmental pollution. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a film that improves the adhesion between polyester film and ethylene-vinyl acetate copolymer film, thereby improving the adhesion between PET copolyester film and EVA film.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] On one hand, a method for preparing an adhesive film that improves the adhesion between a polyester film and an ethylene-vinyl acetate copolymer film includes the preparation of a PET copolyester resin, wherein the PET copolyester resin has the following structural formula:

[0006]

[0007] Where: m:n = 50~99:1~50;

[0008] —R is one of —CH3, —CH2CH3, and —CH2CH2CH3.

[0009] Optionally, the preparation of the PET copolyester resin film includes the following steps:

[0010] S1. Add 1000 parts by weight of terephthalic acid, 298-517 parts by weight of ethylene glycol, 8-486 parts by weight of the third monomer glyceryl monoacetate or glyceryl monopropionate or glyceryl monobutyrate, 0.25-0.35 parts by weight of catalyst, and 0.05-0.1 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0011] S2. When the temperature inside the reactor rises to 240-260℃ and the water output is 200-215 parts by mass, the temperature is raised to 275-285℃ for polycondensation, and a vacuum is slowly evacuated for 2.5-4 hours. When the residual pressure inside the reactor is 20-40 Pa and the resin viscosity is 0.60-0.80 dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0012] S3. 70-98.5 parts by weight of the PET copolyester resin, 0.5-20 parts by weight of rutile titanium dioxide PET masterbatch, and 1-10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at a temperature of 150-170°C for 2.5-4 hours, and then extruded through an extruder at a temperature of 260-290°C, and then cold-drummed at a temperature of 12-20°C to form a cast sheet.

[0013] S4. The cast sheet is first longitudinally stretched by 3.0 ± 0.5 times at a temperature of 60–90°C, then cooled to 15–25°C for 2–5 seconds, and then transversely stretched by 3.0 ± 0.5 times at a temperature of 125 ± 20°C. The biaxially stretched film enters the heat-setting zone of the electrothermal channel, where the temperature of zone one is 200–240°C, the temperature of zone two is 200–240°C, and the temperature of zone three is 160–200°C. The total heat-setting time of the film in the three zones is 0.2–1 min. After passing through the heat-setting zone, the film is cooled at a temperature of 60–80°C for 0.1–0.5 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0014] Optionally, the catalyst is antimony trioxide or antimony glycol.

[0015] Optionally, the stabilizer is triphenyl phosphate or trimethyl phosphate.

[0016] Optionally, the rutile titanium dioxide PET masterbatch has a mass concentration of 60%.

[0017] Optionally, the monomeric aromatic carbodiimide masterbatch has a mass concentration of 13.5%.

[0018] Optionally, the viscosity of the PET copolyester resin is 0.60 dL / g, 0.65 dL / g, 0.70 dL / g, 0.75 dL / g, or 0.80 dL / g.

[0019] The beneficial effects of this invention are as follows: The PET copolyester resin of this invention uses a third monomer, glyceryl monoacetate (or glyceryl monopropionate, or glyceryl monobutyrate), to participate in the copolymerization, which reduces the regularity of the polyester structure and increases the proportion of amorphous parts of the polyester, which is beneficial to the wetting of the ethylene-vinyl acetate copolymer (EVA) film; at the same time, the copolymer chain segment structure of the third monomer is similar to that of the EVA film, which is beneficial to improving the compatibility and lamination adhesion between the PET copolyester film and the EVA film. The 180° interlayer peel strength between the film and the EVA film can reach up to 92 N / cm, which is far greater than the 180° interlayer peel strength of 30 N / cm between the unmodified PET polyester film and the EVA film.

[0020] The preparation process of this invention is simple, the procedures are straightforward, it is easy to operate, and it is highly practical. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited to the following description.

[0022] As one possible embodiment, a method for preparing a polyester film with improved adhesion to an ethylene-vinyl acetate copolymer film includes the preparation of a PET copolyester resin, wherein the PET copolyester resin has the following structural formula:

[0023]

[0024] Where: m:n = 50~99:1~50;

[0025] —R is one of —CH3, —CH2CH3, and —CH2CH2CH3;

[0026] The preparation of PET copolyester resin film includes the following steps:

[0027] S1. Add 1000 parts by weight of terephthalic acid, 298-517 parts by weight of ethylene glycol, 8-486 parts by weight of the third monomer glyceryl monoacetate or glyceryl monopropionate or glyceryl monobutyrate, 0.25-0.35 parts by weight of catalyst, and 0.05-0.1 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0028] S2. When the temperature inside the reactor rises to 240-260℃ and the water output is 200-215 parts by mass, the temperature is raised to 275-285℃ for polycondensation, and a vacuum is slowly evacuated for 2.5-4 hours. When the residual pressure inside the reactor is 20-40 Pa and the resin viscosity is 0.60-0.80 dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0029] S3. 70-98.5 parts by weight of the PET copolyester resin, 0.5-20 parts by weight of rutile titanium dioxide PET masterbatch, and 1-10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at a temperature of 150-170°C for 2.5-4 hours, and then extruded through an extruder at a temperature of 260-290°C, and then cold-drummed at a temperature of 12-20°C to form a cast sheet.

[0030] S4. The cast sheet is first longitudinally stretched by 3.0 ± 0.5 times at a temperature of 60–90°C, then cooled to 15–25°C for 2–5 seconds, and then transversely stretched by 3.0 ± 0.5 times at a temperature of 125 ± 20°C. The biaxially stretched film enters the heat-setting zone of the electrothermal channel, where the temperature of zone one is 200–240°C, the temperature of zone two is 200–240°C, and the temperature of zone three is 160–200°C. The total heat-setting time of the film in the three zones is 0.2–1 min. After passing through the heat-setting zone, the film is cooled at a temperature of 60–80°C for 0.1–0.5 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0031] By first reacting ethylene glycol (EG), terephthalic acid (PTA), and a third monomer, glyceryl monoacetate (or glyceryl monopropionate, or glyceryl monobutyrate), in a certain proportion during the PET polyester synthesis process, the third monomer is copolymerized into the polyester molecular backbone. This reduces the regularity of the polyester structure and increases the content of the amorphous portion of the polyester, which is beneficial for the wetting of EVA film. At the same time, the copolymerization of the third monomer into the polyester molecular chain, with this segment structure similar to the EVA structure, improves the adhesion between the PET copolyester film and the EVA film.

[0032] Example 1

[0033] The preparation of PET copolyester resin film includes the following steps:

[0034] S1. Add 1000 parts by weight of terephthalic acid, 500 parts by weight of ethylene glycol, 8 parts by weight of the third monomer glyceryl monoacetate, 0.25 parts by weight of catalyst, and 0.05 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0035] S2. When the temperature inside the reactor rises to 240℃ and the water output is 200 parts by mass, the temperature is raised to 275℃ for polycondensation, and a vacuum is slowly evacuated for 2.5 hours. When the residual pressure inside the reactor is 20Pa and the resin viscosity is 0.60dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0036] S3. 70 parts by weight of the PET copolyester resin, 0.5 parts by weight of rutile titanium dioxide PET masterbatch, and 1 part by weight of monomeric aromatic carbodiimide masterbatch are dried at 150°C for 2.5 hours, then extruded through an extruder at 288°C, and then cold-drummed at 12°C to form a cast sheet.

[0037] S4. The cast sheet is first stretched longitudinally by 2.9 times at 60°C, then cooled to 15°C for 2 seconds, and then stretched transversely by 3.0 times at 120°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 200°C, zone 2 is 200°C, and zone 3 is 165°C. The total heat setting time of the film in the three zones is 0.3 min. After passing through the heat setting zone, the film is cooled at 60°C for 0.1 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0038] Example 2

[0039] The preparation of PET copolyester resin film includes the following steps:

[0040] S1. Add 1000 parts by weight of terephthalic acid, 476 parts by weight of ethylene glycol, 100 parts by weight of the third monomer glyceryl monoacetate, 0.28 parts by weight of catalyst, and 0.07 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0041] S2. When the temperature inside the reactor rises to 245℃ and the water output is 205 parts by mass, the temperature is raised to 278℃ for polycondensation, and a vacuum is slowly drawn for 3 hours. When the residual pressure inside the reactor is 25Pa and the resin viscosity is 0.65dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0042] S3. 75 parts by weight of the PET copolyester resin, 2 parts by weight of rutile titanium dioxide PET masterbatch, and 2 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 155°C for 3 hours, and then extruded through an extruder at 285°C, and then cold-drummed at 15°C to form a cast sheet.

[0043] S4. The cast sheet is first stretched longitudinally by 3.0 times at 65°C, then cooled to 18°C ​​for 3 seconds, and then stretched transversely by 3.1 times at 125°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 222°C, zone 2 is 222°C, and zone 3 is 190°C. The total heat setting time of the film in the three zones is 0.3 min. After passing through the heat setting zone, the film is cooled at 65°C for 0.2 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0044] Example 3

[0045] The preparation of PET copolyester resin film includes the following steps:

[0046] S1. Add 1000 parts by weight of terephthalic acid, 453 parts by weight of ethylene glycol, 150 parts by weight of the third monomer glyceryl monoacetate, 0.30 parts by weight of catalyst, and 0.06 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0047] S2. When the temperature inside the reactor rises to 250℃ and the water output is 208 parts by mass, the temperature is raised to 280℃ for polycondensation, and a vacuum is slowly evacuated for 3 hours. When the residual pressure inside the reactor is 28Pa and the resin viscosity is 0.70dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0048] S3. 78 parts by weight of the PET copolyester resin, 5 parts by weight of rutile titanium dioxide PET masterbatch, and 4 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 158°C for 3 hours, and then extruded through an extruder at 282°C, and then cold-drummed at 15°C to form a cast sheet.

[0049] S4. The cast sheet is first stretched longitudinally by 3.2 times at 70°C, then cooled to 18°C ​​for 3 seconds, and then stretched transversely by 3.3 times at 128°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 225°C, zone 2 is 225°C, and zone 3 is 185°C. The total heat setting time of the film in the three zones is 0.3 min. After passing through the heat setting zone, the film is cooled at 70°C for 0.2 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0050] Example 4

[0051] The preparation of PET copolyester resin film includes the following steps:

[0052] S1. Add 1000 parts by weight of terephthalic acid, 430 parts by weight of ethylene glycol, 200 parts by weight of the third monomer glyceryl monoacetate, 0.32 parts by weight of catalyst, and 0.07 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0053] S2. When the temperature inside the reactor rises to 253℃ and the output water volume is 210 parts by mass, the temperature is raised to 280℃ for polycondensation, and a vacuum is slowly evacuated for 3.2 hours. When the residual pressure inside the reactor is 30Pa and the resin viscosity is 0.70dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0054] S3. 80 parts by weight of the PET copolyester resin, 10 parts by weight of rutile titanium dioxide PET masterbatch, and 10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 170°C for 3 hours, then extruded through an extruder at 280°C, and then cold-drummed at 18°C ​​to form a cast sheet.

[0055] S4. The cast sheet is first stretched longitudinally by 3.0 times at 80°C, then cooled to 20°C in 3 seconds, and then stretched transversely by 3.0 times at 135°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 230°C, zone 2 is 230°C, and zone 3 is 170°C. The total heat setting time of the film in the three zones is 0.2 min. After passing through the heat setting zone, the film is cooled at 75°C for 0.5 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0056] Example 5

[0057] The preparation of PET copolyester resin film includes the following steps:

[0058] S1. Add 1000 parts by weight of terephthalic acid, 407 parts by weight of ethylene glycol, 250 parts by weight of the third monomer glyceryl monoacetate, 0.34 parts by weight of catalyst, and 0.08 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0059] S2. When the temperature inside the reactor rises to 255℃ and the output water volume is 210 parts by mass, the temperature is raised to 280℃ for polycondensation, and a vacuum is slowly evacuated for 3.0 hours. When the residual pressure inside the reactor is 35Pa and the resin viscosity is 0.72dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0060] S3. 85 parts by weight of the PET copolyester resin, 10 parts by weight of rutile titanium dioxide PET masterbatch, and 6 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 165°C for 3 hours, and then extruded through an extruder at 280°C, and then cold-drummed at 18°C ​​to form a cast sheet.

[0061] S4. The cast sheet is first stretched longitudinally by 3.0 times at 85°C, then cooled to 22°C in 4 seconds, and then stretched transversely by 3.4 times at 135°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 227°C, zone 2 is 227°C, and zone 3 is 175°C. The total heat setting time of the film in the three zones is 0.5 min. After passing through the heat setting zone, the film is cooled at 70°C for 0.2 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0062] Example 6

[0063] The preparation of PET copolyester resin film includes the following steps:

[0064] S1. Add 1000 parts by weight of terephthalic acid, 400 parts by weight of ethylene glycol, 350 parts by weight of the third monomer glyceryl monopropionate, 0.35 parts by weight of catalyst, and 0.1 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0065] S2. When the temperature inside the reactor rises to 255℃ and the output water volume is 215 parts by mass, the temperature is raised to 285℃ for polycondensation, and a vacuum is slowly evacuated for 3.8 hours. When the residual pressure inside the reactor is 40Pa and the resin viscosity is 0.72dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0066] S3. 85 parts by weight of the PET copolyester resin, 12 parts by weight of rutile titanium dioxide PET masterbatch, and 7 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 160°C for 3 hours, then extruded through an extruder at 275°C, and then cold-drummed at 12°C to form a cast sheet.

[0067] S4. The cast sheet is first stretched longitudinally by 3.0 times at a temperature of 83°C, then cooled to 25°C for 2 seconds, and then stretched transversely by 3.2 times at a temperature of 140°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 230°C, zone 2 is 230°C, and zone 3 is 180°C. The total heat setting time of the film in the three zones is 0.2 min. After passing through the heat setting zone, the film is cooled at a temperature of 65°C for 0.2 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0068] Example 7

[0069] The preparation of PET copolyester resin film includes the following steps:

[0070] S1. Add 1000 parts by weight of terephthalic acid, 385 parts by weight of ethylene glycol, 400 parts by weight of the third monomer glyceryl monopropionate, 0.29 parts by weight of catalyst, and 0.08 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0071] S2. When the temperature inside the reactor rises to 257℃ and the output water volume is 212 parts by mass, the temperature is raised to 285℃ for polycondensation, and a vacuum is slowly drawn for 4 hours. When the residual pressure inside the reactor is 30Pa and the resin viscosity is 0.75dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0072] S3. After drying 90 parts by weight of the PET copolyester resin, 15 parts by weight of rutile titanium dioxide PET masterbatch, and 8 parts by weight of monomeric aromatic carbodiimide masterbatch at a temperature of 160°C for 3 hours, the mixture is then extruded through an extruder at a temperature of 270°C and then cold-drummed at a temperature of 13°C to form a cast sheet.

[0073] S4. The cast sheet is first stretched longitudinally by 3.1 times at 80°C, then cooled to 18°C ​​for 3 seconds, and then stretched transversely by 3.3 times at 130°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 233°C, zone 2 is 233°C, and zone 3 is 180°C. The total heat setting time of the film in the three zones is 0.2 min. After passing through the heat setting zone, the film is cooled at 60°C for 0.2 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0074] Example 8

[0075] The preparation of PET copolyester resin film includes the following steps:

[0076] S1. Add 1000 parts by weight of terephthalic acid, 350 parts by weight of ethylene glycol, 450 parts by weight of the third monomer glyceryl monobutyrate, 0.30 parts by weight of catalyst, and 0.05 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction.

[0077] S2. When the temperature inside the reactor rises to 260℃ and the water output is 210 parts by mass, the temperature is raised to 275℃ for polycondensation, and a vacuum is slowly drawn for 3 hours. When the residual pressure inside the reactor is 30Pa and the resin viscosity is 0.80dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained.

[0078] S3. 95 parts by weight of the PET copolyester resin, 20 parts by weight of rutile titanium dioxide PET masterbatch, and 10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 155°C for 2.8 hours, then extruded through an extruder at 265°C, and then cold-drummed at 15°C to form a cast sheet.

[0079] S4. The cast sheet is first stretched longitudinally by 3.0 times at 70°C, then cooled to 20°C for 2 seconds, and then stretched transversely by 3.2 times at 140°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 237°C, zone 2 is 237°C, and zone 3 is 180°C. The total heat setting time of the film in the three zones is 0.2 min. After passing through the heat setting zone, the film is cooled at 70°C for 0.1 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

[0080] Comparative Example

[0081] The preparation of PET polyester resin film includes the following steps:

[0082] S1. Add 1000 parts by mass of terephthalic acid, 523 parts by mass of ethylene glycol, 0.3 parts by mass of catalyst, and 0.1 parts by mass of stabilizer to the reactor, and pressurize to 0.2 MPa to carry out the reaction;

[0083] S2. When the temperature inside the reactor rises to 250℃ and the output water volume is 210 parts by mass, the temperature is raised to 280℃ for polycondensation, and a vacuum is slowly drawn for 3 hours. When the residual pressure inside the reactor is 30Pa and the resin viscosity is 0.75dL / g, nitrogen is introduced to discharge the material, and PET polyester resin is obtained.

[0084] S3. 80 parts by weight of the PET polyester resin, 10 parts by weight of rutile titanium dioxide PET masterbatch, and 10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at 170°C for 3 hours, and then extruded through an extruder at 280°C, and then cold-drummed at 15°C to form a cast sheet.

[0085] S4. The cast sheet is first stretched longitudinally by 3.0 times at a temperature of 83°C, then cooled to 20°C for 2 seconds, and then stretched transversely by 3.0 times at a temperature of 125°C. The biaxially stretched film enters the heat setting zone of the electrothermal channel, where the temperature of zone 1 is 230°C, zone 2 is 230°C, and zone 3 is 175°C. The total heat setting time of the film in the three zones is 0.2 min. After passing through the heat setting zone, the film is cooled at a temperature of 65°C for 0.1 min, then cooled at room temperature, and finally corona-wound to obtain a PET polyester film.

[0086] The peel strength between the PET polyester film and EVA film prepared in Examples 1-8 and the comparative example was tested, and the test results are shown in Table 1.

[0087] Example 1 36 Example 2 55 Example 3 63 Example 4 71 Example 5 78 Example 6 84 Example 7 92 Example 8 88 Comparative Example 30

[0088] Note: The test method for the 180° interlayer peel strength between the film and the EVA film refers to Chapter 6.9 of GB / T 31034-2014.

[0089] As shown in Table 1, the adhesion between the PET copolyester film and the EVA film prepared in this application is much higher than that between the PET polyester film and the EVA film prepared in the comparative example, and the peel strength of the two can reach 92 N / cm.

[0090] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for preparing a polyester film with improved adhesion to an ethylene-vinyl acetate copolymer film, characterized in that: This includes the preparation of PET copolyester resin, wherein the structural formula of the PET copolyester resin is: Where: m:n = 50~99:1~50; —R is one of —CH3, —CH2CH3, and —CH2CH2CH3.

2. The method for preparing a polyester film with improved adhesion to an ethylene-vinyl acetate copolymer film according to claim 1, characterized in that, The preparation of PET copolyester resin film includes the following steps: S1. Add 1000 parts by weight of terephthalic acid, 298-517 parts by weight of ethylene glycol, 8-486 parts by weight of the third monomer glyceryl monoacetate, glyceryl monopropionate, or glyceryl monobutyrate, 0.25-0.35 parts by weight of catalyst, and 0.05-0.1 parts by weight of stabilizer to the reactor and pressurize to 0.2 MPa to carry out the reaction. S2. When the temperature inside the reactor rises to 240-260℃ and the water output is 200-215 parts by mass, the temperature is raised to 275-285℃ for polycondensation, and a vacuum is slowly evacuated for 2.5-4 hours. When the residual pressure inside the reactor is 20-40 Pa and the resin viscosity is 0.60-0.80 dL / g, nitrogen is introduced to discharge the material, and PET copolyester resin is obtained. S3. 70-98.5 parts by weight of the PET copolyester resin, 0.5-20 parts by weight of rutile titanium dioxide PET masterbatch, and 1-10 parts by weight of monomeric aromatic carbodiimide masterbatch are dried at a temperature of 150-170°C for 2.5-4 hours, and then extruded through an extruder at a temperature of 260-290°C, and then cold-drummed at a temperature of 12-20°C to form a cast sheet. S4. The cast sheet is first longitudinally stretched by 3.0 ± 0.5 times at a temperature of 60–90°C, then cooled to 15–25°C for 2–5 seconds, and then transversely stretched by 3.0 ± 0.5 times at a temperature of 125 ± 20°C. The biaxially stretched film enters the heat-setting zone of the electrothermal channel, where the temperature of zone one is 200–240°C, the temperature of zone two is 200–240°C, and the temperature of zone three is 160–200°C. The total heat-setting time of the film in the three zones is 0.2–1 min. After passing through the heat-setting zone, the film is cooled at a temperature of 60–80°C for 0.1–0.5 min, then cooled at room temperature, and finally corona-wound to obtain a PET copolyester film.

3. The method for preparing a polyester film with improved adhesion to an ethylene-vinyl acetate copolymer film according to claim 2, characterized in that: The catalyst is antimony trioxide or antimony glycol.

4. The method for preparing an adhesive film with improved adhesion between polyester film and ethylene-vinyl acetate copolymer according to claim 2, characterized in that: The stabilizer is triphenyl phosphate or trimethyl phosphate.

5. The method for preparing an adhesive film with improved adhesion between polyester film and ethylene-vinyl acetate copolymer according to claim 2, characterized in that: The rutile titanium dioxide PET masterbatch has a mass concentration of 60%.

6. The method for preparing a polyester film with improved adhesion to an ethylene-vinyl acetate copolymer film according to claim 2, characterized in that: The monomeric aromatic carbodiimide masterbatch has a mass concentration of 13.5%.

7. The method for preparing an adhesive film with improved adhesion between polyester film and ethylene-vinyl acetate copolymer according to claim 2, characterized in that: The viscosity of the PET copolyester resin is 0.60 dL / g, 0.65 dL / g, 0.70 dL / g, 0.75 dL / g, or 0.80 dL / g.

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