Antistatic film and its manufacturing method

Abstract

The present invention relates to the field of antistatic coatings, and more specifically to an antistatic film and a method for manufacturing the same. The antistatic film includes a substrate and an antistatic layer provided on at least one side of the substrate. The antistatic layer and the substrate are obtained by synchronously stretching and fixing the antistatic layer in a transverse direction. The antistatic layer includes a conductive material, a modified polyurethane acrylate copolymer resin, a crosslinking agent, and deionized water. Because the antistatic layer of the present invention uses a modified polyurethane acrylate copolymer resin, the antistatic layer exhibits little change in resistance after use and has excellent antistatic properties and weather resistance.

Description

[Technical Field]

[0001] The present invention belongs to the field of antistatic, and specifically relates to an antistatic film and a method for manufacturing the same. [Background technology]

[0002] The use of optical films in LCDs is becoming more and more widespread, and these optical films may be contaminated by static electricity during transportation or deep processing, which will cause various inconveniences during deep processing and affect the overall quality of the optical film. Therefore, it is necessary to cover the surface of the optical film with an antistatic protective film.

[0003] Currently, antistatic films are divided into two types: internally applied and coated. Coated antistatic films are available in two coating processes: offline coating and online coating. Online coating is more widely used due to its relatively high resistance and limited application range. Online coating of antistatic films involves applying an antistatic coating solution to the film surface during the film manufacturing process. However, there are limitations to the coating thickness. The coating is relatively thin, typically only a few tens of nanometers, and requires stretching 3-5 times after coating, which weakens or even eliminates its antistatic properties. Therefore, the performance requirements for the coating material are very high. Therefore, most antistatic films used in the release film and protective film industries are manufactured using offline processes.

[0004] However, conventional antistatic films have the problem of low antistatic properties and low weather resistance.

[0005] Therefore, the present invention is proposed. Summary of the Invention

[0006] Antistatic and weather resistance properties are closely related to the resistance change of the antistatic film. The resistance value of an antistatic film changes after a certain period of use, and the greater the change in resistance, the lower the antistatic and weather resistance properties, while the smaller the change in resistance, the better the antistatic and weather resistance properties.

[0007] To solve the technical problems of the prior art, the present invention provides an antistatic film and a manufacturing method thereof. The antistatic layer of the present invention uses a modified polyurethane acrylate copolymer resin. The antistatic layer exhibits little change in resistance after use and has excellent antistatic properties and weather resistance.

[0008] The present invention includes the following technical solutions:

[0009] In a first aspect of the present invention, there is provided an antistatic film comprising a substrate and an antistatic layer provided on at least one side of the substrate, wherein the antistatic layer and the substrate are synchronously stretched transversely and fixed to obtain an antistatic film, and the antistatic layer comprises a conductive material, a modified polyurethane acrylate copolymer resin, a crosslinking agent, and deionized water.

[0010] Furthermore, the antistatic layer Conductive material 5% to 20% by weight, 5% to 20% by weight of a modified polyurethane acrylate copolymer resin; 0.1% to 5% by weight of a crosslinker, and Contains 55% to 89.9% by weight of deionized water.

[0011] Further, a method for producing the modified polyurethane acrylate copolymer resin includes: Add isocyanate to polyol and heat to react. A chain extender is added and reacted. Diethylenetriamine, a small molecule crosslinker, and an acetone solution of maleic anhydride are added in order, and the mixture is heated to react. Add sodium hydroxide solution and keep warm. An emulsifier and water are added and stirred, a butyl acrylate solution containing an initiator is added, and the mixture is heated to react. After cooling, a modified polyurethane acrylate copolymer resin is obtained. That is the thing.

[0012] Further, the isocyanate includes at least one of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane, and diisocyanate.

[0013] Additionally, the initiator is azobisisobutyronitrile.

[0014] Additionally, the small molecule crosslinker is trimethylolpropane.

[0015] Furthermore, the thickness of the antistatic layer is 5 nm to 2 μm.

[0016] Furthermore, the conductive material is one or more of carbon nanotube powder, polythiophene particles, polyaniline powder, and conductive metal, or the conductive material is one or more of polythiophene dispersion, carbon nanotube dispersion, polyaniline dispersion, silver paste, and silver wire.

[0017] Furthermore, the crosslinking agent is any one of oxazolines, isocyanates, nitrogen pyridines, and melamines.

[0018] In a second aspect of the present invention, there is provided a method for producing the antistatic film, comprising the steps of: feeding a substrate feedstock into an extrusion system, melting the feedstock, and extruding the substrate melt; forming the substrate melt into an amorphous cast thick sheet on a chill roll; A step of preheating the cooled cast thick sheet and longitudinally stretching it 3.0 to 5.0 times to obtain a film sheet; a step of applying an antistatic layer coating liquid to one side of a film sheet; a step of preheating the film sheet coated with the antistatic layer coating liquid and then stretching it laterally 3.0 to 5.0 times to obtain a film; and heat-setting the film to obtain an antistatic film.

[0019] By adopting the above technical solutions, the present invention has the following advantages: 1. The antistatic layer of the present invention uses a modified polyurethane acrylate copolymer resin, and the antistatic layer has little change in resistance after use and is excellent in antistatic properties and weather resistance. 2. In the method of the present invention, a coating solution for an antistatic layer prepared from a modified polyurethane acrylate copolymer resin, an aqueous conductive material, and a crosslinking agent is applied online, and simultaneously stretched transversely and synchronously with the substrate to form a three-dimensional network structure by thermal curing. The resulting antistatic film has a surface resistance of 10 4 Ω~10 11 Ω and has excellent weather resistance and anti-static properties. 3. The modified polyurethane acrylate copolymer resin of the present invention combines the advantages of both polyurethane and polyacrylate, is safe and environmentally friendly, has good film-forming properties, and has excellent physical and mechanical properties. It forms an interpenetrating network with an antistatic agent through online coating, stretching, and molding, and the coating with the interpenetrating polymer network has better optical properties. To improve the weather resistance and antistatic properties of the aqueous antistatic layer coating solution, the modified aqueous polyurethane acrylate copolymer resin, which has low viscosity and molecular controllability, is used as the interpenetrating polymer network. 4. This invention uses molecular structure design to introduce polyacrylic acid resin as a mixed hard segment into polyurethane rubber molecular segments, improving the crosslinking effect and improving the antistatic properties and weather resistance of the coating. At the same time, the modified polyurethane acrylate copolymer resin and water-based conductive polymer material are applied online and synchronously stretched transversely with the substrate, then thermally cured to form a three-dimensional network structure and dense conductive paths. The surface resistance of the resulting antistatic film is 10 4 Ω~10 11 Ω and has excellent antistatic properties.

[0020] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the drawings that need to be used to describe the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram showing the structure of an antistatic film according to an embodiment of the present invention. [Explanation of symbols]

[0022] 1. Base material 2. Antistatic layer DETAILED DESCRIPTION OF THE INVENTION

[0023] In the following description, various embodiments or examples are provided for implementing various features of the present invention. The components and arrangement manners described in the following specific examples are only used to simplify the present invention, and are merely examples rather than limiting the present invention.

[0024] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and are not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0025] Embodiment 1 This embodiment provides an antistatic film, which includes a substrate and an antistatic layer on at least one side of the substrate, and the antistatic layer and the substrate are synchronously stretched transversely and fixed to obtain the antistatic film, as shown in Figure 1. The antistatic layer includes a conductive material, a modified polyurethane acrylate copolymer resin, a crosslinking agent, and deionized water.

[0026] Furthermore, the antistatic layer Conductive material 5% to 20% by weight, 5% to 20% by weight of a modified polyurethane acrylate copolymer resin; 0.1% to 5% by weight of a crosslinker, and Contains 55% to 89.9% by weight of deionized water.

[0027] If the content of the conductive material is too low, the antistatic effect will be reduced, and if the content of the conductive material is too high, the spreading performance of the coating liquid will be reduced, the coating appearance will be poor, and weather resistance will be affected. Therefore, the weight percentage of the conductive material is preferably 5% to 25%. If the content of the modified polyurethane acrylate copolymer resin is too low, the conductive material will not be effectively deposited on the film surface, the coating appearance will be poor, and weather resistance will be affected. If the content of the modified polyurethane acrylate copolymer resin is too high, the conductive material will be wrapped too tightly, and too little conductive material will be exposed on the surface, making it difficult to demonstrate antistatic performance and resulting in poor antistatic effect. Therefore, the weight percentage of the modified polyurethane acrylate copolymer resin is preferably 5% to 25%. If the content of the crosslinking agent is too low, the crosslinking density of the coating will be too low, resulting in a decrease in the hardness and scratch resistance of the antistatic coating and a decrease in weather resistance. If the content of the crosslinking agent is too high, the stability of the coating solution will be poor, and the presence of too many small molecules will result in excessive crosslinking, increasing the risk of precipitation at high temperatures. Therefore, the weight percentage of the crosslinking agent is preferably 0.1% to 5%.

[0028] Further, a method for producing the modified polyurethane acrylate copolymer resin includes: Add isocyanate to polyol and heat to react. A chain extender is added and reacted. Diethylenetriamine, a small molecule crosslinker, and an acetone solution of maleic anhydride are added in order and reacted by heating. Add sodium hydroxide solution and keep warm. Add an emulsifier and water and stir, then add a butyl acrylate solution containing an initiator and heat to react, After cooling, a modified polyurethane acrylate copolymer resin is obtained. Preferably, the isocyanate is added to the polyol, and the mixture is heated to 75°C to 85°C and reacted for 1 to 3 hours. Add a chain extender and react for 1 to 3 hours. Add diethylenetriamine, a small molecule crosslinker, and an acetone solution of maleic anhydride in order, heat to 50-70°C, and react for 1-2 hours. Add sodium hydroxide solution and keep at 45℃-55℃ for 0.5-1.5 hours. Add emulsifier and water and stir, then add butyl acrylate solution containing initiator, emulsify for 30 minutes, then heat to 75-85°C and react for 2.5-3.5 hours, then heat again to 85-95°C and react for 1-2 hours, After cooling, a modified polyurethane acrylate copolymer resin was obtained.

[0029] Further, the isocyanate includes at least one of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane, and diisocyanate.

[0030] Additionally, the initiator is azobisisobutyronitrile.

[0031] Additionally, the small molecule crosslinker is trimethylolpropane.

[0032] If the antistatic layer is too thin, the content of the antistatic agent per unit area of ​​the coating will be low, resulting in poor antistatic effect, fewer polar groups per unit area, and reduced weather resistance.If the antistatic layer is too thick, the content of the antistatic agent per unit area will be high, resulting in good antistatic effect, but the coating appearance will be poor.Furthermore, the thickness of the antistatic layer is 5 nm to 2 μm.

[0033] Furthermore, the conductive material is one or more of carbon nanotube powder, polythiophene particles, polyaniline powder, and conductive metal, or the conductive material is one or more of polythiophene dispersion, carbon nanotube dispersion, polyaniline dispersion, silver paste, and silver wire.

[0034] In order to increase the crosslink density of the antistatic coating, the linear molecules are connected to each other to form a three-dimensional network structure, which improves the weather resistance of the antistatic coating, forms a dense conductive path, and at the same time ensures the stability of the antistatic liquid. In addition, the crosslinking agent is one of oxazolines, isocyanates, nitrogen pyridines, and melamines.

[0035] Embodiment 2 This example provides a method for producing an antistatic film, and the method for producing the antistatic film according to this embodiment is for producing the antistatic film according to embodiment 1, feeding a substrate feedstock into an extrusion system, melting the feedstock, and extruding the substrate melt; forming the substrate melt into an amorphous cast thick sheet on a chill roll; a process of preheating the cooled cast thick sheet and longitudinally stretching it by 3.0 to 5.0 times to obtain a film sheet, in which longitudinal stretching by 3.0 to 5.0 times ensures uniformity of thickness in the longitudinal direction and prevents excessive longitudinal stretching that results in an excessively high degree of orientation, making it difficult to form a film during transverse stretching; a step of applying an antistatic layer coating liquid to one side of a film sheet; a process of preheating the film sheet coated with the antistatic layer coating solution and then stretching it laterally by 3.0 to 5.0 times to obtain a film; stretching it laterally by 3.0 to 5.0 times ensures uniformity in the thickness in the transverse direction and denseness of the carbon nanotube coating applied online, and can form a stable conductive path; if the stretching ratio is too low, the coating will be too thick, and the carbon nanotubes will overlap significantly, which may result in uneven distribution on the polyester film surface; and if the stretching ratio is too high, the coating will break and the conductive path will be damaged, making it impossible to form good antistatic performance; and heat-setting the film to obtain an antistatic film. [Example]

[0036] The preparation of the modified polyurethane acrylate copolymer resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to isophorone diisocyanate and reacted at 75°C for 1 hour. Then, 2,2-bis(hydroxymethyl)propionic acid and butanediol were added and the reaction continued for another hour. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence. The mixture was heated to 50°C and reacted for 1 hour. After that, an appropriate amount of NaOH solution was added, the temperature was maintained at 45°C, and the mixture was incubated for 0.5 hours. Finally, a butyl acrylate solution containing azobisisobutyronitrile as an initiator was added. The mixture was pre-emulsified for a certain period of time and polymerized at 75°C for 2.5 hours. The mixture was then heated to 85°C and reacted for 1 hour. The resulting mixture was then cooled to room temperature to obtain a modified polyurethane acrylate copolymer resin.

[0037] The antistatic layer coating solution was prepared as follows: 5 g of aqueous polythiophene dispersion A200 (Aikefa, the weight ratio of polythiophene in the aqueous polythiophene dispersion is 5%), 5 g of modified polyurethane acrylate copolymer resin, 89.9 g of deionized water, and 0.1 g of oxazoline crosslinker WS-700 (Youon Chemical) were uniformly dispersed in a high-shear emulsifier to prepare an antistatic layer coating solution.

[0038] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and stretched longitudinally at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, then stretched transversely to 3 times its original size, heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 5 nm. [Example]

[0039] The preparation of the modified polyurethane acrylate copolymer resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to diphenylmethane diisocyanate and reacted at 85°C for 3 hours, followed by the addition of 2,2-bis(hydroxymethyl)propionic acid and butanediol, and the reaction continued for another 3 hours. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence, and the mixture was heated to 70°C and reacted for 2 hours. After that, an appropriate amount of NaOH solution was added, the temperature was maintained at 55°C, and the mixture was kept warm for 1.5 hours. PU, emulsifier, and water were then mixed and placed in a four-neck flask. After uniform stirring, a butyl acrylate solution containing azobisisobutyronitrile initiator was added, and the mixture was pre-emulsified for a certain period of time. The mixture was polymerized at 85°C for 3.5 hours, heated to 95°C, reacted for 2 hours, and cooled to room temperature to obtain a modified polyurethane acrylate copolymer resin.

[0040] The antistatic layer coating solution was prepared as follows: 12.5 g of aqueous polyaniline dispersion HS0394 (Foshan Nanhai Jiangshun Chemical Products, 5% polyaniline by weight), 12.5 g of modified polyurethane acrylic copolymer resin, 72.5 g of water, and 2.5 g of oxazoline crosslinker WS-700 (Youon Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0041] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and stretched longitudinally at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, then stretched transversely to 3 times its original size, heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 1 μm. [Example]

[0042] The preparation of the modified polyurethane acrylate copolymer resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to toluene diisocyanate and reacted at 80°C for 2 hours. Then, 2,2-bis(hydroxymethyl)propionic acid and butanediol were added and the reaction continued for another 2 hours. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence. The mixture was heated to 60°C and reacted for 1.5 hours. Then, an appropriate amount of NaOH solution was added, the temperature was maintained at 50°C, and the mixture was kept warm for 1 hour. Then, PU, ​​emulsifier, and water were mixed and placed in a four-neck flask. After uniform stirring, a butyl acrylate solution containing azobisisobutyronitrile initiator was added. The mixture was pre-emulsified for a certain period of time and polymerized at 80°C for 3 hours. The mixture was then heated to 90°C and reacted for 1.5 hours. The mixture was then cooled to room temperature to obtain a modified polyurethane acrylate copolymer resin.

[0043] The antistatic layer coating solution was prepared as follows: 20 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight percentage of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 20 g of modified polyurethane acrylic copolymer resin, 55 g of water, and 5 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0044] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and stretched longitudinally at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, then stretched transversely to 3 times its original size, heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 2 μm. [Example]

[0045] The preparation of the modified polyurethane acrylate copolymer resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to 4,4'-dicyclohexylmethane diisocyanate and reacted at 77.5°C for 1.5 hours, followed by the addition of 2,2-bis(hydroxymethyl)propionic acid and butanediol and the reaction continued for 1.5 hours. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence, and the mixture was heated to 55°C and reacted for 1.25 hours. After that, an appropriate amount of NaOH solution was added and the temperature was maintained at 47.5°C for 0.75 hours. PU, emulsifier, and water were mixed and placed in a four-neck flask. After uniform stirring, a butyl acrylate solution containing azobisisobutyronitrile initiator was added and the mixture was pre-emulsified for a certain period of time. The mixture was polymerized at 77.5°C for 2.75 hours, heated to 87.5°C, reacted for 1.25 hours, and cooled to room temperature to obtain a modified polyurethane acrylate copolymer resin.

[0046] The antistatic layer coating solution was prepared as follows: 16.25 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight ratio of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 16.25 g of modified polyurethane acrylic copolymer resin, 64.25 g of water, and 3.25 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0047] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and longitudinally stretched at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, and then transversely stretched 3 times, further heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 1.5 μm. [Example]

[0048] The preparation of the modified polyurethane acrylate copolymer resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to isophorone diisocyanate and reacted at 82.5°C for 2.5 hours. Then, 2,2-bis(hydroxymethyl)propionic acid and butanediol were added and the reaction continued for another 2.5 hours. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence. The mixture was heated to 65°C and reacted for 1.75 hours. After that, an appropriate amount of NaOH solution was added and the temperature was maintained at 52.5°C for 1.25 hours. PU, emulsifier, and water were mixed and placed in a four-neck flask. After uniform stirring, a butyl acrylate solution containing azobisisobutyronitrile initiator was added. The mixture was pre-emulsified for a certain period of time and polymerized at 82.5°C for 3.25 hours. The mixture was then heated to 92.5°C and reacted for 1.75 hours. The mixture was then cooled to room temperature to obtain a modified polyurethane acrylate copolymer resin.

[0049] The antistatic layer coating solution was prepared as follows: 8.75 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight ratio of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 8.75 g of modified polyurethane acrylic copolymer resin, 82.25 g of water, and 1.25 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0050] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and longitudinally stretched at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, and then transversely stretched 3 times, further heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 0.5 μm.

[0051] Comparative Example 1 The antistatic layer coating solution was prepared as follows: 8.75 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight ratio of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 8.75 g of polyurethane resin, 82.25 g of water, and 1.25 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0052] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and longitudinally stretched at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, and then transversely stretched 3 times, further heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 0.5 μm.

[0053] Comparative Example 2 The antistatic layer coating solution was prepared as follows: 5g of aqueous polythiophene dispersion A200 (Aikefa, 5% by weight of polythiophene in aqueous polythiophene dispersion), 5g of acrylic resin, 89.9g of water, and 0.1g of oxazoline crosslinker WS-700 (Youn Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0054] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and stretched longitudinally at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, then stretched transversely to 3 times its original size, heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 5 nm.

[0055] Comparative Example 3 The antistatic layer coating solution was prepared as follows: 20 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight ratio of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 10 g of polyurethane resin, 10 g of acrylic resin, 55 g of water, and 5 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0056] The production of the antistatic film is as follows: First, crystallized and dried polyester chips were fed into a corresponding extrusion system, melted and extruded, and tape-cast onto a rotating cooling roller. After cooling, the cast sheet was preheated and stretched longitudinally at a longitudinal stretch ratio of 3. The prepared antistatic layer coating solution was applied to one or both sides of the longitudinally stretched film by one of gravure coating, wire coating, and dip coating. The film coated with the antistatic layer coating solution was heated and dried, then stretched transversely to 3 times its original size, heat-set, and wound up to obtain an antistatic film with a dry coating thickness of 2 μm.

[0057] Comparative Example 4 The preparation of the modified polyurethane acrylate composite resin is as follows: Vacuum-dehydrated polyoxypropylene glycol was added to isophorone diisocyanate and reacted at 82.5°C for 2.5 hours. 2,2-bis(hydroxymethyl)propionic acid and butanediol were added and the reaction continued for another 2.5 hours. Next, diethylenetriamine, epichlorohydrin, and maleic anhydride acetone solutions were added dropwise in sequence. The mixture was heated to 65°C and reacted for 1.75 hours. An appropriate amount of NaOH solution was added, and the temperature was maintained at 52.5°C for 1.25 hours. PU, emulsifier, and water were then mixed and placed in a four-neck flask. After uniform stirring, a butyl acrylate solution containing azobisisobutyronitrile initiator was added. The mixture was pre-emulsified for a certain period of time and polymerized at 82.5°C for 3.25 hours. The mixture was then heated to 92.5°C and reacted for 1.75 hours. The mixture was then cooled to room temperature to obtain a modified polyurethane-acrylate composite emulsion.

[0058] The antistatic layer coating solution was prepared as follows: 16.25 g of aqueous carbon nanotube dispersion ML1293 (crystalline antibiotic, the weight ratio of carbon nanotubes in the aqueous carbon nanotube dispersion was 5%), 16.25 g of modified polyurethane acrylic composite resin, 64.25 g of water, and 3.25 g of oxazoline crosslinker WS-700 (Yuen Chemical) were prepared. The mixture was uniformly dispersed using a high-shear emulsifier to prepare an antistatic layer coating solution.

[0059] The production of the antistatic film is as follows: The prepared antistatic layer coating solution was applied to one or both sides of a film (the coating and the film were not stretched synchronously), cured, and wound up to obtain an antistatic film with a dry coating thickness of 5 nm.

[0060] The test methods for each performance are as follows: (1) Surface resistance (antistatic layer): Measured in accordance with GB / T33398. (2) The weather resistance test method was as follows: The manufactured antistatic film was cut into A4 size pieces and left in a constant temperature and humidity environment (85°C, 85% RH) for 200 hours and 500 hours, respectively, and then the surface resistance was measured according to GB / T33398.

[0061] The test results are shown in Table 1. [Table 1]

[0062] As can be seen from the comparison between Comparative Example 1 and Example 5, in Example 5, after using the modified polyurethane acrylic resin, compared with the normal polyurethane, the carbon tube coating was applied online and biaxially stretched, and the surface resistance was 10 6 Ω, and the carbon tube coating liquid has better weather resistance.

[0063] As can be seen from the comparison between Comparative Example 2 and Example 1, in Comparative Example 2, after using unmodified acrylic resin, the polythiophene polymer conductive coating was applied online and biaxially stretched to form a surface resistance of >10 6 Ω, but after 200h and 500h aging tests, the surface resistance was >10 12 Ω, the resistance changed significantly, and the weather resistance was poor.

[0064] As can be seen from the comparison between Comparative Example 3 and Example 3, in Comparative Example 3, a compound of polyurethane resin and acrylic resin was used, and the surface resistance was >1012 It became Omega.

[0065] As can be seen from the comparison between Comparative Example 4 and Example 4, the antistatic coating of Comparative Example 4 was not synchronously stretched transversely with the substrate, but the surface resistance was 10 6 Ω, provided that the surface resistance after 200h aging test is 10 9 After the aging test, the surface resistance was >10 9 Ω, the resistance changed significantly, and the weather resistance was poor.

[0066] As can be seen from a comparison between Example 3 and Example 5, the coating of Example 3 contains more modified polyurethane acrylic resin than Example 5, which improves the dispersibility of carbon nanotubes and the antistatic effect.

[0067] As can be seen from Table 1, the antistatic films prepared in the examples of the present invention have significantly improved antistatic performance and weather resistance of the antistatic layer compared to the antistatic films prepared in the comparative examples. This shows that the antistatic polyester films of the present invention not only have excellent antistatic performance, but also have excellent coating solution stability, good continuous processing performance, and good application prospects.

[0068] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

Claims

1. An antistatic film comprising a substrate (1) and an antistatic layer (2) provided on at least one surface of the substrate (1), the antistatic layer (1) and the substrate being synchronously stretched laterally and fixed together, the antistatic layer comprising a conductive material, a modified polyurethane acrylate copolymer resin, a crosslinking agent, and deionized water.

2. The antistatic layer (2) is conductive material 5% to 20% by weight, 5% to 20% by weight of a modified polyurethane acrylate copolymer resin; 0.1% to 5% by weight of a crosslinker; 2. The antistatic film of claim 1, comprising 55% to 89.9% by weight of deionized water.

3. The method for producing the modified polyurethane acrylate copolymer resin includes: Add isocyanate to polyol and heat to react. A chain extender is added and reacted. Diethylenetriamine, a small molecule crosslinker, and an acetone solution of maleic anhydride are added in order and reacted by heating. Add sodium hydroxide solution and keep warm. An emulsifier and water are added and stirred, a butyl acrylate solution containing an initiator is added, and the mixture is heated to react. Cool to obtain the modified polyurethane acrylate copolymer resin.

3. The antistatic film according to claim 1 or 2, wherein

4. 4. The antistatic film according to claim 3, wherein the isocyanate comprises at least one of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, 4,4'-dicyclohexylmethane, and diisocyanate.

5. 4. The antistatic film according to claim 3, wherein the initiator is azobisisobutyronitrile.

6. 4. The antistatic film of claim 3, wherein the small molecule crosslinking agent is trimethylolpropane.

7. 3. The antistatic film according to claim 1, wherein the thickness of the antistatic layer (2) is 5 nm to 2 μm.

8. 3. The antistatic film according to claim 1, wherein the conductive material is one or more of carbon nanotube powder, polythiophene particles, polyaniline powder, and conductive metal; or the conductive material is one or more of polythiophene dispersion, carbon nanotube dispersion, polyaniline dispersion, silver paste, and silver wire.

9. 3. The antistatic film according to claim 1, wherein the crosslinking agent is any one of oxazolines, isocyanates, nitrogen-containing pyridines, and melamines.

10. A method for producing the antistatic film according to any one of claims 1 to 9, comprising the steps of: feeding a substrate feedstock into an extrusion system, melting the feedstock, and extruding the substrate melt; forming the substrate melt into an amorphous cast thick sheet on a chill roll; a step of preheating the cooled cast thick sheet and longitudinally stretching it 3.0 to 5.0 times to obtain a film sheet; applying an antistatic layer coating liquid to one side of the film sheet; a step of preheating the film sheet coated with the antistatic layer coating liquid and then stretching it laterally at a ratio of 3.0 to 5.0 to obtain a film; heat-setting the film to obtain an antistatic film; A method for producing an antistatic film, comprising:

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