An antistatic film and a preparation method thereof

Abstract

The present invention discloses an antistatic film and a preparation method thereof, belonging to the technical field of polymer processing and modification. The method of the present invention first performs compatibilization modification on polymer A, polymer B and polyether ester amide, and combines the flat film biaxial stretching process to transform polymer B into a large number of two-dimensional sheet structures. Under the action of biaxial stretching, the two-dimensional filler graphene is parallelly oriented on the film surface, and a synergistic effect is generated between polymer B and graphene, greatly increasing the diffusion path of gas small molecules in the film, and reducing its gas permeability coefficient by 1-2 orders of magnitude. In addition, a continuous conductive network is formed by bridging between the two-dimensional filler graphene and polyether ester amide, which can better conduct and leak static charges, so that the surface resistivity of the film reaches 10 to the eighth power to 10 to the ninth power. The solution provided by the present invention effectively enhances various properties of the film, greatly enhances its service life and stability, and effectively enhances the functionality and practicality of the film.

Description

Technical Field

[0001] The present invention relates to an antistatic film and a preparation method thereof, belonging to the technical field of polymer processing and modification. Background Art

[0002] Polyester films are usually colorless, transparent, shiny, and have high toughness. Compared with other plastic films, they have advantages such as high relative density, high tensile strength, and moderate elongation, and are widely used in packaging materials. However, due to the generally poor gas barrier properties of polyester films to water, oxygen and other gases, as packaging materials, the packaged products are easily affected by moisture, oxygen and microorganisms and change. And because the film is exposed to the outdoor environment for a long time during use, due to the electrostatic adsorption effect, dust will adhere to the film, thus reducing the use effect of the product. Therefore, people have been committed to obtaining an antistatic and high-barrier functional film. At present, the barrier modification of polyester mainly focuses on polymer / polymer blends or polymer / inorganic nanoparticle blends. Due to the microtopography of the sea-island structure in the polymer / polymer blend system, the barrier effect on small molecule gases is not good. In the polymer / inorganic nanoparticle blend system, the layered microtopography of the filler is beneficial to extend the gas penetration path and time. However, the inorganic nanoparticles are prone to agglomeration in the matrix, and problems such as random dispersion limit the improvement of their barrier properties and mechanical properties.

[0003] In the existing technology, there are mainly two processing techniques for improving the antistatic performance of polyester materials. One is to add an oil-based antistatic agent to achieve the antistatic effect of the film. The disadvantage is that there will be an oil bleeding phenomenon on the surface layer, and it can only be used for short-term turnover; the other is to coat the antistatic agent on the surface of the film to achieve the antistatic effect, but this process can only ensure an effective antistatic effect within 6 months, and there is no antistatic feature after more than 6 months. Therefore, in view of the current situation of the existing preparation of polyester films, it is of great significance to develop a packaging material with a simple process, a permanent antistatic effect, and easy control of the formation of the internal barrier structure of the film. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an antistatic film and a preparation method thereof, which have excellent gas barrier properties.

[0005] To achieve the above object, the present invention provides a preparation method of an antistatic film, the method comprising:

[0006] According to the weight part ratio, 40-98 parts of polymer A, 1-30 parts of polymer B, 1-30 parts of polyether ester amide, 3-5 parts of two-dimensional filler, 0.01-10 parts of compatibilizer, and 0-10 parts of functional auxiliary agent are melt-processed, and then subjected to biaxial stretching by a flat film biaxial stretching process or traction and winding by a casting process to obtain an antistatic and high-barrier film;

[0007] The polymer A is at least one of polyethylene terephthalate, polyamide, polylactic acid, lactic acid-based copolymer, polyethylene, polypropylene, and vinyl copolymer; the polymer B is at least one of glycolic acid homopolymer, glycolic acid-based copolymer, polyvinyl alcohol, and vinyl alcohol-based copolymer.

[0008] In one embodiment of the present invention, a film or sheet is biaxially stretched at temperature 1 by using melt processing combined with a flat film biaxial stretching process, and then heat-treated at temperature 2 to obtain an antistatic high-barrier film;

[0009] Among them, temperature 1 is 10 - 120°C above the glass transition temperature of polymer A, and temperature 2 is 100 - 160°C.

[0010] In one embodiment of the present invention, temperature 1 is further preferably 10 - 20°C above the glass transition temperature of polymer A.

[0011] In one embodiment of the present invention, melt processing includes melt extrusion, pelletizing, and then forming a sheet by using a casting machine; after melt processing, the sheet is subjected to a flat film biaxial stretching process to obtain a film.

[0012] In one embodiment of the present invention, the casting machine is controlled to prepare a sheet under the conditions of a screw temperature of 260°C and a screw speed of 10 rpm.

[0013] In one embodiment of the present invention, the biaxial stretching ratio in the flat film biaxial stretching process is preferably 4 - 10 times. Preferably 5 - 10 times. More preferably 8 times.

[0014] In one embodiment of the present invention, after melt extrusion and pelletizing, the casting process is used for traction and winding.

[0015] In one embodiment of the present invention, the processing temperature of the casting process is 100 - 260°C, and the draw ratio of traction and winding is 2 - 15 times.

[0016] In one embodiment of the present invention, the processing temperature of melt extrusion is 100 - 260°C, and the screw speed is 300 rpm.

[0017] In one embodiment of the present invention, the polyether ester amide is at least one of polyethylene oxide and polyether ester imide; specifically, MH2030 can be selected.

[0018] In one embodiment of the present invention, by weight ratio, 40 - 80 parts of polymer A, 10 - 30 parts of polymer B, 10 - 30 parts of polyether ester amide, 3 - 5 parts of two-dimensional filler, 0.01 - 10 parts of compatibilizer, and 0 - 10 parts of functional additive. Further, the specific weight ratio of polymer A, polymer B, and polyether ester amide can be: 40 parts of polymer A, 30 parts of polymer B, and 30 parts of polyether ester amide; or 60 parts of polymer A, 20 parts of polymer B, and 20 parts of polyether ester amide; or 80 parts of polymer A, 10 parts of polymer B, and 10 parts of polyether ester amide.

[0019] In one embodiment of the present invention, the two-dimensional filler includes graphene with a sheet diameter of 2 - 3 μm and a specific surface area of 100 - 500 m 2 / g.

[0020] In one embodiment of the present invention, the compatibilizer can specifically be: ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, multi-epoxy functional compatibilizer ADR, or diisocyanate compatibilizer MDI.

[0021] In one embodiment of the present invention, the functional additive includes at least one of a nucleating agent, a hydrolysis inhibitor, an antioxidant, a lubricant, a chain extender, and a light aging inhibitor.

[0022] In the melt blending of the present invention, first, a compatibilizer is added to compatibilize and modify polymer A, high-barrier polymer B, and antistatic polyether ester amide, so that pores are not generated between the two phases during the biaxial stretching process.

[0023] The present invention provides an antistatic film by using the above method.

[0024] The present invention also provides the application of the above antistatic film in packaging materials.

[0025] Compared with the prior art, the present invention mainly has the following outstanding advantages.

[0026] (1) In the present invention, by controlling the biaxial stretching conditions, a large number of two-dimensional sheet-like structures are formed in polymer B, and the two-dimensional filler graphene is oriented parallel to the film surface. A synergistic effect is generated between polymer B and graphene, effectively increasing the diffusion path of gas small molecules in the film, and reducing its gas permeability coefficient by 1 - 2 orders of magnitude.

[0027] (2) In the present invention, by controlling the orderly arrangement of graphene, a conductive network is formed by bridging between graphene and antistatic polyether ester amide, which can better conduct and leak static charges.

[0028] (3) The antistatic high-barrier film of the present invention has a permanent antistatic property, and the surface resistivity can be as low as 10 to the eighth power to 10 to the ninth power, which can avoid short circuits caused by dust pollution and is beneficial to extending the service life of products. Detailed implementation manners

[0029] The present invention will be described in detail below in conjunction with examples and comparative examples. It should be noted that the following examples are only for further illustration of the present invention and should not limit the scope of the present invention.

[0030] Example 1

[0031] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 5 parts of graphene, and 0.7 part of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, the screw temperature was 260 °C, and the screw speed was 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C (20 °C above the glass transition temperature), the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0032] Example 2

[0033] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 3 parts of graphene, and 0.7 part of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, the screw temperature was 260 °C, and the screw speed was 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C, the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0034] Example 3

[0035] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 3 parts of graphene, and 0.7 parts of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, with the screw temperature at 260 °C and the screw speed at 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 5 times, and the longitudinal stretching ratio was 5 times.

[0036] Example 4

[0037] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 3 parts of graphene, and 3 parts of ethylene-methyl acrylate-glycidyl methacrylate copolymer were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, with the screw temperature at 260 °C and the screw speed at 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 5 times, and the longitudinal stretching ratio was 5 times.

[0038] Example 5

[0039] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 3 parts of graphene, and 0.7 parts of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were obtained an antistatic high-barrier film through the traction and winding of a casting machine, where the processing temperature was 260 °C and the draw ratio was 5 times.

[0040] Example 6

[0041] After drying, 40 parts of polyethylene terephthalate, 30 parts of polyglycolic acid, 30 parts of polyether ester amide, 5 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C, and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, with the screw temperature being 260 °C and the screw speed being 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. Among them, the stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0042] Example 7

[0043] After drying, 98 parts of polyethylene terephthalate, 1 part of polyglycolic acid, 1 part of polyether ester amide, 5 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C, and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, with the screw temperature being 260 °C and the screw speed being 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. Among them, the stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0044] Example 8

[0045] After drying, 80 parts of polyethylene terephthalate, 10 parts of ethylene-vinyl alcohol copolymer, 10 parts of polyether ester amide, 5 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C, and the screw speed was 300 rpm. The dried pellets were made into thin sheets through a casting machine, with the screw temperature being 260 °C and the screw speed being 10 rpm. The thin sheets were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. Among them, the stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0046] Example 9

[0047] 80 parts of dried polypropylene, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 5 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin films through a casting machine. The screw temperature was 260 °C and the screw speed was 10 rpm. The thin films were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C, the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0048] Comparative Example 1

[0049] 100 parts of dried polyethylene terephthalate were processed by casting using a casting machine. The screw temperature was 260 °C and the screw speed was 10 rpm.

[0050] Comparative Example 2

[0051] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were stirred in a high-speed mixer for 2 min, and then put into an extruder for continuous melt-extrusion and granulation. The screw temperature was 260 °C and the screw speed was 300 rpm. A polyethylene terephthalate-based film was obtained using a casting machine at a screw temperature of 260 °C and a screw speed of 10 rpm.

[0052] Comparative Example 3

[0053] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 3 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 were stirred in a high-speed mixer for 2 min, and then put into an extruder for continuous melt-extrusion and granulation. The screw temperature was 260 °C and the screw speed was 300 rpm. A polyethylene terephthalate-based film was obtained using a casting machine at a screw temperature of 260 °C and a screw speed of 10 rpm.

[0054] Comparative Example 4

[0055] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, and 10 parts of polyether ester amide are premixed in a high-speed mixer for 2 min and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin films through a casting machine. The screw temperature is 260 °C and the screw speed is 10 rpm. The thin films are biaxially stretched by a flat film biaxial stretching process and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0056] Comparative Example 5

[0057] Referring to Example 1, no antistatic agent and two-dimensional filler are added:

[0058] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 are premixed in a high-speed mixer for 2 min and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin films through a casting machine. The screw temperature is 260 °C and the screw speed is 10 rpm. The thin films are biaxially stretched by a flat film biaxial stretching process and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0059] Comparative Example 6

[0060] Referring to Example 1, no antistatic agent is added:

[0061] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 5 parts of graphene, and 0.7 parts of multi-epoxy functional group compatibilizer ADR4468 are premixed in a high-speed mixer for 2 min and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin films through a casting machine. The screw temperature is 260 °C and the screw speed is 10 rpm. The thin films are biaxially stretched by a flat film biaxial stretching process and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0062] Comparative Example 7

[0063] Referring to Example 1, the dosage of the antistatic agent is adjusted:

[0064] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 40 parts of polyether ester amide, 5 parts of graphene, 0.7 part of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin films through a casting machine, with the screw temperature at 260 °C and the screw speed at 10 rpm. The thin films were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature was 90 °C, the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0065] Comparative Example 8

[0066] Referring to Example 1, adjust the dosage of the antistatic agent:

[0067] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 1 part of polyether ester amide, 5 parts of graphene, 0.7 part of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin films through a casting machine, with the screw temperature at 260 °C and the screw speed at 10 rpm. The thin films were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature was 90 °C, the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0068] Comparative Example 9

[0069] Referring to Example 1, adjust the dosage of the two-dimensional material:

[0070] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 10 parts of graphene, 0.7 part of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min, and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin films through a casting machine, with the screw temperature at 260 °C and the screw speed at 10 rpm. The thin films were biaxially stretched using a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature was 90 °C, the heat treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0071] Comparative Example 10

[0072] Referring to Example 1, adjust the amount of two-dimensional material:

[0073] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, 1 part of graphene, and 0.7 part of multi-epoxy functional group compatibilizer ADR4468 are premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin sheets by a casting machine, the screw temperature is 260 °C, and the screw speed is 10 rpm. The thin sheets are biaxially stretched by a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0074] Comparative Example 11

[0075] 40 parts of dried polyethylene terephthalate, 30 parts of polyglycolic acid, 30 parts of polyether ester amide, and 0.7 part of multi-epoxy functional group compatibilizer ADR4468 are premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin sheets by a casting machine, the screw temperature is 260 °C, and the screw speed is 10 rpm. The thin sheets are biaxially stretched by a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0076] Comparative Example 12

[0077] 60 parts of dried polyethylene terephthalate, 20 parts of polyglycolic acid, 20 parts of polyether ester amide, and 0.7 part of multi-epoxy functional group compatibilizer ADR4468 are premixed in a high-speed mixer for 2 min, and then melt-extruded and granulated through a twin-screw extruder. The screw temperature is 260 °C and the screw speed is 300 rpm. The dried pellets are made into thin sheets by a casting machine, the screw temperature is 260 °C, and the screw speed is 10 rpm. The thin sheets are biaxially stretched by a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film, where the stretching temperature is 90 °C, the heat treatment temperature is 160 °C, the transverse stretching ratio is 8 times, and the longitudinal stretching ratio is 8 times.

[0078] Comparative Example 13

[0079] 80 parts of dried polyethylene terephthalate, 10 parts of polyglycolic acid, 10 parts of polyether ester amide, and 0.7 parts of multi-epoxy functional compatibilizer ADR4468 were premixed in a high-speed mixer for 2 min and then melt-extruded and pelletized through a twin-screw extruder. The screw temperature was 260 °C and the screw speed was 300 rpm. The dried pellets were made into thin films through a casting machine. The screw temperature was 260 °C and the screw speed was 10 rpm. The thin films were biaxially stretched by a flat film biaxial stretching process, and then heat-treated and cooled to room temperature to obtain an antistatic high-barrier film. The stretching temperature was 90 °C, the heat-treatment temperature was 160 °C, the transverse stretching ratio was 8 times, and the longitudinal stretching ratio was 8 times.

[0080] After the films obtained in the examples and comparative examples were fully dried, an oxygen transmission rate tester was used to test the oxygen transmission coefficient of the materials according to the standard method of GB / T 1038. The test conditions were 23 °C, relative humidity 0%, sample thickness 20 μm, and test area 38.48 cm 2 ; The surface resistivity of the film was tested by a surface resistivity tester, and the test results are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] As can be seen from the data in Table 1, polyethylene terephthalate has poor oxygen barrier performance and is insulating (Comparative Example 1). Melting and blending polyethylene terephthalate with polyglycolic acid and polyether ester amide can improve the barrier performance and antistatic performance to a certain extent, but the improvement effect is limited (Comparative Example 2). By changing the contents of polyether ester amide and two-dimensional filler graphene (Comparative Examples 3-10), the barrier performance and antistatic performance of the film are improved to a certain extent, but they are still far from those of the present invention. This is because the free volume between the molecular chains of polyether ester amide is relatively large, and small molecule gases are easy to pass through, resulting in a decrease in the barrier performance of the material. Although the two-dimensional filler graphene can improve the barrier performance of the material, when the content is relatively high, it is easy to agglomerate and form voids in the material, resulting in a decrease in the barrier performance (Comparative Example 9). In the method disclosed in the present invention (such as Example 1), the blend sheet of polyethylene terephthalate, polyglycolic acid and polyether ester amide is biaxially stretched. By controlling the stretching temperature and stretching ratio, the polymer as the dispersed phase is transformed from a zero-dimensional spherical structure into a two-dimensional sheet structure, which greatly increases the diffusion path of small molecule gases. And the polyether ester amide as the antistatic agent can better form a continuous conductive network under the action of biaxial stretching, improving the leakage ability of static charges. Considering the comparative examples and examples together, adding the two-dimensional filler graphene can produce a synergistic effect with the polymer B in the sheet structure, further improving the barrier performance of the material. And it is easier to form a conductive network by bridging between the two-dimensional filler graphene and the antistatic agent polyether ester amide, significantly improving the conductive performance of the material, making the surface resistivity of the film as low as 10 to the eighth power. In addition, an antistatic high-barrier film prepared by the present invention can also be processed and prepared by the method proposed in the present invention (such as Example 8), effectively enhancing the barrier performance and antistatic performance of the film.

[0085] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A method for preparing an antistatic film, characterized in that, the method comprises: According to the weight parts ratio, melt-process 40-98 parts of polymer A, 1-30 parts of polymer B, 1-30 parts of polyether ester amide, 3-5 parts of two-dimensional filler, 0.01-10 parts of compatibilizer, and 0-10 parts of functional additive, and then perform biaxial stretching by a flat film biaxial stretching process or perform traction and winding by a casting process to obtain an antistatic high-barrier film; The polymer A is at least one of polyethylene terephthalate and polypropylene; the polymer B is polyvinyl alcohol or ethylene-vinyl alcohol copolymer; the two-dimensional filler is graphene.

2. The method according to claim 1, characterized in that, Perform biaxial stretching on the film or sheet at temperature 1 by using melt processing combined with a flat film biaxial stretching process, and then perform heat treatment at temperature 2 to obtain an antistatic high-barrier film; wherein, temperature 1 is 10-120 °C above the glass transition temperature of polymer A, and temperature 2 is 100-160 °C.

3. The method according to claim 1, characterized in that, The melt processing includes melt extrusion, granulation, and then forming into a sheet by using a casting machine; after the melt processing, the sheet is subjected to a flat film biaxial stretching process to obtain a film; the biaxial stretching ratio in the flat film biaxial stretching process is 4-10 times.

4. The method according to claim 1, characterized in that, After melt extrusion and granulation, perform traction and winding by using a casting process; the processing temperature of the casting process is 100-260 °C, and the draw ratio of traction and winding is 2-15 times.

5. The method according to claim 1, characterized in that, According to the weight parts ratio, 40-80 parts of polymer A, 10-30 parts of polymer B, 10-30 parts of polyether ester amide, 3-5 parts of two-dimensional filler, 0.01-10 parts of compatibilizer, and 0-10 parts of functional additive.

6. The method according to any one of claims 1-5, characterized in that, The specific compatibilizer options are: ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, multi-epoxy functional compatibilizer ADR, diisocyanate compatibilizer MDI; the functional additive includes at least one of a nucleating agent, an anti-hydrolysis agent, an antioxidant, a lubricant, a chain extender, and an anti-photoaging agent.

7. An antistatic film prepared by the method according to any one of claims 1-6.

8. The application of the antistatic film according to claim 7 in packaging materials.

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