CN211989531U

CN211989531U - Multilayer film

Info

Publication number: CN211989531U
Application number: CN201922492530.3U
Authority: CN
Inventors: 林小锋
Original assignee: Suzhou Puxi Environmental Protection Technology Co ltd
Current assignee: Suzhou Puxi Environmental Protection Technology Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-11-24
Anticipated expiration: 2029-12-31

Abstract

The application discloses a multilayer film and a preparation method thereof. The multilayer film includes: the protective layer comprises a substrate and one or more barrier layers arranged on the substrate, wherein protective layers are arranged on two surfaces of at least one barrier layer in the one or more barrier layers. Because the protective layers are arranged on the two surfaces of at least one barrier layer, the barrier layer is protected by the protective layers arranged on the two surfaces, and even if the barrier layer is in special environments such as acid, alkali or high temperature, the barrier layer is not easy to corrode or oxidize to damage, so that the problems in the prior art are solved.

Description

Multilayer film

Technical Field

The application relates to the technical field of material processing, in particular to a multilayer film.

Background

With the development of society, multilayer films are generally required in the sealing process of food, beverage bottles, pharmaceuticals, optical and electronic industries, etc. Existing multilayer films typically include a substrate and a barrier layer disposed on a surface of the substrate, and may provide hermetic protection primarily through the barrier layer. However, since the multilayer film is widely used, the barrier layer in the multilayer film is easily damaged by corrosion or oxidation in some environments, such as an acid or alkaline environment, a high-temperature environment, and the like, thereby affecting the performance of the multilayer film.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a multilayer film, which is used for solving the problem that a barrier layer in the multilayer film in the prior art is easily corroded or oxidized and damaged.

Embodiments provide a multilayer film, comprising: the protective layer comprises a substrate and one or more barrier layers arranged on the substrate, wherein protective layers are arranged on two surfaces of at least one barrier layer in the one or more barrier layers.

Preferably, the protective layer specifically includes: an oxidation resistant layer, an acid resistant layer, a base resistant layer, a chemical solvent resistant layer, and/or a high temperature resistant layer.

Preferably, the thickness of the protective layer is greater than or equal to 1 nanometer and less than or equal to 20 micrometers.

Preferably, the thickness of the substrate is greater than or equal to 5 micrometers and less than or equal to 250 micrometers.

Preferably, the thickness of the barrier layer is greater than or equal to 20 nanometers and less than or equal to 100 micrometers.

Preferably, the multilayer film comprises a substrate, a first oxidation resistant layer arranged on the surface of the substrate, a barrier layer arranged on the surface of the first oxidation resistant layer, and a second oxidation resistant layer arranged on the surface of the barrier layer.

Preferably, the multilayer film comprises a substrate, a first acid-resistant layer arranged on the surface of the substrate, a barrier layer arranged on the surface of the first acid-resistant layer, and a second acid-resistant layer arranged on the surface of the barrier layer.

The embodiment of the application adopts at least one technical scheme which can achieve the following beneficial effects:

by adopting the multilayer film provided by the embodiment of the application, in the structure of the multilayer film, because the protective layers are arranged on the two surfaces of at least one barrier layer, the barrier layer is protected by the protective layers arranged on the two surfaces, and even if the barrier layer meets special environments such as acidity, alkalinity or high temperature, the barrier layer is not easy to be corroded or oxidized to damage, so that the problem in the prior art is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic cross-sectional view of a multilayer film provided in an embodiment of the present disclosure;

fig. 2 is a schematic flow chart of a method for preparing a multilayer film according to an embodiment of the present disclosure;

fig. 3 is a schematic flow chart illustrating a specific process for preparing a protective layer in a multilayer film preparation method provided in an embodiment of the present application;

fig. 4 is a graph comparing the performance test of a multilayer film provided herein with two multilayer films in a comparative example, provided herein.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

As described above, in the conventional multilayer film, the barrier layer in the multilayer film is easily damaged by corrosion or oxidation in an environment such as an acid or alkaline environment, a high-temperature environment, or the like, thereby affecting the performance of the multilayer film. Based on this, the embodiments of the present application provide a multilayer film, which can be used to solve the problems in the prior art.

Fig. 1 is a schematic structural view of the multilayer film 10. The multilayer film 10 includes: a substrate 11, one or more barrier layers 12 disposed on the substrate, and of the one or more barrier layers, at least one barrier layer is provided with protective layers 13 on both surfaces.

In the structure of the multilayer film 10, the protective layers 13 are provided on both surfaces of at least one barrier layer 12, so that the barrier layer 12 is protected by the protective layers 13 provided on both surfaces, and even if it is subjected to a special environment such as acidic, alkaline, or high temperature, the barrier layer 12 is not easily damaged by corrosion or oxidation, thereby solving the problems in the prior art.

The substrate 11 is used to provide mechanical support and/or fluid flow paths, depending on the particular application. For example, for beverage bottle membranes, they are primarily used to provide a fluid flow path; for the electronics industry, sealing films are used primarily to provide mechanical support.

Also, the material of the substrate 11 may be organic and/or inorganic materials and mixtures thereof, for example, the substrate 11 may be a single block or a structure comprising a plurality of adjacent different blocks of material. The material of the substrate 11 may be a thermoplastic. The material of the substrate 11 may also be an organic polymeric resin such as, but not limited to, polyethylene terephthalate (PET), polyacrylate, polynorbornene, Polycarbonate (PC), silicone, epoxy, silicone-functionalized epoxy, or polyethylene naphthalate (PEN). The material of the further substrate 11 may be an ultra-thin glass layer or a metal foil or a fused ceramic, which has pores, pinholes or cracks. In addition, materials for the substrate 11 of different industry names may include Aclar, Vectran, Tefzel, Surlyn, PET ST504, PET mylar D, Armstrong A661, Tedlar, BRP-C, PVC Black, P0100, P0130, Kapton, PVC clear, Korad, EVA, PVB, TPU, DC Sy1guards, GE RTV 615. It should be noted that a combination of materials formed by a plurality of materials is also within the scope of the present application.

For example, the material of the substrate 11 may be a flexible organic material such as PET, so as to prepare a flexible organic substrate having flexibility; the material of the substrate 11 may also be a metal material such as gold, silver, copper, etc., so that the substrate 11 of the prepared metal foil is processed using these metal materials.

In addition, as for the thickness of the substrate 11, the thickness thereof may be greater than or equal to 5 micrometers and less than or equal to 250 micrometers. For example, the substrate 11 has a thickness of 5 microns, 10 microns, 15 microns, 20 microns, 30 microns, 50 microns, 80 microns, 100 microns, 110 microns, 135 microns, 150 microns, 170 microns, 195 microns, 200 microns, 220 microns, 230 microns, 250 microns, or other thickness values between 5 microns and 250 microns. In practical applications, the specific thickness of the substrate 11 can be determined according to specific application scenarios, the material of the substrate 11, and the like.

One or more barrier layers 12 disposed on the substrate, wherein the specific number of barrier layers 12, which may typically be 1. Of course, when high sealing performance is required, a plurality of barrier layers 12 may be provided, such as 2, 3, 4 or other numbers, and these barrier layers 12 may be stacked on one surface of the substrate 11. In addition, one or more barrier layers 12 may be provided on both surfaces of the substrate 11.

For example, substrate 11 includes a barrier layer 12 on one surface and no barrier layer 12 on the other surface; alternatively, substrate 11 includes one barrier layer 12 on one surface and one or more barrier layers 12 on the other surface; alternatively, the substrate 11 includes a plurality of barrier layers 12 on one surface, a plurality of barrier layers 12 on the other surface, and the like.

The thickness of any one of the barrier layers 12 can be greater than or equal to 20 nanometers and less than or equal to 150 micrometers. For example, the thickness of the barrier layer 12 is 20 nm, 70 nm, 100 nm, 15 nm, 300 nm, 500 nm, 700 nm, 1000nm, 1 micron, 3 microns, 8 microns, 15 microns, 19 microns, 25 microns, 30 microns, 35 microns, 45 microns, 60 microns, 80 microns, 90 microns, 100 microns, 110 microns, 135 microns, 150 microns or other thickness values between 20 nm and 150 microns.

The barrier layer 12 may be formed using a metallic or ceramic material and may be produced by dip coating, spray coating, physical vapor deposition, Chemical Vapor Deposition (CVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), magnetron sputtering, and/or reactive sputtering, or other means.

The material of the barrier layer 12 may be a nitride, such as silicon nitride. The material of the barrier layer 12 may also be an organic material, an inorganic material, a ceramic material, and any combination thereof.

For example, in one example, the material of barrier layer 12 is a recombination product from a reactive plasma species and deposited onto substrate 11. In another example, the material of the barrier layer 12 is an organic barrier coating material, which may generally include carbon and hydrogen, optionally with other elements such as oxygen, nitrogen, silicon, sulfur, and the like.

The material of the barrier layer 12 may also be an inorganic material, a ceramic material, typically including oxides, nitrides, borides, or any combination thereof of elements of groups IIA, IIIA, IVA, VA, VIA, VIIA, IB, or IIB; metals of group IIIB, IVB or VB or of rare earth elements. For example, a barrier layer 12 comprising a silicon carbide material may be deposited onto the substrate 11 by recombination of plasmas generated from silane and organic materials such as methane or xylene. Barrier layer 12 comprising a carbon-containing silicon oxide material may be deposited from a plasma generated from silane, methane and oxygen, or silane and propylene oxide, or from a plasma generated from an organosilicone precursor such as tetraethoxyorthosilicate (TE0S), Hexamethyldisiloxane (HMDS), Hexamethyldisilazane (HMDZ), or octamethylcyclotetrasiloxane (D4). Barrier layer 12 of silicon nitride-containing material may be deposited from a plasma generated from silane and ammonia. Barrier layer 12 comprising a carbon-containing aluminum oxynitride material may be deposited from a plasma generated, for example, from a mixture of aluminum tartrate and ammonia.

In some embodiments, the barrier layer 12 comprising an organic material can be deposited by known methods such as, but not limited to, spin coating, flow coating, blade coating, extrusion, gravure or microgravure printing methods, dip coating, spray coating, vacuum deposition, Chemical Vapor Deposition (CVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), or similar methods such as radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), expanding thermal-plasma chemical vapor deposition, reactive sputtering, electron-cyclotron resonance plasma enhanced chemical vapor deposition (ecrpevd), Inductively Coupled Plasma Enhanced Chemical Vapor Deposition (ICPECVD), sputter deposition, evaporation, layer deposition, or combinations thereof.

Since the metal material has high denseness, a metal material such as gold, silver, or aluminum may be used as the material of the barrier layer 12, and particularly, the barrier layer 12 may be formed by magnetron sputtering of these metal materials. Because the magnetron sputtering mode has low cost and simple operation, the manufacturing cost of the barrier layer 12 can be generally reduced.

The protective layer 13 included in the multilayer film 10 may be an oxidation resistant layer, an acid resistant layer, an alkali resistant layer, a chemical solvent resistant layer, and/or a high temperature resistant layer, according to actual specific needs. Wherein the anti-oxidation layer can be used to prevent the barrier layer 12 from being oxidized; the acid resistant layer can be used to prevent acidic corrosion of barrier layer 12; the alkali-resistant layer can be used to prevent the barrier layer 12 from being corroded by alkali; the refractory layer can be used to protect the barrier layer 12 from damage due to high temperatures.

For example, the multilayer film 10 has three barrier layers 12, which are a barrier layer a, a barrier layer B, and a barrier layer C, wherein two surfaces of the barrier layer a are both provided with an oxidation resistant layer, two surfaces of the barrier layer B are both provided with an acid resistant layer, two surfaces of the barrier layer C are both provided with a chemical solvent resistant layer, and the like, and at this time, two surfaces of the same barrier layer 12 are both provided with the same protective layer.

In addition, two surfaces of the same barrier layer 12 may also be provided with different protective layers, for example, the multilayer film 10 has two barrier layers 12, namely a barrier layer D and a barrier layer E, wherein one surface of the barrier layer D is provided with an anti-oxidation layer, the other surface is provided with an acid-resistant layer, one surface of the barrier layer E is provided with an alkali-resistant layer, and the other surface is provided with a high temperature-resistant layer.

In addition, as for the thickness of the protective layer 13, the greater the thickness of the protective layer 13, the better the protective effect on the barrier layer 12 to be protected, but the higher the corresponding production cost. The specific protective layer 13 thickness may be determined in combination with practical requirements such as acid-base environment, ambient temperature, cost requirements, etc. For example, the thickness of the protective layer 13 may be generally greater than or equal to 1 nm and less than or equal to 20 μm. For example, the thickness may be 1 nm, 5 nm, 47 nm, 80 nm, 120 nm, 150 nm, 180 nm, 200 nm, 260 nm, 310 nm, 380 nm, 400 nm, 450 nm, 500 nm, 537 nm, 600 nm, 680 nm, 730 nm, 810 nm, 870 nm, 930 nm, 1 micron, 3 micron, 5 micron, 8 micron, 10 micron, 12 micron, 15 micron, 17 micron, 19 micron, 20 micron or other thicknesses between 1 nm and 20 micron.

Based on the same concept as the multilayer film 10 provided in the embodiments of the present application, the embodiments of the present application also provide a method for producing a multilayer film, and for the production method, reference may be made to the embodiments of the structural portion of the multilayer film 10, if unclear. As shown in fig. 2, a specific flow diagram of the preparation method is shown, which comprises the following steps:

step S31: a substrate is provided.

The substrate may be any one of the substrates in the multilayer film 10, for example, a substrate made of PET material.

In addition, an additional barrier layer can be formed on the surface of the substrate made of PET material by the following method: polysulfone particles (the content of polysulfone is about 20%) are dispersed in Dimethylformamide (DMF), and then are continuously stirred and dissolved for 6 hours at about 60 ℃, then are filtered by a steel wire mesh with 0.38mm of sieve pores, and then are kept stand and defoamed for 24 hours under the condition of vacuum degree of 80kPa to obtain a clear polysulfone solution.

And uniformly coating the clarified polysulfone solution on a substrate prepared from a PET material by using a coating machine, and performing solidification and cleaning treatment in pure water at 25 ℃ to obtain a polysulfone ultrafiltration membrane substrate, wherein the polysulfone ultrafiltration membrane substrate comprises the substrate prepared from the PET material and an additional barrier layer prepared from polysulfone and arranged on the surface of the substrate.

Step S32: a first protective layer is formed on the provided substrate.

The first protective layer can be an anti-oxidation layer, an acid-resistant layer, an alkali-resistant layer, a chemical solvent-resistant layer or a high-temperature-resistant layer.

For example, when the first protection layer is an anti-oxidation layer, the first protection layer may be formed on the substrate in a manner as shown in fig. 3, which specifically includes the following steps:

step S321: preparing polyvinyl alcohol aqueous solution with preset concentration.

Wherein, the preset concentration can be more than or equal to 10% and less than or equal to 20% in mass fraction. For example, the preset concentration is 10% by mass, 12% by mass, 15% by mass, 17% by mass, 19% by mass, 20% by mass, or other mass between 10% and 20% by mass.

For example, 15 g of polyvinyl alcohol (PVA) having an alcoholysis degree of 98% and a polymerization degree of 1700 may be dispersed in 1000 g of deionized water, stirred, and heated until the PVA is dissolved, thereby obtaining an aqueous polyvinyl alcohol solution having a concentration of about 15%.

Step S322: adding glyoxal into polyvinyl alcohol aqueous solution with preset concentration.

After cooling the prepared PVA solution to room temperature, 10 g of glyoxal may be added under stirring.

Step S323: and adjusting the pH value of the mixed solution after the glyoxal is added to 1-3.

The pH of the mixed solution may be adjusted to 1 to 3 (for example, 2 or other values) by using dilute hydrochloric acid or the like.

Step S324: uniformly coating the mixed solution after the pH value is adjusted on the surface of the provided substrate for generating the first protective layer

The mixed solution after adjusting the pH value can be uniformly coated on the surface of the provided substrate surface, and the coating thickness can be about 0.1 micron to 10 microns.

Step S325: and (3) carrying out heat treatment on the uniformly coated substrate at 70-90 ℃ for 2-5 minutes to initiate a crosslinking reaction between polyvinyl alcohol and glyoxal so as to generate the first protective layer.

And (3) carrying out heat treatment on the uniformly coated substrate at 70-90 ℃ for 2-5 minutes, for example, placing the substrate in an oven at 80 ℃ for heat treatment for 3 minutes, wherein the heat treatment is used for initiating a crosslinking reaction between polyvinyl alcohol and glyoxal to generate a first protective layer.

Step S33: and generating a barrier layer on the surface of the first protective layer.

The barrier layer may be formed in any of the ways described in the above embodiments.

For example, an interfacial polymerization technique may be used to form a barrier layer on the surface of the first protective layer, which is first to prepare an m-phenylenediamine aqueous solution (MPD) with a mass fraction of about 5.0% and a trimesoyl chloride (TMC) cyclohexane solution with a mass fraction of about 0.3%, respectively. And then, placing the substrate in an MPD aqueous solution to be soaked for about 60 seconds, taking out the substrate, removing the excessive solution on the surface of the first protective layer, and then soaking the substrate in a TMC cyclohexane solution to perform interfacial polymerization reaction for about 40 seconds. After the reaction, the solution is left to stand in the indoor environment until the cyclohexane solution on the surface of the first protective layer is completely volatilized, and a barrier layer is generated.

The barrier layer may have a thickness of greater than or equal to 50nm and less than or equal to 1000 nm.

Step S34: and generating a second protective layer on the surface of the barrier layer.

The second protective layer and the first protective layer may be the same or different protective layers, and both the first protective layer and the second protective layer may be independently selected from any one of the following: an oxidation resistant layer, an acid resistant layer, an alkali resistant layer, a chemical solvent resistant layer, or a high temperature resistant layer.

For example, when the second protective layer is also an oxidation resistant layer, a polyvinyl alcohol aqueous solution with a preset concentration may be prepared, glyoxal is added to the polyvinyl alcohol aqueous solution with the preset concentration, the pH value of the mixed solution after the glyoxal is added is adjusted to 1-3, the mixed solution after the pH value is adjusted is uniformly coated on the surface of the provided substrate, the coating thickness of the substrate can be about 10 micrometers, and the uniformly coated substrate is subjected to heat treatment at 70-90 ℃ for about 15 minutes to initiate a crosslinking reaction between polyvinyl alcohol and glyoxal, so that the second protective layer is generated.

For example, when the second protective layer is also an acid-resistant layer or an alkali-resistant layer, the second protective layer may be prepared by using a graphene material, so as to prevent corrosion of acid or alkali to the barrier layer by using the acid-resistant and alkali-resistant characteristics of the graphene material.

The above is a specific content of the multilayer film and the multilayer film manufacturing method provided in the embodiments of the present application, and the following may further explain the effects thereof by combining specific examples.

Comparative example 1: the provided multilayer film includes a polysulfone ultrafiltration membrane substrate and a barrier layer disposed on a surface of the polysulfone ultrafiltration membrane substrate, wherein the barrier layer is the barrier layer generated by the interfacial polymerization reaction of MPD and TMC in step S33.

Comparative example 2: the provided multilayer film comprises a polysulfone ultrafiltration membrane substrate and a barrier layer arranged on the surface of the polysulfone ultrafiltration membrane substrate, wherein the barrier layer is the same as the barrier layer in the comparative example 1; in addition, in the multilayer film of comparative example 2, the outer surface of the barrier layer is provided with the second protective layer (antioxidation layer) as produced in step S34, in which the surface of the barrier layer close to the substrate is referred to as the inner surface and the other surface is referred to as the outer surface.

Example 1: the provided multilayer film comprises a polysulfone ultrafiltration membrane substrate and a barrier layer arranged on the surface of the polysulfone ultrafiltration membrane substrate, wherein the barrier layer is the same as the barrier layer in the comparative example 1; in addition, the first protective layer (oxidation resistant layer) produced in the manner of step S321 to step S325 is provided on the inner surface of the barrier layer, and the second protective layer (oxidation resistant layer) produced in step S34 is provided on the inner surface of the barrier layer.

The multilayer films provided in example 1, comparative example 1 and comparative example 2 were each subjected to oxidation treatment with an aqueous solution of sodium hypochlorite containing 1000ppm of available chlorine, and the performance of each of the multilayer films was measured, and the comparative data are shown in fig. 4:

in this FIG. 4, the ordinate is R relative salt rejection and the abscissa is ppm hours, wherein:

r relative desalination rate is 100 percent of desalination rate/initial desalination rate after sodium hypochlorite soaking treatment

Effective concentration of sodium hypochlorite solution in ppm h (1000ppm) soaking time (h)

As can be seen from fig. 4, the multilayer film provided in example 1 exhibited substantially no tendency of a large decrease in the relative salt rejection rate R with an increase in ppm hours on the abscissa. In contrast, the multilayer films provided in comparative examples 1 and 2 exhibited a sharp decrease in the relative salt rejection rate R with an increase in the abscissa ppm hour, so that example 1 was able to effectively protect the barrier layer against oxidation relative to comparative examples 1 and 2.

Example 2: the provided multilayer film comprises a polysulfone ultrafiltration membrane substrate, a first acid-resistant layer arranged on the surface of the polysulfone ultrafiltration membrane substrate, a barrier layer arranged on the surface of the first acid-resistant layer, and a second acid-resistant layer arranged on the surface of the barrier layer.

The first acid-resistant layer can be formed on the surface of the polysulfone ultrafiltration membrane substrate by the following method: weighing 15 g of PVA with alcoholysis degree of 98% and polymerization degree of 1700, dispersing the PVA in 1000 g of pure water, stirring and heating until the PVA is completely dissolved, cooling the obtained PVA solution to room temperature, adding 10 g of glyoxal under the stirring condition, and adjusting the pH value of the solution to 2 by using dilute hydrochloric acid to obtain a PVA aqueous solution; weighing 0.5 g of graphene oxide powder, placing the graphene oxide powder in 1000 g of pure water, and performing ultrasonic dispersion until the solution does not settle to obtain a graphene aqueous dispersion; and mixing the prepared PVA aqueous solution and the graphene aqueous dispersion, and uniformly stirring to obtain a graphene and PVA mixed solution. The mixed solution was uniformly applied to the surface of the polysulfone ultrafiltration membrane substrate to a thickness of 0.2 μm. And (3) placing the coated film in an oven at 80 ℃ for heat-induced crosslinking treatment, wherein the heat treatment time is 3 min.

The barrier layer in example 2 is the same as in comparative example 1 and is not described in detail here.

The second acid resistant layer may be formed on the surface of the barrier layer by: the surface of the barrier layer was coated again with the mixed solution of graphene and PVA to a thickness of 0.2 μm. And (3) placing the coated film in an oven at 80 ℃ for carrying out heat-induced crosslinking treatment for 3 minutes to obtain the second acid-resistant layer.

Comparative example 3: this comparative example 3 provides a multilayer film without a first acid resistant layer and a second acid resistant layer as compared to the multilayer film of example 2.

Comparative example 4: this comparative example 4 provides a multilayer film without a first acid resistant layer as compared to the multilayer film of example 2.

The film performance of example 2, comparative example 3 and comparative example 4 was tested after soaking in an aqueous solution containing 200000ppm sulfuric acid, and the comparative data are shown in table 1 below;

TABLE 1

Relative desalination rate R is 20% sulfuric acid solution, and desalination rate after soaking treatment/initial desalination rate is 100%

As can be seen from table 1, the decrease in the R relative salt rejection of the multilayer film provided in example 2 is not significant with the lapse of time, in contrast to that of the multilayer film provided in comparative example 3, which is also significantly lower at week 1 in the R relative salt rejection, and that of the multilayer film provided in comparative example 4, which is also greater in the R relative salt rejection with the lapse of time than that of the multilayer film provided in example 2. It can thus be seen that the multilayer film provided in example 2 benefits from the protection of the barrier layer by the acid-resistant layers on both surfaces of the barrier layer, resulting in a significantly stronger acid resistance of the multilayer film.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A multilayer film, comprising: the protective layer comprises a substrate and one or more barrier layers arranged on the substrate, wherein protective layers are arranged on two surfaces of at least one barrier layer in the one or more barrier layers.

2. The multilayer film of claim 1, wherein the protective layer specifically comprises: an oxidation resistant layer, an acid resistant layer, a base resistant layer, a chemical solvent resistant layer, and/or a high temperature resistant layer.

3. The multilayer film of claim 1, wherein the protective layer has a thickness of greater than or equal to 1 nanometer and less than or equal to 20 micrometers.

4. The multilayer film of claim 1, wherein the substrate has a thickness of greater than or equal to 5 microns and less than or equal to 250 microns.

5. The multilayer film of claim 1, wherein the barrier layer has a thickness of greater than or equal to 20 nanometers and less than or equal to 100 micrometers.

6. The multilayer film of claim 1, comprising a substrate, a first oxidation resistant layer disposed on a surface of the substrate, a barrier layer disposed on a surface of the first oxidation resistant layer, and a second oxidation resistant layer disposed on a surface of the barrier layer.

7. The multilayer film of claim 1, comprising a substrate, a first acid resistant layer disposed on a surface of the substrate, a barrier layer disposed on a surface of the first acid resistant layer, and a second acid resistant layer disposed on a surface of the barrier layer.