A composite film suitable for atomic layer deposition process and its preparation method

Abstract

This invention provides a composite film suitable for atomic layer deposition (ALD) and its preparation method. The composite film comprises, from bottom to top, a base film, an organic coating, and an inorganic coating layer. The inorganic coating layer is formed by depositing inorganic materials onto the organic coating using ALD. The organic coating is selected from one or more of polyester, polyurethane, or acrylate coatings. The method of this invention includes: (1) coating the surface of the base film with the raw material for preparing the organic coating, and curing the organic coating by drying or ultraviolet light curing; (2) depositing the inorganic coating layer on the surface of the organic coating using plasma-enhanced ALD to obtain the final composite film. The composite film provided by this invention exhibits excellent water vapor barrier properties and high light transmittance, as the organic coating is less prone to cracking after ALD.

Description

Technical Field

[0001] This invention relates to the technical field of composite membrane materials, and in particular to a composite membrane suitable for atomic layer deposition processes and its preparation method. Background Technology

[0002] Atomic layer deposition (ALD) is a chemical vapor deposition method for thin films based on a self-limiting reaction mechanism. It allows for precise control of film thickness and composition, achieving atomic-level growth. Films deposited via ALD are denser, exhibit better uniformity in composition and thickness, and demonstrate superior shape retention. It has broad application prospects in flexible displays, flexible electronics, flexible photovoltaics, and high-end food and pharmaceutical fields. ALD can be categorized by the energy delivery method into thermal atomic layer deposition (T-ALD) and plasma-enhanced atomic layer deposition (PE-ALD). PE-ALD enables thin film deposition at lower temperatures, making it suitable for preparing thinner films on organic substrates with low heat distortion temperatures.

[0003] Currently, the barrier performance of barrier films has been studied using ALD technology. Patent CN109535459A discloses a barrier film comprising, from top to bottom, a first water-oxygen barrier layer, a second water-oxygen barrier layer, and a substrate layer. The refractive index of the second water-oxygen barrier layer is lower than that of the first water-oxygen barrier layer. The material of the second water-oxygen barrier layer includes one or more of polycarbonate, acrylic resin, and acrylic resin. A metal oxide is deposited or coated on the surface of the second water-oxygen barrier layer using CVD and / or ALD methods to form the first water-oxygen barrier layer. Patent CN109244166A discloses a front-end encapsulation panel, which is a composite film adhered to the upper surface of a solar cell module. The composite film comprises, from top to bottom, a first adhesive layer, a first high water vapor barrier layer, a first modified primer coating, a first thin film substrate layer, a second adhesive layer, a second water vapor barrier layer, a second modified primer coating, a second thin film substrate layer, and a silicone layer. In this design, the first and second film substrate layers are PET films, and the first and second modified primer coatings can be acrylic, polyurethane, or polyester coatings. Two water vapor barrier layers are prepared on the upper surface of the two modified primer coatings using atomic layer deposition (ALD) or magnetron sputtering. Because the acrylic coatings used in the aforementioned patented technology contain thermoplastic acrylic resin, they are prone to cracking during ALD deposition of metal oxides, affecting the material's performance.

[0004] Patent CN105655500B discloses a multifunctional membrane, comprising: a flexible substrate layer including a substrate body and a transition layer and a hardened protective layer disposed on opposite surfaces of the substrate body; and a touch-sensitive membrane assembly with barrier function; wherein the touch-sensitive membrane assembly includes: a first touch-sensitive functional layer, a pretreatment layer, a water sample barrier layer, a planarization layer, and a second touch-sensitive functional layer. This invention uses CVD, PVD, iCVD, or ALD methods to form water and oxygen barrier materials (Al2O3, TiO2, SiN). x (SiO2, HMDSO, or polyester). The substrate transition layer is made of polyester acrylate or epoxy acrylate. The pretreatment layer between the transition layer and the water and oxygen barrier material is made of SiN. x SiO x HMDSO or polyester. This patented technology achieves the composite of ALD coating and substrate film through multi-layer coating, which is a relatively complex process.

[0005] In summary, the current atomic layer deposition (ALD) process for preparing composite films has the following problems: 1) When using acrylic resin containing thermoplastic acrylic resin as an organic layer and depositing metal oxides on its surface using the ALD process, cracking is likely to occur, affecting its performance; 2) The process of coating multiple layers to achieve the composite of ALD coating with other film layers is relatively complex. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a composite film suitable for atomic layer deposition process and its preparation method. The organic coating in the composite film does not crack after atomic layer deposition, has excellent water vapor barrier performance, and also has high light transmittance.

[0007] To achieve the objectives of this invention, the following technical solution is adopted:

[0008] In a first aspect, the present invention provides a composite film suitable for atomic layer deposition processes, wherein the composite film comprises, from bottom to top, a base film, an organic coating layer, and an inorganic coating layer;

[0009] In this process, an inorganic coating layer is formed by depositing inorganic materials onto the organic coating using a plasma-enhanced atomic layer deposition process. The organic coating is selected from one or more of polyester coatings, polyurethane coatings, or acrylic coatings.

[0010] Preferably, the organic coating is selected from one or more of polyurethane coatings containing urethane groups or polyurethane acrylate coatings.

[0011] In some specific embodiments of the composite film provided by the present invention, the polyurethane acrylate coating is obtained by reacting polyurethane acrylic resin, reactive monomer diluent and initiator as raw materials; in some preferred embodiments, the amount of polyurethane acrylic resin added is 60-99 parts by weight, the amount of reactive monomer diluent added is 0-40 parts by weight, and the amount of initiator added is 1-5 parts by weight.

[0012] In some specific embodiments, the above-mentioned active monomer diluent is selected from one or more of the following: trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, pentaerythritol tetraacrylate, dimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, and their derivatives.

[0013] In some specific embodiments, the initiator is selected from one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-4'-(methylthio)-2-morpholinoacetophenone, 2-phenyl-2,2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and its derivatives.

[0014] In some specific embodiments of the composite membrane provided by the present invention, the polyurethane coating is prepared by reacting isocyanate and its derivatives with polyol as raw materials; in some preferred embodiments, the amount of isocyanate and its derivatives added is 55-100 parts by weight, and the amount of polyol added is 0-45 parts by weight; more preferably, the ratio of isocyanate groups in the isocyanate and its derivatives to hydroxyl groups in the polyol is greater than 1.2.

[0015] In some specific embodiments, the polyurethane coating is prepared by reacting isocyanate and its derivatives, polyol and amino-terminated polyether as raw materials; preferably, the amount of isocyanate and its derivatives added is 55-100 parts by weight, the amount of polyol added is 0-45 parts by weight, and the amount of amino-terminated polyether added is 0-20 parts by weight.

[0016] In some specific embodiments of the composite film provided by the present invention, the polyester coating is made of unsaturated polyester. Specifically, the unsaturated polyester can be obtained by photocuring or other methods to form a polyester coating.

[0017] In the composite film provided by the present invention, the inorganic coating layer is selected from one or more of silicon oxide, aluminum oxide, or zinc oxide; the base film is selected from one of polyethylene, polypropylene, polycarbonate, Teflon, polyethylene naphthalate, polyethersulfone, polysulfone, polyimide, or polyethylene terephthalate; in some preferred embodiments, the base film is selected from one of polycarbonate, Teflon, polyethylene naphthalate, polyethersulfone, polysulfone, polyimide, or polyethylene terephthalate.

[0018] In a second aspect, the present invention provides a method for preparing the above-mentioned composite membrane, comprising the following steps:

[0019] (1) The raw material for preparing the organic coating is coated on the surface of the base film and cured by drying or ultraviolet light curing process;

[0020] (2) An inorganic coating layer is deposited on the surface of the organic coating using a plasma-enhanced atomic layer deposition process to obtain the final composite film;

[0021] In step (1), the drying process is preferably carried out at 70-100°C for 60-180 minutes; the ultraviolet curing process is preferably carried out by irradiating with an ultraviolet curing lamp in the wavelength range of 400-220nm for 2-5 minutes to complete the coating curing.

[0022] In a specific embodiment of the preparation method of the present invention, the thickness of the base film is 25-200 μm, preferably 50-150 μm.

[0023] In some specific embodiments, an organic coating with a thickness of 0.05 to 200 μm, preferably 1 to 30 μm, is formed by drying or ultraviolet curing.

[0024] In some specific embodiments, an inorganic coating layer of 10–1000 nm is deposited using an atomic layer deposition process, preferably 10–100 nm.

[0025] The above technical solution achieves the following technical effects:

[0026] This invention utilizes plasma-enhanced atomic layer deposition (ALD) to form an inorganic coating layer on an organic coating, resulting in a composite film suitable for ALD processes. This invention selects one or more of a polyurethane coating containing urethane groups or a polyurethane acrylate coating as the organic coating, ensuring that the organic coating in the resulting composite film is less prone to cracking after ALD. The composite film exhibits excellent water vapor barrier properties while also possessing high light transmittance. Attached Figure Description

[0027] Figure 1 The surface morphology of the composite film obtained in specific embodiment 1 of the present invention;

[0028] Figure 2 : Surface morphology of the composite film obtained in Comparative Example 1 of the present invention;

[0029] Figure 3 : Surface morphology of the composite film obtained in Comparative Example 2 of the present invention;

[0030] Figure 4 : Surface morphology of the composite film obtained in Comparative Example 4 of the present invention. Detailed Implementation

[0031] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] Where specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps or conditions in this technical field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0034] The sources of raw materials used in the following embodiments and comparative examples of this invention are as follows:

[0035] Polyurethane acrylic resin, model: 6145-100, purchased from Changxing Chemical.

[0036] Polyurethane acrylic resin, model: U25, purchased from DSM;

[0037] Polyurethane resin, model: TSP-2296, purchased from Arakawa, Japan;

[0038] Unsaturated polyester, model: N61, purchased from Norland, USA;

[0039] Diluent 1, model: HDDA, purchased from Changxing Chemical;

[0040] Diluent 2, model: TMPTA, purchased from Kaiyin Chemical;

[0041] Polysiloxane, model: PDMS 184, purchased from Dow Corning;

[0042] Thermoplastic acrylic resins, models: MB2952, LR7671, BR113, BR85, purchased from Mitsubishi, Japan.

[0043] The performance testing methods for the composite membranes prepared in the following embodiments and comparative examples are as follows:

[0044] (1) Test method for water vapor transmission rate: According to GB / T 21529-2008 "Test of water vapor transmission rate of plastic films and sheets by electrolytic sensor", the test sample is tested at 38℃ and 90% relative humidity.

[0045] (2) Film thickness test method: According to GB / T6672-2001 "Determination of thickness of plastic film and sheet - Mechanical measurement method", the thickness of the film was tested using a Nikon MH-15M film thickness measuring instrument.

[0046] (3) Test method for transmittance: According to GB / T2410-2008 "Test method for transmittance and haze of transparent plastic", the transmittance of the film was tested using a Shimadzu UV-3600 ultraviolet-visible-near-infrared spectrophotometer with a wavelength scanning range of 400-1200nm. The average transmittance within this wavelength range was calculated.

[0047] (4) Surface morphology of composite membrane: The surface morphology of the membrane was examined using a Keyence VK X1100 three-dimensional optical microscope.

[0048] Example 1

[0049] (1) A slit coating apparatus was used to coat a 75 μm thick polyethylene terephthalate substrate film with polyurethane acrylic resin (97.5 parts by weight, model: 6145-100) and 1-hydroxycyclohexyl benzophenone (2.5 parts by weight) as the initiator. The coating was then cured by irradiation with a 365 nm ultraviolet light curing lamp for 2 to 5 minutes to form an organic coating with a thickness of 7.8 μm.

[0050] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1.

[0051] Example 2

[0052] (1) Two polyurethane acrylic resins (49 parts by weight each, model: 6145-100, U25) and 1-hydroxycyclohexyl benzophenone (2 parts by weight) were coated on a polyethylene terephthalate base film with a thickness of 75 μm using a slit coating apparatus. The coating was then cured by irradiation with a UV curing lamp with a wavelength of 365 nm for 2 to 5 minutes to form an organic coating with a thickness of 10.5 μm.

[0053] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 2.

[0054] Example 3

[0055] (1) A slit coating apparatus was used to coat a 125 μm thick polyethylene terephthalate base film with polyurethane resin (100 parts by weight, model: TSP-2296), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an organic coating with a thickness of 8.1 μm.

[0056] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 3.

[0057] Example 4

[0058] (1) Using a slit coating machine, unsaturated polyester (100 parts by weight; model: N61) was coated on a polyethylene terephthalate substrate film with a thickness of 125 μm, and the coating was cured by irradiation with a UV curing lamp with a wavelength of 365 nm for 2 to 5 minutes to form an organic coating with a thickness of 10.2 μm.

[0059] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 4.

[0060] Example 5

[0061] (1) A slit coating apparatus was used to coat a 125 μm thick polyethylene terephthalate base film with polyurethane acrylic resin (90 parts by weight, model: U25), active monomer diluent (10 parts by weight, model: TMPTA), and 1-hydroxy-cyclohexyl benzophenone (2 parts by weight) as the initiator. The coating was then cured by irradiation with a 365 nm ultraviolet light curing lamp for 2 to 5 minutes to form an organic coating with a thickness of 9.5 μm.

[0062] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum on the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 5.

[0063] Example 6

[0064] (1) A slit coating apparatus was used to coat a 75 μm thick polyethylene terephthalate substrate film with polyurethane acrylic resin (90 parts by weight, model: 6145-100), active monomer diluent (10 parts by weight, model: HDDA), and 1-hydroxycyclohexyl benzophenone (2 parts by weight) as the initiator. The coating was then cured by irradiation with a 365 nm ultraviolet light curing lamp for 2 to 5 minutes to form an organic coating with a thickness of 8.9 μm.

[0065] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum on the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is denoted as composite film 6.

[0066] Comparative Example 1

[0067] (1) A slit coating apparatus was used to coat a 75 μm thick polyethylene terephthalate base film with polysiloxane (100 parts by weight, model: PDMS 184), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an organic coating with a thickness of 11 μm.

[0068] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1-1.

[0069] Comparative Example 2

[0070] (1) A slit coating apparatus was used to coat a 75 μm thick polyethylene terephthalate base film with thermoplastic acrylic resin (100 parts by weight, model: MB2952), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an 8 μm thick organic coating.

[0071] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Next, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1-2.

[0072] Comparative Example 3

[0073] (1) A slit coating apparatus was used to coat a 125 μm thick polyethylene terephthalate base film with thermoplastic acrylic resin (100 parts by weight, model: LR7671), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an organic coating with a thickness of 8.6 μm.

[0074] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1-3.

[0075] Comparative Example 4

[0076] (1) A slit coating apparatus was used to coat a 125 μm thick polyethylene terephthalate base film with thermoplastic acrylic resin (100 parts by weight, model: BR113), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an organic coating with a thickness of 8.7 μm.

[0077] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum from the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1-4.

[0078] Comparative Example 5

[0079] (1) A slit coating apparatus was used to coat a 75 μm thick polyethylene terephthalate base film with thermoplastic acrylic resin (100 parts by weight, model: BR85), and the film was placed in an oven at 80°C for 2 hours for heat curing to complete the coating curing and form an organic coating with a thickness of 9.8 μm.

[0080] (2) The PET film coated with the organic coating formed above is placed in the reaction chamber of the plasma-enhanced atomic layer deposition system. The temperature of the reaction chamber is raised to 80°C to ensure uniform heating of the organic coating. Trimethylaluminum is introduced into the reaction chamber as a precursor for 0.1 s. Then, inert gas is used to purge for 6 s to remove the unadsorbed trimethylaluminum on the surface. Then, oxygen plasma is generated by an oxygen plasma generator, and oxygen plasma is introduced into it for 26 s. Then, inert gas is introduced again for 6 s to purge the reaction byproducts and unreacted oxygen plasma. The above steps of introducing trimethylaluminum as a precursor are repeated for 150 cycles to obtain an inorganic aluminum oxide coating layer with a thickness of 18 nm. The composite film prepared by the above method is referred to as composite film 1-5.

[0081] The composite membrane prepared above was tested, and the performance data are shown in Table 1 below:

[0082] Table 1

[0083]

[0084] As can be seen from Table 1 and the accompanying drawings of this invention, the organic coating in the composite membrane prepared by this invention is not prone to cracking after atomic layer deposition of the inorganic coating layer. The composite membrane prepared by this invention has excellent water vapor barrier properties and also has a light transmittance of over 88%.

[0085] Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A composite film suitable for atomic layer deposition processes, characterized in that, The composite membrane comprises, from bottom to top, a base membrane, an organic coating, and an inorganic coating layer; In this process, an inorganic coating layer is formed by depositing inorganic materials onto the organic coating using a plasma-enhanced atomic layer deposition process. The organic coating is selected from one or more of polyester coatings, polyurethane coatings, or acrylic coatings. The inorganic coating layer is selected from one or more of silicon oxide, aluminum oxide, or zinc oxide; The base film is selected from one of polyethylene, polypropylene, polycarbonate, Teflon, polyethylene naphthalate, polyethersulfone, polysulfone, polyimide or polyethylene terephthalate.

2. The composite membrane according to claim 1, characterized in that, The organic coating is selected from one or more of polyurethane coatings containing urethane groups or polyurethane acrylate coatings.

3. The composite membrane according to claim 1, characterized in that, The polyurethane acrylate coating is obtained by reacting polyurethane acrylic resin, reactive monomer diluent and initiator as raw materials.

4. The composite membrane according to claim 3, characterized in that, The amount of polyurethane acrylic resin added is 60-99 parts by weight, the amount of the active monomer diluent added is 0-40 parts by weight, and the amount of the initiator added is 1-5 parts by weight.

5. The composite membrane according to claim 3, characterized in that, The active monomer diluent is selected from one or more of the following: trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, pentaerythritol tetraacrylate, dimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, and their derivatives.

6. The composite membrane according to any one of claims 3 to 5, characterized in that, The initiator is selected from one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-4'-(methylthio)-2-morpholinoacetophenone, 2-phenyl-2,2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and its derivatives.

7. The composite membrane according to claim 1, characterized in that, The polyurethane coating is prepared by reacting isocyanate and its derivatives with polyols.

8. The composite membrane according to claim 7, characterized in that, The amount of the isocyanate and its derivatives added is 55-100 parts by weight, and the amount of the polyol added is 0-45 parts by weight.

9. The composite membrane according to claim 8, characterized in that, The ratio of isocyanate groups to hydroxyl groups in the isocyanate and its derivatives is greater than 1.

2.

10. The composite membrane according to claim 1 or 7, characterized in that, The polyurethane coating is prepared by reacting isocyanate and its derivatives, polyols and amino-terminated polyethers as raw materials.

11. The composite membrane according to claim 10, characterized in that, The amount of the isocyanate and its derivatives added is 55-100 parts by weight, the amount of the polyol added is 0-45 parts by weight, and the amount of the terminal amino polyether added is 0-20 parts by weight.

12. The composite membrane according to claim 1, characterized in that, The polyester coating is made of unsaturated polyester.

13. The composite membrane according to any one of claims 1-5, 7-9, 11, and 12, characterized in that, The base film is selected from one of polycarbonate, Teflon, polyethylene naphthalate, polyethersulfone, polysulfone, polyimide or polyethylene terephthalate.

14. A method for preparing a composite membrane according to any one of claims 1 to 13, characterized in that, Includes the following steps: (1) The raw material for preparing the organic coating is coated on the surface of the substrate film and cured by drying or ultraviolet light curing process; (2) An inorganic coating layer is deposited on the surface of the organic coating by using plasma-enhanced atomic layer deposition process to obtain the final composite film.

15. The preparation method according to claim 14, characterized in that, In step (1), the drying process is carried out at 70~100℃ for 60~180 min.

16. The preparation method according to claim 14, characterized in that, In step (1), the ultraviolet curing process uses an ultraviolet curing lamp with a wavelength range of 400~220 nm to irradiate for 2~5 minutes to complete the coating curing.

17. The preparation method according to any one of claims 14 to 16, characterized in that, The thickness of the base membrane is 25~200 μm; The thickness of the organic coating is 0.05~200 μm; The thickness of the inorganic coating layer is 10~1000 nm.

18. The preparation method according to claim 17, characterized in that, The thickness of the basement membrane is 50~150 μm.

19. The preparation method according to claim 17, characterized in that, The thickness of the organic coating is 1~30 μm.

20. The preparation method according to claim 17, characterized in that, The thickness of the inorganic coating layer is 10~100nm.

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