A flexible high-barrier composite film, its preparation method and application

Abstract

This application relates to the field of thin film technology, and discloses a flexible high-barrier composite film, a preparation method thereof, and an application. The flexible high-barrier composite film includes a substrate, a barrier layer disposed on the surface of the substrate, and a protective layer disposed on the surface of the barrier layer; the barrier layer includes a first barrier layer and a second barrier layer, the first barrier layer is disposed on the surface of the substrate, and the second barrier layer is disposed on the surface of the first barrier layer; the first barrier layer is a SiO 2 thin film; the second barrier layer is an Al 2 O 3 / ZnO nano-stacked thin film; the protective layer is an organic polysilazane or polysiloxane. In the flexible high-barrier composite film of this application, the introduction of ZnO in the second barrier layer can avoid the accumulation and expansion of defects in the pure Al 2 O 3 thin film, and a stable and dense interfacial layer structure is formed between Al 2 O 3 and ZnO through the bonding of Zn-Al-O, improving the water vapor barrier ability. In addition, the second barrier layer can repair the defects existing in the first barrier layer, further improving the water vapor barrier performance.

Description

Technical Field

[0001] The present application relates to the technical field of thin films, and particularly to a flexible high-barrier composite film, a preparation method thereof, and an application thereof. Background Art

[0002] Flexible barrier films are commonly used to protect devices such as flexible thin-film solar cells and organic light-emitting diodes (OLEDs) from the erosion of water and oxygen, thereby improving their service life and performance. With the continuous progress of flexible electronic technology, the application of flexible barrier films in the fields of flexible display, flexible lighting, etc. has been continuously expanded, ushering in new development opportunities.

[0003] Most of the existing barrier films are based on PET, and through a combination of various materials, a good water vapor barrier effect is achieved. Among them, inorganic / organic composite multilayer films are a commonly used material system, which uses a structurally dense inorganic layer to provide barrier performance, and at the same time combines an organic layer to improve its defect decoupling ability, improve the film flatness, and can also make the composite film have a certain flexibility. For example, Patent CN1048463350A discloses an organic-inorganic hybrid high-barrier film, and by controlling the ratio between the organic component and the inorganic component, a barrier film with both good barrier properties and flexibility is obtained. However, due to the excessive thickness of the barrier layer, reaching the micron level, and due to the increase in the number of coating layers, the light transmittance of the film decreases. In addition, constructing a multilayer inorganic / inorganic composite barrier film is also a technical solution to improve the barrier performance. For example, Patent CN105449123B discloses a preparation method of a water and oxygen barrier layer, and a composite barrier structure is formed by depositing multilayer inorganic thin films with different properties by changing the preparation process parameters. However, due to the small difference in the layer structure of the composite film layers, the film decoupling effect is not obvious, and the continuous growth of defects cannot be effectively prevented, resulting in poor stability of the barrier performance.

[0004] In summary, developing a barrier film with both high barrier performance, high mechanical performance, and high light transmittance is of great significance for its application in the field of flexible optoelectronic packaging. Summary of the Invention

[0005] The present application provides a flexible high-barrier composite film, a preparation method thereof, and an application thereof, aiming to solve the problems of poor barrier performance and low light transmittance existing in the existing composite barrier films.

[0006] In order to achieve the above object, the present application adopts the following technical solutions to be realized.

[0007] In the first aspect of the present application, there is provided a flexible high-barrier composite film, including a substrate, a barrier layer disposed on the surface of the substrate, and a protective layer disposed on the surface of the barrier layer; the barrier layer includes a first barrier layer and a second barrier layer, the first barrier layer is disposed on the surface of the substrate, and the second barrier layer is disposed on the surface of the first barrier layer;

[0008] The first barrier layer is SiO 2 thin film; the second barrier layer is Al 2 O 3 / ZnO nano stacked thin film; the protective layer is organopolysilazane or polysiloxane.

[0009] In some embodiments, the Al 2 O 3 / ZnO nano stacked thin film includes a plurality of stacked units, and each of the stacked units includes a layer of Al 2 O 3 film and a layer of ZnO film deposited on the Al 2 O 3 film.

[0010] In some embodiments, the number of the stacked units is 2 to 12; in the stacked units, the thickness ratio of the Al 2 O 3 and ZnO film layers is (4:3) to (2:5).

[0011] In some embodiments, the substrate is selected from at least one of polyethylene terephthalate, polyethylene naphthalate, polycarbonate or polyimide.

[0012] In some embodiments, the thickness of the substrate is 50 to 130 μm, and the light transmittance > 80%;

[0013] the thickness of the barrier layer ≤ 300 nm; wherein, the thickness of the SiO 2 thin film is 30 to 200 nm, and the density is 2.0 to 3.0 g / cm 3 ; the thickness of the Al 2 O 3 / ZnO nano stacked thin film is 30 to 100 nm;

[0014] the thickness of the protective layer is 100 to 2000 nm.

[0015] In the second aspect of the present application, a method for preparing the above flexible high-barrier composite thin film is provided, including:

[0016] S1, activating the surface of the substrate;

[0017] S2, depositing a SiO 2 thin film on the surface of the substrate by plasma enhanced chemical vapor deposition as the first barrier layer;

[0018] S3, depositing an Al 2 O 3 / ZnO nano stacked thin film on the surface of the first barrier layer by plasma enhanced atomic layer deposition as the second barrier layer;

[0019] S4. Coating an organic polysilazane or polysiloxane on the surface of the second barrier layer by using a spraying / spin coating composite process, and then performing a curing treatment to obtain a flexible high-barrier composite film.

[0020] In some embodiments, the activation treatment includes: treating the surface of the substrate by using plasma, glow discharge, corona or microwave.

[0021] In some embodiments, for the plasma enhanced chemical vapor deposition in step S2, the temperature is 70-140 °C, and the radio frequency power is 250-650 W;

[0022] In step S3, the deposition temperature of the plasma enhanced atomic layer deposition is 70-160 °C.

[0023] In some embodiments, in step S4, an organic polysilazane or polysiloxane is sprayed on the surface of the substrate, then spin-coated, and heated for curing after spin-coating;

[0024] The curing temperature is 60-140 °C, and the curing time is 2-6 h.

[0025] In the third aspect of the present application, there is provided an application of the above flexible high-barrier composite film or the flexible high-barrier composite film prepared by the above preparation method in a flexible thin-film solar cell or an organic electroluminescent device.

[0026] Compared with the prior art, the beneficial effects of the present application are:

[0027] The flexible high-barrier composite film of the present application uses an SiO 2 film as the first barrier layer, and grows an Al 2 O 3 / ZnO nano-stack structure as the second barrier layer on the surface of the first barrier layer to improve the water vapor barrier performance of the film. The introduction of ZnO in the second barrier layer can avoid the accumulation and expansion of defects in the pure Al 2 O 3 film, and a stable and dense interfacial layer structure is formed between Al 2 O 3 and ZnO through the bonding of Zn-Al-O to improve the water vapor barrier ability. In addition, the second barrier layer can repair the defects existing in the first barrier layer, further improving the water vapor barrier performance. By setting an organic polysilazane or polysiloxane protective layer, the light transmittance of the film is improved.

[0028] The flexible high-barrier composite film of the present application has high barrier performance and light transmittance, and its water vapor transmission rate ≤ 5×10 -5 g / (m 2.day), the light transmittance is ≥89%, which is suitable for the encapsulation of flexible devices and can significantly improve the service life of flexible devices. Detailed implementation manners

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0030] In the following description of this embodiment, the terms "include", "comprise", "have" and "contain" are all open-ended terms, that is, they are meant to include but not limited to.

[0031] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist at the same time. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0032] In the following description of this embodiment, the term "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression below refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b or c", or, "at least one (item) of a, b and c" can both represent: a, b, c, a-b (that is, a and b), a-c, b-c, or a-b-c, where a, b, c can be single or multiple respectively.

[0033] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0034] Those skilled in the art should understand that in the following description of the embodiments of the present application, the sequence numbers do not mean the order of execution, and some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0035] Those skilled in the art should understand that the numerical ranges in the embodiments of the present application should be understood as specifically disclosing each intermediate value between the upper and lower limits of the range. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present application. The upper and lower limits of these smaller ranges may be independently included or excluded within the range.

[0036] Unless otherwise specified, the technical / scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0037] In a first aspect, the present application provides a flexible high-barrier composite film, including a substrate, a barrier layer disposed on the surface of the substrate, and a protective layer disposed on the surface of the barrier layer; the barrier layer includes a first barrier layer and a second barrier layer, the first barrier layer is disposed on the surface of the substrate, and the second barrier layer is disposed on the surface of the first barrier layer;

[0038] In the present application, the barrier layer is used to improve the water vapor barrier performance. The total thickness of the barrier layer ≤ 300 nm,

[0039] wherein the first barrier layer is a SiO 2 film, and the second barrier layer is an Al 2 O 3 / ZnO nano stacked film. Preferably, the thickness of the SiO 2 film in the present application is 30 - 200 nm, and its density is 2.0 - 3.0 g / cm 3 ; preferably, the thickness of the Al 2 O 3 / ZnO nano stacked film is 30 - 100 nm. More preferably, the thickness of the SiO 2 film is 50 - 150 nm, and the thickness of the Al 2 O 3 / ZnO nano stacked film is 40 - 70 nm.

[0040] Among them, the Al 2 O 3 / ZnO nano stacked film includes 2 - 12 stacking units, preferably including 4 - 8 stacking units. Each stacking unit includes a layer of Al 2 O 3 film and a layer deposited on the Al 2 O 3ZnO film on the membrane; in each stacking unit, Al 2 O 3 and the thickness ratio of the ZnO film layer is (4:3) to (2:5).

[0041] In this application, the protective layer is used to improve the light transmittance. The protective layer is an organic polysilazane or polysiloxane, and the thickness of the protective layer is preferably 100-2000 nm, more preferably 500-1000 nm.

[0042] In this application, the substrate is selected from at least one of polyethylene terephthalate, polyethylene naphthalate, polycarbonate or polyimide. The thickness of the substrate is 50-100 μm, and the light transmittance of the substrate > 80%, more preferably the light transmittance ≥ 85%.

[0043] The flexible high-barrier composite film of this application uses SiO 2 film as the first barrier layer, and grows an Al 2 O 3 / ZnO nano-stack structure on the surface of the first barrier layer as the second barrier layer to improve the water vapor barrier performance of the film. The introduction of ZnO in the second barrier layer can avoid the accumulation and expansion of defects in the pure Al 2 O 3 film, and a stable and dense interfacial layer structure is formed between Al 2 O 3 and ZnO through Zn-Al-O bonding to improve the water vapor barrier ability. In addition, the second barrier layer can repair the defects existing in the first barrier layer, further improving the water vapor barrier performance. By setting an organic polysilazane or polysiloxane protective layer, the light transmittance of the film is improved.

[0044] In the second aspect, this application provides a method for preparing the above flexible high-barrier composite film, including:

[0045] S1, activating the surface of the substrate;

[0046] Specifically, the surface of the substrate can be activated by plasma, glow discharge, corona or microwave. For example, setting the power of the plasma to 250 W and performing surface treatment on the substrate for 8 min can complete the activation of the substrate surface.

[0047] S2, depositing SiO 2 film on the surface of the substrate by plasma enhanced chemical vapor deposition as the first barrier layer;

[0048] Specifically, the plasma enhanced chemical vapor deposition uses SiH 4 and O 2 as reaction gases, the deposition temperature is 70-140 °C, and the radio frequency power is 250-650 W.

[0049] S3. Deposit Al 2 O 3 / ZnO nano stacked film as the second barrier layer on the surface of the first barrier layer by plasma enhanced atomic layer deposition; 2 O 3 wherein, the deposition temperature of the plasma enhanced atomic layer deposition is 70 - 160 °C and the power is 2500 - 3000 W.

[0050] Specifically, using trimethylaluminum (TMA) as the precursor and oxygen plasma as the oxygen source, deposit a high-purity and highly uniform alumina film on the substrate surface by plasma enhanced atomic layer deposition; using diethylzinc as the precursor and oxygen plasma as the oxygen source, deposit a high-purity and highly uniform zinc oxide film on the surface of the alumina film by plasma enhanced atomic layer deposition to form a stacked unit;

[0051] Deposit an alumina film on the surface of the zinc oxide film again and deposit a zinc oxide film on the surface of the alumina film again by the same method to form a second stacked unit; and so on until the target number of units or layers is reached to obtain the Al 2 O 3 / ZnO nano stacked film.

[0052] In this application, preferably, the number of the stacked units is 2 - 12; in the stacked unit, the thickness ratio of the Al 2 O 3 and ZnO film layers is (4:3) - (2:5). 2 O 3 / ZnO nano stacked film.

[0053] In this application, preferably, the number of the stacked units is 2 - 12; in the stacked unit, the thickness ratio of the Al 2 O 3 and ZnO film layers is (4:3) - (2:5). 2 O 3 and ZnO film layer thickness ratio is (4:3) - (2:5).

[0054] S4. Coating an organic polysilazane or polysiloxane on the surface of the second barrier layer by a spray / spin - coating composite process, and then performing a curing treatment to obtain a flexible high - barrier composite film.

[0055] Specifically, spray an organic polysilazane or polysiloxane on the substrate surface and then perform spin - coating; after spin - coating, heat to 60 - 140 °C for curing, and the curing time is 2 - 6 h.

[0056] The flexible high - barrier composite film of this application has high barrier performance and light transmittance. Its water vapor transmission rate ≤ 5×10 -5 g / (m 2 .day), and the light transmittance ≥ 89%, and it can be used as a flexible encapsulation material for flexible devices such as thin - film solar cells, OLED devices, and quantum dot display devices, and can significantly extend their service life. -5 g / (m 2 .day), the light transmittance ≥ 89%, and it can be used as a flexible encapsulation material for

[0057] flexible devices such as thin - film solar cells, OLED devices, and quantum dot display devices, and can significantly extend their service life.

[0058] The following further illustrates this application through examples.

[0059] In the embodiment of the present application, the base material is a commercially available polymer film, and its specifications are as follows:

[0060] Polyethylene naphthalate (PEN) film (teonex Q65HA), thickness 100 μm, water vapor transmission rate 1.63 g / (m2.day), light transmittance 87.5%;

[0061] Polyethylene naphthalate (PEN) film (teonex Q65HA), thickness 125 μm, water vapor transmission rate 1.7 g / (m2·day), light transmittance 87.3%.

[0062] Polyethylene terephthalate film (PET) film (Toray U483, Japan), thickness 125 μm, water vapor transmission rate 5.06 g / (m2·day), light transmittance 89.5%.

[0063] Example 1

[0064] S1, select PEN with a thickness of 100 μm as the substrate, clean it with acetone, ethanol and deionized water in sequence, and then blow it dry with nitrogen; use 250W plasma to treat the surface of the PEN substrate for 8 minutes.

[0065] S2, SiH 4 and O 2 As the reaction gas, SiO with a thickness of 50 nm was deposited on the PEN substrate by plasma enhanced chemical vapor deposition at a temperature of 120 °C and a radio frequency power of 500 W. 2 Film, as the first barrier layer;

[0066] S3, at 120°C and a plasma power of 2500 W, using trimethylaluminum (TMA) as a precursor and oxygen plasma as an oxygen source, a 4.5 nm thick aluminum oxide film is deposited on the substrate surface by plasma enhanced atomic layer deposition; then using diethyl zinc as a precursor and oxygen plasma as an oxygen source, a 6 nm thick zinc oxide film is deposited on the surface of the aluminum oxide film by plasma enhanced atomic layer deposition to form a stacking unit; four stacking units are deposited in sequence to form an Al2O3 film with a thickness of 42 nm. 2 O 3 / ZnO nano-stacked film as the second barrier layer;

[0067] S4, spraying the organic polysilazane on the surface of the second barrier layer, and then spin coating at a rotation speed of 5000 rpm to form an organic polysilazane layer with a thickness of 500 nm, and then curing at 100° C. for 3 hours to obtain a flexible high-barrier composite film.

[0068] Example 2

[0069] S1. Select PEN with a thickness of 100 μm as the substrate, clean it successively with acetone, ethanol and deionized water, and then dry it with nitrogen; treat the PEN substrate with plasma at a power of 250 W for 8 min.

[0070] S2. Using SiH 4 and O 2 as the reaction gases, deposit a SiO 2 film with a thickness of 50 nm on the PEN substrate by plasma enhanced chemical vapor deposition under the conditions of a temperature of 120 °C and a radio frequency power of 500 W as the first barrier layer;

[0071] S3. Under the conditions of 120 °C and a plasma power of 2500 W, using trimethylaluminum (TMA) as the precursor and oxygen plasma as the oxygen source, deposit an aluminum oxide film with a thickness of 4 nm on the substrate surface by plasma enhanced atomic layer deposition; then using diethylzinc as the precursor and oxygen plasma as the oxygen source, deposit a zinc oxide film with a thickness of 4 nm on the surface of the aluminum oxide film by plasma enhanced atomic layer deposition to form 1 stacking unit; deposit 8 stacking units in sequence to form an Al 2 O 3 / ZnO nano stacked film as the second barrier layer;

[0072] S4. Spray organic polysilazane on the surface of the second barrier layer, then spin coat it at a speed of 5000 rpm to form an organic polysilazane layer with a thickness of 500 nm, and then cure it at 100 °C for 3 h to obtain a flexible high barrier composite film.

[0073] Example 3

[0074] S1. Select PEN with a thickness of 100 μm as the substrate, clean it successively with acetone, ethanol and deionized water, and then dry it with nitrogen; treat the PEN substrate with plasma at a power of 250 W for 8 min.

[0075] S2. Using SiH 4 and O 2 as the reaction gases, deposit a SiO 2 film with a thickness of 50 nm on the PEN substrate by plasma enhanced chemical vapor deposition under the conditions of a temperature of 140 °C and a radio frequency power of 500 W as the first barrier layer;

[0076] S3. Under the conditions of 120 °C and a plasma power of 2500 W, using trimethylaluminum (TMA) as a precursor and oxygen plasma as an oxygen source, deposit an alumina film with a thickness of 4.5 nm on the substrate surface by plasma-enhanced atomic layer deposition; then, using diethylzinc as a precursor and oxygen plasma as an oxygen source, deposit a zinc oxide film with a thickness of 6 nm on the surface of the alumina film by plasma-enhanced atomic layer deposition to form 1 stacking unit; deposit 4 stacking units in sequence to form an Al 2 O 3 / ZnO nano-stacked film as the second barrier layer;

[0077] S4. Spray organic polysilazane on the surface of the second barrier layer, then spin-coat it at a speed of 5000 rpm to form a polydimethylsiloxane layer with a thickness of 500 nm, and then cure it at 80 °C for 3 h to obtain a flexible high-barrier composite film.

[0078] Example 4

[0079] S1. Select a PEN with a thickness of 100 μm as the substrate, clean it successively with acetone, ethanol, and deionized water, and then dry it with nitrogen; perform surface treatment on the PEN substrate with a plasma of 250 W for 8 min.

[0080] S2. Using SiH 4 and O 2 as reaction gases, deposit a SiO 2 film with a thickness of 150 nm on the PEN substrate by plasma-enhanced chemical vapor deposition under the conditions of a temperature of 120 °C and a radio frequency power of 400 W as the first barrier layer;

[0081] S3. Under the conditions of 120 °C and a plasma power of 2500 W, using trimethylaluminum (TMA) as a precursor and oxygen plasma as an oxygen source, deposit an alumina film with a thickness of 4.5 nm on the substrate surface by plasma-enhanced atomic layer deposition; then, using diethylzinc as a precursor and oxygen plasma as an oxygen source, deposit a zinc oxide film with a thickness of 6 nm on the surface of the alumina film by plasma-enhanced atomic layer deposition to form 1 stacking unit; deposit 4 stacking units in sequence to form an Al 2 O 3 / ZnO nano-stacked film as the second barrier layer;

[0082] S4. Spray organic polysilazane on the surface of the second barrier layer, then spin-coat it at a speed of 5000 rpm to form an organic polysilazane layer with a thickness of 800 nm, and then cure it at 80 °C for 4 h to obtain a flexible high-barrier composite film.

[0083] Example 5

[0084] S1. Select PET with a thickness of 125 μm as the substrate, clean it successively with acetone, ethanol and deionized water, and then dry it with nitrogen; perform surface treatment on the PEN substrate with a plasma power of 250 W for 8 min.

[0085] S2. Use SiH 4 and O 2 as reaction gases. Under the conditions of a temperature of 120 °C and a radio frequency power of 500 W, deposit a SiO 2 film with a thickness of 50 nm on the PEN substrate by plasma enhanced chemical vapor deposition as the first barrier layer;

[0086] S3. Under the conditions of 120 °C and a plasma power of 2500 W, use trimethylaluminum (TMA) as the precursor and oxygen plasma as the oxygen source to deposit an aluminum oxide film with a thickness of 4.5 nm on the substrate surface by plasma enhanced atomic layer deposition; then use diethylzinc as the precursor and oxygen plasma as the oxygen source to deposit a zinc oxide film with a thickness of 6 nm on the surface of the aluminum oxide film to form 1 stacking unit; deposit 6 stacking units in sequence to form an Al 2 O 3 / ZnO nano-stack film as the second barrier layer;

[0087] S4. Spray organic polysilazane on the surface of the second barrier layer, and then spin-coat it at a speed of 5000 rpm to form a polydimethylsiloxane layer with a thickness of 1000 nm, and then cure it at 100 °C for 2 h to obtain a flexible high-barrier composite film.

[0088] Example 6

[0089] S1. Select PEN with a thickness of 125 μm as the substrate, clean it successively with acetone, ethanol and deionized water, and then dry it with nitrogen; perform surface treatment on the PEN substrate with a plasma power of 250 W for 8 min.

[0090] S2. Use SiH 4 and O 2 as reaction gases. Under the conditions of a temperature of 120 °C and a radio frequency power of 500 W, deposit a SiO 2 film with a thickness of 50 nm on the PEN substrate by plasma enhanced chemical vapor deposition as the first barrier layer;

[0091] S3. Under the conditions of 120 °C and a plasma power of 2500 W, using trimethylaluminum (TMA) as the precursor and oxygen plasma as the oxygen source, deposit an aluminum oxide film with a thickness of 3.6 nm on the substrate surface by plasma-enhanced atomic layer deposition; then, using diethylzinc as the precursor and oxygen plasma as the oxygen source, deposit a zinc oxide film with a thickness of 6 nm on the surface of the aluminum oxide film by plasma-enhanced atomic layer deposition to form 1 stacking unit; deposit 4 stacking units in sequence to form an Al 2 O 3 / ZnO nano-stack film as the second barrier layer;

[0092] S4. Spray the organic polysilazane on the surface of the second barrier layer, then spin-coat it at a speed of 5000 rpm to form a polydimethylsiloxane layer with a thickness of 500 nm, and then cure it at 90 °C for 4 h to obtain a flexible high-barrier composite film.

[0093] Comparative Example 1

[0094] The difference between Comparative Example 1 and Example 1 is that there is no second barrier layer, and the rest are the same as in Example 1.

[0095] Comparative Example 2

[0096] The difference between Comparative Example 2 and Comparative Example 1 is that the temperature for depositing the SiO 2 film is 150 °C, and the rest are the same as in Comparative Example 1.

[0097] Comparative Example 3

[0098] The difference between Comparative Example 3 and Example 1 is that its barrier layer is an Al film with a thickness of 42 nm 2 O 3 film, and the rest are the same as in Example 1.

[0099] Comparative Example 4

[0100] The difference between Comparative Example 4 and Example 1 is that its second barrier layer is an Al film with a thickness of 42 nm 2 O 3 film, and the rest are the same as in Example 1.

[0101] Comparative Example 5

[0102] The difference between Comparative Example 5 and Example 1 is that there is no first barrier layer, and the rest are the same as in Example 1.

[0103] Characterize the films prepared in Examples 1-6 and Comparative Examples 1-5, and test the water vapor transmission rate and light transmittance. Among them, the water vapor transmission rate is measured according to the method of GB / T 21529-2008; the light transmittance is measured according to the method of ASTM D1003-13. The test results are shown in Table 1.

[0104] Table 1 Test data of different films

[0105]

[0106]

[0107] As can be seen from Table 1, the flexible high-barrier composite films prepared in this application all have excellent water barrier performance and light transmittance. For the flexible high-barrier composite films of Examples 1-6, the water vapor transmission rate ≤ 5×10 -5 g / (m 2 .day), and the light transmittance ≥ 89%.

[0108] As can be seen from Example 1 and Comparative Example 1, Comparative Example 1 only has the silicon oxide film in the first layer, and its water barrier performance is much lower than that of Example 1. In Comparative Example 2, the ICPECVD deposition temperature of the silicon oxide film was increased, resulting in warping of the composite film and a decrease in the barrier performance. In Comparative Example 3, only one layer of aluminum oxide film was deposited, which could not provide high water barrier performance. In Comparative Example 4, the SiO 2 film was used as the first barrier layer and the aluminum oxide film was used as the second barrier layer, without the Al 2 O 3 / ZnO nano stacked film layer, and its water vapor transmission rate was one order of magnitude higher than that of Example 1. In Comparative Example 5, there was only the Al 2 O 3 / ZnO nano stacked film layer, and its water barrier performance was also lower than that of the flexible high-barrier composite film of Example 1. In the flexible high-barrier composite film of this application, the introduction of ZnO in the second barrier layer can avoid the accumulation and expansion of defects in the pure Al 2 O 3 film, and a stable and dense interfacial layer structure is formed by the bonding of Zn-Al-O between Al 2 O 3 and ZnO, improving the water vapor barrier ability. In addition, the second barrier layer can repair the defects existing in the first barrier layer, further improving the water vapor barrier performance.

[0109] Although this application has been described in detail with general descriptions and specific implementation examples in this specification, based on this application, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of this application all fall within the scope of protection required by this application.

Claims

1. A flexible high barrier composite film, characterized in that: It comprises a substrate, a barrier layer arranged on the surface of the substrate, and a protective layer arranged on the surface of the barrier layer; the barrier layer comprises a first barrier layer and a second barrier layer, the first barrier layer is arranged on the surface of the substrate, and the second barrier layer is arranged on the surface of the first barrier layer; The first barrier layer is a SiO2 film; the second barrier layer is an Al2O3 / ZnO nano-stacked film; the protective layer is an organic polysilazane or polysiloxane; The Al2O3 / ZnO nano-stacked film includes a plurality of stacking units, each of which includes a layer of Al2O3 film and a layer of ZnO film deposited on the Al2O3 film; The thickness of the barrier layer is ≤300nm; Among them, the thickness of SiO2 film is 30~200nm, and the density is 2.0~3.0 g / cm 3 ; The thickness of Al2O3 / ZnO nanostacked film is 30~100nm.

2. The flexible high barrier composite film according to claim 1, characterized in that: The number of the stacking units is 2 to 12; in the stacking units, the thickness ratio of the Al2O3 and ZnO film layers is (4:3) to (2:5).

3. The flexible high barrier composite film according to claim 1, characterized in that: The substrate is selected from at least one of polyethylene terephthalate, polyethylene naphthalate, polycarbonate or polyimide.

4. The flexible high barrier composite film according to claim 1, characterized in that: The thickness of the substrate is 50-130 μm, and the light transmittance is greater than 80%; The thickness of the protective layer is 100-2000 nm.

5. The method for preparing the flexible high-barrier composite film according to any one of claims 1 to 4, characterized in that: include: S1, activation treatment of the substrate surface; S2, depositing a SiO2 thin film as a first barrier layer on the substrate surface by plasma enhanced chemical vapor deposition; S3, using plasma enhanced atomic layer deposition to deposit an Al2O3 / ZnO nano-stacked film on the surface of the first barrier layer as the second barrier layer; S4. Coat the surface of the second barrier layer with organic polysilazane or polysiloxane by a spray / spin coating composite process, and then perform a curing treatment to obtain a flexible high-barrier composite film.

6. The preparation method according to claim 5, characterized in that: The activation treatment is: using plasma, glow discharge, corona or microwave to treat the surface of the substrate.

7. The preparation method according to claim 5, characterized in that: In step S2, the temperature of the plasma enhanced chemical vapor deposition is 70-140° C., and the radio frequency power is 250-650 W; In step S3, the deposition temperature of plasma enhanced atomic layer deposition is 70-160°C.

8. The preparation method according to claim 5, characterized in that: In step S4, organic polysilazane or polysiloxane is sprayed on the surface of the substrate, and then spin-coated, and then heated to cure after spin-coating; The curing temperature is 60~140℃ and the curing time is 2~6h.

9. Use of the flexible high-barrier composite film according to any one of claims 1 to 4 or the flexible high-barrier composite film prepared by the preparation method according to any one of claims 5 to 8 in flexible thin-film solar cells or organic electroluminescent devices.

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