Ultrahigh-performance water and oxygen barrier film and preparation method thereof

Abstract

The embodiment of the invention provides an ultrahigh-performance water and oxygen barrier film and a preparation method thereof. The ultra-high-performance water and oxygen barrier film sequentially comprises a high-molecular polymer base material, a pretreatment layer, a first inorganic barrier layer, an organic barrier layer and a second inorganic barrier layer from bottom to top. The ultra-high-performance water and oxygen barrier film can improve the barrier property to water and oxygen and can improve the light transmittance.

Description

Technical Field

[0001] The present invention relates to the technical field of optical thin films, and in particular to an ultra-high performance water and oxygen barrier film and a preparation method thereof. Background Art

[0002] The new generation of flexible electronic devices such as display, lighting, and photovoltaics have broad application prospects in the fields of information, energy, medical care, and national defense due to their unique bendability and roll-to-roll continuous production. Among them, organic thin-film solar cells (OPVs), organic electroluminescent diodes (OLEDs), and quantum dot displays are the representatives. Organic thin-film solar cells have gradually become the best choice to replace traditional crystalline silicon solar cells due to their significant features such as low cost, less consumables, light weight, bendability, large-area film formation, and easy portability and transportation. However, when flexible electronic devices are directly exposed to the atmosphere, their electrode materials, organic polymers and other components will quickly fail due to the influence of water vapor and oxygen in the air. They must be effectively encapsulated with a packaging film with water and oxygen barrier properties to ensure efficient and stable operation of the device and extend its service life. Organic luminescent materials are extremely sensitive to water and oxygen. Defects such as pixel blackening and accumulation caused by water and oxygen leakage and interface diffusion will cause device function degradation and failure. Water and oxygen barrier films are crucial to the performance and life of flexible electronic devices.

[0003] Chinese patent application CN114515682A discloses a flexible transparent ultra-low water vapor transmission rate barrier film and its preparation method, comprising an organic flexible substrate, one or more layers of water-proof and oxygen-proof films with a wrinkled morphology, and an organic layer, which are compounded from bottom to top. The water-proof and oxygen-proof films are compounded from bottom to top by an organic polymer layer and an inorganic oxide layer. However, the flexible transparent ultra-low water vapor transmission rate barrier film only studies the barrier performance for water vapor. The influence of oxygen on the barrier performance of the barrier film cannot be ignored.

[0004] Chinese patent application CN107644943A discloses a water vapor oxygen barrier film and a preparation method thereof, wherein the water vapor oxygen barrier film comprises a substrate layer, a first organic barrier layer, a first inorganic barrier layer, a second organic barrier layer, a second inorganic barrier layer, a third organic barrier layer and a third inorganic barrier layer in sequence. The disadvantages of this process are that inkjet printing coating is prone to nozzle clogging due to its narrow coating liquid application range and solvent volatilization, and is affected by rheological properties such as coating liquid surface tension and density in order to produce stable droplets, and has limited applicability.

[0005] Chinese patent application CN117089097A discloses a primer-treated water vapor barrier film and a preparation method thereof. The primer-treated water vapor barrier film prepared thereby comprises a four-layer structure from bottom to top, namely, an organic polymer substrate layer, a multifunctional primer layer, an inorganic oxide coating layer and a top-coated protective / barrier layer.

[0006] Among them, the barrier films obtained by using processes such as corona, electron beam evaporation coating, resistive thermal evaporation coating, and ceramic roller coating have average water vapor permeability and oxygen permeability performance. Summary of the invention

[0007] In order to improve the water and oxygen barrier performance of a water and oxygen barrier film and to improve the problems of poor light transmittance and poor display effect, the present invention provides an ultra-high performance water and oxygen barrier film and a preparation method thereof.

[0008] The inorganic / organic / inorganic stacked structure design of the water and oxygen barrier film provided by the present invention is the most effective means to obtain ultra-high barrier films in the field of flexible packaging. The organic layer adopts vacuum negative pressure low-viscosity slit coating process technology to prepare a tens of nanometer organic barrier layer. The inorganic layer adopts magnetron vacuum sputtering process technology, and the water vapor transmission rate is less than 3.7×10 -5 g / m 2 / day, oxygen transmission rate is less than 5.3×10 -4 g / m 2 / day, visible light transmittance>90%, greatly improving the barrier and light transmittance.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions.

[0010] The present invention provides an ultra-high performance water and oxygen barrier film, which comprises, from bottom to top, a polymer substrate, a pretreatment layer, a first inorganic barrier layer, an organic barrier layer, and a second inorganic barrier layer.

[0011] Furthermore, the polymer substrate is a highly transparent substrate with a thickness of 50-200 μm, preferably 100 μm.

[0012] Furthermore, the high molecular polymer substrate includes at least one of polyethylene terephthalate film (PET), polypropylene film (BOPP, OPP), polyethylene film (PE) and polycarbonate film (PC).

[0013] Furthermore, the pretreatment layer is an acrylate hardening coating, and the thickness of the pretreatment layer is 1-5 μm, preferably 2-3 μm.

[0014] The pretreatment layer is located between the high molecular polymer substrate and the first inorganic barrier layer, and can flatten the rough microstructure on the surface of the substrate and improve the adhesion of the first inorganic barrier layer.

[0015] Furthermore, the first inorganic barrier layer and the second inorganic barrier layer are respectively formed by roll-to-roll PVD (Physical Vapor Deposition) vacuum magnetron sputtering process technology, and the preparation method comprises the following steps: (1) a polymer substrate coated with a pretreatment layer and an organic barrier layer (i.e., an organic barrier layer formed on the first inorganic barrier layer) are respectively used as substrates; (2) a silicon target or an aluminum target is used to pass nitrogen or oxygen, and each inorganic barrier layer passes through a chamber and is connected to a medium frequency power supply or a direct current power supply for magnetron sputtering; (3) the power of the power supply is 150W-400W, Ar gas is used as the protective gas, O2 is introduced as the oxygen source (or N2 as the nitrogen source) during the sputtering process, the flow rate of the oxygen source or the nitrogen source is 15-32sccm, and the deposition temperature is 75-150°C. (4) By adjusting the target sputtering power, the same or different target material is sputtered onto the pretreatment layer and the organic barrier layer to form a first inorganic barrier layer on the pretreatment layer and a second inorganic barrier layer on the organic barrier layer.

[0016] Furthermore, the first inorganic barrier layer and / or the second inorganic barrier layer are SiO x Coating, Si x N y A laminate of one or at least two of a coating and an Al2O3 coating.

[0017] Furthermore, the first inorganic barrier layer and / or the second inorganic barrier layer are SiO x Coating and Si x N y The number of layers of the coating layer (plating layer) stack is 3-7. Increasing the number of layers significantly promotes the reduction of water vapor and oxygen permeability. For cost considerations, 4-6 layers are preferred, and the thickness is preferably 100-200 nm.

[0018] Furthermore, the first inorganic barrier layer and / or the second inorganic barrier layer are SiO x Layer and Si x N y Layer stack, SiO x Where x is 1.5 to 3, Si x N y Here x is 2 to 4, and y is 2 to 5.

[0019] Furthermore, the first inorganic barrier layer and / or the second inorganic barrier layer are SiO x Coating and Si x N y Coating stack, SiO x Where x is preferably 1.5 to 2.5, Si x N yHere, x is preferably 2.5 to 3.5, and y is preferably 2.5 to 4.5.

[0020] Furthermore, the organic barrier layer is made of an organic coating through a vacuum negative pressure low-viscosity slit coating process, the coating thickness of the organic coating is 80 to 150 nm, and the coating speed is 2 to 20 m / min. Herein, "low viscosity" means that the viscosity of the organic coating is 1 to 3 cps. The vacuum negative pressure low-viscosity slit coating process can be used to produce an ultra-thin, low-roughness organic barrier layer, which not only improves the barrier effect of water and oxygen, but also is located between the first inorganic barrier layer and the second inorganic barrier layer, which can decouple the defects of adjacent inorganic barrier layers and improve the flatness and flexibility of the barrier film (first inorganic barrier layer / organic barrier layer / second inorganic barrier layer).

[0021] Furthermore, the organic coating comprises the following components in parts by mass: 40-50 parts of resin, 1-3 parts of nanofiller, 3-6 parts of photoinitiator, 1-4 parts of leveling agent, and 50-80 parts of solvent.

[0022] Furthermore, the resin is one of epoxy acrylate, polyurethane acrylate, polyester acrylate, polysiloxane-acrylic composite resin, polysiloxane-polyurethane composite resin, or a mixture of at least two of them.

[0023] Furthermore, the nanofiller is nano-inorganic particles, the nano-inorganic particles are selected from at least one of silicon dioxide particles, titanium dioxide particles, graphene, carbon nanotubes, calcium carbonate particles and silicon nitride particles, and the particle size of the nano-inorganic particles is between 2nm and 60nm.

[0024] Furthermore, the photoinitiator is a cleavage-type initiator, and the cleavage-type initiator is selected from one or a combination of at least two of 1-hydroxycyclohexyl phenyl ketone (184), 2-hydroxy-methylphenylpropane-1-one (1173), 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (907), benzoin dimethyl ether (651) and 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide (TPO).

[0025] Furthermore, the photoinitiator is a hydrogen abstraction type initiator, and the hydrogen abstraction type initiator is selected from one or a combination of at least two of xylene ketone (BP) and 2-isopropylthioxanthone (ITX).

[0026] Furthermore, the photoinitiator is preferably 1-hydroxycyclohexyl phenyl ketone (184).

[0027] Furthermore, the leveling agent is one or a combination of at least two selected from BYK Additive & Instruments' BYK-333, BYK-378, Dainippon Ink & Chemicals' MEGAFACE F440, F445, F470, and EVONIK's Flow300, Flow370.

[0028] Furthermore, the leveling agent preferably includes one or a combination of MEGAFACE F440 and F445.

[0029] Furthermore, the solvent includes one of methyl isobutyl ketone, ethyl acetate, propylene glycol methyl ether, and isopropanol, or a mixture of at least two of them.

[0030] Limiting the formula of the organic coating to the above-mentioned preferred parameter range can ensure that the organic coating is evenly coated on the surface of the first inorganic barrier layer.

[0031] The technical solution provided by the present invention has the following beneficial effects compared with the prior art:

[0032] The barrier film in the present invention includes a stacked first inorganic barrier layer, an organic barrier layer and a second inorganic barrier layer. The barrier performance of the inorganic / organic / inorganic stacked structure formed by these three layers is greatly improved compared with the barrier performance of a single structure film, the water vapor barrier is improved by four orders of magnitude, the oxygen barrier is improved by three orders of magnitude, and the organic barrier layer is located between the two inorganic barrier layers, which can "decouple" the defects of adjacent inorganic barrier layers. The organic barrier layer prepared by the vacuum negative pressure low-viscosity slit coating process technology can improve the flatness and flexibility of the barrier film (the above-mentioned inorganic / organic / inorganic stacked structure) and further improve the barrier performance. The inorganic barrier layer adopts the vacuum magnetron sputtering process technology to ensure a high barrier rate. The laminated structure of the inorganic barrier layer is optimized to make the structure more compact. In addition, the inorganic nanofiller has a good effect on filling the defects of the inorganic barrier layer and improving the barrier performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of an ultra-high performance water and oxygen barrier film according to an embodiment of the present invention;

[0034] Figure 2 This is a physical product picture of the ultra-high performance water and oxygen barrier film according to an embodiment of the present invention.

[0035] The above-mentioned drawings include the following reference numerals:

[0036] a, high molecular polymer substrate; b, pretreatment layer; c, first inorganic barrier layer; d, organic barrier layer; e, second inorganic barrier layer. DETAILED DESCRIPTION

[0037] The technical scheme of the present invention is further described below by specific examples. In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art, and the methods in the embodiments, unless otherwise specified, are conventional methods in the art.

[0038] The performance of the ultra-high performance water and oxygen barrier film provided by the embodiment of the present invention is tested according to the following method:

[0039] (1) Haze and total light transmittance: Haze was measured by the transmitted light method using a Nippon Denshoku NDH2000N haze meter.

[0040] (2) Water vapor transmission rate test: Cut at least 4 samples from the ultra-high performance water and oxygen barrier film in the width direction and then test them on the AQUATRAN 3 series water vapor transmission rate meter. The test area is 50 cm 2 , the test chamber temperature is 38°C, the humidity is 90RH%, and the average water vapor transmission rate of all test samples is taken.

[0041] (3) Oxygen permeability test: The above samples were tested for oxygen permeability using an Ox-tran 2 / 22 series oxygen permeability tester with a test area of ​​50 cm 2 , the test chamber temperature is 38°C, the humidity is 90RH%, and the average value of the oxygen transmission rate of all test samples is taken.

[0042] Example 1

[0043] A method for preparing an ultra-high performance water and oxygen barrier film is as follows:

[0044] Step 1: A pretreatment layer with a thickness of 2 μm is coated on the surface of a polypropylene film substrate by a micro-dimpled coating method.

[0045] The process of micro-concave coating method includes: unwinding → tension control → coating → drying → curing → winding. The unwinding and winding speed is 5-12m / min; the tension is controlled at 110-250N; the coating thickness is 2um; the curing temperature is 40-90℃; and the UV curing energy is 700mJ.

[0046] By the above-mentioned dimple coating method, a uniform and flat pretreatment layer can be formed on the surface of the polypropylene film substrate.

[0047] Step 2: On the pre-treated layer obtained in step 1, Si is sputtered by vacuum magnetron sputtering. x N y and SiO xIn step 2, Si is sputtered by a roll-to-roll PVD vacuum magnetron sputtering process. x N y and SiO x The four-layer laminate comprises: a polypropylene film substrate coated with a pre-treated layer on the surface is used as a substrate, a silicon target is used in different chambers, and nitrogen is introduced into the sputtering chamber to form Si x N y layer, oxygen is introduced to form SiO x , nitrogen and oxygen are introduced alternately to form Si x N y Layer, SiO x Layer, Si x N y Layer and SiO x The stacked body is stacked in order. During the sputtering process, the power of the instrument is 150W-400W, Ar gas is used as the protective gas, O2 or N2 is introduced as the oxygen source or nitrogen source respectively during the sputtering process, the flow rate is 15-32sccm, and the deposition temperature is 75-150°C.

[0048] Step 3: Then, an organic barrier layer is coated on the first inorganic barrier layer by using a low-viscosity slot coating process.

[0049] The organic formula of the organic barrier layer includes: 40 parts by weight of polyester acrylate polysiloxane-acrylic composite resin, 2.0 parts by weight of silica particles, 4.0 parts by weight of photoinitiator 1-hydroxycyclohexyl phenyl ketone (184), 2.0 parts by weight of leveling agent F445 and 52 parts by weight of solvent, wherein the solvent includes 26 parts by weight of methyl isobutyl ketone and 26 parts by weight of ethyl acetate.

[0050] Step 4: On the organic barrier layer coated in step 3, Si is sputtered by magnetron sputtering. x N y and SiO x A five-layer stack of as the second inorganic barrier layer.

[0051] More detailed composition ratios and barrier film properties are shown in Tables 1 and 2, respectively.

[0052] The preparation methods of the ultra-high performance water and oxygen barrier films involved in Examples 2-6 are the same as those in Example 1, and the corresponding organic coating ratios and water and oxygen barrier film properties are shown in Tables 1 and 2, respectively.

[0053] Comparative Example 1

[0054] The water and oxygen barrier film does not contain the pretreatment layer (b).

[0055] Comparative Example 2

[0056] The first inorganic barrier layer (c) in the middle is Si x N y and SiO x A two-layer laminate.

[0057] Comparative Example 3

[0058] The water and oxygen barrier film does not include the first inorganic barrier layer (c).

[0059] Comparative Example 4

[0060] No nano filler is added to the organic layer coating liquid.

[0061] Comparative Example 5

[0062] The main difference from other embodiments is that the organic barrier layer is coated by a micro-dimpled coating method.

[0063] Table 1 Examples and Comparative Examples Proportions and Requirements

[0064]

[0065]

[0066] Next, the ultra-high performance water and oxygen barrier films in Examples 1-7 and Comparative Examples 1-5 were tested for performance using instruments such as a haze meter, a water vapor transmission rate tester, and an oxygen transmission rate tester. The test results are shown in Table 2.

[0067] Table 2 Test results

[0068]

[0069] The ultra-high performance water and oxygen barrier film provided by the present invention has ultra-high water and oxygen barrier performance. As can be seen from Table 2, the water vapor transmission rate and oxygen transmission rate of Example 4 can reach 3.7×10 -5 g·m -2 ·day -1 , 5.3×10 -4 g·m -2 ·day -1 , improving the barrier performance against water and oxygen. In addition, it has the characteristics of high light transmittance and excellent adhesion between the barrier layer and the polymer substrate layer, which can extend the service life of the display device. From the experimental results, it can be obtained that increasing the thickness of the inorganic barrier layer can promote the improvement of barrier performance. The organic barrier layer can improve the overall flatness and flexibility of the barrier layer, further improving the barrier performance. The laminated structure of the inorganic barrier layer is optimized and designed, and the structure is more compact. The inorganic barrier layer prepared by vacuum magnetron sputtering ensures a high barrier rate.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An ultra-high performance water and oxygen barrier film, characterized in that: The ultra-high performance water and oxygen barrier film comprises, from bottom to top, a high molecular polymer substrate, a pretreatment layer, a first inorganic barrier layer, an organic barrier layer, and a second inorganic barrier layer.

2. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The high molecular polymer substrate is a transparent substrate, and the thickness of the substrate is 50-200 μm.

3. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The high molecular polymer substrate includes at least one of a polyethylene terephthalate film, a polypropylene film, a polyethylene film and a polycarbonate film.

4. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The pretreatment layer is an acrylic ester hardening coating, and the thickness of the pretreatment layer is 1-5 μm.

5. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The first inorganic barrier layer and the second inorganic barrier layer are respectively formed by a vacuum magnetron sputtering process.

6. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The first inorganic barrier layer and / or the second inorganic barrier layer are SiO x Coating, Si x N y A laminate of one or at least two of a coating and an Al2O3 coating.

7. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The thickness of the first inorganic barrier layer and the second inorganic barrier layer are respectively 10-200 nm.

8. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The organic barrier layer is made of organic coating through a vacuum negative pressure low viscosity slit coating process.

9. The ultra-high performance water and oxygen barrier film according to claim 1, characterized in that: The organic coating comprises the following components in parts by mass: 40-50 parts of resin, 1-3 parts of nano filler, 3-6 parts of photoinitiator, 1-4 parts of leveling agent and 50-80 parts of solvent.

10. The ultra-high performance water and oxygen barrier film according to claim 9, characterized in that: The resin is one of epoxy acrylate, polyurethane acrylate, polyester acrylate polysiloxane-acrylic composite resin, polysiloxane-polyurethane composite resin, or a mixture of at least two of them.

11. The ultra-high performance water and oxygen barrier film according to claim 9, characterized in that: The nano filler is nano inorganic particles, which are selected from at least one of silicon dioxide particles, titanium dioxide particles, graphene, carbon nanotubes, calcium carbonate particles and silicon nitride particles, and the particle size of the nano inorganic particles is between 2nm and 60nm.

12. A method for preparing an ultra-high performance water and oxygen barrier film according to any one of claims 1 to 11, characterized in that: The preparation method comprises: Step 1: coating a pretreatment layer on the surface of a polymer substrate by a micro-dimpled coating process; Step 2: On the pre-treated layer obtained in step 1, SiO x Coating, Si x N y A single layer or two to seven layers of inorganic coating, such as Al2O3 coating, to prepare a first inorganic barrier layer; Step 3: on the first inorganic barrier layer obtained in step 2, an organic barrier layer is prepared by a low-viscosity slot coating process; Step 4: On the organic barrier layer obtained in step 3, SiO x Coating, Si x N y A single layer of coating, Al2O3 coating or two to seven layers of inorganic coating serve as the second inorganic barrier layer.

13. The preparation method according to claim 12, wherein the optimal water vapor transmission rate of the ultra-high performance water and oxygen barrier film is 3.7×10 -5 g / m 2 / day, oxygen permeability is 5.3×10 -4 cm 3 / m 2 / day, visible light transmittance>90%.

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