Organic packaging material and preparation method thereof, display device and preparation method thereof

Abstract

The present application discloses an organic encapsulation material and a preparation method thereof, a display device and a preparation method thereof, wherein the organic encapsulation material comprises: a base material and a water-absorbing material containing a hydroxyl group, wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000‑29:100000. The present application defines the mass ratio of the hydroxyl group in the water-absorbing material to the base material, which can ensure the water absorption of the organic encapsulation layer formed by the organic encapsulation material, and then utilizes the hydroxyl group in the water-absorbing material to absorb the water vapor in the cured base material, which can effectively prevent the water vapor in the organic encapsulation layer from invading the OLED device, thereby improving the preparation yield and display effect of the display device.

Description

Technical Field

[0001] The present application relates to the field of flexible display technology, and in particular to organic packaging materials and preparation methods thereof, display devices and preparation methods thereof. Background Art

[0002] Organic Light-Emitting Diode (OLED) is a device that uses a multi-layer organic thin film structure to generate electroluminescence. Due to its self-luminous properties and the ability to be used for flexible displays, it has been widely used in the field of flexible display technology.

[0003] The organic light-emitting materials in OLED devices are extremely sensitive to water vapor and oxygen. If water and oxygen invade the organic light-emitting materials, it will often cause defects in the OLED devices, which will then lead to problems such as black spots and display abnormalities in the display products. Therefore, after the organic light-emitting materials are evaporated, thin film encapsulation technology is needed to encapsulate the OLED devices. In the prior art, inorganic film layers and organic film layers are generally deposited alternately on the OLED devices by CVD (chemical vapor deposition) and inkjet printing to prevent water and oxygen from invading the OLED devices.

[0004] However, there will be residual moisture in the organic film layer formed by inkjet printing. During actual storage and operation, the water vapor in the organic film layer will still diffuse into the inorganic film layer and invade the OLED device through the inorganic film layer, thereby affecting the function and life of the OLED device and causing product defects. Summary of the invention

[0005] The main technical problem solved by the present application is to provide an organic encapsulation material and a preparation method thereof, a display device and a preparation method thereof, which can solve the problem that water vapor in the organic encapsulation layer in the prior art easily invades the OLED device.

[0006] To solve the above technical problems, the first technical solution adopted in the present application is to provide an organic packaging material, including: a base material and a hydroxyl-containing water-absorbing material, wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000.

[0007] The mass ratio of the water-absorbing material to the matrix material is 1:10000 to 1:1000.

[0008] The water-absorbing material includes a hydroxyl-containing oligomer.

[0009] The hydroxyl-containing oligomer includes polypropylene alcohol oligomer, the polymerization degree of the polypropylene alcohol oligomer is 5-10, and the relative molecular mass of the polypropylene alcohol oligomer is 290-1300.

[0010] Wherein, the matrix material includes methyl methacrylate.

[0011] In order to solve the above technical problems, the second technical solution adopted in the present application is to provide a method for preparing an organic packaging material, comprising: obtaining a base material and a hydroxyl-containing water-absorbing material; wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; and, adding the water-absorbing material into the base material according to the mass ratio, and obtaining the organic packaging material after high-speed stirring.

[0012] In order to solve the above technical problems, the third technical solution adopted in the present application is to provide a display device, comprising: a substrate; a light-emitting functional layer, arranged on the substrate; an organic encapsulation layer, arranged on the side of the light-emitting functional layer away from the substrate; wherein the organic encapsulation material forming the organic encapsulation layer comprises a base material and a water-absorbing material containing hydroxyl groups; wherein the mass ratio of the hydroxyl groups of the water-absorbing material to the base material is 29:1000000-29:100000.

[0013] To solve the above technical problems, the fourth technical solution adopted in the present application is to provide a method for preparing a display device, comprising: providing a substrate and forming a light-emitting functional layer on the substrate; obtaining an organic encapsulation material; wherein the organic encapsulation material comprises a base material and a hydroxyl-containing water-absorbing material, and the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; using the organic encapsulation material to form an organic encapsulation material layer on the side of the light-emitting functional layer away from the substrate; curing the organic encapsulation material layer to form an organic encapsulation layer; and drying the organic encapsulation layer.

[0014] The step of curing the organic encapsulation material layer to form the organic encapsulation layer includes: curing the organic encapsulation material layer using ultraviolet light in a nitrogen atmosphere and / or an inert gas atmosphere to form the organic encapsulation layer.

[0015] The step of drying the organic encapsulation layer comprises: heating the organic encapsulation layer under vacuum conditions, the heating temperature being 50-70° C. and the heating time being 2-4 hours.

[0016] The beneficial effect of the present application is as follows: Different from the prior art, the present application provides an organic encapsulation material and a preparation method thereof, a display device and a preparation method thereof, and forms an organic encapsulation material by adding a hydroxyl-containing water-absorbing material to a base material, and limits the mass ratio of the hydroxyl groups in the water-absorbing material to the base material, thereby ensuring the water absorption of an organic encapsulation layer formed by the organic encapsulation material, and then utilizing the hydroxyl groups in the water-absorbing material to absorb water vapor in the cured base material, thereby effectively preventing water vapor in the organic encapsulation layer from invading the OLED device, thereby improving the preparation yield and display effect of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the example description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing an organic encapsulation material of the present application;

[0019] Figure 2 It is a schematic structural diagram of an embodiment of a display device of the present application;

[0020] Figure 3 It is a schematic flow chart of an implementation method of a method for preparing a display device of the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] 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", "said", and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless otherwise clearly indicated above, and "multiple" generally includes at least two, but does not exclude the inclusion of at least one.

[0023] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0024] It should be understood that the terms "include", "comprises" or any other variations used herein are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0025] The organic light-emitting materials in OLED devices are extremely sensitive to water vapor and oxygen. If water and oxygen invade the organic light-emitting materials, it will often cause defects in OLED devices, which will then lead to problems such as black spots and display abnormalities in display products. Therefore, after the organic light-emitting materials are evaporated, thin-film encapsulation technology is needed to encapsulate the OLED devices.

[0026] In the prior art, inorganic and organic film layers are usually deposited alternately on OLED devices by CVD (chemical vapor deposition) and inkjet printing to prevent water and oxygen from invading OLED devices. However, there will be residual moisture in the organic film layer formed by inkjet printing. During actual storage and operation, the water vapor in the organic film layer will still diffuse into the inorganic film layer and invade the OLED device through the inorganic film layer, thereby affecting the function and life of the OLED device and causing product defects.

[0027] Based on the above situation, the present application provides an organic encapsulation material and a preparation method thereof, a display device and a preparation method thereof, which can solve the problem in the prior art that water vapor in the organic encapsulation layer easily invades the OLED device.

[0028] The organic packaging material provided in the present application comprises a base material and a water-absorbing material containing hydroxyl groups, wherein the mass ratio of the hydroxyl groups of the water-absorbing material to the base material is 29:1000000-29:100000.

[0029] In this embodiment, the matrix material includes methyl methacrylate.

[0030] In this embodiment, the water-absorbing material includes a hydroxyl group-containing oligomer.

[0031] Among them, the oligomer has better dispersibility and can be dispersed more evenly in the acrylic resin.

[0032] Among them, hydroxyl group is a hydrophilic functional group.

[0033] Specifically, methyl methacrylate will polymerize to form acrylic resin after being irradiated with ultraviolet light (UV), and water vapor will remain in the acrylic resin. The hydroxyl group has good water absorption, so the hydroxyl-containing oligomer is filled in the acrylic resin, and the hydroxyl group can effectively absorb the water vapor in the acrylic resin to prevent the water vapor from diffusing into the inorganic encapsulation layer and invading the OLED device layer. At the same time, during actual storage and operation, the hydroxyl group of the absorption material can also continue to absorb the water vapor that invades the acrylic resin from the outside, thereby preventing the outside water vapor from invading the OLED device layer through the acrylic resin. So far, the organic encapsulation material of the present application solves the problem that the water vapor in the organic encapsulation layer is easy to invade the OLED device.

[0034] It can be understood that by limiting the mass ratio of the hydroxyl group in the water-absorbing material to the base material, the organic encapsulating material can include a sufficient amount of hydrophilic functional groups, thereby ensuring the water absorption of the organic encapsulating layer formed by the organic encapsulating material.

[0035] In this embodiment, the hydroxyl-containing oligomer includes polypropylene alcohol oligomer, wherein the polymerization degree of the polypropylene alcohol oligomer is 5-10, and the relative molecular mass of the polypropylene alcohol oligomer is 290-1300.

[0036] It can be understood that the polymerization degree of polypropylene alcohol oligomer is relatively small, and its relative molecular weight is relatively small, so it is easy to disperse in methyl methacrylate.

[0037] In this embodiment, the mass ratio of the polypropylene alcohol oligomer to the matrix material is 1:10000-1:1000.

[0038] It is understandable that since polypropylene alcohol oligomer is a colorless to light yellow viscous liquid, if the content of polypropylene alcohol oligomer in the organic encapsulation material is too much, the film layer of the formed organic encapsulation layer will turn yellow, thereby affecting the light transmittance of the film layer and then affecting the display effect. If the content of polypropylene alcohol oligomer is too little, it will lead to a small number of hydroxyl groups included, the water absorption performance of the organic film layer will decrease, and the water vapor will diffuse into the inorganic layer and then invade the OLED device layer, thereby affecting the function and life of the OLED device layer, and then affecting the preparation yield of the display device.

[0039] In actual production, the inventors of the present application have found through a large amount of production practice that controlling the mass ratio of polypropylene alcohol oligomer to methyl methacrylate to be 1:10000-1:1000 and simultaneously controlling the mass ratio of the hydroxyl group of the polypropylene alcohol oligomer to methyl methacrylate to be 29:1000000-29:100000 can not only ensure the water absorption performance of the polypropylene alcohol oligomer, but also reduce the influence of the polypropylene alcohol oligomer on the light transmittance of the film layer, thereby ensuring the light transmittance of the formed organic encapsulation layer, and then improving the preparation yield and display effect of the display device.

[0040] In other embodiments, the water-absorbing material may also be an oligomer with an amino group or an oligomer with a carboxyl group, as long as the oligomer has a hydrophilic functional group and has good water absorption after UV curing, and the present application does not limit this.

[0041] Different from the prior art, this embodiment forms an organic encapsulation material by adding a hydroxyl-containing water-absorbing material to a base material, and limits the mass ratio of the hydroxyl group in the water-absorbing material to the base material, thereby ensuring the water absorption of the organic encapsulation layer formed by the organic encapsulation material, and then using the hydroxyl group in the water-absorbing material to absorb the water vapor in the cured base material, which can effectively prevent the water vapor in the organic encapsulation layer from invading the OLED device, thereby improving the preparation yield and display effect of the display device. Furthermore, by limiting the mass ratio of the water-absorbing material to the base material, the light transmittance of the organic encapsulation layer can also be ensured, thereby better improving the display effect of the display device.

[0042] Correspondingly, the present application provides a method for preparing an organic packaging material.

[0043] Specifically, see Figure 1 , Figure 1 1 is a flow chart of an embodiment of a method for preparing an organic encapsulation material of the present application. In this embodiment, the method for preparing an organic encapsulation material comprises:

[0044] S11: Obtain a base material and a water-absorbing material containing hydroxyl groups; wherein the mass ratio of the hydroxyl groups of the water-absorbing material to the base material is 29:1000000-29:100000.

[0045] In this embodiment, the base material includes methyl methacrylate, and the water-absorbing material includes a hydroxyl-containing oligomer.

[0046] The hydroxyl-containing oligomer includes polypropylene alcohol oligomer, wherein the polymerization degree of the polypropylene alcohol oligomer is 5-10, and the relative molecular mass of the polypropylene alcohol oligomer is 290-1300.

[0047] It can be understood that by limiting the mass ratio of the hydroxyl group in the water-absorbing material to the base material, the organic encapsulating material can include a sufficient amount of hydrophilic functional groups, thereby ensuring the water absorption of the organic encapsulating layer formed by the organic encapsulating material.

[0048] In this embodiment, the mass ratio of the water-absorbing material to the base material is 1:10000-1:1000.

[0049] It can be understood that controlling the mass ratio between polyacryl alcohol oligomer and methyl methacrylate can reduce the effect of polyacryl alcohol oligomer on the light transmittance of the film layer, thereby ensuring the light transmittance of the formed organic encapsulation layer, and then improving the preparation yield and display effect of the display device.

[0050] S12: adding the water-absorbing material into the base material according to the mass ratio, and stirring at a high speed to obtain an organic encapsulation material.

[0051] In this embodiment, the high-speed stirring is controlled for 1-1.5 hours.

[0052] It can be understood that ensuring sufficient stirring time can make the reaction of the polyacryl alcohol oligomer and methyl methacrylate more uniform, so as to ensure that the polyacryl alcohol oligomer is uniformly dispersed in the polyacryl alcohol oligomer, thereby effectively absorbing water vapor.

[0053] See also Figure 2 , Figure 2 It is a schematic structural diagram of an embodiment of a display device of the present application.

[0054] In this embodiment, the display device 200 includes a substrate 10, a light-emitting functional layer 20, an inorganic encapsulation layer 30, and an organic encapsulation layer 40. The light-emitting functional layer 20 is disposed on a side surface of the substrate 10. The inorganic encapsulation layer 30 is disposed on a side surface of the light-emitting functional layer 20 away from the substrate 10, and surrounds the light-emitting functional layer 20 to encapsulate the light-emitting functional layer 20. The organic encapsulation layer 40 is disposed on a side surface of the inorganic encapsulation layer 30 away from the light-emitting functional layer 20.

[0055] The light-emitting functional layer 20 is an OLED device layer.

[0056] The organic encapsulation material forming the organic encapsulation layer 40 includes a base material and a water-absorbing material containing hydroxyl groups filled in the base material, wherein the mass ratio of the hydroxyl groups in the water-absorbing material to the base material is 29:1000000-29:100000.

[0057] In this embodiment, the matrix material includes methyl methacrylate.

[0058] In this embodiment, the water-absorbing material includes a hydroxyl-containing oligomer, wherein the hydroxyl-containing oligomer includes a polypropylene alcohol oligomer, wherein the degree of polymerization of the polypropylene alcohol oligomer is 5-10, and the relative molecular mass of the polypropylene alcohol oligomer is 290-1300.

[0059] It can be understood that the hydroxyl group of the polypropylene alcohol oligomer has good water absorption and can effectively absorb water vapor in the acrylic resin formed by the polymerization of methyl methacrylate to prevent the water vapor from diffusing into the inorganic encapsulation layer and invading the OLED device layer.

[0060] It can be understood that by limiting the mass ratio of the hydroxyl group in the water-absorbing material to the base material, the organic encapsulating material can include a sufficient amount of hydrophilic functional groups, thereby ensuring the water absorption of the organic encapsulating layer formed by the organic encapsulating material.

[0061] In this embodiment, the mass ratio of the polypropylene alcohol oligomer to the matrix material is 1:10000-1:1000.

[0062] It can be understood that the mass ratio of polyacryl alcohol oligomer to methyl methacrylate in the organic encapsulation layer 40 is 1:10000-1:1000, which can reduce the effect of polyacryl alcohol oligomer on the light transmittance of the film layer, thereby ensuring the light transmittance of the organic encapsulation layer 40 and further improving the display effect of the display device 200.

[0063] Correspondingly, the present application provides a method for preparing a display device.

[0064] Specifically, see Figure 3 , Figure 3 1 is a schematic flow chart of an embodiment of a method for preparing a display device of the present application. In this embodiment, the method for preparing a display device includes:

[0065] S31: providing a substrate, and forming a light-emitting functional layer on the substrate.

[0066] In this embodiment, an inorganic packaging layer is further provided on a surface of the light-emitting functional layer that is away from the flexible substrate.

[0067] Among them, the light-emitting functional layer is the OLED device layer, and the inorganic encapsulation layer is formed on the surface of the OLED device layer away from the flexible substrate by chemical vapor deposition, and surrounds the OLED device layer to perform inorganic thin film encapsulation on the OLED device layer.

[0068] S32: Acquire an organic encapsulation material; wherein the organic encapsulation material comprises a base material and a water-absorbing material containing a hydroxyl group, and the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000.

[0069] In this embodiment, the base material includes methyl methacrylate, and the water-absorbing material includes a hydroxyl-containing oligomer.

[0070] The hydroxyl-containing oligomer includes polypropylene alcohol oligomer, wherein the polymerization degree of the polypropylene alcohol oligomer is 5-10, and the relative molecular mass of the polypropylene alcohol oligomer is 290-1300.

[0071] In this embodiment, the mass ratio of the polypropylene alcohol oligomer to the matrix material is 1:10000-1:1000.

[0072] S33: using an organic encapsulation material to form an organic encapsulation material layer on a side of the light-emitting functional layer away from the substrate.

[0073] In this embodiment, the organic encapsulation material is printed on the surface of the inorganic encapsulation layer away from the light-emitting functional layer by inkjet dripping, so that the organic encapsulation material completely covers the surface of the inorganic encapsulation layer away from the light-emitting functional layer to form an organic encapsulation material layer.

[0074] S34: curing the organic encapsulation material layer to form an organic encapsulation layer.

[0075] In this embodiment, the organic encapsulation material layer is cured by ultraviolet light under a nitrogen atmosphere and / or an inert gas atmosphere to form an organic encapsulation layer.

[0076] The inert gas includes helium and / or argon.

[0077] The UV irradiation time is controlled to be 0.5-1 hour.

[0078] Specifically, methyl methacrylate will polymerize to form acrylic resin after UV irradiation. Water vapor remains in the acrylic resin, and the hydroxyl group has good water absorption. Polypropylene alcohol oligomers are evenly distributed in the acrylic resin and can effectively absorb water vapor in the acrylic resin to prevent water vapor from diffusing into the inorganic encapsulation layer and invading the OLED device layer.

[0079] S35: Drying the organic encapsulation layer.

[0080] In this embodiment, the substrate to be encapsulated with the organic encapsulation layer formed thereon is dried in order to evaporate the water in the acrylic resin and reduce the water content in the organic encapsulation layer.

[0081] In a specific implementation scenario, the organic encapsulation layer is heated under vacuum conditions at a temperature of 50-70° C. for 2-4 hours.

[0082] It can be understood that controlling the appropriate heating temperature and heating time is beneficial to further remove the moisture in the organic encapsulation layer.

[0083] Different from the prior art, this embodiment adds a water-absorbing material to the base material to form an organic encapsulation material, and uses inkjet dripping to print the organic encapsulation material on the non-polar encapsulation layer of the substrate to be encapsulated, and uses UV irradiation to cure the organic encapsulation material. The water-absorbing material can absorb the water vapor in the cured base material to prevent the water vapor in the organic encapsulation layer from invading the OLED device. After UV curing, the organic encapsulation layer is dried using vacuum evaporation technology to further remove moisture from the organic encapsulation layer. Furthermore, by limiting the mass ratio of the water-absorbing material to the base material, it is possible to ensure both the water absorption of the organic encapsulation layer formed by the organic encapsulation material and the light transmittance of the organic encapsulation layer, thereby improving the display effect of the display device.

[0084] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An organic packaging material, characterized in that: include: A base material and a hydroxyl-containing water-absorbing material, wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; the mass ratio of the water-absorbing material to the base material is 1:10000-1:1000; the water-absorbing material comprises a hydroxyl-containing oligomer; and the base material comprises methyl methacrylate.

2. The organic encapsulation material according to claim 1, characterized in that: The hydroxyl-containing oligomer includes polypropylene alcohol oligomer, the polymerization degree of the polypropylene alcohol oligomer is 5-10, and the relative molecular weight of the polypropylene alcohol oligomer is 290-1300.

3. A method for preparing an organic packaging material, characterized in that: include: A base material and a hydroxyl-containing water-absorbing material are obtained; wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; the mass ratio of the water-absorbing material to the base material is 1:10000-1:1000; the water-absorbing material includes a hydroxyl-containing oligomer; the base material includes methyl methacrylate; and, The water-absorbing material is added into the base material according to the mass ratio, and the organic encapsulation material is obtained after high-speed stirring.

4. A display device, characterized in that: include: substrate; A light-emitting functional layer is disposed on the substrate; An organic encapsulation layer is arranged on a side of the light-emitting functional layer away from the substrate; wherein the organic encapsulation material forming the organic encapsulation layer includes a base material and a hydroxyl-containing water-absorbing material; wherein the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; the mass ratio of the water-absorbing material to the base material is 1:10000-1:1000; the water-absorbing material includes a hydroxyl-containing oligomer; and the base material includes methyl methacrylate.

5. A method for preparing a display device, characterized in that: include: Providing a substrate and forming a light-emitting functional layer on the substrate; An organic encapsulation material is obtained; wherein the organic encapsulation material comprises a base material and a hydroxyl-containing water-absorbing material, and the mass ratio of the hydroxyl group of the water-absorbing material to the base material is 29:1000000-29:100000; the mass ratio of the water-absorbing material to the base material is 1:10000-1:1000; the water-absorbing material comprises a hydroxyl-containing oligomer; the base material comprises methyl methacrylate; Using the organic encapsulation material to form an organic encapsulation material layer on a side of the light-emitting functional layer away from the substrate; curing the organic encapsulation material layer to form an organic encapsulation layer; and, The organic encapsulation layer is dried.

6. The preparation method according to claim 5, characterized in that: The step of curing the organic encapsulation material layer to form an organic encapsulation layer comprises: The organic encapsulation material layer is cured by ultraviolet light under a nitrogen atmosphere and / or an inert gas atmosphere to form the organic encapsulation layer.

7. The preparation method according to claim 5, characterized in that: The step of drying the organic encapsulation layer comprises: The organic encapsulation layer is heated under vacuum conditions at a temperature of 50-70° C. for 2-4 hours.

Images