Protective film, preparation method thereof and folding screen assembly
阅读说明：本技术 一种保护膜及其制备方法与折叠屏组件 (Protective film, preparation method thereof and folding screen assembly ) 是由 文偲嘉 王娟娟 王鹏 胡洋 于 2021-01-08 设计创作，主要内容包括：本申请公开了一种保护膜及其制备方法与折叠屏组件,所述保护膜包括至少一保护层,所述保护层包括一有机材料层和一无机材料层,其中,所述有机材料层的质地较软以赋予所述保护膜理想的弯折性能,所述无机材料层的质地较硬以赋予所述保护膜良好的强度,并且所述无机材料层的厚度不均一,即：所述无机材料层上需要弯折的区域厚度较薄,以便于所述保护膜弯折,所述保护膜具有保护效果理想、制造难度小且成本低、不易划伤等优点,所述保护膜可以应用于所述折叠屏组件中以保护柔性显示面板。(The application discloses a protective film and a preparation method thereof and a folding screen assembly, wherein the protective film comprises at least one protective layer, the protective layer comprises an organic material layer and an inorganic material layer, wherein the organic material layer is soft in texture to endow the protective film with ideal bending performance, the inorganic material layer is hard in texture to endow the protective film with good strength, and the thickness of the inorganic material layer is not uniform, namely: the region thickness that need buckle on the inorganic material layer is thinner, so that the protection film is buckled, the protection film has advantages such as protection effect ideal, the manufacturing degree of difficulty is little and with low costs, difficult fish tail, the protection film can be applied to in order to protect flexible display panel in the folding screen subassembly.)
1. A protective film, comprising at least one protective layer, the protective layer comprising:
an organic material layer; and
an inorganic material layer stacked on one surface of the organic material layer, the inorganic material layer having a non-uniform thickness;
wherein the inorganic material layer includes: the protective device comprises a first protective region, a second protective region and a third protective region, wherein the second protective region is positioned between the first protective region and the third protective region, and the thickness of the second protective region is smaller than that of the first protective region and that of the third protective region.
2. The protective film of claim 1, wherein the second protective region is located at a center of the inorganic material layer.
3. The protective film of claim 2, wherein the thickness of the first protective region and the thickness of the third protective region are equal.
4. The protective film according to claim 1, characterized in that the protective film comprises: the two protective layers are stacked and respectively comprise a first protective layer and a second protective layer.
5. The protective film according to claim 4, further comprising: and the optical transparent adhesive layer is arranged between the first protective layer and the second protective layer.
6. Protective film according to any one of claims 1 to 5, characterized in that the material of the organic material layer is selected from one or more of polyethylene terephthalate, polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyphenylene sulfide, polyallyl ester, polyimide, polycarbonate or cellulose acetate propionate.
7. The protective film according to any one of claims 1 to 5, wherein a material of the inorganic material layer is a transparent metal oxide or a non-metal oxide.
8. The preparation method of the protective film is characterized by comprising the following steps:
providing an organic material layer, and plating an inorganic material on one surface of the organic material layer by adopting a film plating process to form an inorganic film layer with uniform thickness, wherein a first protection area, a second protection area and a third protection area are predefined on the inorganic film layer, and the second protection area is positioned between the first protection area and the third protection area; and
providing a baffle plate to block the second protection area, and continuously plating the inorganic material on the inorganic film layer to form an inorganic material layer with non-uniform thickness, wherein the thickness of the second protection area is less than that of the first protection area and that of the third protection area.
9. The method according to claim 8, wherein the coating process is a magnetron sputtering process.
10. A folding screen assembly, comprising:
the flexible display panel is provided with a light emergent surface and a bending area; and
the protective film according to any one of claims 1 to 7, stacked on the light-emitting surface of the flexible display panel, wherein the second protective region corresponds to the bending region.
Technical Field
The application relates to the technical field of display, in particular to a protective film, a preparation method of the protective film and a folding screen assembly.
Background
Along with the rapid development of the intelligent mobile terminal technology, the product form of the mobile terminal is increasingly rich, wherein the folding mobile terminal is favored by consumers with the unique folding function, and the user experience of the consumers is improved due to the fact that the folding mobile terminal is provided with the flexible display panel capable of changing the size of the display area.
The folding mobile terminal has a high requirement on the flexible display panel, and because the light-emitting surface of the flexible display panel is easy to be damaged due to folding, a protective film needs to be attached to the light-emitting surface of the flexible display panel to reduce the risk of damage, and therefore, the quality of the protective film affects the service life of the flexible display panel. In the prior art, the protective film made of flexible material has good folding performance to meet the folding requirement, for example: the protective film is composed of a first Polyethylene terephthalate (PET) layer, a first Optically Clear Adhesive (OCA) layer and a second PET layer which are sequentially stacked. However, the protective film generally has the problems of insufficient hardness, unsatisfactory protective effect on the flexible display panel, easy occurrence of screen scratch and the like.
Still provide a protection film among the prior art, this protection film comprises first PET layer, first OCA layer, an ultra-thin glass (thickness is 30 microns), second OCA layer and the second PET layer that stacks gradually the setting. The protective film has the advantages that the strength of the protective film is enhanced by additionally arranging the ultrathin glass between the first PET layer and the second PET layer, but the ultrathin glass is easy to crack in a bending region, so that the protective film has the defect of short service life. In addition, the ultrathin glass is prepared by adopting a thinning glass method at present, and the defects of high operation difficulty, high cost, difficulty in thickness control and low yield are caused. Therefore, the development of a protective film with ideal bending performance, long service life, simple preparation and ideal protective effect on the flexible display panel is urgently needed.
Disclosure of Invention
Aiming at the defects of the prior art, the application provides the protective film, the preparation method thereof and the folding screen assembly, wherein the protective film has ideal bending performance to realize the folding function and good strength to effectively protect the flexible display panel.
In a first aspect, the present application provides a protective film comprising at least one protective layer, the protective layer comprising:
an organic material layer; and
an inorganic material layer stacked on one surface of the organic material layer, the inorganic material layer having a non-uniform thickness;
wherein the inorganic material layer includes: the protective device comprises a first protective region, a second protective region and a third protective region, wherein the second protective region is positioned between the first protective region and the third protective region, and the thickness of the second protective region is smaller than that of the first protective region and that of the third protective region.
In some embodiments of the present application, the second protective region is located at a center of the inorganic material layer.
In some embodiments of the present application, the thickness of the first protective region and the thickness of the third protective region are equal.
In some embodiments of the present application, the protective film comprises: the two protective layers are stacked and respectively comprise a first protective layer and a second protective layer.
In some embodiments of the present application, the protective film further comprises: and the optical transparent adhesive layer is arranged between the first protective layer and the second protective layer.
In some embodiments of the present application, the material of the organic material layer is selected from one or more of polyethylene terephthalate, polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyphenylene sulfide, polyallyl ester, polyimide, polycarbonate, and cellulose acetate propionate.
In some embodiments of the present application, the material of the inorganic material layer is a transparent metal oxide or nonmetal oxide.
In a second aspect, the present application provides a method for preparing a protective film, which is used for preparing the protective film of any one of the first aspect, and comprises the following steps:
providing an organic material layer, and plating an inorganic material on one surface of the organic material layer by adopting a film plating process to form an inorganic film layer with uniform thickness, wherein a first protection area, a second protection area and a third protection area are predefined on the inorganic film layer, and the second protection area is positioned between the first protection area and the third protection area; and
providing a baffle plate to block the second protection area, and continuously plating the inorganic material on the inorganic film layer to form an inorganic material layer with non-uniform thickness, wherein the thickness of the second protection area is less than that of the first protection area and that of the third protection area.
In some embodiments of the present application, the coating process is a magnetron sputtering process.
In a third aspect, the present application provides a folding screen assembly comprising:
the flexible display panel is provided with a light emergent surface and a bending area; and
the protective film according to any one of the first aspect is stacked on the light emitting surface of the flexible display panel, wherein the second protective region corresponds to the bending region.
The application provides a protective film, a preparation method thereof and a folding screen assembly, wherein the protective film comprises at least one protective layer, the protective layer mainly comprises an organic material layer and an inorganic material layer, wherein the organic material layer is soft in texture to endow the protective film with ideal bending performance, the inorganic material layer is hard in texture to endow the protective film with good strength, and the thickness of the inorganic material layer is not uniform, namely: the thickness of the region needing to be bent on the inorganic material layer is smaller, so that the protective film can be bent conveniently. Compare in the protection film of making by flexible material entirely, the protection film of this application has the advantage to flexible display panel protection effect ideal, difficult fish tail. Compare in the protection film that contains ultra-thin glass, the protection film of this application has that the manufacturing degree of difficulty is little, low in manufacturing cost, thickness is easily controlled, advantage that the yields is high.
The folding screen assembly mainly comprises a flexible display panel and a protective film which is stacked on a light-emitting surface of the flexible display panel, can be applied to various folding mobile terminals, and has the advantages of long service life and difficult damage to a bending part.
Drawings
The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of an embodiment of a protective film provided in an embodiment of the present application.
Fig. 2 is a schematic structural diagram of the inorganic material layer in fig. 1.
Fig. 3 is a schematic structural diagram of another embodiment of the protective film provided in the embodiment of the present application.
Fig. 4 is a flowchart of a method for manufacturing a protective film provided in an embodiment of the present application.
Figure 5 is a schematic structural view of one embodiment of a folding screen assembly provided in embodiments of the present application.
Fig. 6 is a schematic structural diagram of an embodiment of a flexible display panel provided in an embodiment of the present application.
Fig. 7 is a schematic structural diagram of another embodiment of the flexible display panel provided in the embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "vertical", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
In a first aspect, the embodiments of the present application provide a protective film, as shown in fig. 1 and fig. 2, the protective film includes at least one protective layer 1, where the protective layer 1 mainly includes: an organic material layer 11 and an inorganic material layer 12 are stacked, wherein the organic material layer 11 has a uniform thickness, and the inorganic material layer 12 has a non-uniform thickness.
Specifically, the material of the organic material layer 11 is selected from one or more of polyethylene terephthalate, polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyphenylene sulfide, polyallyl ester, polyimide, polycarbonate, or cellulose acetate propionate. The material of the organic material layer 11 is preferably Polyethylene terephthalate (PET).
The inorganic material layer 12 is divided into a first protection region 121, a second protection region 122, and a third protection region 123, the second protection region 122 is located between the first protection region 121 and the third protection region 123, and a thickness of the second protection region 122 is smaller than a thickness of the first protection region 121 and a thickness of the third protection region 123. It should be noted that the thickness of each protection region, the difference between the thicknesses of the first protection region 121 and the second protection region 122, and the difference between the thicknesses of the third protection region 123 and the second protection region 122 are not particularly limited, and can be selected according to actual requirements.
The material of the inorganic material layer 12 is transparent metal oxide or nonmetal oxide. The metal oxide may, for example, beIs indium tin oxide (In)2O3Sn, ITO), indium zinc oxide (ZnO: In, IZO), gallium zinc oxide (ZnO: Ga, GZO), aluminum zinc oxide (ZnO: Al, AZO), etc., and the non-metal oxide may be, for example, graphene, carbon nanotubes, etc. The material of the inorganic material layer is preferably ITO.
Preferably, the second protective region 122 is located at the center of the inorganic material layer. Preferably, the thickness of the first protection region 121 and the thickness of the third protection region 123 are equal, for example: the thickness of the first protection region 121 and the thickness of the third protection region 123 are both 30 micrometers, and the thickness of the second protection region 122 is 15 micrometers.
In another embodiment of the present application, as shown in fig. 3, the protective film is composed of a first protective layer 10, an optically transparent adhesive layer 20 and a second protective layer 30, which are sequentially stacked, wherein the first protective layer 10 is composed of a first PET layer 101 and a first ITO layer 102, which are stacked, and the second protective layer 30 is composed of a second PET layer 301 and a second ITO layer 302, which are stacked. The first ITO layer 102 and the second ITO layer 302 are respectively divided into a first protection region, a second protection region and a third protection region, the second protection region is located between the first protection region and the third protection region, and the thickness of the second protection region is smaller than the thickness of the first protection region and the thickness of the third protection region. The second protection region of the first ITO layer 102 corresponds in position to the second protection region of the second ITO layer 302. It should be noted that the first protection layer 10 and the second protection layer 30 may be completely the same or different, and may be selected according to actual needs.
In a second aspect, the present application provides a method for preparing a protective film, as shown in fig. 4, comprising the steps of:
s1, providing an organic material layer, and plating an inorganic material on one side of the organic material layer by adopting a plating process to form an inorganic film layer with uniform thickness, wherein a first protection area, a second protection area and a third protection area are predefined on the inorganic film layer, and the second protection area is positioned between the first protection area and the third protection area;
and 2, providing a baffle plate to block the second protection region, and continuously plating the inorganic material on the inorganic film layer to form an inorganic material layer with non-uniform thickness, wherein the thickness of the second protection region is less than that of the first protection region and that of the third protection region.
In one embodiment of the present application, in steps S1 and S2, the plating process is preferably a magnetron sputtering process.
Specifically, in step S1, when the magnetron sputtering process is used to plate the inorganic film layer at a low temperature, no barrier is disposed between the inorganic material to be plated and the organic material layer, so as to ensure that the inorganic material can uniformly form a film on the surface of the organic material layer. For step S2, the baffle is located between the inorganic material to be plated and the organic material layer, and the position of the baffle corresponds to the position of the predefined second protection region, for example: when the predefined second protection zone is located in the middle of the inorganic film layer, correspondingly, the forward projection of the baffle on the inorganic film layer is also located in the middle of the inorganic film layer, and the forward projection completely coincides with the predefined second protection zone.
It should be noted that the plating process may also adopt other processes for plating inorganic materials, such as: for the material adopting the transparent metal oxide as the inorganic material layer, processes such as direct current sputtering, radio frequency sputtering, plasma coating, ion plating and the like can also be adopted; for the material using the transparent non-metal oxide as the inorganic material layer, the inorganic material layer may be plated by a Chemical Vapor Deposition (CVD) process.
The above production method may be used for producing any one of the protective films described in the first aspect.
In a third aspect, the present application provides a folding screen assembly, comprising: the flexible display panel is provided with a light emergent surface and a bending area; and the protective film is arranged on the light-emitting surface of the flexible display panel in a laminated manner, and the second protective area corresponds to the bending area.
Specifically, the protective film is attached to the light emitting surface of the flexible display panel through the OCA.
In one embodiment of the present application, as shown in fig. 5, the folding screen assembly includes: a flexible display panel 100 having a light emitting surface, and a protective film 200 attached on the light emitting surface, wherein the protective film 200 completely covers the light emitting surface.
The flexible display panel 100 is divided into a first non-folding area 1001, a bending area 1002 and a second non-folding area 1003, the bending area 1002 is located between the first non-folding area 1001 and the second non-folding area 1003, and the bending area 1002 is located in the middle of the flexible display panel 100.
The structural composition of the protection film 200 refers to the protection film shown in fig. 3, specifically, the protection film 200 is composed of a first protection layer, an OCA layer, and a second protection layer, which are sequentially stacked, the first protection layer and the second protection layer are completely the same, and the description is given below by taking the first protection layer as an example, and the second protection layer refers to the first protection layer and is not repeated.
The first protective layer is composed of a PET layer and an ITO layer which are stacked, the PET layer has uniform thickness, and the thickness of the ITO layer is not uniform. The ITO layer is divided into a first protection area, a second protection area and a third protection area, the second protection area is located between the first protection area and the third protection area, and the second protection area is located in the middle of the ITO layer. The first protective region and the third protective region are equal in thickness, and the thickness of the second protective region is smaller than the thickness of the first protective region and the thickness of the third protective region. The second protection area corresponds to the bending area to assist the bending area to bend.
When the flexible display panel 100 is converted from the flat state to the folded state, the bending region 1002 can be bent to a certain arc to make the first non-folding region 1001 and the second non-folding region 1003 approach each other until overlapping; correspondingly, the second protection zone can be bent to a certain radian so that the first protection zone and the third protection zone are close to each other until being overlapped. When the flexible display panel 100 is converted from a folded state to a flattened state, the bending region 1002 and the second protection region can be converted from a bent arc state to a straight state.
In an embodiment of the present application, the flexible display panel is an Organic Light-Emitting Diode (OLED) display panel, as shown in fig. 6, and the flexible display panel includes a flexible substrate 1004, a Thin Film Transistor (TFT) layer 1005, an OLED layer 1006, and a Thin Film Encapsulation (TFE) layer 1007 sequentially stacked.
Specifically, the material of the flexible substrate 1004 may be selected from one or more of polyimide, polyethersulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyarylate, and glass fiber reinforced plastic. Polyimide is preferred as the material of the flexible substrate 1004 in the embodiments of the present application. The preparation method of the flexible substrate 1004 can be, for example: providing a bearing substrate, coating the material of the flexible substrate 1004 on the bearing substrate, and then drying to form the flexible substrate 1004, wherein the bearing substrate is preferably a glass substrate.
The structure of the TFT layer 1005 is not particularly limited, and may be selected according to actual needs. The TFT layer 1005 may be formed on one side of the flexible substrate 1004 by means of electronic printing. For example, comprising the steps of: preparing electronic ink; printing a patterned gate electrode on the flexible substrate; printing a grid electrode insulating layer on the flexible substrate, wherein the grid electrode insulating layer covers the grid electrode; printing a patterned source electrode and a patterned drain electrode on the gate insulating layer; printing a patterned active layer between the source electrode and the drain electrode, wherein two ends of the active layer are respectively connected with the source electrode and the drain electrode.
The OLED layer 1006 includes an anode layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode layer, which are sequentially stacked. The OLED layer can be formed on one side, away from the flexible substrate, of the TFT layer in an electronic printing mode.
The material of the TFE layer 1007 is an inert compound and may be selected from silicon oxide (SiO)x) Silicon nitride (SiN)x) And alumina (Al)2O3) One or more of (a). The TFE layer may have a single-layer structure or a multi-layer structure. The TFE layer can be formed by electronic printing on the side of the OLED layer facing away from the TFT layer.
In another embodiment of the present application, as shown in fig. 7, the flexible display panel includes a flexible substrate 1004, a TFT layer 1005, an OLED layer 1006, a TFE layer 1007, a touch layer 1008, and a polarizer layer 1009, which are sequentially stacked.
Specifically, the touch layer 1008 is used for realizing human-computer interaction, and can be attached to the TFE layer 1007 through the OCA, so that the touch layer 1008 is glued to the surface of the TFE layer 1007 facing away from the OLED layer 1006, and the touch layer 1008 can also be prepared in an electronic printing manner.
The polarizer layer 1009 has an anti-reflection function to increase the display contrast of the flexible display panel 100 under strong light. The polarizer layer 1009 may be attached to a surface of the touch layer 1008 facing away from the TFE layer 1007 by OCA.
It should be noted that the structure of the flexible display panel 100 is not limited to the two structural forms listed above, and the flexible display panel may also adopt other layer structural forms on the premise of satisfying the requirement of the folding display.
The folding screen assembly described in the third aspect may be applied as a display screen in a folding mobile terminal, which may be, for example: the system comprises a mobile phone, a tablet personal computer, a digital camera, a digital video camera, a game machine, an audio reproduction device, an information terminal, intelligent wearable equipment, an intelligent weighing electronic scale, an on-vehicle display, a television and the like, wherein the intelligent wearable equipment can be an intelligent bracelet, an intelligent watch, intelligent glasses and the like.
The protective film, the preparation method thereof and the folding screen assembly provided by the embodiment of the application are described in detail above. The principle and the implementation of the present application are explained by applying specific examples, and the above description of the embodiments is only used to help understanding the technical solution and the core idea of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.