Flexible protective layer, preparation method thereof, flexible cover plate, flexible screen and foldable electronic device

Abstract

Embodiments of the present application provide a flexible protective layer, a preparation method thereof, a flexible cover plate, a flexible screen and a foldable electronic device. The flexible protective layer comprises a first base layer, a first fiber layer and a second base layer which are sequentially stacked. The material of the first base layer and the second base layer comprises a first polymer containing boron-oxygen coordination bonds and / or continuous boron-oxygen coordination bonds in the main chain. The first fiber layer comprises a plurality of first glass fibers extending in a first direction. The first fiber layer comprises a first region and a second region located on one side of the first region. The arrangement density of the plurality of first glass fibers in the first region is greater than or equal to the arrangement density in the second region. Through the combined action of the plurality of glass fibers and the boron-oxygen coordination bonds and / or continuous boron-oxygen coordination bonds in the molecular chain of the first polymer, the flexible protective layer has excellent impact resistance and extrusion resistance, thereby improving the reliability of the flexible screen.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of materials, and in particular to a flexible protective layer, a preparation method thereof, a flexible cover plate, a flexible screen, and a foldable electronic device. BACKGROUND

[0002] The flexible screen in the foldable electronic device has the performance of flexibility and bendability, and can provide a good folding experience. However, the flexible screen currently mostly uses flexible organic polymer materials, which results in poor impact resistance and extrusion resistance of the flexible screen. In daily use, some slight bumps may cause the flexible screen to crack or break, resulting in display abnormalities of the flexible screen, such as display defects of broken bright spots and black spots, and reduced reliability of the flexible screen. SUMMARY

[0003] Embodiments of the present application provide a flexible protective layer, a preparation method thereof, a flexible cover plate, a flexible screen, and a foldable electronic device. The flexible protective layer has excellent impact resistance and extrusion resistance, which is beneficial to improve the reliability of the flexible screen.

[0004] In a first aspect, a flexible protective layer is provided, comprising: a first base layer, a first fiber layer, and a second base layer which are stacked, the first fiber layer is located between the first base layer and the second base layer,

[0005] The material of the first base layer and the second base layer comprises a first polymer, wherein the first polymer contains at least one of a boron-oxygen coordination bond and a boron-oxygen coordination bond in the main chain,

[0006] The first fiber layer comprises a plurality of first glass fibers, and the first glass fibers extend along a first direction,

[0007] The first fiber layer comprises a first region and a second region, the second region is located on one side of the first region, the first region is bendable, and the arrangement density of the plurality of first glass fibers in the first region is greater than or equal to the arrangement density in the second region.

[0008] In the present application, the plurality of glass fibers in the fiber layer and the boron-oxygen coordination bond and / or boron-oxygen coordination bond in the first polymer molecular chain work together, which is beneficial to make the flexible protective layer have excellent impact resistance and extrusion resistance.

[0009] First, the plurality of glass fibers in the fiber layer has a high modulus (for example, 60Gpa~70Gpa), which can resist the deformation caused by low strain rate extrusion, and is beneficial to make the flexible protective layer have excellent extrusion resistance.

[0010] In another aspect, at least one of boron-oxygen coordination bond or catenated boron-oxygen coordination bond is introduced into the molecular chain of the first polymer. Due to the boron-oxygen coordination bond or catenated boron-oxygen coordination bond, there is enough time for the fracture behavior to occur under the action of low strain rate, so that the molecular chain has flexibility and foldability under the action of low strain rate. Under the action of high strain rate, the time scale of molecular chain movement is much smaller than the time scale of boron-oxygen coordination bond or catenated boron-oxygen coordination bond fracture, and the unbroken boron-oxygen coordination bond or catenated boron-oxygen coordination bond can hinder the movement of the molecular chain, thereby hindering the disentanglement of the molecular chain, which can exhibit the characteristics of rigidity and elasticity in the macroscopic aspect. The unique fracture and bonding behavior of the above-mentioned boron-oxygen coordination bond or catenated boron-oxygen coordination bond can make the flexible protective layer have the characteristics of absorbing impact energy when subjected to high strain rate impact, which is beneficial to make the flexible protective layer have better impact resistance.

[0011] It can be understood that increasing the arrangement density of the glass fibers can better improve the extrusion resistance, and therefore the arrangement density of the glass fibers in different regions of the fiber layer can be set according to actual needs.

[0012] For example, the arrangement density of the glass fibers in the first region of the fiber layer is greater than that in the second region of the fiber layer, which is beneficial to make the first region have better extrusion resistance. When the flexible protective layer is applied to the flexible screen, the flexible screen includes a main body region and a folding region, the main body region is located on one side of the folding region, and the flexible screen can be folded relative to the folding axis of the folding region. By arranging the first region of the fiber layer opposite the folding region of the flexible screen and arranging the second region of the fiber layer opposite the main body region of the flexible screen, the extrusion resistance of the folding region of the flexible screen can be better improved, and the reliability of the flexible screen can be improved.

[0013] In a possible implementation manner, different directions of glass fibers can be arranged on the fiber layer according to actual needs. For example, the first fiber layer can further include a plurality of fourth glass fibers, the fourth glass fibers extend along a fourth direction, and the fourth direction is different from the first direction.

[0014] In some embodiments, the plurality of fourth glass fibers can be arranged in the first region, the plurality of first glass fibers can be arranged in the second region, and the arrangement density of the plurality of fourth glass fibers in the first region is greater than the arrangement density of the plurality of first glass fibers in the second region.

[0015] In combination with the first aspect, in some implementation manners of the first aspect, the first direction is parallel or inclined relative to the folding axis of the first region.

[0016] It should be noted that parallelism can be understood as the angle between the bending axis of the first direction and the bending axis of the first region being 0°, and inclination can be understood as the angle between the bending axis of the first direction and the bending axis of the first region being greater than 0° and less than 90°.

[0017] In this application, the bending axis of the first region of the fiber layer is in the same direction as the bending axis of the flexible screen's bending region. When the flexible protective layer is applied to the flexible screen, the extension direction of the glass fiber is parallel to the bending axis of the fiber layer, which can reduce the bending stress experienced by the flexible protective layer when the flexible screen is bent, thereby reducing the deformation of the flexible protective layer and improving the reliability of the flexible screen.

[0018] In one possible implementation, the flexible protective layer experiences minimal bending stress when the direction of glass fiber extension is parallel to the bending axis of the first region.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the flexible protective layer further includes a third matrix layer and a second fiber layer stacked together.

[0020] The second fiber layer is located between the second matrix layer and the third matrix layer, and the second fiber layer and the first fiber layer are two adjacent fiber layers.

[0021] The second fiber layer includes a plurality of second glass fibers extending along a second direction.

[0022] In the embodiments of this application, the flexible protective layer may have multiple fiber layers, and as the number of fiber layers in the flexible protective layer increases, the content of glass fiber increases, which is beneficial to better improve the extrusion resistance of the flexible protective layer.

[0023] In conjunction with the first aspect, in certain implementations of the first aspect, the flexible protective layer satisfies at least one of the following:

[0024] The extension direction of at least one of the first glass fiber and the second glass fiber is parallel to the bending axis of the first region;

[0025] The plurality of first glass fibers and the plurality of second glass fibers have different arrangement densities.

[0026] In this embodiment, the arrangement density of glass fibers on different fiber layers can be set according to actual needs, which helps the flexible protective layer meet different application requirements. For example, the arrangement density of glass fibers can be set higher in the area of ​​the fiber layer corresponding to the bending area of ​​the flexible screen, which helps the bending area of ​​the flexible screen to have better resistance to extrusion deformation.

[0027] In some implementations of the first aspect, the flexible protective layer further includes a third fiber layer, the third fiber layer and the second fiber layer are two adjacent fiber layers,

[0028] The spacing between the third fiber layer and the second fiber layer is different from the spacing between the second fiber layer and the first fiber layer.

[0029] In the embodiments of the present application, the extrusion resistance of the flexible protective layer can be increased as the spacing between the two adjacent fiber layers decreases. Therefore, the spacing between different fiber layers can be set according to actual needs, which is beneficial to make the flexible protective layer meet different application requirements.

[0030] In some implementations of the first aspect, the thickness of the flexible protective layer is 10-150 μm, and the spacing between the first fiber layer and the second fiber layer is 0-140 μm.

[0031] In some implementations of the first aspect, the plurality of first glass fibers satisfy at least one of the following conditions:

[0032] The mass fraction of the plurality of first glass fibers in the flexible protective layer is 5-80%;

[0033] The spacing between two adjacent first glass fibers is 0-1000 μm;

[0034] The diameter of the first glass fiber is 5-100 μm;

[0035] The length of the first glass fiber is greater than or equal to 5 cm;

[0036] The difference between the refractive index of the first glass fiber and the refractive index of the first matrix layer and the second matrix layer is 0-0.1.

[0037] In the embodiments of the present application, the extrusion resistance of the flexible protective layer is improved on the one hand as the content of the glass fiber in the flexible protective layer increases, and on the other hand as the arrangement density of the glass fiber in the fiber layer increases. Therefore, a wider range of mass fraction of the glass fiber is beneficial to meet the needs of adjusting the content of the glass fiber flexibly according to actual needs, and a wider range of spacing between the glass fibers is beneficial to meet the needs of adjusting the arrangement density of the glass fiber flexibly according to actual needs.

[0038] In addition, the difference between the refractive index of the fiber layer and the refractive index of the matrix layer is small, which is beneficial to reduce the refraction of light at the interface between the fiber layer and the matrix layer, and is beneficial to ensure the overall light transmittance of the flexible protective layer, so that when the flexible protective layer is applied to the flexible screen, the display of the flexible screen can not be affected.

[0039] With reference to the first aspect, in some implementations of the first aspect, the first base layer and the second base layer satisfy at least one of the following:

[0040] The modulus of the first base layer and the second base layer is 10 Kpa-500 MPa;

[0041] The refractive index of the first base layer and the second base layer is 1.420-1.650;

[0042] The light transmittance of the first base layer and the second base layer is greater than or equal to 80%;

[0043] The haze of the first base layer and the second base layer is less than or equal to 5%.

[0044] In the embodiments of the present application, the base layer in the flexible protective layer can have the characteristics of good light transmittance and low haze, which is beneficial to make the flexible protective layer have excellent optical performance, and is beneficial to make the flexible protective layer meet the requirements of the flexible screen on the optical performance, so that the flexible protective layer can be applied to the flexible screen.

[0045] With reference to the first aspect, in some implementations of the first aspect, the end group and / or side chain of the first polymer comprises at least one of a hydroxyl group, an acrylate group, and a vinyl group,

[0046] The material of the first base layer and the second base layer further comprises an adhesive base,

[0047] The adhesive base comprises at least one of a siloxane resin, an epoxy alkane resin, and an acrylate monomer.

[0048] In the embodiments of the present application, the adhesive base is included in the base layer, which is beneficial to make the base layer have good adhesion, so as to be beneficial to make the flexible protective layer have good adhesion, so that the flexible protective layer can be used as an adhesive material, for example, the flexible screen can be adhered by the flexible protective layer.

[0049] In addition, the end group and / or side chain of the first polymer introduces active groups such as end hydroxyl group, end acrylate group, and end vinyl group, which is beneficial to cross-linking reaction between the acrylate monomer, the siloxane resin, and the epoxy resin in the adhesive base, and is beneficial to make the first polymer and the adhesive base be bonded and cross-linked into a stable structure.

[0050] In a possible implementation, the chemical structure of the first polymer can be as shown in formula (1) or formula (2):

[0051]

[0052] R1, R2may be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group and an aryl group. The adhesive matrix can include at least one of a silicone resin and an epoxy resin.

[0053] In the embodiments of the present application, the first polymer represented by formula (1) and formula (2) introduces a terminal hydroxyl group, which is conducive to cross-linking reaction with the silicone resin or the epoxy alkane resin in the adhesive matrix, is conducive to good bonding performance of the matrix layer, and is conducive to good bonding performance of the flexible protective layer.

[0054] In some embodiments, the chemical structure of the first polymer can be as shown in formula (3)-formula (6):

[0055]

[0056] R1, R2may be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group and an aryl group. The adhesive matrix can include an acrylate monomer.

[0057] In the embodiments of the present application, the terminal group of the first polymer represented by formula (3)-formula (6) introduces an acrylate group, which is conducive to cross-linking reaction with the acrylate monomer in the adhesive matrix, is conducive to good bonding performance of the matrix layer, and is conducive to good bonding performance of the flexible protective layer.

[0058] In some embodiments, the chemical structure of the first polymer can be as shown in formula (7)-formula (8):

[0059]

[0060] R1, R2may be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group and an aryl group. The adhesive matrix can include a silicone resin.

[0061] In the embodiments of the present application, the terminal group of the first polymer represented by formula (7) and formula (8) introduces a vinyl group, which is conducive to cross-linking reaction with the silicone resin in the adhesive matrix, is conducive to good bonding performance of the matrix layer, and is conducive to good bonding performance of the flexible protective layer.

[0062] With reference to the first aspect, in some implementations of the first aspect, the flexible protective layer further includes a first release film and a second release film,

[0063] The first release film is located on a side of the first base layer away from the first fiber layer, and the second release film is located on a side of the second base layer away from the first fiber layer.

[0064] In the embodiments of the present application, the first release film and the second release film can serve as protective films of the flexible protective layer, which is conducive to keeping the flexible protective layer clean and flat.

[0065] In a second aspect, a preparation method of a flexible protective layer is provided, including:

[0066] coating a first base resin on a carrier to prepare a first base layer on the carrier;

[0067] arranging a plurality of first glass fibers on a side surface of the first base layer away from the carrier to prepare a first fiber layer on the first base layer;

[0068] coating a second base resin on a side surface of the first fiber layer away from the first base layer to prepare a second base layer on the first fiber layer, and the first base layer and the second base layer cover the first fiber layer;

[0069] The first base layer and the second base layer include a first polymer, and the first polymer includes at least one of a boron-oxygen coordination bond and a boron-oxygen bridging bond in a main chain thereof,

[0070] The first glass fibers extend along a first direction, the first fiber layer includes a first region and a second region, the second region is located on a side of the first region, the first region is bendable, and an arrangement density of the plurality of first glass fibers in the first region is greater than or equal to an arrangement density in the second region.

[0071] In the preparation method of the flexible protective layer provided in the embodiments of the present application, the base layer is prepared by a coating process, which is conducive to accurately controlling the thickness of the prepared base layer and the uniformity of the base layer, and is conducive to adjusting the thickness of the base layer to meet different actual needs. In addition, the glass fibers are arranged on the base layer, which is conducive to controlling the arrangement density of the glass fibers and meeting different application requirements.

[0072] In the present application, through the joint action of the plurality of glass fibers in the fiber layer and the boron-oxygen coordination bond and / or the boron-oxygen bridging bond in the molecular chain of the first polymer, the flexible protective layer has excellent impact resistance and extrusion resistance.

[0073] In combination with the second aspect, in some implementations of the second aspect, the first direction is parallel or inclined relative to a bending axis of the first region.

[0074] With reference to the second aspect, in some implementations of the second aspect, the method further includes:

[0075] spreading a plurality of second glass fibers on a side surface of the second matrix layer away from the first fiber layer to produce a second fiber layer on the second matrix layer;

[0076] coating a third matrix resin on a side surface of the second fiber layer away from the second matrix layer to produce a third matrix layer on the second fiber layer, the second matrix layer and the third matrix layer covering the second fiber layer, the third glass fibers extending along a third direction,

[0077] covering a second release film on a side of the third matrix layer away from the second fiber layer to produce a flexible protective layer, and then winding the flexible protective layer.

[0078] In the method for producing the flexible protective layer provided in the embodiments of the present application, the plurality of matrix layers can be produced through a coating process, which is advantageous for precisely controlling the thickness of each matrix layer and the uniformity of the matrix layers, and is advantageous for adjusting the thickness of the matrix layers to meet different actual requirements. In addition, the plurality of layers of glass fibers are spread on the plurality of matrix layers, which is advantageous for controlling the arrangement density of each layer of glass fibers, and is advantageous for meeting different application requirements.

[0079] With reference to the second aspect, in some implementations of the second aspect, the flexible protective layer meets at least one of the following:

[0080] the extension direction of at least one of the first glass fibers and the second glass fibers is parallel to the bending axis of the first region;

[0081] the arrangement densities of the plurality of first glass fibers and the plurality of second glass fibers are different.

[0082] With reference to the second aspect, in some implementations of the second aspect, the plurality of first glass fibers meet at least one of the following:

[0083] the mass fraction of the plurality of first glass fibers in the flexible protective layer is 5% to 80%;

[0084] the spacing between two adjacent first glass fibers is 0 to 1000 μm;

[0085] the diameter of the first glass fibers is 5 μm to 100 μm;

[0086] the length of the first glass fibers is greater than or equal to 5 cm;

[0087] the difference between the refractive index of the first glass fibers and the refractive index of the first matrix layer and the second matrix layer is 0 to 0.1.

[0088] With reference to the second aspect, in some implementations of the second aspect, the first base layer satisfies at least one of the following:

[0089] The modulus of the first base layer and the second base layer is 10 KPa to 500 MPa;

[0090] The refractive index of the first base layer and the second base layer is 1.420 to 1.650;

[0091] The light transmittance of the first base layer and the second base layer is greater than or equal to 80%;

[0092] The haze of the first base layer and the second base layer is less than or equal to 5%.

[0093] With reference to the second aspect, in some implementations of the second aspect, the end group and / or side chain of the first polymer comprises at least one of a hydroxyl group, an acrylate group, and a vinyl group,

[0094] The material of the first base layer and the second base layer further comprises an adhesive matrix,

[0095] The adhesive matrix comprises at least one of a siloxane resin, an alkylene oxide resin, and an acrylate monomer.

[0096] The third aspect provides a flexible cover plate, characterized in that comprising the flexible protective layer according to any one of the first aspect and a plurality of cover substrate layers arranged in a stack, the flexible protective layer is arranged between two adjacent cover substrate layers.

[0097] The fourth aspect provides a flexible screen, comprising a flexible display panel, a polarizing sheet and a flexible cover plate according to the third aspect arranged in a stack.

[0098] In a possible implementation, the flexible screen comprises a main area and a bending area, the main area is located on one side of the bending area, the main area is arranged opposite to the second area, and the bending area is arranged opposite to the first area.

[0099] In a possible implementation, a flexible protective layer according to any one of the first aspect can also be arranged between the flexible display panel and the polarizing sheet or between the polarizing sheet and the flexible cover plate.

[0100] The fifth aspect provides a foldable electronic device, comprising a flexible screen according to any one of the fourth aspect and a housing assembly, the flexible screen is connected to the housing assembly.

[0101] In a sixth aspect, there is provided an optical adhesive film comprising the flexible protective layer and the adhesive as defined in any one of the first aspect, and the flexible protective layer and the adhesive are blended and can be applied to bond each film layer in a flexible screen.

[0102] The beneficial effects of the second to sixth aspects can be found in the beneficial effects of the first aspect, which are not repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0103] Figure 1 is a schematic structural diagram of a foldable electronic device provided by an embodiment of the present application.

[0104] Figure 2 is a schematic structural diagram of a foldable electronic device provided by an embodiment of the present application.

[0105] Figure 3 is a partial cross-sectional view of a foldable electronic device provided by an embodiment of the present application.

[0106] Figure 4 is a partial cross-sectional view of a foldable electronic device provided by an embodiment of the present application.

[0107] Figure 5 is a front view structural schematic diagram of a flexible protective layer provided by an embodiment of the present application.

[0108] Figure 6 is a possible cross-sectional structural schematic diagram of a flexible protective layer provided by an embodiment of the present application.

[0109] Figure 7 is a possible cross-sectional structural schematic diagram of a flexible protective layer provided by an embodiment of the present application.

[0110] Figure 8 is a schematic structural diagram of different views of a flexible protective layer provided by an embodiment of the present application.

[0111] Figure 9 is a schematic structural diagram of different structures of a flexible protective layer provided by an embodiment of the present application.

[0112] Figure 10 is a schematic structural diagram of different structures of a flexible protective layer provided by an embodiment of the present application.

[0113] Figure 11 is a schematic structural diagram of different structures of a flexible protective layer provided by an embodiment of the present application.

[0114] Figure 12 is a schematic block diagram of a preparation method of a flexible protective layer provided by an embodiment of the present application.

[0115] Figure 13is a schematic flow chart of a method for preparing a flexible protective layer.

[0116] Figure 14 is a schematic flow chart of a method for preparing a flexible protective layer. DETAILED DESCRIPTION

[0117] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0118] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the specification and appended claims, the singular forms "a," "an" and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "and / or," "comprises," "comprising," "includes," and / or "including," as used herein, are intended to mean "one or more of the listed items." It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0119] The terms "first", "second", etc. appearing in the present application are only for distinguishing different objects, and "first", "second" themselves do not limit the actual order or function of the objects they modify. Any embodiment or design scheme described as "exemplary", "example", "for example", "optionally" or "in some implementation manners" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, these words are used to present the relevant concept in a specific manner.

[0120] Reference in the specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, although it can. The terms "comprise", "comprising", "have", "having", "include", "including", and "contain", "containing" and their variants are meant to be construed either as "including but not limited to" or "including at least" unless otherwise noted.

[0121] Figure 1FIG. 1 is a structural schematic diagram of a foldable electronic device 100 provided by an embodiment of the present application. The foldable electronic device 100 can include, but is not limited to, a foldable mobile phone, a tablet computer, a notebook computer, a vehicle-mounted computer, a foldable display device (such as a television), a wearable device, an augmented reality (AR) device, a virtual reality (VR) device, an audio or video playing device, a personal digital assistant (PDA), and the like. It can be understood that the foldable electronic device 100 can also not be limited to the above devices, but can include newly developed electronic devices. Embodiments of the present application do not specially limit the specific product form of the foldable electronic device 100. Figure 1 The embodiment shown takes a foldable mobile phone as an example for illustration.

[0122] Reference Figure 1 The foldable electronic device 100 can include a housing assembly 10 and a flexible screen 30, and the housing assembly 10 can be connected with the flexible screen 30. The flexible screen 30 can also be referred to as a folding screen, and the flexible screen 30 can form a display surface of the foldable electronic device 100, for displaying information and providing an interactive interface for a user.

[0123] In addition, the foldable electronic device 100 can also include a hinge mechanism 20, and the hinge mechanism 20 can be used to realize folding and unfolding of the foldable electronic device 100.

[0124] For example, the housing assembly 10 can include a first housing 11 and a second housing 12, and the hinge mechanism 20 can be arranged between the first housing 11 and the second housing 12. The hinge mechanism 20 can be a mechanism composed of several components, and the hinge mechanism 20 can generate a mechanism movement. The opposite sides of the hinge mechanism 20 are respectively connected with the first housing 11 and the second housing 12, so that the first housing 11 and the second housing 12 realize relative rotation, and the rotation axis direction of the hinge mechanism 20 can be exemplarily shown as a straight line A in FIG. 1. Figure 1

[0125] In some embodiments, the first housing 11 and the second housing 12 can serve as the outer shell of the foldable electronic device 100, that is, the first housing 11 and the second housing 12 can serve as the appearance part of the foldable electronic device 100, that is, the components exposed to the outside and directly observed by the user. In other embodiments, the foldable electronic device 100 can include an outer shell as an appearance part, and the first housing 11 and the second housing 12 can be mounted as non-appearance parts (for example, a middle frame) in the outer shell. The first housing 11 and the second housing 12 are used to mount and carry the flexible screen 30, and drive the flexible screen 30 to bend and unfold.

[0126] Figure 1 ​The pattern filled with dots can schematically represent the flexible screen 30. The flexible screen 30 has flexibility and can be folded and unfolded. As shown in Figure 1 The flexible screen 30 can include a main body area 31 and a folding area 32. The main body area 31 can be located on one side of the folding area 32. The folding axis of the folding area 32 can be the same as the rotation axis direction of the hinge mechanism 20, i.e., the folding axis of the folding area 32 can be schematically shown as a straight line A in Figure 1

[0127] Specifically, the flexible screen 30 can include two main body areas 31, and the folding area 32 can be connected between the two main body areas 31. In addition, the two main body areas 31 can be fixed on the first shell 11 and the second shell 12, respectively. The folding area 33 can not be connected with the first shell 11 and the second shell 12, so that the folding area 33 can be spaced apart from the hinge 20 in the unfolded state and the folded state to avoid mutual interference.

[0128] The two main body areas 31 will not or substantially not be deformed during the opening and closing of the flexible screen 30, and can maintain the original flat state. The folding area 33 can be folded and unfolded to realize the folding and unfolding of the flexible screen 30, so that the foldable electronic device 100 is in an unfolded or folded state.

[0129] Figure 1 The foldable electronic device 100 shown in the unfolded state is currently in an unfolded state. In the unfolded state, the angle between the first shell 11 and the second shell 12 can be about 180°. The flexible screen 30 can be in Figure 1 the unfolded state shown in the figure.

[0130] Figure 2 A possible folded state of the foldable electronic device 100 is shown. Among them, Figure 2 The outward folding state of the foldable electronic device 100 is shown. Figure 2 The outward folding state shown can be, for example, a left-right outward folding state or an up-down outward folding state. Figure 2 The pattern filled with dots can schematically represent the flexible screen 30. As shown in the figure, in the folded state, the flexible screen 30 can be in Figure 2 the folded state shown in the figure.

[0131] In combination with Figure 1 and as Figure 2 ​When the foldable electronic device 100 is in the outward-folded state, the first housing 11 and the second housing 13 can approach each other, and the two main body regions 31 can approach each other. The two main body regions 31 and the bending region 32 can form a housing region for accommodating the first housing 11, the second housing 12, and the hinge 20. That is, the first housing 11, the second housing 12, and the hinge 30 can be accommodated in the space between the two main body regions 31.

[0132] In other embodiments, the foldable electronic device 100 can be in an inward-folding state, such as a left-right inward folding state or a top-bottom inward folding state. When the foldable electronic device 100 is in the inward-folding state, the first housing 11 and the second housing 12 can be brought close to each other, and the two main body regions 31 can be brought close to each other. The first housing 11, the second housing 12, and the hinge 20 can form a housing area for accommodating the flexible screen 30. That is, the flexible screen 30 can be accommodated in the space between the first housing 11, the second housing 12, and the hinge 20.

[0133] Figure 3 An example is shown Figure 1 The diagram shows the structural schematic of the BB' cross-section of the flexible screen 30.

[0134] like Figure 3 As shown, the flexible screen 30 may include a substrate 34, a flexible display panel 35, a polarizer 36, and a flexible cover plate 38 stacked together.

[0135] The substrate 34 can be located on the backlight side of the flexible display panel 35 to protect the flexible display panel 35. The polarizer 36 can be located on the light-emitting side of the flexible display panel. The flexible cover plate 38 can be located on the side of the polarizer 36 away from the flexible display panel 35 to protect the polarizer 36 and the flexible display panel 35 and to provide a user touch interface.

[0136] It should be noted that the light-emitting side can be understood as the side of the flexible display panel 35 that can emit light, and the backlight side can be understood as the side of the flexible display panel 35 that does not emit light, opposite to the light-emitting side.

[0137] In addition, both the flexible display panel 35 and the flexible cover plate 38 can be bent and unfolded, and both can have portions distributed in the two main areas 31 and the bending area 32.

[0138] The flexible display panel 35 may, for example, adopt any one of a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light emitting diode (AMOLED), a flexible light-emitting diode (FLED), a quantum dot light emitting diode (QLED), and the like, and embodiments of the present application do not limit the flexible display panel 35.

[0139] The flexible cover plate 38 may, for example, be made of a transparent organic polymer material such as a polyimide (PI) film, a polyethylene glycol terephthalate (PET) film, a polycarbonate (PC) film, a polycrylate film, a polymethyl methacrylate (PMMA) film, and a clear polyimide (CPI) film. These materials are flexible, and the modulus thereof is generally 3 Gpa to 8 Gpa, and the impact resistance and the extrusion resistance of the material are poor, and the material is easily deformed when subjected to an external force.

[0140] In one possible example, the flexible cover plate 38 can include at least one cover plate substrate layer, for example, as shown in FIG. 3A, the flexible cover plate 38 can include a first cover plate substrate layer 381 and a second cover plate substrate layer 382. The materials of the first cover plate substrate layer 381 and the second cover plate substrate layer 382 can include one or a combination of the above-mentioned organic polymer materials. Figure 3

[0141] In addition, the materials of the first cover plate substrate layer 381 and the second cover plate substrate layer 382 can also include ultra thin glass (UTG). The modulus of the UTG is generally 60 Gpa to 90 Gpa, and the ability to resist deformation is relatively strong, which helps to improve the impact resistance and the extrusion resistance of the flexible cover plate 38. However, there is a certain limit to the thickness of the flexible cover plate 38 in the flexible display panel 30, which limits the thickness of the UTG used in the flexible cover plate 38 to generally 30 μm to 50 μm, which limits the effect of the UTG on improving the impact resistance and the extrusion resistance of the flexible cover plate 38.

[0142] ​In some embodiments, the film layers of the flexible screen 30 can be attached together by an adhesive layer, so that the layers become an integral whole. For example, as shown in Figure 3 the first cover substrate layer 381 and the second cover substrate layer 382 in the flexible cover plate 38 can be attached together by the adhesive layer 37.

[0143] At present, the material of the adhesive layer 37 is mainly optical clear adhesive (OCA). Among them, the commonly used OCA is mostly acrylate polymer system or silicone polymer system, and the modulus is too low, generally in 10Kpa~500Kpa, and the impact resistance and extrusion resistance are also poor.

[0144] In summary, the flexible cover plate 38 prepared by using the above flexible organic high polymer material and the adhesive layer 37 prepared by using OCA both have poor impact resistance and extrusion resistance, so that the flexible screen 30 also has poor extrusion resistance and impact resistance, and thus the flexible screen 30 is easy to crack or break when subjected to impact or extrusion, resulting in failure of the flexible screen 30.

[0145] Figure 4 Exemplary structure schematic diagram of the flexible screen 30 when subjected to external force extrusion or impact is shown.

[0146] As shown in Figure 4 the second cover substrate layer 382 in the flexible cover plate 38 is subjected to external force impact or extrusion in the direction as shown by the arrow, and since the organic high polymer material in the second cover substrate layer 382 has flexibility, it cannot well absorb the external force impact, and is easy to deform in the direction of the adhesive layer 37, so that a stronger extrusion external force acts on the adhesive layer 37. And the adhesive layer 37 cannot resist the deformation caused by extrusion due to poor impact resistance and extrusion resistance, so that the stress and strain can be further transmitted to the flexible display panel 35, which may cause the flexible display panel 35 to appear display defects such as bright spots, black spots, etc., so that the flexible screen 30 fails.

[0147] Based on the above, the embodiments of the present application provide a flexible protective layer with relatively optimal impact resistance and extrusion resistance, which can be applied to the flexible screen 30 to improve the impact resistance and extrusion resistance of the flexible screen 30. For example, the flexible protective layer can be arranged between the flexible cover plate 38 and the polarizing plate 36, specifically between the adhesive layer 37 and the polarizing plate 36, or can be arranged between the polarizing plate 36 and the flexible display panel 35, to improve the impact resistance and extrusion resistance of the flexible screen 30.

[0148] In addition, the flexible protective layer can also be used in the flexible cover plate 38. For example, the flexible protective layer can be disposed between two adjacent cover plate substrate layers in the flexible cover plate 38 to improve the impact resistance and compression resistance of the flexible cover plate 38.

[0149] Furthermore, this flexible protective layer has good adhesive properties, and can therefore be used directly as an adhesive material to bond different film layers in the foldable electronic device 100. For example, this flexible protective layer can directly replace the adhesive layer 37 to bond the first cover plate substrate layer 381 and the second cover plate substrate layer 382, ​​or to bond the polarizer 36 and the first cover plate substrate layer 381.

[0150] It is understood that the above-mentioned application scenarios of flexible protective layers are merely examples and are not intended to limit this application.

[0151] Figure 5 This is a front view structural diagram of a flexible protective layer 500 provided in an embodiment of this application. Figure 6 This is a schematic diagram of a possible top cross-sectional structure of the flexible protective layer 500, in which... Figure 6 (a) is a top view cross-sectional diagram of a possible flexible protective layer 500. Figure 6 (b) is a top view cross-sectional diagram of another possible flexible protective layer 500.

[0152] See also Figure 5 , Figure 6 (a) and Figure 6 In (b), the flexible protective layer 500 may include a first substrate layer 510, a first fiber layer 520 and a second substrate layer 530 stacked together, wherein the first fiber layer 520 may be located between the first substrate layer 510 and the second substrate layer 520.

[0153] The materials of the first matrix layer 510 and the second matrix layer 530 may include a first polymer, the main chain of which may include at least one of boron-oxygen coordination bonds and tandem boron-oxygen coordination bonds. The first fiber layer 520 may include a plurality of first glass fibers 521. The first glass fibers 521 may extend along a first direction. The first fiber layer 520 may include a first region 520a and a second region 520b, the second region 520b may be located on one side of the first region 520a, and the first region 520a may be bendable. The arrangement density of the plurality of first glass fibers 521 in the first region 520a may be greater than or equal to the arrangement density in the second region 520b.

[0154] In some embodiments, such as Figure 6 (a) and Figure 6As shown in (b) of FIG. 5A, the bending axis of the first region 520a of the fiber layer 520 is shown as a straight line A'. The plurality of first glass fibers 521 can be arranged on the surface of the first matrix layer 510, and the first glass fibers 521 can extend along a first direction. Herein, the first direction can be parallel, inclined or perpendicular to the bending axis A' of the first region 520a.

[0155] It should be understood that parallel can mean that the included angle between the first direction and the bending axis A' of the first region 520a is 0°, inclined can mean that the included angle between the first direction and the bending axis A' of the first region 520a is greater than 0° and less than 90°, and perpendicular can mean that the included angle between the first direction and the bending axis A' of the first region 520a is 90°.

[0156] For example, as shown in (a) of FIG. 5A, the first direction is parallel to the bending axis A' of the first region 520a, that is, the included angle between the first direction and the bending axis A' is 0°. Figure 6 For example, as shown in (a) of FIG. 5A, the first direction is parallel to the bending axis A' of the first region 520a, that is, the included angle between the first direction and the bending axis A' is 0°. Figure 6 For example, as shown in (b) of FIG. 5A, the first direction is inclined to the bending axis A' of the first region 520a, that is, the included angle between the first direction and the bending axis A' can be greater than 0° and less than 90°, for example, the included angle can be 30°, 60° or 75°, which is not limited in the present application.

[0157] It can be understood that in the embodiments of the present application, when the flexible protective layer 500 is applied to the flexible screen 30 as shown in FIG. 3, the bending axis A' of the first region 520a is the same as the bending axis A of the bending region 32 of the flexible screen 30. Figure 1 It can be understood that in the embodiments of the present application, when the flexible protective layer 500 is applied to the flexible screen 30 as shown in FIG. 3, the bending axis A' of the first region 520a is the same as the bending axis A of the bending region 32 of the flexible screen 30.

[0158] In the embodiments of the present application, when the flexible protective layer 500 is applied to the flexible screen 30, the first direction is parallel to the bending axis A' of the first region 520a, which is beneficial to reduce the bending stress of the flexible protective layer 500 when the flexible screen 30 is bent, so as to reduce the deformation of the flexible protective layer 500 and improve the reliability of the flexible protective layer 500. In one example, when the first direction is parallel to the bending axis A', the bending stress of the flexible protective layer 500 can be the smallest.

[0159] In addition, the arrangement density of the first glass fibers 521 in different regions of the first fiber layer 520 can be different.

[0160] For example, as shown in (a) of FIG. 5A and (b) of FIG. 5B, the arrangement density of the plurality of first glass fibers 521 in the first region 520a can be equal to the arrangement density in the second region 520b. Figure 6 Figure 6 For example, as shown in (a) of FIG. 5A and (b) of FIG. 5B, the arrangement density of the plurality of first glass fibers 521 in the first region 520a can be equal to the arrangement density in the second region 520b.

[0161] For example, as shown in (a) of FIG. 5A and (b) of FIG. 5B, the arrangement density of the plurality of first glass fibers 521 in the first region 520a can be equal to the arrangement density in the second region 520b. Figure 7 ​As shown in (a), the arrangement density of the plurality of first glass fibers 521 in the first region 520a can be greater than the arrangement density in the second region 520b.

[0162] It is understandable that when the flexible protective layer 500 is applied... Figure 1 When the flexible screen 30 is shown, the first region 520a can be set opposite to the bending region 32 of the flexible screen 30, and the second region 520b can be set opposite to the main body region 31 of the flexible screen 30.

[0163] In this embodiment, increasing the arrangement density of glass fibers can better improve the compressive strength. Therefore, a larger arrangement density of multiple first glass fibers 521 in the first region 520a helps to improve the compressive strength of the bending region 32 when the flexible screen 30 is bent.

[0164] In one possible implementation, the glass fibers arranged in different regions of the first fiber layer 520 may extend in different directions.

[0165] For example, Figure 7 (b) in the example shows a schematic diagram of the first fiber layer 520 with glass fibers arranged in different extension directions.

[0166] like Figure 7 As shown in (b), the first fiber layer 520 may include a first region 520a and a second region 520b. A plurality of first glass fibers 521 may be arranged in the second region 520b, and the first glass fibers 521 may extend along a first direction. The first fiber layer 520 may also include a plurality of fourth glass fibers 522, which may be arranged in the first region 520b. The fourth glass fibers 522 may extend along a fourth direction, which may be different from the first direction.

[0167] For example, in Figure 7 In the flexible protective layer 500 shown in (b), the first direction can be inclined with respect to the bending axis A' of the first region 520a, and the fourth direction can be parallel to the bending axis A'.

[0168] In one possible example, the arrangement density of the plurality of first glass fibers 521 in the second region 520b may be less than the arrangement density of the plurality of fourth glass fibers 522 in the first region 520a.

[0169] Next, the first glass fiber 521 involved in the embodiments of this application will be described in detail.

[0170] For example, the first glass fiber 521 in the first fiber layer 520 may be any one of E-glass fiber, S-glass fiber or C-glass fiber, and this application does not limit it.

[0171] In some embodiments, the first glass fiber 521 can satisfy at least one of the following parameters:

[0172] The diameter of the first glass fiber 521 can be 5-100 μm;

[0173] The length of the first glass fiber 521 can be greater than or equal to 5 cm;

[0174] The elongation at break of the first glass fiber 521 can be greater than or equal to 2% to have good toughness and be able to adapt to a bending application scenario;

[0175] The difference between the refractive index of the first glass fiber 521 and the refractive index of the first matrix layer 510 and the second matrix layer 520 is 0-0.1 (≤0.1);

[0176] The mass fraction of the plurality of first glass fibers 521 in the flexible protective layer 500 can be 5-80%;

[0177] The spacing between two adjacent first glass fibers 521 can be 0-1000 μm.

[0178] The diameter of the first glass fiber 521 can be 5 μm, 25 μm, 45 μm, 65 μm, 85 μm, or 100 μm, etc. The length of the first glass fiber 521 can be 5 cm, 15 cm, 25 cm, 45 cm, 65 cm, etc. The present application does not limit this.

[0179] The difference between the refractive index of the first glass fiber 521 and the refractive index of the first matrix layer 510 and the second matrix layer 520 is 0-0.1, that is, the refractive index of the first fiber layer 520 is close to the refractive index of the first matrix layer 510 and the second matrix layer 530. This can reduce the light refraction at the interface between the first fiber layer 520 and the first matrix layer 510 and the interface between the first fiber layer 520 and the second matrix layer 520, which helps to ensure the overall light transmittance of the flexible protective layer 500, so that when the flexible protective layer 500 is applied to the flexible screen 30 as shown in the figure, the display of the flexible screen 30 can not be affected. Figure 1

[0180] The mass fraction of the plurality of first glass fibers 521 in the flexible protective layer 500 can be 5-80%, for example, the mass fraction of the plurality of first glass fibers 521 can be 5%, 30%, 55%, or 80%, etc. The present application does not limit this. In addition, the anti-extrusion performance of the flexible protective layer 500 can be improved with the increase of the content of the plurality of first glass fibers 521 in the flexible protective layer 500, so the content of the plurality of first glass fibers 521 in the flexible protective layer 500 can be flexibly set according to actual needs.​

[0181] In addition, the plurality of first glass fibers 521 can be arranged at equal intervals on the first fiber layer 520, or can also be arranged at unequal intervals, which is not limited in the present application.

[0182] It should be noted that the related description of the fourth glass fiber can refer to the related description of the first glass fiber 521 described above, which will not be described here.

[0183] The first base layer 510 and the second base layer 520 in the flexible protective layer will be described in detail below.

[0184] In some embodiments, in order to have excellent optical performance, the first base layer 510 and the second base layer 530 can satisfy at least one of the following conditions:

[0185] The refractive index of the first base layer 510 and the second base layer 530 can be 1.420-1.650;

[0186] The light transmittance of the first base layer 510 and the second base layer 530 can be greater than or equal to 80%;

[0187] The haze of the first base layer 510 and the second base layer 530 can be less than or equal to 5%.

[0188] In the embodiments of the present application, the base layer in the flexible protective layer can have the characteristics of good light transmittance and low haze, which is beneficial to make the flexible protective layer have excellent optical performance, and is beneficial to make the flexible protective layer meet the requirements of the flexible screen for optical performance, so that the flexible protective layer can be applied to the flexible screen.

[0189] In some embodiments, in addition to including the first polymer, the first base layer 510 and the second base layer 530 can also include an adhesive base. For example, the adhesive base can include at least one of the base of an acrylate pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, or an epoxy resin pressure-sensitive adhesive. For example, the adhesive base can include at least one of an acrylate monomer, a siloxane resin, and an epoxy resin.

[0190] In the embodiments of the present application, the first base layer 510 and the second base layer 530 include an adhesive base, which is beneficial to make the first base layer 510 and the second base layer 530 have good bonding performance, and is beneficial to make the flexible protective layer 500 have good bonding performance, so that the flexible protective layer 500 can be used as a bonding material for bonding the film layers in the foldable electronic device 100.

[0191] For example, when the first base layer 510 and the second base layer 530 include an adhesive base, in the process of bonding the film layers in the foldable electronic device 100, the first base layer 510 and the second base layer 530 can be used as a bonding material to bond the film layers in the foldable electronic device 100. Figure 3In the flexible screen 30 shown, the flexible protective layer 500 can directly replace the adhesive layer 37, and is attached between the first cover substrate layer 381 and the second cover substrate layer 382, for bonding the first cover substrate layer 381 and the second cover substrate layer 382 together.

[0192] In another possible example, the adhesive matrix can include any necessary and non-essential components required by conventional pressure-sensitive adhesives in addition to the above-mentioned components. For example, it can include photoinitiators, antioxidants, plasticizers, etc. required by acrylate pressure-sensitive adhesives, or it can include catalysts and fillers, etc. required by silicone pressure-sensitive adhesives, or it can include crosslinking agents, etc. required by epoxy resin pressure-sensitive adhesives.

[0193] It can be understood that the components of the adhesive matrix described above are only examples and are not a limitation of the present application.

[0194] In some embodiments, the end groups and / or side chains of the first polymer can include at least one of a hydroxyl group, an acrylate group, and a vinyl group, so as to facilitate crosslinking reactions between the first polymer and the acrylate monomers, the silicone resin, and the epoxy resin in the adhesive matrix, and facilitate the first polymer and the adhesive matrix to be crosslinked into a stable structure.

[0195] In some embodiments, the chemical structure of the first polymer in the first matrix layer 510 and the second matrix layer 520 can be different according to different adhesive matrices.

[0196] In one example, the chemical structure of the first polymer can be as shown in formula (1) to formula (2):

[0197]

[0198] wherein R1, R2 can be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group, and an aryl group, at which time the adhesive matrix can include at least one of a silicone resin and an epoxy resin.

[0199] In formula (1) and formula (2), the first polymer introduces a terminal hydroxyl group, which facilitates crosslinking reactions with the silicone resin or the epoxy alkane resin in the adhesive matrix, and facilitates the matrix layer to have good bonding properties and the flexible protective layer to have good bonding properties.

[0200] In another example, the chemical structure of the first polymer can be as shown in formula (3) to formula (6):

[0201]

[0202] R1, R2may be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group and an aryl group, and the adhesive matrix can include a siloxane resin.

[0203] In the formula (3) to formula (6), the end group of the first polymer introduces an acrylate group, which is beneficial to cross-linking reaction with the acrylate monomer in the adhesive matrix, and is beneficial to the adhesive matrix layer having good adhesion, thereby being beneficial to the flexible protective layer having good adhesion.

[0204] In yet another example, the chemical structure of the first polymer can be as shown in formula (7) to formula (8):

[0205]

[0206] R1, R2may be independently selected from a group consisting of an alkyl group, an alkoxy group, an alkenyl group, a cycloalkyl group and an aryl group, and the adhesive matrix can include a siloxane resin.

[0207] In the formula (7) and formula (8), the end group of the first polymer introduces a vinyl group, which is beneficial to cross-linking reaction with the siloxane resin in the adhesive matrix, and is beneficial to the adhesive matrix layer having good adhesion, thereby being beneficial to the flexible protective layer having good adhesion.

[0208] Table 1 below is the size tube between the first matrix layer 510, the first fiber layer 520 and the second matrix layer 530 in the flexible protective layer 500.

[0209] Table 1

[0210]

[0211] As shown in Table 1, the thickness of the flexible protective layer 500 can be 5 μm to 150 μm, for example, can be 5 μm, 30 μm, 55 μm, 80 μm, 105 μm, 135 μm or 150 μm, which is not limited in the present application.

[0212] The distance between the first fiber layer 520 and the side of the first matrix layer 510 away from the first fiber layer 520 can be 0 μm to 145 μm, for example, can be 5 μm, 35 μm, 65 μm, 95 μm, 125 μm or 145 μm, which is not limited in the present application.

[0213] The distance between the first fiber layer 520 and the side of the second matrix layer 530 away from the first fiber layer 520 can be 0 μm to 145 μm, for example, can be 10 μm, 30 μm, 50 μm, 80 μm, 110 μm or 145 μm, which is not limited in the present application.

[0214] In some embodiments, the flexible protective layer 500 can further include a first release film and a second release film, wherein the first release film can be located on a side of the first base layer 510 away from the first fiber layer 520, and the second release film can be located on a side of the second base layer 530 away from the first fiber layer 520. Specifically, the first release film can cover a side surface of the first base layer 510 away from the first fiber layer 520, and the second release film can cover a side surface of the second base layer 530 away from the first fiber layer 520, so that the first release film and the second release film can be used as protective films of the flexible protective layer 500, which is conducive to keeping the flexible protective layer 500 clean and flat. When the flexible protective layer 500 needs to be used, the first release film and the second release film can be removed before use.

[0215] In the embodiments of the present application, the first fiber layer 520 includes a plurality of first glass fibers 521, which have a relatively high modulus (for example, 60 Gpa-70 Gpa), and are conducive to resisting deformation caused by extrusion at a low strain rate, so that the flexible protective layer 500 has relatively good extrusion resistance.

[0216] In addition, at least one of a boron-oxygen coordination bond and a boron-oxygen coordination bond is introduced into the molecular chain of the first polymer. Since the boron-oxygen coordination bond or the boron-oxygen coordination bond has sufficient time to break under the action of a low strain rate, the molecular chain has flexibility and foldability under the action of a low strain rate. Under the action of a high strain rate, the time scale of the molecular chain movement is much smaller than the time of the boron-oxygen coordination bond or the boron-oxygen coordination bond breaking, and the unbroken boron-oxygen coordination bond or the boron-oxygen coordination bond can hinder the movement of the molecular chain, thereby hindering the disentanglement of the molecular chain, which can exhibit the characteristics of rigidity and elasticity in the macroscopic. The unique breaking and bonding behavior of the above-mentioned boron-oxygen coordination bond or boron-oxygen coordination bond can enable the flexible protective layer 500 to have the characteristics of absorbing impact energy when subjected to a high strain rate impact, which is conducive to making the flexible protective layer 500 have relatively good impact resistance.

[0217] In the embodiments of the present application, the flexible protective layer 500 can include a plurality of fiber layers. The structures of the flexible protective layers provided by the embodiments of the present application are described below in conjunction with Figures 8 to 11 The structures of the flexible protective layers provided by the embodiments of the present application are described below in conjunction with

[0218] Figure 8 The structures of the flexible protective layers provided by the embodiments of the present application are described below in conjunction with

[0219] In conjunction with Figure 8 (a) and Figure 8 (b), wherein Figure 8(a) is a schematic view of a top view structure of the flexible protection layer 800, Figure 8 (b) is a schematic view of a cross-sectional structure of the first fiber layer 520 in the flexible protection layer 800.

[0220] With reference to the embodiment shown in Figures 5 to 7 Similarly to the embodiment shown in Figure 8 The first fiber layer 520 can include a plurality of first glass fibers 521 arranged on a surface of the first matrix layer 510, and the first glass fibers 521 can extend along a first direction. The first fiber layer 520 includes a first region 520a and a second region 520b, and a bending axis of the first region 520a is shown by a straight line A’ in (b) of

[0221] With reference to the embodiment shown in Figures 5 to 7 Unlike the embodiment shown in Figure 8 The flexible protection layer 800 can further include a second fiber layer 810 and a third matrix layer 820 arranged in a stack, as shown in (a) of

[0222] Figure 8 (c) is a schematic view of a cross-sectional structure of a possible second fiber layer 810, Figure 8 (d) is a schematic view of another possible cross-sectional structure of the second fiber layer 810.

[0223] With reference to (c) of Figure 8 and (d) of Figure 8 The second fiber layer 810 can include a plurality of second glass fibers 811 arranged on a surface of the second matrix layer 530 away from the first fiber layer 520, and the second glass fibers 811 can extend along a second direction.

[0224] In some embodiments, the second direction can be parallel, inclined or perpendicular to the bending axis A’ of the first region 520a, and the first direction and the second direction can be different or can be the same, which is not limited in the present application.

[0225] For example, as shown in (b) of Figure 8 The first direction can be parallel to the bending axis A’ of the first region 520a. As shown in (c) of Figure 8 The second direction can be parallel to the bending axis A’. Alternatively, as shown in (d) of Figure 5 to 7As shown in (d) of FIG. 8, the second direction is inclined relative to the bending axis A'.

[0226] In some embodiments, the flexible protective layer 800 can satisfy at least one of the following:

[0227] The extending direction of at least one of the first glass fibers 521 and the second glass fibers 811 can be parallel to the bending axis A' of the first region 520a.

[0228] The arrangement densities of the plurality of first glass fibers 521 and the plurality of second glass fibers 811 can be different.

[0229] It can be understood that the extending direction of at least one of the first glass fibers 521 and the second glass fibers 811 is parallel to the bending axis A' of the first region 520a, which helps to reduce the bending stress of the flexible protective layer 800 when the flexible protective layer 800 is applied to the flexible screen 30, so as to reduce the deformation of the flexible protective layer 800 and improve the reliability of the flexible screen 30.

[0230] It should be noted that the related description of the second glass fibers 811 can be referred to the related description of the first glass fibers 521 in the embodiments shown in FIG. 8, and the description of the first glass fibers 521 in the embodiments shown in FIG. 8 will not be repeated here. Figures 5 to 7 It should be noted that the related description of the second glass fibers 811 can be referred to the related description of the first glass fibers 521 in the embodiments shown in FIG. 8, and the description of the first glass fibers 521 in the embodiments shown in FIG. 8 will not be repeated here.

[0231] Table 2 below shows the size relationship between the first base layer 510, the first fiber layer 520, the second base layer 530, the second fiber layer 810 and the third base layer 820 in the flexible protective layer 800.

[0232] Table 2

[0233]

[0234] As shown in Table 2, the thickness of the flexible protective layer 800 can be 10 μm to 150 μm, for example, can be 10 μm, 30 μm, 50 μm, 80 μm, 110 μm, 140 μm or 150 μm, which is not limited in the present application.

[0235] In the above table 2, the distance between the first fiber layer 520 and the side of the first base layer 510 away from the first fiber layer 520 can be 0 μm to 140 μm, for example, can be 5 μm, 35 μm, 65 μm, 95 μm, 125 μm or 140 μm, which is not limited in the present application.

[0236] The distance between the first fiber layer 520 and the second fiber layer 810 can be 0-140 μm, for example, can be 10 μm, 30 μm, 50 μm, 80 μm, 110 μm or 140 μm, the distance between the second fiber layer 810 and the side of the third matrix layer 820 away from the second fiber layer 810 can be 0-140 μm, for example, can be 15 μm, 30 μm, 45 μm, 70 μm, 95 μm or 140 μm, which is not limited in the present application.

[0237] It should be noted that the related description of the third matrix layer 820 can refer to the related description of the first matrix layer 510 and the second matrix layer 520 in Figures 5 to 7 , and the related description of the second fiber layer 810 can refer to the related description of the first fiber layer 520 in the embodiment shown in Figure 9 , which will not be repeated here in the present application.

[0238] Figure 9 Exemplary different structural schematic diagrams of the flexible protective layer provided by the embodiment of the present application are shown.

[0239] Firstly, refer to (a) in Figure 9 and (b) in Figure 9 . Wherein, Figure 9 (a) is a front structural schematic diagram of the flexible protective layer 901 provided by the embodiment of the present application, Figure 8 (b) is a top view structural schematic diagram of the flexible protective layer 901.

[0240] Similar to the embodiment shown in Figure 8 , the flexible protective layer 901 can include the first matrix layer 510, the first fiber layer 520, the second matrix layer 530, the second fiber layer 810 and the third matrix layer 820 which are stacked.

[0241] Wherein, the related description of each layer can refer to the embodiment shown in Figure 8 , which will not be repeated here in the present application.

[0242] Different from the embodiment shown in Figure 9 , the flexible protective layer 901 can further include the third fiber layer 910 and the fourth matrix layer 920 which are stacked. Wherein, the third fiber layer 910 can be located between the third matrix layer 820 and the fourth matrix layer 920, and the third fiber layer 910 and the second fiber layer 910 are two adjacent fiber layers.

[0243] As shown in (b) in Figure 9 , the third fiber layer 910 can include a plurality of third glass fibers 911, and the third glass fibers 911 can extend along the third direction.

[0244] It should be noted that the first direction, the second direction, and the third direction can be the same direction or they can be different directions. This application does not impose any restrictions on this.

[0245] In some embodiments, the spacing between the first fiber layer 520 and the second fiber layer 810 may be the same as or different from the spacing between the second fiber layer 810 and the third fiber layer 910, and this application does not limit this.

[0246] For example, such as Figures 5 to 7 As shown in (b), the second direction can be parallel to the bending axis A' of the first region 520a, and both the first and third directions can be inclined relative to the bending axis A', wherein the inclination angles of the first and fourth directions relative to the bending axis A' are different.

[0247] It should be noted that the relevant description of the fourth matrix layer 920 can be found in [reference needed]. Figures 5 to 7 The descriptions of the first substrate layer 510 and the second substrate layer 520 in the illustrated embodiment, and the description of the third fiber layer 910, can be found in [reference needed]. Figure 9 To avoid repetition, the relevant descriptions of the first fiber layer 520 in the illustrated embodiment will not be repeated here.

[0248] See also Figure 9 (c) and Figure 9 (d) in the middle. Figure 9 (c) is a schematic diagram of the main structure of the flexible protective layer 902 provided in the embodiment of this application. Figure 9 (d) in the figure is a top view cross-sectional diagram of the flexible protective layer 902.

[0249] and Figure 9 (a) and Figure 9 Similar to the embodiment shown in (b), the flexible protective layer 902 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, and a fourth substrate layer 920 stacked together.

[0250] For a more detailed description of each of the above layers, please refer to [link / reference]. Figure 9 (a) and Figure 9 The embodiment shown in (b) is not described again here to avoid repetition.

[0251] and Figure 9 (a) and Figure 9 The embodiment shown in (b) differs from that shown in the example below, as Figure 9As shown in (d), both the first and second directions can be inclined relative to the bending axis A' of the first region 520a, and the third direction can be parallel to the bending axis A'. The inclination angles of the first and second directions relative to the bending axis A' are different.

[0252] See also Figure 9 (e) and Figure 9 (f) in the middle. Figure 9 (e) in the figure is a schematic diagram of the main structure of the flexible protective layer 903 provided in the embodiment of this application. Figure 9 (f) in the figure is a top view cross-sectional diagram of the flexible protective layer 903.

[0253] and Figure 9 (a) and Figure 9 Similar to the embodiment shown in (b), the flexible protective layer 903 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, and a fourth substrate layer 920 stacked together.

[0254] For a more detailed description of each of the above layers, please refer to [link / reference]. Figure 9 (a) and Figure 9 The embodiment shown in (b) is not described again here to avoid repetition.

[0255] and Figure 9 (a) and Figure 9 The embodiment shown in (b) differs from that shown in the example below, as Figure 10 As shown in (f), the first direction, the second direction, and the third direction can all be parallel to the bending axis A' of the first region 520a.

[0256] Figure 10 Exemplary schematic diagrams show different structures of a flexible protective layer including four fiber layers provided in embodiments of this application.

[0257] Please refer to both at the beginning. Figure 10 (a) and Figure 10 As shown in (b) of the diagram. Wherein, Figure 10 (a) is a schematic diagram of the main structure of the flexible protective layer 1001 provided in an embodiment of this application. Figure 9 (b) is a top view cross-sectional diagram of the flexible protective layer 1001.

[0258] and Figure 9 Similar to the embodiments shown, the flexible protective layer 1001 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, and a fourth substrate layer 920 stacked together.

[0259] For a more detailed description of each of the above layers, please refer to [link / reference]. Figure 9 The embodiments shown are not described in detail here to avoid repetition.

[0260] and Figure 10 The embodiment shown differs from the one described above, as follows: Figure 10 As shown in (a), the flexible protective layer 1001 may further include a fourth fiber layer 1010 and a fifth substrate layer 1020 stacked together, wherein the fourth fiber layer 1010 may be located between the fourth substrate layer 920 and the fifth substrate layer 1020, and the third fiber layer 910 and the fourth fiber layer 1010 are two adjacent fiber layers.

[0261] like Figure 10 As shown in (b), the fourth fiber layer 1010 may include a plurality of fifth glass fibers 1011, and the fifth glass fibers 1011 may extend along a fifth direction.

[0262] It should be noted that the first direction, the second direction, the third direction, and the fifth direction can be the same direction or they can be different directions. This application does not impose any restrictions on this.

[0263] For example, such as Figures 5 to 7 As shown in (b), the first direction and the third direction can be inclined relative to the bending axis A' of the first region 520a, and the second direction and the fifth direction can be parallel relative to the bending axis A', wherein the inclination angles of the first direction and the third direction relative to the bending axis A' are different.

[0264] It should be noted that the relevant description of the fifth matrix layer 1020 can be found in [reference needed]. Figures 5 to 7 The descriptions of the first matrix layer 510 and the second matrix layer 520 in the illustrated embodiment, and the description of the fourth fiber layer 1010, can be found in [reference needed]. Figure 10 To avoid repetition, the relevant descriptions of the first fiber layer 520 in the illustrated embodiment will not be repeated here.

[0265] See also Figure 10 (c) and Figure 10 (d) in the middle. Figure 10 (c) is a schematic diagram of the main structure of the flexible protective layer 1002 provided in the embodiment of this application. Figure 10 (d) in the figure is a top view cross-sectional diagram of the flexible protective layer 1002.

[0266] and Figure 10 (a) and Figure 10Similar to the embodiments shown in (a) and (b) of FIG. 10, the flexible protective layer 1002 can include the first matrix layer 510, the first fiber layer 520, the second matrix layer 530, the second fiber layer 810, the third matrix layer 820, the third fiber layer 910, the fourth matrix layer 920, the fourth fiber layer 1010, and the fifth matrix layer 1020 arranged in a stack.

[0267] For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10. Figure 10 Figure 10 For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10.

[0268] Different from the embodiments shown in (a) and (b) of FIG. 10, as shown in (c) of FIG. 10, the first direction, the second direction, and the third direction can be parallel to the bending axis A' of the first area 520a, and the fifth direction can be inclined relative to the bending axis A'. Figure 10 Figure 10 Different from the embodiments shown in (a) and (b) of FIG. 10, as shown in (d) of FIG. 10, the first direction, the second direction, and the third direction can be inclined relative to the bending axis A' of the first area 520a, and the fifth direction can be parallel to the bending axis A'. Among them, the first direction and the second direction have the same inclination angle relative to the bending axis A', and the first direction and the third direction have different inclination angles relative to the bending axis A'. Figure 10 For the related descriptions of the layers, please refer to the embodiments shown in (e) and (f) of FIG. 10.

[0269] Figure 10 (e) of FIG. 10 is a schematic structural diagram of the front view of the flexible protective layer 1003 provided by the embodiments of the present application, Figure 10 (f) of FIG. 10 is a schematic structural diagram of the top view of the flexible protective layer 1003. Figure 10 Figure 10 Similar to the embodiments shown in (a) and (b) of FIG. 10, the flexible protective layer 1003 can include the first matrix layer 510, the first fiber layer 520, the second matrix layer 530, the second fiber layer 810, the third matrix layer 820, the third fiber layer 910, the fourth matrix layer 920, the fourth fiber layer 1010, and the fifth matrix layer 1020 arranged in a stack.

[0270] For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10. Figure 10 Figure 10 For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10.

[0271] For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10. Figure 10 Figure 11 For the related descriptions of the layers, please refer to the embodiments shown in (a) and (b) of FIG. 10.

[0272] Different from the embodiments shown in (a) and (b) of FIG. 10, as shown in (c) of FIG. 10, the first direction, the second direction, and the third direction can be parallel to the bending axis A' of the first area 520a, and the fifth direction can be inclined relative to the bending axis A'. Figure 11 Figure 11 Different from the embodiments shown in (a) and (b) of FIG. 10, as shown in (d) of FIG. 10, the first direction, the second direction, and the third direction can be inclined relative to the bending axis A' of the first area 520a, and the fifth direction can be parallel to the bending axis A'. Among them, the first direction and the second direction have the same inclination angle relative to the bending axis A', and the first direction and the third direction have different inclination angles relative to the bending axis A'. Figure 11 ​​​​​​​As shown in (f), the first direction, the third direction, and the fifth direction can all be parallel to the bending axis A' of the first region 520a, and the second direction can be perpendicular to the bending axis A'.

[0273] Figure 11 Exemplary schematic diagrams show different structures of a flexible protective layer including five fiber layers provided in embodiments of this application.

[0274] Please refer to both at the beginning. Figure 10 (a) and Figure 10 (b) in the middle. Figure 10 (a) is a front view schematic diagram of the flexible protective layer 1101 provided in an embodiment of this application. Figure 11 (b) is a top view of the cross-sectional structure of the flexible protective layer 1101.

[0275] and Figure 11 Similar to the embodiments shown, the flexible protective layer 1101 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, a fourth substrate layer 920, a fourth fiber layer 1010, and a fifth substrate layer 1020 stacked together.

[0276] For a more detailed description of each of the above layers, please refer to [link / reference]. Figure 11 The embodiments shown will not be described again to avoid repetition.

[0277] and Figures 5 to 7 The embodiment shown differs from the one described above, as follows: Figures 5 to 7 As shown in (a), the flexible protective layer 1101 may further include a fifth fiber layer 1110 and a sixth substrate layer 1120 stacked together, wherein the fifth fiber layer 1110 may be located between the fifth substrate layer 1020 and the sixth substrate layer 1120, and the fifth fiber layer 1110 and the fourth fiber layer 1010 are two adjacent fiber layers.

[0278] like Figure 11 As shown in (b), the fifth fiber layer 1110 may include a plurality of sixth glass fibers 1111, and the sixth glass fibers 1111 may extend along a sixth direction.

[0279] It should be noted that the first direction, the second direction, the third direction, the fifth direction, and the sixth direction can be the same direction or they can be different directions. This application does not impose any restrictions on this.

[0280] For example, such as Figure 11As shown in (b), the first direction and the third direction can be inclined relative to the bending axis A' of the first region 520a, and the second direction, the fifth direction and the sixth direction can all be perpendicular to the bending axis A', wherein the first direction and the third direction have different inclination angles relative to the axis A.

[0281] It should be noted that the relevant description of the sixth matrix layer 1120 can be found in [reference needed]. Figure 11 The descriptions of the first substrate layer 510 and the second substrate layer 530 in the illustrated embodiment, and the description of the fifth fiber layer 1110, can be found in [reference needed]. Figure 11 To avoid repetition, the relevant descriptions of the first fiber layer 520 in the illustrated embodiment will not be repeated here.

[0282] See also Figure 11 (c) and Figure 11 (d) in the middle. Figure 11 (c) is a schematic diagram of the main structure of the flexible protective layer 1102 provided in the embodiment of this application. Figure 11 (d) in the figure is a top view cross-sectional diagram of the flexible protective layer 1102.

[0283] and Figure 11 (a) and Figure 11 Similar to the embodiment shown in (b), the flexible protective layer 1102 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, a fourth substrate layer 920, a fourth fiber layer 1010, a fifth substrate layer 1020, a fifth fiber layer 110, and a sixth substrate layer 1120 stacked together.

[0284] For a more detailed description of each of the above layers, please refer to [link / reference]. Figure 11 (a) and Figure 11 The embodiment shown in (b) is not described again here to avoid repetition.

[0285] and Figure 11 (a) and Figure 10 The embodiment shown in (b) differs from that shown in the example below, as Figure 11 As shown in (d), the first direction, the second direction, and the third direction can all be inclined relative to the bending axis A' of the first region 520a, and the fifth direction and the sixth direction can both be perpendicular to the bending axis A'. Among them, the first direction and the second direction have different inclination angles relative to the bending axis A', while the second direction and the third direction have the same inclination angle relative to the bending axis A'.

[0286] See also Figure 11 (e) and Figure 11 (f) in the middle.Figure 11 (e) is a schematic diagram of the main structure of the flexible protective layer 1003 provided in the embodiment of this application. Figure 11 (f) in the figure is a top view cross-sectional diagram of the flexible protective layer 1003.

[0287] and Figure 11 (a) and Figure 11 Similar to the embodiment shown in (b), the flexible protective layer 1103 may include a first substrate layer 510, a first fiber layer 520, a second substrate layer 530, a second fiber layer 810, a third substrate layer 820, a third fiber layer 910, a fourth substrate layer 920, a fourth fiber layer 1010, a fifth substrate layer 1020, a fifth fiber layer 1110, and a sixth substrate layer 1120 stacked together.

[0288] For a more detailed description of each of the above layers, please refer to [link / reference]. Figures 5 to 11 (a) and Figure 12 The embodiment shown in (b) is not described again here to avoid repetition.

[0289] and Figure 12 (a) and Figure 12 The embodiment shown in (b) differs from that shown in the example below, as Raw material As shown in (f), the first direction, the fifth direction and the sixth direction can all be parallel to the bending axis A' of the first region 520a, and the second direction and the third direction can both be perpendicular to the bending axis A'.

[0290] The flexible protective layer provided according to the embodiments of this application can have multiple fiber layers, and the extension direction of the glass fibers on different fiber layers can be different, so that the extension direction of the glass fibers on different fiber layers can be flexibly adjusted according to actual needs to meet different application requirements.

[0291] The above combination Typical type / grade The structure of the flexible protective layer provided in the embodiments of this application is described in detail below. Mass fraction This application provides a detailed description of the method for preparing the flexible protective layer according to its embodiments.

[0292] PBDMS 1 or PBDMS 2 This is a schematic block diagram illustrating a method 1200 for preparing a flexible protective layer according to an embodiment of this application. Method 1200 may include steps S1210-S1230. For example... First base resin preparation example 1 As shown, preparation method 1200 may specifically include:

[0293] S1210, a first matrix resin is coated onto a carrier to form a first matrix layer on the carrier. The first matrix layer comprises a first polymer, the main chain of which contains at least one of boron-oxygen coordination bonds and tandem boron-oxygen coordination bonds.

[0294] Specifically, first, the first base resin and the coating solvent can be mixed to configure a first base resin coating, and the first base resin coating can be coated on a carrier. Then, the coating solvent in the first base resin coating can be removed by a heating drying treatment. Finally, the first base resin coating after the heating drying treatment can be subjected to a curing treatment to obtain a first base layer on the carrier.

[0295] In some embodiments, the coating solvent can include, but is not limited to, one or more of methanol, toluene, tetrahydrofuran, ethyl acetate.

[0296] In some embodiments, the carrier described above can serve as a protective film of the flexible protective layer. For example, the carrier described above can be a release film, such as a PET release film or a polyethylene (PE) release film, which is not limited in the present application.

[0297] In some embodiments, the key parameters of the heating drying treatment can include a drying temperature and a drying time. For example, the drying temperature can be set to 50-120°C, such as 50°C, 60°C, 70°C, 90°C or 120°C, etc. The drying time can be set to be greater than or equal to 1 hour, which is not limited in the present application.

[0298] In some embodiments, the curing treatment can include a heating curing treatment and / or a moisture curing treatment.

[0299] In one example, the heating temperature during the heating curing treatment can be set to 20-130°C, such as 20°C, 40°C, 60°C, 90°C or 130°C, etc. The heating time can be set to be greater than or equal to 1 minute, which is not limited in the present application.

[0300] In another example, the humidity during the moisture curing treatment can be set to 10-90%, such as 10%, 25%, 40%, 60% or 90%, etc. The treatment temperature can be set to 20-130°C, such as 20°C, 45°C, 70°C, 95°C or 130°C, etc. The heating time can be set to be greater than or equal to 1 minute, which is not limited in the present application.

[0301] It should be noted that the synthesis method of the first base resin will be described below, and will not be described here.

[0302] S1220, a plurality of first glass fibers are laid on the side surface of the first base layer away from the first fiber layer to obtain a first fiber layer on the first base layer, wherein the first glass fibers extend in the first direction.

[0303] Exemplarily, the plurality of first glass fibers can be laid on the surface of the first base layer in a roll-laying manner, and the application does not make any limitation in this aspect.

[0304] S1230, coating a second base resin on the side surface of the first fiber layer away from the first base layer to prepare a second base layer on the first fiber layer. Wherein, the first base layer and the second base layer wrap the first fiber layer.

[0305] Similar to the preparation of the first base layer, the second base resin and the coating solvent can be first mixed to configure a second base resin coating, and the second base resin coating can be coated on the first fiber layer. Then, the coating solvent in the second base resin coating can be removed by heating and drying treatment, and the second base resin coating after the heating and drying treatment can be subjected to a curing treatment to prepare the second base layer on the first fiber layer.

[0306] Wherein, the related description of the coating solvent, the heating and drying treatment and the curing treatment can be referred to S1210, and will not be repeated here.

[0307] In some embodiments, the coating solvent in the second base resin coating can also be removed by vacuum drying treatment instead of heating and drying treatment, and vacuum degassing can also be performed by vacuum drying treatment. Exemplarily, the vacuum degree during the vacuum drying treatment can be set to -0.095Mpa to -0.06Mpa, for example, the vacuum degree can be set to -0.095Mpa, -0.085Mpa, -0.075Mpa or -0.06Mpa, etc. The processing temperature can be set to 20℃ to 100℃, for example, it can be 20℃, 45℃, 70℃, 95℃ or 100℃, etc. The vacuum treatment time can be set to be greater than or equal to 1 minute, and the application does not make any limitation in this aspect.

[0308] In some embodiments, the method 1200 can further include:

[0309] The surface of the prepared second base layer away from the first fiber layer can be covered with a second release film, and then rolled up to prepare a flexible protective layer.

[0310] Wherein, the second release film, similar to the carrier, can also serve as a protective film of the flexible protective layer. The second release film can be, for example, a PET release film or a polyethylene (PE) release film, and the application does not make any limitation in this aspect.

[0311] When the flexible protective layer is actually needed to be applied, the above-mentioned protective film (such as the carrier and the second release film) can be first torn off before being applied to other devices, for example, applied to foldable electronic devices.

[0312] In some embodiments, when the flexible protective layer includes a plurality of fiber layers, for example, when the flexible protective layer includes two fiber layers, the method 1200 can further include:

[0313] spreading a plurality of second glass fibers on a surface of the prepared second matrix layer away from the first fiber layer to prepare a second fiber layer on the second matrix layer, wherein the second glass fibers extend in the second direction when being spread;

[0314] coating a third matrix resin on a surface of the second fiber layer away from the second matrix layer to prepare a third matrix layer on the second fiber layer, wherein the second matrix layer and the third matrix layer cover the second fiber layer;

[0315] covering the second release film on a surface of the prepared third matrix layer away from the second fiber layer, and then winding to prepare a flexible protective layer product.

[0316] In some embodiments, the preparation of the second fiber layer and the third matrix layer can refer to the preparation of the first fiber layer and the second matrix layer described above, and will not be described here.

[0317] It should be noted that in the embodiments of the present application, the matrix resin (for example, the first matrix resin, the second matrix resin and the third matrix resin) for preparing each matrix layer can be obtained by the same preparation method. In the following, the preparation method of the matrix resin of each matrix layer will be specifically introduced taking the first matrix resin as an example.

[0318] Preparation Example One:

[0319] Step S11: Synthesis of the first polymer.

[0320] The polyborodimethylsiloxane (PBDMS) (referred to as PBDMS1) containing boron-oxygen coordination bonds in the main chain and / or the PBDMS (referred to as PBDMS2) containing continuous boron-oxygen coordination bonds in the main chain are synthesized by the chain extension reaction of the terminal hydroxyl silicone oil with boric acid and / or diboric acid, and the first polymer includes at least one of PBDMS1 and PBDMS2.

[0321] The chemical structures of the generated PDBMS1 and PBDMS2 can be respectively shown as formula (1) and formula (2):

[0322]

[0323] In formula (1) and formula (2), R1 and R2 can each independently be selected from a group consisting of free alkyl groups, alkenyl groups, cycloalkyl groups and aryl groups.

[0324] The reaction process for synthesizing PBDMS1 by reacting hydroxyl-terminated silicone oil and boric acid can be shown in the following reaction formula (I):

[0325] The reaction process for synthesizing PBDMS2 by reacting hydroxyl-terminated silicone oil and diboric acid can be shown in the following reaction formula (II):

[0326]

[0327] In the reaction formula (I) and the reaction formula (II), R1 and R2 can each independently be selected from a group consisting of an alkyl group, an alkenyl group, a cycloalkyl group and an aryl group.

[0328] Specifically, each raw material can be used in the proportions shown in Table 3 to synthesize PBDMS1 or PBDMS2 according to the reaction formula (I) or the reaction formula (II).

[0329] Table 3

[0330]

[0331] Each raw material in Table 3 is added to a reaction container (such as a beaker, a flask or a reaction kettle) in the corresponding proportions, and is stirred at a first preset stirring speed for a first preset time period at room temperature and a first preset vacuum degree until the raw materials are uniformly mixed in the reaction container. Then the temperature of the reaction environment in the reaction container is raised to a first preset temperature, and the uniformly mixed raw materials are allowed to react in the reaction container for a second preset time period under the conditions of maintaining the above-mentioned preset stirring speed and the above-mentioned preset vacuum degree, thereby obtaining PBDMS1 or PBDMS2.

[0332] The first preset vacuum degree can be, for example, -0.095 MPa to -0.08 MPa, such as -0.095 MPa, -0.091 MPa, -0.087 MPa or -0.085 MPa, but the present application is not limited thereto.

[0333] The first preset stirring speed can be, for example, 5 rpm to 5000 rpm, such as 5 rpm, 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 3000 rpm, 4000 rpm or 5000 rpm, but the present application is not limited thereto.

[0334] The first preset time period can be, for example, greater than or equal to 2 hours, but the present application is not limited thereto.

[0335] The first preset temperature can be, for example, 50°C to 100°C, such as 50°C, 55°C, 60°C, 70°C, 85°C or 100°C, but the present application is not limited thereto.

[0336] The second preset time length may be greater than or equal to 4 hours, which is not limited in the application.

[0337] It can be understood that the uniform mixing of the above raw materials in the reaction container can be specifically manifested as uniform dispersion of each raw material, no particle sedimentation, and no phase separation.

[0338] Step S12: mixing the first polymer (PBDMS1 and / or PBDMS2) and the condensation-cured silicone resin to prepare a first matrix resin.

[0339] The condensation-cured silicone resin is the base silicone resin of the condensation-cured optical organosilicon pressure-sensitive adhesive system. In the embodiments of the application, the chemical structure of the condensation-cured silicone resin can be as shown in formula (9):

[0340]

[0341] Wherein, n is an integer greater than or equal to 1.

[0342] Under the condition of moisture, the hydroxyl group on the first polymer (PBDMS1 and PBDMS2) can react with the alkoxy group on the condensation-cured silicone shown in formula (9) under the condition of room temperature moisture, and finally generate a cross-linked and cured first matrix resin, which contains boron-oxygen coordination and / or boron-oxygen coordination bonds in the molecular chain. The cross-linking reaction process of the first polymer (PBDMS1 and PBDMS2) and the condensation-cured silicone shown in formula (9) can be as shown in the following reaction formula (III):

[0343]

[0344] Wherein, n is an integer greater than or equal to 1.

[0345] Specifically, the first matrix resin can be prepared according to the above reaction formula (III) by using the proportions of each raw material shown in Table 4.

[0346] Table 4

[0347]

[0348] Each raw material in Table 4 is added to the reaction container (beaker, flask or reaction kettle, etc.) in the corresponding proportion, and each raw material is uniformly stirred under the second preset vacuum degree and at the second preset stirring speed, and then the temperature of the reaction environment in the reaction container is raised to the second preset temperature, and each raw material is reacted in the reaction container for a third preset time, thereby obtaining the first matrix resin, which is ready for use.

[0349] The second preset vacuum degree may be greater than or equal to -200 Kpa, which is not limited in the application.

[0350] The second preset stirring speed may be exemplarily 5-5000 rpm, for example, 5 rpm, 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 3000 rpm, 4000 rpm or 5000 rpm, which is not limited in the present application.

[0351] The second preset temperature may be exemplarily greater than or equal to 60°C, which is not limited in the present application.

[0352] The third preset time length may be exemplarily greater than or equal to 1 hour, which is not limited in the present application.

[0353] According to the preparation example one, the first base resin can be prepared by condensation reaction and cross-linking curing of the first polymer and the base siloxane resin of the condensation curing type optical organic silicone pressure-sensitive adhesive system. The siloxane resin can make the first base resin have good bonding performance. At least one of boron-oxygen coordination bond and boron-oxygen coordination bond is introduced into the molecular chain of the first base resin. Due to the unique breaking and bonding behavior of the boron-oxygen coordination bond or the boron-oxygen coordination bond, the first base resin can have better buffering, energy absorption and impact resistance performance on the premise of good bonding performance. In addition, the first polymer (PBDMS1 and / or PBDMS2) containing boron-oxygen coordination bond or boron-oxygen coordination bond is cured and formed by the condensation curing type siloxane resin to form a new structure polymer, which is beneficial to avoid the defects that the first polymer containing boron-oxygen coordination bond or boron-oxygen coordination bond itself is prone to creep and flow and has no peeling strength.

[0354] Preparation example two:

[0355] Step S21: synthesis of the first polymer.

[0356] Firstly, the PBDMS1 and / or PBDMS2 synthesized in step S11 of the preparation example one can be capped by vinyl silicone oil to obtain modified silicone oil polymers PBDMSC1 and / or PBDMSC2, wherein the end groups and / or side chains of PBDMSC1 and PBDMSC2 contain vinyl groups. The first polymer can include at least one of PBDMSC1 and PBDMSC2.

[0357] The chemical structures of PBDMSC1 and PBDMSC2 can be respectively shown in formula (10) and formula (11):

[0358]

[0359] In formula (10) and formula (11), R1, R2may be each independently selected from the group consisting of free alkyl groups, alkenyl groups, cycloalkyl groups and aryl groups.

[0360] In the embodiments of the present application, the chemical structure of the vinyl silicone oil can be as shown in formula (12):

[0361]

[0362] The reaction process of synthesizing PBDMSC1 or PDBMSC2 by reacting the vinyl silicone oil and PBDMS1 or PBDMS2 can be as shown in the following reaction formula (IV):

[0363]

[0364] Specifically, each raw material ratio shown in Table 5 can be used to synthesize PBDMSC1 or PBDMSC2 according to the reaction formula (IV).

[0365] Table 5

[0366] Vinyl silicone oil Formula (12) Solvent Methanol, toluene, THF, ethyl acetate, etc. Catalyst 40～70 Lithium hydroxide Figure 13 15～25 Figure 14 Figure 13 5～40 Figure 13 Figure 14 0～5

[0367] PBDMS1 or PBDMS2, vinyl silicone oil, solvent, and catalyst in Table 5 are added to a reaction container (beaker, flask, or reaction kettle, etc.) in proportion, and PBDMSC1 or PBDMSC2 is obtained by reaction at room temperature.

[0368] Step S22: mixing the first polymer (PBDMSC1 and / or PBDMSC2) and the heat-curable silicone resin to prepare a first matrix resin.

[0369] The heat-curable silicone resin is a base silicone resin of an addition type optical organic silicone pressure-sensitive adhesive system, and in the embodiments of the present application, the chemical structure of the heat-curable silicone resin can be as shown in formula (13):

[0370]

[0371] wherein n is an integer greater than or equal to 1.

[0372] Under the heating condition, the vinyl groups on the first polymer (PBDMSC1 and / or PBDMSC2) can add polymerize with the active hydrogen atoms on the heat-curable silicone shown in formula (13), and finally generate a cross-linked and cured first matrix resin, which contains boron-oxygen coordination and / or continuous boron-oxygen coordination bonds in the molecular chain. The first matrix resin contains boron-oxygen coordination and / or continuous boron-oxygen coordination bonds in the molecular chain. The cross-linking reaction process of the first polymer (PBDMSC1 and / or PBDMSC2) and the heat-curable silicone shown in formula (13) can be as shown in the following reaction formula (V):

[0373]

[0374] wherein n is an integer greater than or equal to 1.

[0375] Specifically, each raw material ratio shown in Table 6 below can be used to prepare the first base resin according to the reaction formula (V).

[0376] Table 6

[0377]

[0378]

[0379] Specifically, each raw material in Table 6 is added to a reaction container (beaker, flask, or reaction kettle, etc.) in a corresponding proportion, and each raw material is stirred uniformly at a third preset stirring speed under a third preset vacuum degree. Then, the temperature of the reaction environment in the reaction container is raised to a third preset temperature, and each raw material is allowed to react in the reaction container for a fourth preset time period, thereby obtaining the first base resin, which is ready for use.

[0380] The third preset vacuum degree can be greater than or equal to -200 Kpa, for example, and the present application does not limit this.

[0381] The third preset stirring speed can be 5-5000 rpm, for example, such as 5 rpm, 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 3000 rpm, 4000 rpm, or 5000 rpm, and the present application does not limit this.

[0382] The third preset temperature can be greater than or equal to 60°C, for example, and the present application does not limit this.

[0383] The fourth preset time period can be greater than or equal to 1 hour, for example, and the present application does not limit this.

[0384] It can be understood that the above first base resin preparation examples one and two are only examples, and the embodiments of the present application can also synthesize the first base resin according to actual needs, and the present application does not limit this.

[0385] The first base resin can be prepared by addition polymerization reaction and cross-linking curing of the first polymer and a base silicone resin of the addition type optical organic silicone pressure-sensitive adhesive system. The silicone resin can make the first base resin have good bonding performance. At least one of boron-oxygen coordination bond and boron-oxygen coordination bond is introduced into the molecular chain of the first base resin. Due to the unique breaking and bonding behavior of the boron-oxygen coordination bond or the boron-oxygen coordination bond, the first base resin can have better buffering, energy absorption and impact resistance performance on the premise of having good bonding performance. In addition, the first polymer (PBDMS1 and / or PBDMS2) containing the boron-oxygen coordination bond or the boron-oxygen coordination bond is cured by the addition curing type silicone resin to form a new structure polymer, which is beneficial to avoid the defects that the first polymer containing the boron-oxygen coordination bond or the boron-oxygen coordination bond is prone to creep and has no peeling strength.

[0386] In the preparation method of the flexible protective layer provided in the embodiments of the present application, the base layer is prepared by a coating process, which is beneficial to accurately control the thickness of the prepared base layer and the uniformity of the base layer, and is beneficial to adjust the thickness of the base layer to meet different actual needs. In addition, the glass fibers are laid on the base layer, which is beneficial to control the density of the arrangement of the glass fibers and is beneficial to meet different application requirements.

[0387] In the flexible protective layer prepared according to the above preparation method, the fiber layer includes a plurality of glass fibers. Since the glass fibers have a high modulus (for example, 60 Gpa-70 Gpa), they are beneficial to resist the deformation caused by low strain rate extrusion, so that the flexible protective layer can have better extrusion resistance.

[0388] In addition, at least one of boron-oxygen coordination bond and boron-oxygen coordination bond is introduced into the molecular chain of the first polymer. Since the boron-oxygen coordination bond or the boron-oxygen coordination bond has enough time to break under the action of low strain rate, the molecular chain can have flexibility and foldability under the action of low strain rate. Under the action of high strain rate, the time scale of the molecular chain movement is much smaller than the breaking time of the boron-oxygen coordination bond or the boron-oxygen coordination bond, and the unbroken boron-oxygen coordination bond or the boron-oxygen coordination bond can hinder the movement of the molecular chain, thereby hindering the disentanglement of the molecular chain, which can exhibit the characteristics of rigidity and elasticity in the macroscopic. The unique breaking and bonding behavior of the boron-oxygen coordination bond or the boron-oxygen coordination bond can make the flexible protective layer have the characteristics of absorbing impact energy when it is impacted by high strain rate, which is beneficial to make the flexible protective layer have better impact resistance.

[0389] The embodiments of the present application will be further described below. Figure 14 and Figure 13 The embodiments of the present application will be further described below.

[0390] Figure 3 is a schematic flowchart of a preparation method 1300 of a flexible protective layer, Figure 14 Cross-sectional schematic diagrams of the steps of the method 1300 are shown.

[0391] S1301, a first base resin coating is applied on a first release film 1321.

[0392] The first base resin can be prepared by the preparation method of Preparation Example One in the above method 1200.

[0393] S1302, the first release film 1321 coated with the first base resin coating is subjected to a heating and drying treatment to dry and remove the coating solvent in the first base resin coating.

[0394] The drying temperature during the heating and drying treatment can be set to 70°C, and the drying time can be set to 2 hours.

[0395] S1303, the first base resin coating after the heating and drying treatment is subjected to a heating and curing treatment to prepare a first base layer 1322 on the first release film 1321.

[0396] The heating temperature during the heating and curing treatment is set to 100°C, and the heating time is set to 3 minutes.

[0397] S1304, a plurality of first glass fibers extending in a first direction are laid on the side surface of the first base layer 1322 away from the first release film 1321 in a roll-laying manner to prepare a first fiber layer 1323 on the first base layer 1322.

[0398] The diameter of the first glass fiber is 10 μm.

[0399] S1305, a second base resin coating is applied on the side of the first fiber layer 1323 away from the first base layer 1322.

[0400] The second base resin is the same as the first base resin in S1301.

[0401] S1306, the first release film 1321 coated with the second base resin coating is subjected to a vacuum drying treatment to dry and remove the coating solvent in the second base resin coating, and vacuum degassing is performed at the same time.

[0402] The vacuum degree during the vacuum drying treatment is set to -0.085 Mpa, the treatment temperature is set to 70°C, and the treatment time is set to 2 minutes.

[0403] S1307, the second base resin coating after the vacuum drying treatment is subjected to a moisture curing treatment to obtain a second base layer 1324 on the first fiber layer 1323, thereby obtaining the flexible protective layer A.

[0404] In the moisture curing treatment, the humidity can be set to 40%, the treatment temperature can be set to 95°C, and the heating time can be set to 5 minutes.

[0405] S1308, a second release film 1325 is covered on the side surface of the second base layer 1324 away from the first fiber layer 1323, and then rolled up.

[0406] The first release film 1321 and the second release film 1325 serve as protective layers of the flexible protective layer A.

[0407] Figure 3 A schematic flowchart of a method 1400 for preparing a flexible protective layer is shown in FIG. 13B. Figure 3 FIG. 13C shows a cross-sectional schematic diagram of each step in the method 1400.

[0408] S1401, a first base resin coating is applied on a first release film 1421.

[0409] The first base resin is the same as the first base resin in S1301.

[0410] S1402, the first base resin coating applied on the first release film 1421 is subjected to a heating and drying treatment to remove the coating solvent in the first base resin coating.

[0411] S1403, the first base resin coating after the heating and drying treatment is subjected to a curing treatment to obtain a first base layer 1422 on the first release film 1421.

[0412] S1404, a plurality of first glass fibers extending in a first direction are arranged on the side surface of the first base layer 1422 away from the first release film 1421 by roll pasting to obtain a first fiber layer 1423 on the first base layer 1422.

[0413] S1405, a second base resin coating is applied on the side of the first fiber layer 1423 away from the first base layer 1422.

[0414] The second base resin is the same as the first base resin in S1301.

[0415] Specifically, the related treatment parameters in S1401 to S1405 are the same as those in S1301 to S1305, which will not be repeated here.

[0416] S1406, the first release film 1421 coated with the second matrix resin coating is subjected to a heating drying treatment to dry and remove the coating solvent in the second matrix resin coating.

[0417] The related parameters in the heating drying treatment are the same as those in S1402, which are not described herein again.

[0418] S1407, the second matrix resin coating after the heating curing treatment is subjected to a heating curing treatment to prepare a second matrix layer 1424 on the first fiber layer 1423.

[0419] The related parameters in the heating curing treatment are the same as those in S1403, which are not described herein again.

[0420] S1408, a plurality of second glass fibers extending along the second direction are laid on the side surface of the second matrix layer 1424 away from the first fiber layer 1423 by roll pasting to prepare a second fiber layer 1425 on the second matrix layer 1424.

[0421] The diameter of the third glass fiber is 10 μm.

[0422] S1409, the third matrix resin coating is coated on the side surface of the second fiber layer 1425 away from the second matrix layer 1424.

[0423] The third matrix resin is the same as the first matrix resin in S1301.

[0424] S1410, the first release film 1421 coated with the third matrix resin coating is subjected to a vacuum drying treatment to dry and remove the coating solvent in the third matrix resin coating, and vacuum defoaming is performed at the same time.

[0425] The related parameters in the vacuum drying treatment are the same as those in S1306, which are not described herein again.

[0426] S1411, the third matrix resin coating after the vacuum drying treatment is subjected to a moisture curing treatment to prepare a third matrix layer 1426 on the second fiber layer 1425, thereby obtaining the flexible protective layer B.

[0427] The related parameters in the moisture curing treatment are the same as those in S1307, which are not described herein again.

[0428] S1412, the second release film 1427 is covered on the side surface of the third matrix layer 1426 away from the second fiber layer 1425, and then it is wound up. The first release film 1421 and the second release film 1427 serve as the protective layer of the flexible protective layer B.

[0429] The embodiments provided by the present application are further described below through a plurality of embodiments.

[0430] [Example 1]

[0431] The flexible protective layer A with a single layer of fiber layer obtained according to the embodiment shown in ​ is applied to the flexible screen 30 shown in ​ . In the flexible screen 30, the thicknesses of the adhesive layer 37, the first cover substrate layer 381 and the second cover substrate layer 382 are all 50 μm, and the adhesive layer 37 is the flexible protective layer A.

[0432] [Example 2]

[0433] The flexible protective layer B with two layers of fiber layer obtained according to the embodiment shown in ​ is applied to the flexible screen 30 shown in ​ . In the flexible screen 30, the thicknesses of the adhesive layer 37, the first cover substrate layer 381 and the second cover substrate layer 382 are all 50 μm, and the adhesive layer 37 is the flexible protective layer B.

[0434] [Comparative Example 1]

[0435] In the flexible screen 30 shown in ​ , the thicknesses of the adhesive layer 37, the first cover substrate layer 381 and the second cover substrate layer 382 are all 50 μm, and the adhesive layer 37 is the optical adhesive film of the existing silicone adhesive system.

[0436] The flexible screens 30 in the above-mentioned Example 1, Example 2 and Comparative Example 1 are respectively subjected to extrusion, impact and bending simulation experiments, and the experimental data in Comparative Example 1 are taken as the benchmark, the changes of the experimental data in Example 1 and Example 2 relative to the benchmark are calculated, and the results are shown in Table 7.

[0437] Table 7

[0438]

[0439]

[0440] It can be seen from Table 7 that the impact resistance and extrusion resistance of the flexible screens 30 in Example 1 and Example 2 are both obviously improved compared with the flexible screen 30 in Comparative Example 1. The extrusion resistance of the flexible screen 30 in Example 1 is improved by 10.3%, and the impact resistance is improved by 20% to 30% compared with the flexible screen 30 in Comparative Example 1. The extrusion resistance of the flexible screen 30 in Example 2 is improved by 27.1%, and the impact resistance is improved by 20% to 30% compared with the flexible screen 30 in Comparative Example 1.

[0441] It is shown that the flexible protective layer provided by the embodiments of the present application can improve the poor impact resistance and extrusion resistance of the flexible screen 30, and is conducive to improving the reliability of the flexible screen 30. The reason is that: on the one hand, in the flexible protective layer provided by the embodiments of the present application, the fiber layer includes a plurality of glass fibers, and since the glass fibers have a high modulus (for example, 60Gpa~70Gpa), they are conducive to resisting the deformation caused by low strain rate extrusion, so that the flexible protective layer has better extrusion resistance. On the other hand, the first polymer has at least one of boron-oxygen coordination bond and boron-oxygen coordination bond in the molecular chain. Through the unique breaking and bonding behavior of the above boron-oxygen coordination bond or boron-oxygen coordination bond, the flexible protective layer can have the characteristics of absorbing impact energy when subjected to high strain rate impact, and is conducive to making the flexible protective layer have better impact resistance.

[0442] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A flexible shield characterized by, Comprise: A first base layer, a first fiber layer and a second base layer are stacked, the first fiber layer is located between the first base layer and the second base layer, The material of the first base layer and the second base layer comprises a first polymer, the main chain of the first polymer comprises at least one of boron-oxygen coordination bond and boron-oxygen coordination bond, The first fiber layer comprises a plurality of first glass fibers, the first glass fibers extend along a first direction, The first fiber layer comprises a first region and a second region, the second region is located on one side of the first region, the first region is bendable, the arrangement density of the plurality of first glass fibers in the first region is greater than that in the second region.

2. The flexible blanket of claim 1, wherein, The first direction is parallel or inclined to the bending axis of the first region.

3. The flexible blanket of claim 2, wherein, The flexible protective layer further comprises a third base layer and a second fiber layer stacked, The second fiber layer is located between the second base layer and the third base layer, the second fiber layer and the first fiber layer are two adjacent fiber layers, The second fiber layer comprises a plurality of second glass fibers, the second glass fibers extend along a second direction.

4. The flexible blanket of claim 3, wherein, The flexible protective layer satisfies at least one of the following: The extension direction of at least one of the first glass fibers and the second glass fibers is parallel to the bending axis of the first region; The arrangement density of the plurality of first glass fibers and the plurality of second glass fibers is different.

5. The flexible blanket according to claim 3 or 4, characterized in that The flexible protective layer further comprises a third fiber layer, the third fiber layer and the second fiber layer are two adjacent fiber layers, The spacing between the third fiber layer and the second fiber layer is different from the spacing between the second fiber layer and the first fiber layer.

6. The flexible blanket of claim 3 or 4, wherein, The thickness of the flexible protective layer is 10 μm ~ 150 μm, the spacing between the first fiber layer and the second fiber layer is 0 μm ~ 140 μm.

7. The flexible blanket according to any one of claims 1 to 4, wherein, The plurality of first glass fibers satisfies at least one of the following: The mass fraction of the plurality of first glass fibers in the flexible protective layer is 5% ~ 80%; The spacing between two adjacent first glass fibers is 0 ~ 1000 μm; The diameter of the first glass fiber is 5 μm ~ 100 μm; The length of the first glass fiber is greater than or equal to 5 cm; The difference between the refractive index of the first glass fiber and the refractive index of the first base layer and the second base layer is 0 ~ 0.

1.

8. The flexible blanket of any one of claims 1 to 4, wherein, The first base layer satisfies at least one of the following: The modulus of the first base layer and the second base layer is 10 Kpa ~ 500 MPa; The refractive index of the first base layer and the second base layer is 1.420 ~ 1.650; The light transmittance of the first base layer and the second base layer is greater than or equal to 80%; The haze of the first base layer and the second base layer is less than or equal to 5%.

9. The flexible blanket of any one of claims 1 to 4, wherein, The end group and / or side chain of the first polymer comprises at least one of hydroxyl, acrylate group and vinyl group, The material of the first base layer and the second base layer further comprises an adhesive matrix, Wherein, the adhesive matrix comprises at least one of siloxane resin, alkylene oxide resin and acrylate monomer.

10. The flexible blanket of any one of claims 1 to 4, wherein, The flexible protective layer further comprises a first release film and a second release film, The first release film is located on a side of the first base layer away from the first fiber layer, and the second release film is located on a side of the second base layer away from the first fiber layer.

11. A method of making a flexible barrier, characterized by, The method comprises: coating a first base resin on a carrier to form a first base layer on the carrier; arranging a plurality of first glass fibers on a side surface of the first base layer away from the carrier to form a first fiber layer on the first base layer; coating a second base resin on a side surface of the first fiber layer away from the first base layer to form a second base layer on the first fiber layer, the first base layer and the second base layer covering the first fiber layer; The first base layer and the second base layer comprise a first polymer, the main chain of the first polymer comprising at least one of a boron-oxygen coordination bond and a boron-oxygen coordination bond, The first glass fibers extend in a first direction, the first fiber layer comprises a first region and a second region, the second region being located on a side of the first region, the first region being bendable, and the arrangement density of the plurality of first glass fibers in the first region being greater than that in the second region.

12. The method of claim 11, wherein, The method further comprises: arranging a plurality of second glass fibers on a side surface of the second base layer away from the first fiber layer to form a second fiber layer on the second base layer, the second glass fibers extending in a second direction; coating a third base resin on a side surface of the second fiber layer away from the second base layer to form a third base layer on the second fiber layer, the second base layer and the third base layer covering the second fiber layer; covering the third base layer with a second release film to form a flexible protective layer, and then winding the flexible protective layer.

13. A flexible cover sheet characterized by The flexible protective layer comprises a first release film and a second release film, 14. A flexible screen, characterized by, The first release film is located on a side of the first base layer away from the first fiber layer, and the second release film is located on a side of the second base layer away from the first fiber layer.

15. The flexible screen of claim 14, wherein, The method comprises:

16. A foldable electronic device, characterized by coating a first base resin on a carrier to form a first base layer on the carrier; arranging a plurality of first glass fibers on a side surface of the first base layer away from the carrier to form a first fiber layer on the first base layer; coating a second base resin on a side surface of the first fiber layer away from the first base layer to form a second base layer on the first fiber layer, the first base layer and the second base layer covering the first fiber layer; The first base layer and the second base layer comprise a first polymer, the main chain of the first polymer comprising at least one of a boron-oxygen coordination bond and a boron-oxygen coordination bond, The first glass fibers extend in a first direction, the first fiber layer comprises a first region and a second region, the second region being located on a side of the first region, the first region being bendable, and the arrangement density of the plurality of first glass fibers in the first region being greater than that in the second region. The method further comprises: arranging a plurality of second glass fibers on a side surface of the second base layer away from the first fiber layer to form a second fiber layer on the second base layer, the second glass fibers extending in a second direction; coating a third base resin on a side surface of the second fiber layer away from the second base layer to form a third base layer on the second fiber layer, the second base layer and the third base layer covering the second fiber layer; covering the third base layer with a second release film to form a flexible protective layer, and then winding the flexible protective layer. The flexible protective layer comprises a first release film and a second release film, The first release film is located on a side of the first base layer away from the first fiber layer, and the second release film is located on a side of the second base layer away from the first fiber layer. The method comprises: coating a first base resin on a carrier to form a first base layer on the carrier; arranging a plurality of first glass fibers on a side surface of the first base layer away from the carrier to form a first fiber layer on the first base layer; coating a second base resin on a side surface of the first fiber layer away from the first base layer to form a second base layer on the first fiber layer, the first base layer and the second base layer covering the first fiber layer; The first base layer and the second base layer comprise a first polymer, the main chain of the first polymer comprising at least one of a boron-oxygen coordination bond and a boron-oxygen coordination bond, The first glass fibers extend in a first direction, the first fiber layer comprises a first region and a second region, the second region being located on a side of the first region, the first region being bendable, and the arrangement density of the plurality of first glass fibers in the first region being greater than that in the second region. The method further comprises: arranging a plurality of second glass fibers on a side surface of the second base layer away from the first fiber layer to form a second fiber layer on the second base layer, the second glass fibers extending in a second direction; coating a third base resin on a side surface of the second fiber layer away from the second base layer to form a third base layer on the second fiber layer, the second base layer and the third base layer covering the second fiber layer; covering the third base layer with a second release film to form a flexible protective layer, and then winding the flexible protective layer. The flexible protective layer comprises a first release film and a second release film, The first release film is located on a side of the first base layer away from the first fiber layer, and the second release film is located on a side of the second base layer away from the first fiber layer.

Images