CN117841493A

CN117841493A - Composite film layer, manufacturing method thereof, foldable supporting piece and foldable display device

Info

Publication number: CN117841493A
Application number: CN202410122757.1A
Authority: CN
Inventors: 曾佳; 曾伟; 王志会; 张磊
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2024-01-29
Filing date: 2024-01-29
Publication date: 2024-04-09

Abstract

The embodiment of the disclosure provides a composite film layer, a manufacturing method thereof, a foldable support piece and a foldable display device, and belongs to the technical field of display. The composite film layer comprises M supporting layers and M+1 protective layers which are alternately laminated, M is an integer, and M is larger than 0. The protective layer is made of thermoplastic materials. According to the embodiment of the disclosure, the protective layer material and the supporting layer material in the composite film layer can be separated and recovered in a melting mode, so that the cost is saved.

Description

Composite film layer, manufacturing method thereof, foldable supporting piece and foldable display device

Technical Field

The embodiment of the disclosure relates to the technical field of display, in particular to a composite film layer, a manufacturing method thereof, a foldable support piece and a foldable display device.

Background

With the development of technology, the display device has been widely used, and has become one of important tools in daily work and life, wherein the foldable display device has the advantage of convenient carrying, and is popular with the masses.

In the related art, a foldable display device includes a display panel and a foldable support member, the foldable support member is made of a composite film layer including a plurality of support layers and a plurality of protective layers alternately laminated, wherein the protective layers are made of a thermosetting material.

However, since the thermosetting material forms a crosslinked network structure after heat curing and cannot be rebuilt, it cannot be repeatedly formed by hot melting, and thus there is a problem in that recycling is difficult.

Disclosure of Invention

The embodiment of the disclosure provides a composite film, a manufacturing method thereof, a foldable support and a foldable display device, wherein protective layer materials and support layer materials in the composite film can be separated and recycled in a melting mode, so that the cost is saved. The technical scheme is as follows:

in one aspect, an embodiment of the present disclosure provides a composite film layer, where the composite film layer includes M support layers and m+1 protection layers that are alternately stacked, M is an integer, and M is greater than 0; the protective layer is made of thermoplastic materials.

Optionally, the protective layer is made of a blend of a first material and a second material, the peak temperature of the melting peak of the first material being 20 ℃ to 100 ℃ lower than the peak temperature of the melting peak of the second material.

Alternatively, the blend of the first material and the second material has only one melting peak.

Optionally, the composite film layer includes one supporting layer, the protective layer includes a first sub-layer and a second sub-layer, the first sub-layer is made of a first material, the second sub-layer is made of a second material, the first sub-layer is located on one side of the second sub-layer, close to the supporting layer, and the peak temperature of a melting peak of the first material is 20-100 ℃ lower than the peak temperature of a melting peak of the second material.

Optionally, the first material is a polypropylene copolymer, and the second material is an isotactic polypropylene; alternatively, the first material is a low density polyethylene and the second material is a high density polyethylene.

Optionally, the M support layers include a first support layer, a second support layer, and a third support layer adjacent in a stacking direction, the second support layer including a plurality of fibrous materials extending in a first direction, the first support layer and the third support layer including a plurality of fibrous materials extending in a second direction, the first direction and the second direction intersecting.

Optionally, the fiber material is carbon fiber or glass fiber.

In another aspect, an embodiment of the present disclosure provides a method for manufacturing a composite film layer, where the method includes: forming M support layers and M+1 isolation layers which are alternately stacked, wherein M is an integer and is larger than 0, and the isolation layers are made of thermoplastic materials; the M support layers are connected through the M+1 isolation layers to obtain a composite film layer, wherein the composite film layer comprises M support layers and M+1 protection layers which are alternately laminated; wherein the protective layer is made of thermoplastic materials.

Optionally, M is an integer, M is greater than 1, and the forming of the M support layers and the m+1 isolation layers that are alternately stacked includes: forming an initial protective layer at a first temperature using a first material and a second material, the initial protective layer comprising a first initial sub-layer and a second initial sub-layer stacked, the first initial sub-layer being formed of the first material and the second initial sub-layer being formed of the second material, a peak temperature of a melting peak of the first material being 20 ℃ to 100 ℃ lower than a peak temperature of a melting peak of the second material, the first temperature being higher than a peak temperature of a melting peak of the second material; covering two sides of each supporting layer with one initial protective layer respectively, wherein in each initial protective layer, the first initial sub-layer is positioned on one side of the second initial sub-layer, which is close to the supporting layer; performing a pre-soaking process on each supporting layer and two initial protection layers respectively positioned at two sides of the supporting layer at a second temperature to form M pre-treated structures, stacking the M pre-treated structures, wherein the isolation layers positioned between two adjacent supporting layers comprise the two initial protection layers after the pre-soaking process, the isolation layers positioned at two sides of the M supporting layers comprise one initial protection layer after the pre-soaking process, and the second temperature is between the peak temperature of a melting peak of the first material and the peak temperature of a melting peak of the second material; the connecting the M support layers through the m+1 isolation layers includes: and hot-pressing the laminated M pretreatment structures at a third temperature, wherein the third temperature is higher than the peak temperature of the melting peak of the second material.

Optionally, M is equal to 1, the forming of M support layers and m+1 isolation layers alternately stacked, and the connecting the M support layers through the m+1 isolation layers includes: forming an initial protective layer with a first material and a second material at a temperature lower than a first temperature, the initial protective layer comprising a first initial sub-layer and a second initial sub-layer stacked, the first initial sub-layer being formed of the first material and the second initial sub-layer being formed of the second material, a peak temperature of a melting peak of the first material being 20 ℃ to 100 ℃ lower than a peak temperature of a melting peak of the second material, the first temperature being higher than a peak temperature of a melting peak of the second material; the two sides of the supporting layer are respectively covered with one initial protection layer, and in each initial protection layer, the first initial sub-layer is positioned on one side, close to the supporting layer, of the second initial sub-layer; and carrying out a pre-soaking process on the supporting layer and two initial protection layers respectively positioned at two sides of the supporting layer at a second temperature to form a pre-treatment structure, wherein the pre-treatment structure is the composite film layer, the isolation layer comprises one initial protection layer after the pre-soaking process, the protection layer is the isolation layer, and the second temperature is between the peak temperature of the melting peak of the first material and the peak temperature of the melting peak of the second material.

In yet another aspect, an embodiment of the present disclosure provides a foldable support, including a support body including a first planar region, a first bending region, and a second planar region connected in sequence, the support body being made of any one of the foregoing composite film layers.

In yet another aspect, an embodiment of the present disclosure provides a foldable display device, where the foldable display device includes a display panel and the foregoing foldable support, where the display panel is located on one side of the foldable support, and the display panel includes a third planar area, a second bending area, and a fourth planar area that are sequentially connected, and an orthographic projection of the first bending area on a bearing surface of the foldable support and an orthographic projection of the second bending area on the bearing surface of the foldable support at least partially overlap.

The beneficial effects that this disclosure provided technical scheme brought include at least: the protective layer in the composite film layer is made of thermoplastic materials, so that the protective layer material and the supporting layer material in the composite film layer can be separated and recycled in a melting mode, and the cost is saved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic cross-sectional view of a composite membrane layer provided in an embodiment of the present disclosure;

FIG. 2 is a differential scanning calorimetric diagram of a first material, a second material, a blend of the first material and the second material provided by an embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional view of another composite membrane layer provided in an embodiment of the disclosure;

FIG. 4 is a schematic plan view of a plurality of support layers of a composite membrane layer according to an embodiment of the present disclosure;

fig. 5 is a schematic flow chart of a method for manufacturing a composite film according to an embodiment of the disclosure;

FIG. 6 is a schematic cross-sectional view of an initial protective layer provided in an embodiment of the present disclosure;

FIG. 7 is a schematic illustration of a first material and a second material being co-extruded as provided by an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a support layer and initial protection layers on two sides of the support layer as a pre-treatment structure according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a plurality of pre-treatment structures stacked and hot pressed provided by an embodiment of the present disclosure;

fig. 10 is a schematic plan view of a foldable support provided in an embodiment of the present disclosure.

Legend description:

x, first direction y, second direction

A. First material B, second material C, blend of first material and second material

D. A first plane area E, a first bending area F and a second plane area

10. Support layer 11, first support layer 12, second support layer 13, third support layer

20. Protective layer 21, first sub-layer 22, second sub-layer

31. First cavity 32, second cavity

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present disclosure more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The terminology used in the description of the embodiments of the disclosure is for the purpose of describing the embodiments of the disclosure only and is not intended to be limiting of the disclosure. Unless defined otherwise, technical or scientific terms used in the embodiments of the present disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure belongs. The terms "first," "second," "third," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are present in front of "comprising" or "comprising" are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. References to directional terms in this disclosure, such as "top", "bottom", "upper", "lower", "left" or "right", etc., are merely with reference to the orientation of the drawings, and thus are used in order to better and more clearly illustrate and understand the disclosed embodiments, rather than to indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the disclosed embodiments.

Fig. 1 is a schematic cross-sectional structure of a composite film according to an embodiment of the present disclosure. As shown in fig. 1, the composite film layer includes M support layers 10 and m+1 protective layers 20 alternately stacked, M is an integer, and M is greater than 1, and the protective layers 20 are made of thermoplastic materials. Because the protective layer 20 is made of thermoplastic materials, the protective layer in the composite film layer can be recovered in a hot melting mode, and meanwhile, the protective layer and the supporting layer are separated, so that the cost is reduced, and the environmental protection is facilitated. As shown in fig. 1, the composite film layer includes 3 support layers 10 and 4 protective layers 20. In other possible embodiments, M is greater than or equal to 2, the composite film layer may also include more or less support layers 10, and correspondingly, the composite film layer includes m+1 protective layers 20.

In another possible embodiment, the composite film layer includes only one support layer 10, i.e. M is equal to 1, and the protective layers 20 are formed on both sides of the support layer 10, and the protective layers 20 are made of thermoplastic materials.

The protective layer 20 is exemplified below, and the protective layer 20 may comprise one or more thermoplastic materials. In one possible embodiment, the protective layer 20 comprises a thermoplastic material. The composite film layer may be formed by alternately laminating and hot-pressing M support layers and m+1 thermoplastic material layers.

In another possible embodiment, the protective layer 20 may also comprise two thermoplastic materials. Illustratively, the protective layer 20 is made from a blend C of a first material A and a second material B.

Fig. 2 is a differential scanning calorimetric diagram of a first material a, a second material B, a blend C of the first material and the second material provided in an embodiment of the present disclosure. As shown in fig. 2, the peak temperature T1 of the melting peak of the first material a is 20 to 100 ℃ lower than the peak temperature T2 of the melting peak of the second material B. The difference between the peak temperature of the melting peak of the first material a and the peak temperature of the melting peak of the second material B may be used as the processing window.

Here, the processing window means: in the manufacturing process of the composite film layer, the first material A and the second material B are in different states by utilizing the difference value between the peak temperature of the melting peak of the first material A and the peak temperature of the melting peak of the second material B so as to process a required structure. For example, an initial protective layer may be first fabricated, the initial protective layer comprising a first portion and a second portion that are laminated, wherein the first portion is fabricated from a first material a and the second portion is fabricated from a second material B. One initial protective layer is respectively covered on two sides of the supporting layer, in each initial protective layer, the first part is positioned on one side of the second part close to the supporting layer, the first part close to the supporting layer 10 is melted under the temperature condition between the peak temperature of the melting peak of the first material A and the peak temperature of the melting peak of the second material B, at the moment, the first part fully covers and combines fiber materials in the supporting layer to realize presoaking, and the second part is not melted, and one supporting layer 10 and two initial protective layers 20 form a pretreatment structure after cooling.

Illustratively, the peak temperature of the melting peak of the first material a is about 120 ℃ to 140 ℃, and the peak temperature of the melting peak of the second material B is about 160 ℃ to 180 ℃.

If the composite film layer has a plurality of support layers 10, a plurality of pretreatment structures may be stacked and hot-pressed under a condition of a peak temperature higher than a melting peak of the second material B, so that the first material a and the second material B located between two adjacent support layers 10 are melted to form a blend, and at the same time, the plurality of pretreatment structures are connected to form the composite film layer. Each protective layer 20 is in this embodiment a melt formed blend of a first material a and a second material B.

Fig. 3 is a schematic cross-sectional structure of another composite film layer provided in an embodiment of the present disclosure. As shown in fig. 3, if the composite film layer has only one supporting layer, the above-mentioned pretreatment structure may be used as a composite film layer, that is, in the composite film layer, the protective layer includes a first sub-layer 21 and a second sub-layer 22 stacked together, the first sub-layer 21 is located on one side of the second sub-layer 22 close to the supporting layer 10, the first sub-layer 21 is made of a first material a, the second sub-layer 22 is made of a second material B, and the peak temperature of the melting peak of the first material a is 20 ℃ to 100 ℃ lower than that of the melting peak of the second material B. Since the composite film has only one support layer, the process for manufacturing the composite film is relatively simple compared with the process for manufacturing the composite film including the plurality of support layers 10.

If the composite film layer has only one support layer 10, the protective layer 20 on both sides of the support layer may be made of a blend C of the first material and the second material instead of the first sub-layer 21 and the second sub-layer 22. For example, a support layer 10 may be provided, one side of the support layer 10 is covered with a thermoplastic material layer made of a first material and a thermoplastic material layer made of a second material, the other side of the support layer 10 is also covered with a thermoplastic material layer made of a first material and a thermoplastic material layer made of a second material, and hot-pressing is performed under a condition higher than the peak temperature of the melting peak of the second material B, so that the first material a and the second material B located on the same side of the support layer 10 are melted to form a blend, and the protective layers 20 located on both sides of the support layer 10 are obtained after cooling. The embodiments of the present disclosure do not limit the stacking order of the thermoplastic material layer made of the first material and the thermoplastic material layer made of the second material.

In other possible embodiments, M is greater than or equal to 2, that is, the composite film layer has a plurality of support layers 10, the protective layer 20 between two adjacent support layers is made of one of a first material a and a second material B, the protective layer 20 on both sides of the M support layers includes a first sub-layer 21 and a second sub-layer 22 stacked, the first sub-layer 21 is located on a side of the second sub-layer 22 adjacent to the support layer 10, the first sub-layer 21 is made of the first material a, and the second sub-layer 22 is made of the second material B.

The different processing modes can be flexibly selected according to the number of layers comprising the support layer 10 in the composite film layer.

Illustratively, as shown in fig. 3, the blend C of the first material a and the second material B has only one melting peak. The blend C has only one melting peak C', which indicates that the first material A and the second material B have good compatibility, and the blend C is convenient to be melted by a heating mode, for example, so as to realize recycling. The recovered blend C can be used to make low end products such as plastic pots.

Illustratively, the first material a is a copolymerized polypropylene (copolymerized Polypropylene, coPP) and the second material B is an isotactic polypropylene (isotactic Polypropylene, iPP). Alternatively, the first material a is a low density polyethylene (Low Density Polyethylene, LDPE) and the second material B is a high density polyethylene (High Density Polyethylene, HDPE). These first material a and second material B each meet the following conditions: the peak temperature of the melting peak of the first material a and the peak temperature of the melting peak of the second material B differ by 20 ℃ to 100 ℃, and the blend C formed by the first material a and the second material B has only one melting peak. For example, the peak temperature of the melting peak of the copolymer polyethylene differs from the peak temperature of the melting peak of the isotactic polyethylene by about 30℃to 60℃and the peak temperature of the melting peak of the low-density polyethylene differs from the peak temperature of the melting peak of the high-density polyethylene by about 20℃to 50 ℃. Wherein, the copolymer polypropylene and the isotactic polypropylene are the same system polymer, and the compatibility is good; the low-density polyethylene and the high-density polyethylene are the same system polymer, and have good compatibility. It should be noted that, when the first material a and the second material B are low-density polyethylene and high-density polyethylene, respectively, the densities of the first material a and the second material B are relatively low, and the density of the first material a is smaller than the density of the second material B.

The support layer 10 is exemplarily described below. Fig. 4 is a schematic plan view of a plurality of support layers of a composite film according to an embodiment of the present disclosure. Referring to fig. 1 and 4, the m support layers 10 include a first support layer 11, a second support layer 12, and a third support layer 13 adjacent in the lamination direction, the second support layer 12 including a plurality of fibrous materials extending in a first direction x, the first support layer 11 and the third support layer 13 including a plurality of fibrous materials extending in a second direction y, the first direction x and the second direction y being perpendicular. The fibers in the first support layer 11, the second support layer 12 and the third support layer 13 are arranged in a crossed manner, so that the support strength of the composite film layer can be improved. In other possible embodiments, the first direction x and the second direction y intersect and are not perpendicular.

In other possible embodiments, the M support layers include 2, 4, 5 or more support layers 10. When M is greater than 3, for two adjacent support layers, the directions of extension of the fibrous materials in the two support layers intersect; for two support layers separated by one support layer, the extension direction of the spacing material in the two support layers is the same.

When the support layer 10 includes a plurality of fibrous materials, the protective layers 20 located at both sides of the support layer may be connected by gaps between the fibrous materials.

Illustratively, the fibrous material is carbon fiber or glass fiber. The carbon fiber material and the glass fiber material have high strength and can be used as support layer materials, wherein the carbon fiber material is favorable for reducing the weight of the composite film layer, the composite film layer is convenient to be used on products such as foldable display equipment, the weight of the products is reduced, and the use of users is convenient.

In other possible embodiments, the fibrous material in the support layer 10 may not extend in one direction, but may be in a woven structure, i.e. the support layer 10 comprises fibrous material extending in two directions, for example comprising a plurality of fibrous materials extending in the first direction x and a plurality of fibrous materials extending in the second direction y. The embodiments of the present disclosure do not limit the weave pattern of the woven structure in the support layer 10.

When M is greater than 2 and M is an odd number, in embodiments in which each support layer 10 includes only fibrous material extending in one direction, there are (M-1)/2 support layers 10 including fibrous material extending in one direction (e.g., in the first direction x) and (m+1)/2 support layers 10 including fibrous material extending in another direction (e.g., in the second direction y), and thus the composite film layer is relatively more pliable and has an extension direction of the bending axis that is the same as the first direction x and is less pliable in the second direction y, and thus the length of the bending region of the foldable support made with the composite film layer may be the first direction.

Illustratively, as shown in fig. 1, the thicknesses of the first, second, and third support layers 11, 12, and 13 are t1, t2, and t3, respectively. t1 ranges from 10 to 100 μm, t2 ranges from 10 to 100 μm, and t3 ranges from 10 to 100 μm. If the support layer 10 is too thick, the composite film layer is thicker, and if the support layer 10 is too thin, the strength of the composite film layer is insufficient.

Fig. 5 is a flow chart of a method for manufacturing a composite film according to an embodiment of the disclosure. As shown in fig. 5, the method includes:

in step S1, M support layers and m+1 isolation layers are formed alternately, wherein M is an integer and M is greater than 0, and wherein the isolation layers are made of a thermoplastic material.

In step S2, M support layers are connected through m+1 isolation layers, so as to obtain a composite film layer, where the composite film layer includes M support layers and m+1 protection layers that are alternately stacked.

Wherein, the protective layer is made of thermoplastic materials.

Illustratively, M is greater than 1, the composite film layer shown in FIG. 1 is fabricated in the following manner. Fig. 6 is a schematic cross-sectional structure of an initial protection layer according to an embodiment of the present disclosure, and fig. 7 is a schematic diagram of a support layer and initial protection layers disposed on two sides of the support layer according to an embodiment of the present disclosure. Forming M support layers and m+1 isolation layers alternately stacked, including:

in the first step, as shown in fig. 6, an initial protective layer is formed using a first material a and a second material B at a first temperature, the initial protective layer including a first initial sub-layer and a second initial sub-layer stacked, the first initial sub-layer being formed of the first material a, the second initial sub-layer being formed of the second material B, the peak temperature of the melting peak of the first material a being lower than the peak temperature of the melting peak of the second material B by 30 ℃ to 100 ℃, the first temperature being lower than the peak temperature of the melting peak of the first material a.

Optionally, fig. 7 is a schematic diagram of co-extruding a first material a and a second material B according to an embodiment of the disclosure, where, as shown in fig. 7, the first material a and the second material B are formed into an initial protective layer by co-extrusion and stretching at a first temperature, and the first temperature is 30 to 100 ℃ higher than a peak temperature of a melting peak of the first material B. For example, the first temperature may be 200 ℃ to 240 ℃. At a first temperature, both the first material a and the second material B melt, are deformable for coextrusion, and the first material a and the second material B can be well combined to form an initial protective layer.

Alternatively, as shown in fig. 7, the coextrusion apparatus comprises a first chamber 31 for heating the first material a and a second chamber 32 for heating the second material B. The first material a and the second material B were co-extruded to form a continuous thicker, narrower planar structure, which was stretched to form the initial protective layer shown in fig. 6.

Alternatively, in the initial protective layer, the first material a is formed to have a first portion having a thickness of 5 μm to 30 μm and the second material B is formed to have a second portion having a thickness of 5 μm to 30 μm. If the thickness of the first portion and the second portion in the initial protective layer is too thick, the finally formed composite film layer is thicker, and if the thickness of the first portion and the second portion is thinner, the film forming difficulty is high.

In the second step, as shown in fig. 8, two sides of each supporting layer 10 are covered with an initial protection layer, and in each initial protection layer, the first initial sub-layer is located at one side of the second initial sub-layer close to the supporting layer 10.

And thirdly, carrying out a pre-soaking process on each supporting layer and two initial protection layers respectively positioned at two sides of the supporting layer at a second temperature to form M pre-treated structures, stacking the M pre-treated structures, wherein the isolation layers positioned between two adjacent supporting layers comprise the two initial protection layers after the pre-soaking process, and the isolation layers positioned at two sides of the M supporting layers comprise one initial protection layer after the pre-soaking process. The second temperature is between the peak temperature of the melting peak of the first material a and the peak temperature of the melting peak of the second material B. At the second temperature, the first portion melts and fully coats the fibrous material in the support layer 10 to achieve pre-preg, while the second portion does not melt, preventing the second material B in the second portion from adhering to the roller surface during the pre-preg process. One support layer 10 and two initial protective layers 20 form a pre-treatment structure after cooling. Optionally, the pre-impregnation process includes sequentially performing the following treatments on the supporting layer and two initial protective layers respectively located on two sides of the supporting layer: the rolling is performed by using a roller heated to a second temperature, the heating plate with the second temperature is used for continuous heating, the rolling is performed by using the roller for the second time, and the cooling is performed by using a cooling plate. Optionally, after the pretreatment structure is manufactured, protective films made of polyethylene or other materials can be covered on two sides of the pretreatment structure to protect the pretreatment structure, and the pretreatment structure is rolled and stored.

Fig. 9 is a schematic diagram of stacking and hot pressing a plurality of pretreatment structures provided in an embodiment of the present disclosure. As shown in fig. 9, connecting M support layers through m+1 isolation layers includes: and hot-pressing the laminated M pretreatment structures at a third temperature, wherein the third temperature is higher than the peak temperature of the melting peak of the second material. Alternatively, the third temperature is similar to the first temperature, e.g., the third temperature may be the same as the first temperature.

Optionally, the direction of extension of the fibrous material of the support layer 10 in adjacent two pretreatment structures is different. At a third temperature, the first material a and the second material B form a blend C, i.e. form the protective layer 20. Optionally, the stacked plurality of pre-treatment structures are hot pressed by means of a die press or autoclave. In the related art, the protective layer is made of thermosetting materials, and after hot pressing, the temperature needs to be reduced to be cured, and the process is about 10 hours. In the embodiment of the disclosure, the first material a and the second material B are both thermoplastic materials, and only the temperature needs to be reduced and the temperature needs to be waited for below the peak temperature of the melting peak of the first material a, and the time needed in the process is only about 10min or even shorter, so that the production efficiency is greatly improved.

For example, if M is equal to 1, the pretreatment structure formed in the above method steps may also be used as a composite film layer including only one support layer as shown in fig. 3, where the isolation layer is the protection layer 20, and the protection layer 20 includes a first sub-layer 21 and a second sub-layer 22, where the first sub-layer 21 is formed by a first initial sub-layer, and the second sub-layer 22 is formed by a second initial sub-layer.

For example, if M is equal to 1, the pre-treated structure formed in the above method steps may be hot-pressed to form a composite film layer including only one support layer, wherein each of the protective layers 20 is a blend of the first material a and the second material B.

In another possible embodiment, the pretreatment structure is not formed first and then the composite film layer may be formed directly. Illustratively, M support layers and m+1 thermoplastic layers are alternately placed and hot pressed to form a composite film layer. The thermoplastic material layer between two adjacent support layers may include one or more of the first material a and the second material B, and may also be other thermoplastic materials.

Compared with the two methods, the presoaking process is adopted firstly and then the hot pressing process is adopted, and the presoaking process can enable the supporting layer, such as the supporting layer made of fiber materials, to be combined with the protecting layer more tightly.

In another possible embodiment, M is greater than or equal to 2, that is, the composite film layer has a plurality of support layers 10, the protective layer 20 between two adjacent support layers is made of one of a first material a and a second material B, the protective layer 20 on both sides of the M support layers includes a first sub-layer 21 and a second sub-layer 22 stacked, the first sub-layer 21 is located on a side of the second sub-layer 22 adjacent to the support layer 10, the first sub-layer 21 is made of the first material a, and the second sub-layer 22 is made of the second material B. The composite film layer can be manufactured in the following manner: firstly, carrying out hot pressing on M support layers and M-1 thermoplastic material layers which are alternately stacked, then manufacturing the initial protection layer, wherein two sides of the M support layers and the M-1 thermoplastic material layers which are alternately stacked are respectively covered with the initial protection layer, and the M-1 thermoplastic material layers are manufactured by adopting one of a first material A and a second material B. In each initial protective layer, the first part is located at one side of the second part near the supporting layer, and under the temperature condition between the peak temperature of the melting peak of the first material A and the peak temperature of the melting peak of the second material B, the whole of M supporting layers, M-1 thermoplastic material layers and two initial protective layers is subjected to a pre-soaking process, so that the first part near the supporting layer 10 in the initial protective layers is melted, for example, the fiber materials in the supporting layers are fully coated and combined, the pre-soaking is realized, the melted first part forms a first sub-layer after cooling, and the second part is not melted to form a second sub-layer.

Fig. 10 is a schematic plan view of a foldable support provided in an embodiment of the present disclosure. As shown in fig. 10, the foldable support member includes a support body, where the support body includes a first planar area D, a first bending area E, and a second planar area F that are sequentially connected, and the support body is made of any one of the foregoing composite film layers.

The composite film layer adopted by the support body is the composite film layer shown in fig. 1, and the length direction of the first bending region E is the second direction y. In the composite film layer shown in fig. 1, the extending directions of the fiber materials in the two supporting layers are the second direction y, and the extending direction of the fiber material in one supporting layer is the first direction x, so that the length direction of the bending region E is determined to be the second direction y, and bending is facilitated.

Alternatively, as shown in fig. 10, the first bending region E may further include a plurality of openings, where the plurality of openings are staggered, and the extending direction of the plurality of openings is also the second direction y, so as to facilitate bending. Here, the staggered arrangement means that the plurality of openings are divided into a plurality of rows of openings, each row of openings including a plurality of openings arranged in the second direction y, and for adjacent first and second rows of openings, the first row of openings includes the first opening, and the second row of openings includes the second and third openings. The orthographic projection of the first opening on the reference surface coincides with the orthographic projection of the second opening on the reference surface, and the orthographic projection of the first opening on the reference surface coincides with the orthographic projection of the third opening on the reference surface. The reference surface is perpendicular to the plane of the support body and parallel to the second direction y.

In other possible embodiments, the first inflection zone E may not include an opening.

The embodiment of the disclosure further provides a foldable display device, which comprises a display panel and the foldable support, wherein the display panel is located at one side of the foldable support, and comprises a third plane area, a second bending area and a fourth plane area which are sequentially connected, and the orthographic projection of the bearing surface of the foldable support in the first bending area is located in the orthographic projection of the bearing surface of the second bending area and the bearing surface of the foldable support, so that the orthographic projection of the bearing surface of the foldable support is at least partially overlapped. Illustratively, the display panel is a flexible display panel. The embodiments of the present disclosure are not limited to the type of flexible display panel, including but not limited to OLED (Organic Light Emitting Diode ) display panels, QLED (Quantum Dot Light Emitting Diode, quantum dot light emitting diode) display panels, and the like.

The display device provided by the embodiment of the disclosure may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like.

The foldable display device has the same effects as the aforementioned foldable support member, and will not be described herein.

The foregoing is merely an alternative embodiment of the present disclosure, and is not intended to limit the present disclosure, any modification, equivalent replacement, improvement, etc. that comes within the spirit and principles of the present disclosure are included in the scope of the present disclosure.

Claims

1. The composite film layer is characterized by comprising M supporting layers and M+1 protective layers which are alternately laminated, wherein M is an integer and is more than 0;

the protective layer is made of thermoplastic materials.

2. The composite film layer of claim 1, wherein the protective layer is made from a blend of a first material and a second material, the peak temperature of the melting peak of the first material being 20 ℃ to 100 ℃ lower than the peak temperature of the melting peak of the second material.

3. The composite film layer of claim 2, wherein the blend of the first material and the second material has only one melting peak.

4. The composite film of claim 1, wherein the composite film comprises one of the support layers and the first protective layer comprises a laminated first sub-layer and a second sub-layer, the first sub-layer being positioned on a side of the second sub-layer adjacent to the support layer, the first sub-layer being formed of a first material and the second sub-layer being formed of a second material, the peak temperature of the melting peak of the first material being 20 ℃ to 100 ℃ lower than the peak temperature of the melting peak of the second material.

5. The composite film layer of any one of claims 2 to 4, wherein the first material is a copolymerized polypropylene and the second material is an isotactic polypropylene; or,

the first material is low density polyethylene and the second material is high density polyethylene.

6. A composite film layer according to any one of claims 1 to 3, wherein the M support layers comprise a first support layer, a second support layer and a third support layer adjacent in a stacking direction, the second support layer comprising a plurality of fibrous materials extending in a first direction, the first support layer and the third support layer comprising a plurality of fibrous materials extending in a second direction, the first direction and the second direction intersecting.

7. The composite film layer of claim 6, wherein the fibrous material is carbon fiber or glass fiber.

8. The manufacturing method of the composite film layer is characterized by comprising the following steps:

forming M support layers and M+1 isolation layers which are alternately stacked, wherein M is an integer and is larger than 0, and the isolation layers are made of thermoplastic materials;

the M support layers are connected through the M+1 isolation layers to obtain a composite film layer, wherein the composite film layer comprises M support layers and M+1 protection layers which are alternately laminated;

wherein the protective layer is made of thermoplastic materials.

9. The method of claim 8, wherein M is an integer, M is greater than 1, and the forming of the M support layers and the m+1 spacer layers alternately stacked comprises:

forming an initial protective layer at a first temperature using a first material and a second material, the initial protective layer comprising a first initial sub-layer and a second initial sub-layer stacked, the first initial sub-layer being formed of the first material and the second initial sub-layer being formed of the second material, a peak temperature of a melting peak of the first material being 20 ℃ to 100 ℃ lower than a peak temperature of a melting peak of the second material, the first temperature being higher than a peak temperature of a melting peak of the second material;

covering two sides of each supporting layer with one initial protective layer respectively, wherein in each initial protective layer, the first initial sub-layer is positioned on one side of the second initial sub-layer, which is close to the supporting layer;

performing a pre-soaking process on each supporting layer and two initial protection layers respectively positioned at two sides of the supporting layer at a second temperature to form M pre-treated structures, stacking the M pre-treated structures, wherein the isolation layers positioned between two adjacent supporting layers comprise the two initial protection layers after the pre-soaking process, the isolation layers positioned at two sides of the M supporting layers comprise one initial protection layer after the pre-soaking process, and the second temperature is between the peak temperature of a melting peak of the first material and the peak temperature of a melting peak of the second material;

the connecting the M support layers through the m+1 isolation layers includes:

and hot-pressing the laminated M pretreatment structures at a third temperature, wherein the third temperature is higher than the peak temperature of the melting peak of the second material.

10. The method of claim 8, wherein M is equal to 1, said forming M support layers and m+1 spacer layers alternately stacked, and said connecting said M support layers through said m+1 spacer layers, comprises:

forming an initial protective layer with a first material and a second material at a temperature lower than a first temperature, the initial protective layer comprising a first initial sub-layer and a second initial sub-layer stacked, the first initial sub-layer being formed of the first material and the second initial sub-layer being formed of the second material, a peak temperature of a melting peak of the first material being 20 ℃ to 100 ℃ lower than a peak temperature of a melting peak of the second material, the first temperature being higher than a peak temperature of a melting peak of the second material;

the two sides of the supporting layer are respectively covered with one initial protection layer, and in each initial protection layer, the first initial sub-layer is positioned on one side, close to the supporting layer, of the second initial sub-layer;

and carrying out a pre-soaking process on the supporting layer and two initial protection layers respectively positioned at two sides of the supporting layer at a second temperature to form a pre-treatment structure, wherein the pre-treatment structure is the composite film layer, the isolation layer comprises one initial protection layer after the pre-soaking process, the protection layer is the isolation layer, and the second temperature is between the peak temperature of the melting peak of the first material and the peak temperature of the melting peak of the second material.

11. A foldable support comprising a support body comprising a first planar region, a first bending region and a second planar region connected in sequence, the support body being made of a composite film layer according to any one of claims 1 to 7.

12. A foldable display device, wherein the foldable display device comprises a display panel and the foldable support member according to claim 11, the display panel is located at one side of the foldable support member, the display panel comprises a third plane area, a second bending area and a fourth plane area which are sequentially connected, and the orthographic projection of the first bending area on the bearing surface of the foldable support member is at least partially overlapped with the orthographic projection of the second bending area on the bearing surface of the foldable support member.