A protective film and a display module

Abstract

The present application relates to the technical field of folding display screens, and in particular to a protective film and a display module. The protective film includes a first adhesive layer, which is used to bond with the cover plate of the display module, and the first adhesive layer includes a first adhesive. The protective film has a bending area, and the bending area is used to fit with the axial area of ​​the cover plate. The part of the first adhesive layer located in the bending area has a glue-containing portion, and the glue-containing portion is used to fill a second adhesive with a greater adhesive force than the first adhesive. The present application increases the viscosity of the bending area of ​​the first adhesive layer by providing a second adhesive in the bending area of ​​the first adhesive layer, thereby improving the bonding strength between the bending area of ​​the first adhesive layer and the axial area of ​​the cover plate, and reducing the risk of peeling between the bending area of ​​the protective film and the axial area of ​​the cover plate due to repeated bending.

Description

Technical Field

[0001] The present application relates to the technical field of foldable display screens, and in particular to a protective film and a display module. Background Art

[0002] With the development of flexible screen technology, there are more and more foldable screen mobile phones and other devices with folding functions on the market. The foldable screen uses a single-layer protective film or a multi-layer protective film to stick on the cover to protect the cover. The materials of each layer of the single-layer / multi-layer protective film are designed to be flat and integrated and compounded together.

[0003] The protective film and the cover plate are fitted together, but the flatness is poor due to the axial parts provided in the axial area of ​​the cover plate, resulting in poor fitting effect between the protective film and the cover plate in the axial area. There are problems such as fitting bubbles and insufficient bonding force. During normal use by users, the protective film and the cover plate are prone to partial peeling in the axial area. Summary of the invention

[0004] The present application provides a protective film and a display module, aiming to reduce the risk of separation between a bending area of ​​the protective film and an axis area of ​​the display module.

[0005] The present application provides a protective film for a display module, the protective film comprising a first adhesive layer, the first adhesive layer being used to bond with a cover plate of the display module, the first adhesive layer comprising a first adhesive;

[0006] The protective film has a bending area, and the bending area is used to fit with the axial area of ​​the cover plate. The portion of the first adhesive layer located in the bending area has a glue-containing portion, and the glue-containing portion is used to be filled with a second adhesive.

[0007] In the present application, a glue-receiving portion is provided in the bending area of ​​the first adhesive layer, and the glue-receiving portion is used to fill the second adhesive, and the second adhesive needs to be a strong adhesive with a greater adhesive force than the first adhesive. When bonding the protective film and the cover plate, by filling the second adhesive in the glue-receiving portion of the first adhesive layer, the viscosity of the bending area of ​​the first adhesive layer is increased, thereby improving the bonding strength between the bending area of ​​the first adhesive layer and the axial area of ​​the cover plate.

[0008] In a possible design, along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion, and the adhesive receiving portion includes at least a first adhesive receiving portion;

[0009] The first adhesive receiving portion is arranged at the edge portion.

[0010] In the present application, a first adhesive-receiving portion is provided at the edge portion, and a second adhesive is filled in the first adhesive-receiving portion so that the second adhesive bonds the edge portion to the edge of the axis area, thereby reducing the risk of peeling off between the edge portion of the bending area of ​​the protective film and the edge of the axis area of ​​the cover plate due to repeated bending.

[0011] In a possible design, the protective film further includes an adjacent layer bonded to the first adhesive layer;

[0012] The adjacent layer is provided with a first recessed portion, and the first adhesive can flow into the first recessed portion to form the first adhesive receiving portion at the edge portion.

[0013] In the present application, a first recessed portion can be formed on the adjacent layer while the adjacent layer is being manufactured. By providing the first recessed portion at the edge of the adjacent layer, the first adhesive at the edge of the first adhesive layer can flow to the first recessed portion, so that the edge of the first adhesive layer forms a recessed first adhesive receiving portion, and the second adhesive can be filled in the first adhesive receiving portion. The present application can also use an auxiliary member to press the edge of the first adhesive layer so that the first adhesive can flow into the first recessed portion.

[0014] In a possible design, the first recessed portion is a notch penetrating the adjacent layer along the width direction of the protective film, so that the first adhesive holding portion is a notch penetrating the first adhesive layer along the width direction of the protective film.

[0015] In the present application, the first recessed portion penetrates the adjacent layer along the width direction of the protective film, so that the first recessed portion formed at the edge portion is a notch structure, so that the first adhesive-containing portion formed at the edge portion of the first adhesive layer is a notch, and the outermost edge of the bending area also has the second adhesive, thereby reducing the risk of the outermost edge of the bending area of ​​the protective film warping.

[0016] In a possible design, the protective film further includes an adjacent layer bonded to the first adhesive layer;

[0017] Along the width direction of the protective film, the outer edge of the edge portion is located inside the outer edge of the adjacent layer, so that a step portion is formed between the first adhesive layer and the adjacent layer, and the step portion is the first adhesive receiving portion.

[0018] In the present application, holes can be directly punched at the edge of the first adhesive layer to form a first adhesive holding portion with a notch structure on the first adhesive layer, thereby reducing the step of setting the first recessed portion on the adjacent layer and simplifying the manufacturing process.

[0019] In a possible design, the first adhesive containing portion covers the edge portion.

[0020] In the present application, the edge portion can be entirely configured as the first adhesive receiving portion to increase the amount of the second adhesive that can be filled in the edge portion, thereby further enhancing the bonding strength between the edge portion and the edge of the shaft region.

[0021] In a possible design, along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion, and the adhesive receiving portion includes a plurality of second adhesive receiving portions;

[0022] A plurality of the second adhesive containing portions are arranged at intervals in the middle portion.

[0023] In the present application, in addition to setting the first adhesive accommodating portion at the edge portion of the first adhesive layer, a second adhesive accommodating portion is also set in the middle portion, so that both the edge portion and the middle portion can be filled with the second adhesive, thereby increasing the viscosity of the bending zone of the first adhesive layer, thereby improving the bonding strength between the bending zone of the first adhesive layer and the axial zone of the cover plate.

[0024] In a possible design, the protective film also includes an adjacent layer bonded to the first adhesive layer, the adjacent layer is provided with a plurality of second recessed portions, and the first adhesive located in the middle part can flow to the second recessed portions to form a plurality of second adhesive-containing portions in the middle part of the first adhesive layer.

[0025] In the present application, a second recessed portion is formed on the adjacent layer while the adjacent layer is being manufactured. By providing the second recessed portion in the adjacent layer, part of the first adhesive in the middle portion of the first adhesive layer can flow to the second recessed portion, so that the middle portion of the first adhesive layer forms a recessed second adhesive holding portion, and the second adhesive can be filled in the second adhesive holding portion. The present application can also use an auxiliary member to press the middle portion of the first adhesive layer so that the first adhesive can flow into the second recessed portion.

[0026] In a possible design, along the thickness direction of the protective film, the second adhesive holding portion is a through hole penetrating the first adhesive layer.

[0027] In the present application, a hole can be directly punched in the middle portion of the first adhesive layer to form a second adhesive holding portion with a through-hole structure on the first adhesive layer, thereby reducing the step of setting a second recessed portion on the adjacent layer and simplifying the manufacturing process.

[0028] In a possible design, along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion;

[0029] The edge portion is provided with a first adhesive receiving portion, and the middle portion is provided with a plurality of second adhesive receiving portions distributed at intervals. Along the length direction of the protective film, the length of the first adhesive receiving portion is greater than the length of a single second adhesive receiving portion.

[0030] In the present application, the proportion of the second adhesive in the edge portion is larger than that in the middle portion, which ensures the bonding strength between the bending area of ​​the protective film and the axial area of ​​the cover plate, while further strengthening the bonding strength between the edge portion and the edge of the axial area. At the same time, it prevents too much second adhesive from being set in the bending area, which causes the bonding strength between the protective film and the cover plate to be too strong, thereby making it impossible to directly replace the protective film of the display module.

[0031] In a possible design, the total area of ​​the plurality of second adhesive-containing portions accounts for 50%-90% of the total area of ​​the middle portion of the bending zone.

[0032] In the present application, the proportion of the second adhesive portion in the middle portion can be limited according to actual conditions, and then the proportion of the second adhesive in the middle portion can be limited, for example, the ratio can be 50%, 60%, 70%, 80%, etc.

[0033] The ratio of the total area of ​​the multiple second adhesive portions to the total area of ​​the middle part should not be too large or too small. If the ratio is too large (such as greater than 90%), too much second adhesive is set in the middle part, which may cause the display module to be torn when the protective film of the display module is replaced; if the ratio is too small (such as less than 50%), too little second adhesive is set in the middle part, resulting in poor bonding between the bending area of ​​the protective film and the axial area of ​​the cover plate, resulting in problems such as bonding bubbles and insufficient bonding force.

[0034] In a second aspect, the present application provides a protective film for a foldable display module, the protective film comprising a first adhesive layer, the first adhesive layer being used to bond to a cover plate of the display module, the first adhesive layer comprising a first adhesive;

[0035] The protective film has a bending area, the bending area is used to fit with the shaft area of ​​the cover plate, and the first adhesive layer located in the bending area has a glue-containing portion, and the glue-containing portion is filled with a second adhesive;

[0036] Wherein, the adhesive force of the second adhesive is greater than the adhesive force of the first adhesive layer.

[0037] In the present application, a glue-receiving portion is provided in the bending area of ​​the first adhesive layer, and the glue-receiving portion is filled with a second adhesive, and the second adhesive is a strong adhesive with a greater adhesive force than the first adhesive. When bonding the protective film and the cover plate, since the glue-receiving portion of the first adhesive layer is filled with the second adhesive, the viscosity of the bending area of ​​the first adhesive layer is increased, thereby improving the bonding strength between the bending area of ​​the first adhesive layer and the axial area of ​​the cover plate.

[0038] The present application also provides a display module, the display module comprising:

[0039] Cover plate;

[0040] A protective film, wherein the protective film is the protective film described above and is bonded to the cover plate;

[0041] The adhesive containing portion of the first adhesive layer is filled with a second adhesive, and the adhesive force of the second adhesive is greater than the adhesive force of the first adhesive layer.

[0042] In the present application, the display module includes but is not limited to mobile phones, tablet computers, notebooks, computers, ultra-mobile personal computers (UMPC), handheld computers, walkie-talkies, netbooks and other mobile or fixed terminals with bending functions. The present application provides a second adhesive on the edge of the bending area of ​​the first adhesive layer and the middle of the bending area to enhance the viscosity of the bending area of ​​the first adhesive layer, thereby improving the bonding strength between the bending area of ​​the protective film and the shaft area of ​​the cover plate.

[0043] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a cross-sectional schematic diagram of a single-layer protective film in the prior art;

[0045] Figure 2 It is a cross-sectional schematic diagram of a multi-layer protective film in the prior art;

[0046] Figure 3 is a schematic diagram of the structure of the cover plate;

[0047] Figure 4 A cross-sectional schematic diagram of the display module provided in this application;

[0048] Figure 5 A schematic cross-sectional view of a single-layer protective film provided in this application;

[0049] Figure 6 A plan view of the display module provided in this application;

[0050] Figure 7 A schematic plan view of a single-layer protective film provided in this application;

[0051] Figure 8 A schematic plan view of a single-layer protective film provided in this application;

[0052] Fig. 9 for Figure 8 Schematic diagram of the cross section along the AA direction;

[0053] Fig.10 A schematic cross-sectional view of a single-layer protective film provided in the present application in a specific embodiment;

[0054] Fig.11 for Fig.10 Schematic diagram of the cross section along the BB direction;

[0055] Fig.12 A schematic plan view of another specific embodiment of the single-layer protective film provided in the present application;

[0056] Fig.13 For along Fig.12 Schematic diagram of the cross section in the CC direction;

[0057] Fig.14 This is a schematic diagram of the structure of the roller provided in this application;

[0058] Fig.15 A schematic cross-sectional view of a first adhesive-containing portion of a single-layer protective film provided in the present application along a length direction in another specific embodiment;

[0059] Fig.16 A schematic cross-sectional view of a first adhesive-containing portion of a single-layer protective film provided in the present application along a width direction in another specific embodiment;

[0060] Fig.17 A schematic cross-sectional view of the second adhesive-containing portion of the single-layer protective film provided in the present application along the length direction in another specific embodiment;

[0061] Fig.18 A schematic cross-sectional view of the multi-layer protective film provided in this application;

[0062] Fig.19 This is a schematic cross-sectional view of the first adhesive holding portion and the third recessed portion of the multi-layer protective film provided in the present application along the length direction;

[0063] Fig. 20 For along Fig.19 Schematic diagram of the cross section in the middle DD direction;

[0064] Fig.21 This is a schematic cross-sectional view of the second adhesive holding portion and the fourth recessed portion of the multi-layer protective film provided by the present application along the length direction;

[0065] Fig. 22 A schematic cross-sectional view of a first adhesive-containing portion of the multi-layer protective film provided by the present application in another specific embodiment along the length direction;

[0066] Fig.23 A schematic cross-sectional view of a first adhesive-containing portion of the multi-layer protective film provided in the present application in another specific embodiment along the width direction;

[0067] Fig.24 A schematic cross-sectional view of a second adhesive-containing portion of the multi-layer protective film provided in the present application in another specific embodiment along the length direction;

[0068] Fig.25 This is a schematic diagram of the structure of the second adhesive containing part provided in this application;

[0069] Fig.26 This is the arrangement method of the second adhesive containing portion provided in this application.

[0070] Reference numerals:

[0071] 1′-protective film, 11′-optical coating, 12′-support layer, 13′-first adhesive layer, 14′-buffer layer, 15′-second adhesive layer;

[0072] 2′-cover plate, 21′-axis area, 22′-non-axis area;

[0073] 1-display module, 11-cover plate, 111-axis area, 12-protective film, 121-optical coating, 122-support layer, 122a-first recessed portion, 122b-second recessed portion, 123-first adhesive layer, 123a-first adhesive holding portion, 123b-second adhesive holding portion, 124-bending area, 124a-edge portion, 124b-middle portion, 125-second adhesive layer, 126-buffer layer, 126a-third recessed portion, 126b-fourth recessed portion;

[0074] 2-roller, 21-protrusion.

[0075] X-width direction, Y-length direction, Z-thickness direction.

[0076] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0077] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0078] In a specific embodiment, the present application is further described in detail below through a specific embodiment and in conjunction with the accompanying drawings.

[0079] like Figure 1 The structure of a single-layer protective film 1' in the prior art is shown, which includes an optical coating 11', a support layer 12' and a first adhesive layer 13' stacked in sequence. The optical coating 11' is used to reduce reflectivity and improve light transmittance, the support layer 12' plays a protective role such as scratch prevention, isolation, and object protection, and the first adhesive layer 13' is used to bond the cover plate of the display module so that the protective film 1' fits the cover plate.

[0080] like Figure 2The structure of a multilayer protective film 1' in the prior art is shown, which includes an optical coating 11', a support layer 12', a second adhesive layer 15', a buffer layer 14' and a first adhesive layer 13' stacked in sequence. The optical coating 11' is used to reduce reflectivity and improve light transmittance. The support layer 12' plays a protective role such as scratch prevention, isolation, and anti-object protection. The second adhesive layer 14' is used to bond the support layer 12' and the buffer layer 15'. The buffer layer 15' is used to reduce impact force. The first adhesive layer 13' is used to bond the cover plate of the display module so that the protective film 1' fits the cover plate.

[0081] like Figure 3 The structure of the cover plate 2′ is shown. Along the length direction Y of the cover plate 2′, the cover plate 2′ includes an axis area 21′ and a non-axis area 22′. The non-axis area 22′ is located on both sides of the axis area 21′. The axis area 21′ corresponds to and is connected to the rotating shaft mechanism of the electronic device. The non-axis area 22′ corresponds to and is connected to the shell of the electronic device. Driven by the shell, the non-axis areas 22′ on both sides can rotate relative to the axis area 21′ to realize the folding or unfolding of the electronic device.

[0082] In the prior art, the single-layer / multi-layer protective film 1' is laminated with the cover plate 2', and the non-axial area 22' of the cover plate 2' has a higher flatness, so the protective film 1' and the cover plate 2' have a better lamination effect. Since the axial area 21' of the cover plate 2' is connected to the rotating shaft mechanism of the electronic device, the flatness of the axial area 21' is lower, resulting in a poor lamination effect between the protective film 1' and the axial area 21', and it is easy to produce lamination bubbles and insufficient lamination bonding force. As a result, the protective film 1' and the axial area 21' of the cover plate 2' are easily separated during use of the display module.

[0083] The embodiments of the present application provide a protective film and a display module, which can effectively solve the technical problem that the axial area of ​​the protective film and the cover plate are easily separated.

[0084] Specifically, the present embodiment provides a display module, which includes but is not limited to a display module on a mobile or fixed terminal with a bending function, such as a mobile phone, a tablet computer, a notebook, a computer, an ultra-mobile personal computer (UMPC), a handheld computer, a walkie-talkie, and a netbook. It should be noted that the length direction Y, the width direction X, and the thickness direction Z described in the present embodiment are all based on the orientation of the display module in the unfolded state.

[0085] like Figure 4 As shown, the display module 1 includes a cover plate 11 and a protective film 12 which are stacked, and the protective film 12 is bonded to the cover plate 11 .

[0086] like Figure 5As shown, in some embodiments, the protective film 12 may include an optical coating 121, a support layer 122 and a first adhesive layer 123 which are stacked in sequence. The optical coating 121 is used to reduce reflectivity and improve light transmittance. The support layer 122 plays a protective role such as scratch protection, isolation, and anti-object protection. The support layer 122 can be polyethylene terephthalate (PET for short). The first adhesive layer 123 is used to bond with the cover plate 11 to achieve the connection between the protective film 12 and the cover plate 11. The first adhesive layer 123 includes a first adhesive (not shown in the figure), which can be an adhesive such as optical glue, silicone, etc., which is not specifically limited in this embodiment. In other embodiments, the protective film may also include other layers, and the specific structure of the protective film is not limited in this application.

[0087] like Figure 6 As shown, it is a schematic diagram of the cover plate 11, and the cover plate 11 is provided with an axis area 111 (such as Figure 6 The portion indicated by the dotted line frame).

[0088] like Figure 7 As shown, it is a schematic diagram of the protective film 12, and the protective film includes a folding area 124 (such as Figure 7 The portion indicated by the dotted line frame).

[0089] Please refer to Figure 6 and Figure 7 After the protective film 12 is bonded to the cover plate 11, the bending area 124 can fit with the axial area 111 of the cover plate 11, and in the figure, along the thickness direction Z of the protective film 12, the projections of the bending area 124 and the axial area 111 along the thickness direction coincide with each other.

[0090] like Figure 8 As shown, the first adhesive layer 123 located in the bending area 124 has a glue-receiving portion. Fig. 9 The adhesive holding portion may specifically include a first adhesive holding portion 123a. Taking the first adhesive holding portion 123a as an example, the adhesive holding portion is used to fill the second adhesive. The adhesive force of the second adhesive is greater than the adhesive force of the first adhesive. When the protective film 12 is bonded to the cover plate 11, the two are bonded not only by the first adhesive, but also by the second adhesive with greater adhesive force, thereby improving the bonding reliability of the protective film 12 and the cover plate 11 and reducing the risk of the two being separated.

[0091] Specifically, Figure 8 , which is a schematic diagram of the protective film 12. Along the width direction X of the protective film 12, the bending area 124 of the protective film 12 includes a middle portion and edge portions 124a located on both sides of the middle portion. It should be noted that the edge portions 124a of the bending area 124 (such as Figure 8The portion shown in the dotted line frame) refers to the edge regions on both sides of the bending region 124 along the width direction X of the protective film 12, and the width of the region may account for 1 / 10 to 1 / 20 of the total width of the bending region 124. Alternatively, the range of the edge portion 124a of the bending region 124 may be limited according to the actual filling conditions. The middle region is the portion between the two edge regions.

[0092] During actual use of electronic devices, due to frequent folding of the display module and the contact and friction between the edge of the display module and other materials, the edge of the surface of the display module may be warped, and the edge of the cover plate and the protective film may be easily disconnected.

[0093] In order to solve this technical problem, Figure 8 In the illustrated embodiment, the first adhesive layer 123 at the edge portion 124a on both sides of the bending area 124 has a first adhesive portion 123a, and the first adhesive portion 123a is used to fill the second adhesive (not shown in the figure), and the second adhesive is a strong adhesive with a greater adhesive force than the first adhesive. By providing the second adhesive at the edge portion 124a of the bending area 124 of the first adhesive layer 123, the viscosity of the edge portion 124a of the bending area 124 of the first adhesive layer 123 is increased, thereby improving the bonding strength between the edge portion 124a of the bending area 124 of the first adhesive layer 123 and the edge of the shaft area 111 of the cover plate 11, and reducing the risk of peeling of the edges of the bending area 124 of the protective film 12 and the shaft area 111 of the cover plate 11 due to repeated bending.

[0094] The second adhesive may be a pressure-sensitive adhesive, an optical adhesive, etc. The second adhesive is in a colloid state (a substance between a liquid and a solid state) and has low fluidity. The first adhesive and the second adhesive may be the same adhesive. When the first adhesive and the second adhesive are the same adhesive, the viscosity of the adhesive used by the second adhesive is greater than the viscosity of the adhesive used by the first adhesive.

[0095] The structure of the first adhesive receiving portion 123a can be combined with reference to Fig. 9 (along Figure 8 In the cross-sectional schematic diagram along the AA direction, the optical coating 121, the support layer 122 and the first adhesive layer 123 are stacked in sequence, and the opening of the first adhesive portion 123a is toward the side of the first adhesive layer 123 away from the support layer 122, that is, the first adhesive portion 123a is arranged on the side of the first adhesive layer 123 that is bonded to the cover plate 12.

[0096] The following focuses on describing the specific structure and formation method of the first adhesive containing portion 123 a.

[0097] like Fig.10As shown, the protective film 12 includes an optical coating 121, a support layer 122 and a first adhesive layer 123 which are stacked in sequence. The support layer 122 is an adjacent layer bonded to the first adhesive layer 123. A first recessed portion 122a is provided on one side of the support layer 122 close to the first adhesive layer 123, so that at least part of the first adhesive of the first adhesive layer 123 can flow to the first recessed portion 122a, so as to form a first adhesive holding portion 123a at an edge portion 124a of a bending zone 124 of the first adhesive layer 123, and then the second adhesive can be filled in the first adhesive holding portion 123a.

[0098] In this embodiment, the first concave portion 122a can be formed on the supporting layer 122 while the supporting layer 122 is manufactured by the salivation process. Specifically, a protruding structure can be provided on the metal belt of the salivation machine, and the solution of the supporting layer 122 can be evenly distributed on the continuously running metal belt, and the supporting layer 122 can be formed through evaporation, drying, quenching and other steps as the metal belt moves. After the supporting layer 122 is removed from the metal belt, the first concave portion 122a is formed on one side surface of the supporting layer 122.

[0099] In this embodiment, a coating process can be used to apply a layer of first adhesive on the support layer 122 to form a first adhesive layer 123 on the support layer 122 , and at the same time, part of the first adhesive flows to the first recessed portion 122a to form a first adhesive-containing portion 123a on one side surface of the first adhesive layer 123 .

[0100] Specifically, in this embodiment, a pressing plate (not shown) having the same cross-section as the first recessed portion 122a may be used to press the edge portion 124a of the bending region 124 of the first adhesive layer 123 to allow the first adhesive to flow into the first recessed portion 122a.

[0101] The first adhesive accommodating portion 123a may be provided in plurality, and the plurality of first adhesive accommodating portions 123a are uniformly provided at the edge portion 124a of the bending area 124 of the first adhesive layer 123. Alternatively, the first adhesive accommodating portion 123a may be provided in one, and one first adhesive accommodating portion 123a covers the edge portion 124a, so that the second adhesive is fully distributed over the edge portion 124a of the bending area 124 of the first adhesive layer 123, thereby increasing the bonding strength between the edge portion 124a of the bending area 124 of the first adhesive layer 123 and the edge of the shaft area 111 of the cover plate 11.

[0102] like Fig.11 As shown (along Fig.10In the cross-sectional schematic diagram along the BB direction, the first recessed portion 122a is a notch that penetrates the supporting layer 122 along the width direction X of the protective film 12, so that the first adhesive portion 123a is a notch that penetrates the first adhesive layer 123 along the width direction X of the protective film 12, so that the outermost edge of the bending area 124 also has the second adhesive, reducing the risk of the outermost edge of the bending area 124 of the protective film 12 being lifted.

[0103] To further increase the bonding strength between the bending area 124 of the protective film 12 and the axial area of ​​the cover plate 11, as Fig.12 As shown, the adhesive receiving portion includes a plurality of second adhesive receiving portions 123b, and the plurality of second adhesive receiving portions 123b are spaced apart in the middle portion 124b (such as Fig.12 That is, the plurality of second adhesive accommodating portions 123 b are arranged between the first adhesive accommodating portions 123 a, and the plurality of second adhesive accommodating portions 123 b do not completely cover the middle portion 124 b of the bending region 124 of the first adhesive layer 123 .

[0104] In addition to setting the first adhesive holding portion 123a at the edge portion 124a, the present embodiment also sets a plurality of second adhesive holding portions 123b at the middle portion 124b, and the second adhesive holding portions 123b are also used to fill the second adhesive. By also setting the second adhesive in the middle portion 124b, the viscosity of the entire bending zone 124 of the first adhesive layer 123 is increased, thereby improving the bonding strength between the bending zone 124 of the first adhesive layer 123 and the axial zone of the cover plate 11, and reducing the risk of the protective film 12 being separated from the cover plate 11. Moreover, in the present embodiment, adjacent second adhesive holding portions 123b may be provided with a gap so that the second adhesive covers the entire middle portion 124b of the bending zone 124, thereby ensuring the bonding strength between the protective film 12 and the cover plate 11, and reducing the risk of damage to the display module 1 when the display module 1 is normally replaced with the protective film 12.

[0105] Please continue to refer to Fig.12 , along the length direction Y of the protective film 12, the first adhesive accommodating portion 123a is set as one, and the second adhesive accommodating portion 123b is set as four rows, and the second adhesive accommodating portions 123b in each row are arranged at intervals. Along the length direction Y of the protective film 12, the length of the first adhesive accommodating portion 123a is greater than the length of a single second adhesive accommodating portion 123b, so that the proportion of the second adhesive in the edge portion 124a of the bending area 124 is larger than the proportion of the second adhesive in the middle portion 124b of the bending area 124, while ensuring the bonding force between the bending area 124 of the protective film 12 and the shaft area 111 of the cover plate 11, further strengthen the bonding strength between the edge portion 124a of the bending area 124 and the edge of the shaft area 111, and prevent too much second adhesive from being set in the bending area 124, resulting in excessive bonding strength between the protective film 12 and the cover plate 11, and further causing the display module 1 to be unable to directly replace the protective film 12.

[0106] Among them, this embodiment can limit the proportion of the second adhesive in the middle part 124b of the bending zone 124 according to actual conditions, such as the total area of ​​the plurality of second adhesive-containing portions 123b accounts for 50%-90% of the total area of ​​the middle part 124b of the bending zone 124, so as to limit the bonding area of ​​the second adhesive disposed in the middle part 124b of the bending zone 124 to 50%-90% of the total area of ​​the middle part 124b of the bending zone 124. Exemplarily, the ratio can be 50%, 60%, 70%, 80%, etc.

[0107] In this embodiment, the ratio of the total area of ​​the plurality of second adhesive portions 123b to the total area of ​​the middle portion 124b of the bending zone 124 should not be too large or too small. If the ratio is too large (e.g., greater than 90%), too much second adhesive is disposed in the middle portion 124b of the bending zone 124, which may cause the display module 1 to be torn when the protective film 12 is replaced. If the ratio is too small (e.g., less than 50%), too little second adhesive is disposed in the middle portion 124b of the bending zone 124, resulting in poor lamination between the bending zone 124 of the protective film 12 and the shaft zone 111 of the cover plate 11, and problems such as lamination bubbles and insufficient lamination force may occur.

[0108] The following focuses on describing the specific structure and formation method of the second adhesive containing portion.

[0109] like Fig.13 As shown (along Fig.12 The protective film 12 includes an optical coating 121, a support layer 122 and a first adhesive layer 123 which are stacked in sequence. The support layer 122 is an adjacent layer close to the first adhesive layer 123. A second recessed portion 122b is further provided on one side of the support layer 122 close to the first adhesive layer 123, so that part of the first adhesive of the first adhesive layer 123 can flow to the second recessed portion 122b, so as to form a second adhesive holding portion 123b in the first adhesive layer 123, and then the second adhesive can be filled in the second adhesive holding portion 123b.

[0110] In this embodiment, the support layer 122 can be manufactured by the casting process, and the second recessed portion 122b can be formed on the support layer 122. Specifically, a protruding structure can be provided on the metal belt of the casting machine, and the solution of the support layer 122 can be evenly distributed on the continuously running metal belt, and the support layer 122 can be formed through evaporation, drying, quenching and other steps as the metal belt moves. After the support layer 122 is removed from the metal belt, the second recessed portion 122b is formed on one side surface of the support layer 122.

[0111] In this embodiment, a coating process can be used to apply a layer of first adhesive on the support layer 122 to form a first adhesive layer 123 on the support layer 122 , and at the same time, part of the first adhesive flows to the second recessed portion 122 b to form a second adhesive portion 123 b on one side surface of the first adhesive layer 123 .

[0112] Specifically, this embodiment can adopt the following Fig.14 The roller 2 shown presses the middle portion 124b of the bending area 124 of the first adhesive layer 123. A plurality of protrusions 21 are provided on the roller 2, and the plurality of protrusions 21 are provided correspondingly to the plurality of second recessed portions 122b. The roller 2 is used to press the first adhesive layer 123, so that the plurality of protrusions 21 can press the first adhesive to flow into the second recessed portions 122b, so that the middle portion 124b of the bending area 124 of the first adhesive layer 123 forms a recessed second adhesive holding portion 123b.

[0113] In this embodiment, the manufacturing steps of the protective film 12 may be: laminating the support layer 122 on the optical coating 121, and applying the first adhesive on the support layer 122 to form the first adhesive layer 123. The first adhesive has poor fluidity, and an auxiliary component may be used to press the bending area 124 of the first adhesive layer 123, so that part of the first adhesive in the bending area 124 can flow to the first recessed portion 122a and the second recessed portion 122b, so as to form the first adhesive holding portion 123a and the second adhesive holding portion 123b in the bending area 124, and finally a release film is laminated on the upper and lower surfaces of the protective film 12 to protect the protective film 12.

[0114] In this embodiment, the second adhesive can be filled in the first adhesive portion 123a and the second adhesive portion 123b before the protective film 12 is bonded to the cover plate 11. After the second adhesive is filled, the protective film 12 is bonded to the cover plate 11. Alternatively, the second adhesive can be filled in the first adhesive portion 123a and the second adhesive portion 123b when the protective film 12 is manufactured. After the second adhesive is filled, a release film is used to adhere to the upper and lower surfaces of the protective film 12 to protect the protective film 12. When bonding the protective film 12 to the cover plate 11, the release film is directly torn off and the two are bonded, which is convenient to use.

[0115] In some embodiments, the first adhesive layer 123 may be directly punched with holes to fill the second adhesive. Fig.15 As shown, the protective film 12 includes an optical coating 121, a support layer 122 and a first adhesive layer 123 which are stacked in sequence. In this embodiment, the support layer 122 is not provided with the first recessed portion 122a mentioned above, and a hole can be directly punched at the edge portion 124a of the bending area 124 of the first adhesive layer 123 to form a first adhesive portion 123a that penetrates the first adhesive layer 123 along the thickness direction Z of the protective film 12, thereby simplifying the manufacturing process. Fig.16Along the width direction X of the protective film 12 , the first adhesive portion 123 a also penetrates the edge portion 124 a of the bending area 124 to form a gap in the edge portion 124 a of the bending area 124 , so that the outermost edge of the bending area 124 also has the second adhesive.

[0116] like Fig.17 As shown, the protective film 12 includes an optical coating 121, a support layer 122 and a first adhesive layer 123 which are stacked in sequence. In this embodiment, the support layer 122 is not provided with a second recessed portion 122b, and a hole can be directly punched in the middle portion 124b of the bending area 124 of the first adhesive layer 123 to form a plurality of second adhesive portions 123b penetrating the first adhesive layer 123 along the thickness direction Z of the protective film 12, thereby simplifying the manufacturing process.

[0117] like Fig.18 As shown, in some embodiments, the protective film 12 may include an optical coating 121, a support layer 122, a second adhesive layer 125, a buffer layer 126 and a first adhesive layer 123 which are stacked in sequence. The optical coating 121 is used to reduce reflectivity and improve light transmittance. The support layer 122 plays a protective role such as scratch resistance, isolation, and object protection. The support layer 122 may be polyethylene terephthalate (PET for short). The second adhesive layer 125 is used to bond the support layer 122 and the buffer layer 126. The buffer layer 126 is used to reduce impact force and may be made of thermoplastic polyurethane elastomer (TPU), silicone, etc. The first adhesive layer 123 is used to bond with the cover plate 11 to achieve the connection between the protective film 12 and the cover plate 11. The first adhesive layer 123 and the second adhesive layer 125 both include a first adhesive (not shown in the figure), which may be an adhesive such as optical glue and silicone, and is not specifically limited in this embodiment. In other embodiments, the protective film may further include other layers, and the present application does not limit the specific structure of the protective film.

[0118] like Fig.19 As shown, the protective film 12 includes an optical coating 121, a support layer 122, a second adhesive layer 125, a buffer layer 126 and a first adhesive layer 123 which are stacked in sequence. Fig.10 The protective film shown is different in that a buffer layer 126 and a second adhesive layer 125 are added. The buffer layer 126 is an adjacent layer arranged close to the first adhesive layer 123, and a third recessed portion 126a (same as the first recessed portion 123a) is provided on one side of the buffer layer 126 close to the first adhesive layer 123, so that the first adhesive of the first adhesive layer 123 can flow to the third recessed portion 126a, so as to form a first adhesive holding portion 123a in the first adhesive layer 123, and then the second adhesive can be filled in the first adhesive holding portion 123a.

[0119] In this embodiment, a coating process can be used to form the third recessed portion 126a on the buffer layer 126 while manufacturing the buffer layer 126. Specifically, a protruding structure can be provided on the substrate, a layer of buffer layer 126 liquid can be coated on the substrate, and the coated liquid coating can be subjected to steps such as drying, drying, and curing to form the buffer layer 126. After the buffer layer 126 is removed from the substrate, the third recessed portion 126a is formed on one side surface of the buffer layer 126.

[0120] In this embodiment, a first adhesive layer may be applied on the buffer layer 126 by a coating process to form a first adhesive layer 123 on the buffer layer 126 , and a portion of the first adhesive flows to the first recessed portion 122 a to form a first adhesive receiving portion 123 a on one side surface of the first adhesive layer 123 .

[0121] Specifically, in this embodiment, a pressing plate (not shown) having the same cross-section as the third recessed portion 126a may be used to press the edge portion 124a of the bending region 124 of the first adhesive layer 123 to allow the first adhesive to flow into the third recessed portion 126a.

[0122] The first adhesive accommodating portion 123a may be provided in a plurality, and the plurality of first adhesive accommodating portions 123a are uniformly provided at the edge portion 124a of the bending area 124 of the first adhesive layer 123. Alternatively, the first adhesive accommodating portion 123a may be provided in a single portion, and the single first adhesive accommodating portion 123a covers the edge portion 124a, so that the second adhesive is fully distributed over the edge portion 124a of the bending area 124 of the first adhesive layer 123, thereby increasing the bonding strength between the edge portion of the bending area 124 of the first adhesive layer 123 and the edge of the shaft area 111 of the cover plate 11.

[0123] like Fig. 20 As shown (along Fig.19 In the cross-sectional schematic diagram along the DD direction in the middle), along the width direction X of the protective film 12, the third recessed portion 126a is a gap penetrating the buffer layer 126 along the width direction X of the protective film 12, so that the first adhesive portion 123a is a gap penetrating the first adhesive layer 123 along the width direction X of the protective film 12, so that the outermost edge of the bending area 124 also has the second adhesive, ensuring the bonding strength between the edge portion 124a of the bending area 124 of the first adhesive layer 123 and the axial area 111 of the cover plate 11.

[0124] like Fig.21 As shown, the protective film 12 includes an optical coating 121, a support layer 122, a second adhesive layer 125, a buffer layer 126 and a first adhesive layer 123 which are stacked in sequence. Fig.15The protective film shown is different in that a buffer layer 126 and a second adhesive layer 125 are added, and the buffer layer 126 is an adjacent layer arranged near the first adhesive layer 123. The adhesive holding portion includes a plurality of second adhesive holding portions 123b, and the plurality of second adhesive holding portions 123b are arranged at intervals in the middle portion 124b, and a fourth recessed portion 126b (same as the second recessed portion 123b) is provided on one side of the buffer layer 126 near the first adhesive layer 123, so that part of the first adhesive of the first adhesive layer 123 can flow to the fourth recessed portion 126b, so as to form the second adhesive holding portion 123b in the first adhesive layer 123, and then the second adhesive can be filled in the second adhesive holding portion 123b.

[0125] In this embodiment, a coating process can be used to form a fourth recessed portion 126b on the buffer layer 126 while manufacturing the buffer layer 126. Specifically, a protruding mechanism can be provided on the substrate, a layer of buffer layer 126 liquid can be coated on the substrate, and the coated liquid coating can be subjected to steps such as drying, drying, and curing to form the buffer layer 126. After the buffer layer 126 is removed from the substrate, a fourth recessed portion 126b is formed on one side surface of the buffer layer 126.

[0126] Specifically, this embodiment can adopt the following Fig.14 The roller 2 shown presses the middle portion 124b of the bending area 124 of the first adhesive layer 123. A plurality of protrusions 21 are provided on the roller 2, and the plurality of protrusions 21 are provided correspondingly to the plurality of fourth recesses 126b. The roller 2 is used to press the first adhesive layer 123, so that the plurality of protrusions 21 can press the first adhesive to flow into the fourth recess 126b, so that the middle portion 124b of the bending area 124 of the first adhesive layer 123 forms a recessed second adhesive holding portion 123b.

[0127] In this embodiment, the steps of making the multilayer protective film may be: laminating the support layer 122 on the optical coating 121, coating the second adhesive on the support layer 122 to form the second adhesive layer 125, laminating the buffer layer 126 on the second adhesive layer 125, and coating the first adhesive on the buffer layer 126 to form the first adhesive layer 123. Since the fluidity of the first adhesive is poor, an auxiliary component may be used to press the bending area 124 of the first adhesive layer 123, so that part of the first adhesive in the bending area 124 can flow to the third recessed portion 126a and the fourth recessed portion 126b, so as to form the first adhesive holding portion 123a and the second adhesive holding portion 123b in the bending area 124, and finally a release film is laminated on the upper and lower surfaces of the protective film 12 to protect the protective film 12.

[0128] In addition, other parts of the structure and process steps of the protective film in this embodiment are similar to those in Figures 4 to 13 The protective films shown are the same and will not be described one by one here.

[0129] In some embodiments, in the protective film, holes may be directly punched on the first adhesive layer 123 to fill the second adhesive. Fig. 22 As shown, the protective film 12 includes an optical coating 121, a support layer 122, a second adhesive layer 125, a buffer layer 126 and a first adhesive layer 123 which are stacked in sequence. The buffer layer 126 is not provided with the third recessed portion 126a mentioned above, and a hole can be directly punched at the edge portion 124a of the bending area 124 of the first adhesive layer 123 to form a first adhesive portion 123a that penetrates the first adhesive layer 123 along the thickness direction Z of the protective film 12, thereby simplifying the manufacturing process. Fig.23 Along the width direction X of the protective film 12 , the first adhesive portion 123 a also penetrates the edge portion 124 a of the bending area 124 to form a gap in the edge portion 124 a of the bending area 124 , so that the outermost edge of the bending area 124 also has the second adhesive.

[0130] like Fig.24 As shown, the protective film 12 includes an optical coating 121, a support layer 122, a second adhesive layer 125, a buffer layer 126 and a first adhesive layer 123 which are stacked in sequence. The buffer layer 126 is not provided with a fourth recessed portion 126b, and a hole can be directly punched in the middle portion 124b of the bending area 124 of the first adhesive layer 123 to form a plurality of second adhesive portions 123b penetrating the first adhesive layer 123 along the thickness direction Z of the protective film 12, thereby simplifying the manufacturing process.

[0131] In the above embodiments, the shape of the second adhesive containing portion 123b (the second recessed portion 122b / the fourth recessed portion 126b) is not limited. Fig.25 As shown, it can be circular, elliptical, square, diamond, etc. And the arrangement of the second adhesive holding portion 123b (second recessed portion 122b / fourth recessed portion 126b) is not limited, such as Fig.26 As shown, a plurality of second adhesive containing portions 123b may be evenly distributed in the bending area 124, the second adhesive containing portions 123b in adjacent columns may be staggered, or fewer second adhesive containing portions 123b may be provided in the two outermost columns.

[0132] It should be noted that in the above embodiments, the first adhesive and the second adhesive are transparent adhesives, and the second adhesive container 123b can be arranged at the position where the axial area simulation separation stress of the cover plate 11 is the largest or arranged according to the shape of the axial area parts of the cover plate 2.

[0133] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A protective film for a foldable display module, characterized in that: The protective film comprises a first adhesive layer, the first adhesive layer is used to be bonded to the cover plate of the display module, and the first adhesive layer comprises a first adhesive; The protective film has a bending area, the bending area is used to fit with the shaft area of ​​the cover plate, and the first adhesive layer located in the bending area has a glue-containing portion, and the glue-containing portion is used to fill a second adhesive having a greater adhesive force than the first adhesive; Along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion, and the adhesive receiving portion includes at least a first adhesive receiving portion, and the first adhesive receiving portion is arranged at the edge portion; The protective film further comprises an adjacent layer bonded to the first adhesive layer; The adjacent layer is provided with a first recessed portion, and the first adhesive can flow into the first recessed portion to form the first adhesive receiving portion at the edge portion.

2. The protective film according to claim 1, characterized in that: The first recessed portion is a notch penetrating the adjacent layer along the width direction of the protective film, so that the first adhesive holding portion is a notch penetrating the first adhesive layer along the width direction of the protective film.

3. The protective film according to claim 1, characterized in that: The protective film further comprises an adjacent layer bonded to the first adhesive layer; Along the width direction of the protective film, the outer edge of the edge portion is located inside the outer edge of the adjacent layer, so that a step portion is formed between the first adhesive layer and the adjacent layer, and the step portion is the first adhesive holding portion.

4. The protective film according to claim 1, characterized in that: The first adhesive receiving portion covers the edge portion.

5. The protective film according to claim 1, characterized in that: Along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion, and the adhesive receiving portion includes a plurality of second adhesive receiving portions; A plurality of the second adhesive containing portions are arranged at intervals in the middle portion.

6. The protective film according to claim 5, characterized in that: The protective film also includes an adjacent layer bonded to the first adhesive layer, the adjacent layer is provided with a plurality of second recessed portions, and the first adhesive located in the middle portion can flow to the second recessed portions to form a plurality of second adhesive holding portions in the middle portion.

7. The protective film according to claim 5, characterized in that: Along the thickness direction of the protective film, the second adhesive holding portion is a through hole penetrating the first adhesive layer.

8. The protective film according to claim 1, characterized in that: Along the width direction of the protective film, the bending area includes a middle portion and edge portions located on both sides of the middle portion; The edge portion is provided with a first adhesive receiving portion, and the middle portion is provided with a plurality of second adhesive receiving portions distributed at intervals. Along the length direction of the protective film, the length of the first adhesive receiving portion is greater than the length of a single second adhesive receiving portion.

9. The protective film according to claim 8, characterized in that: The total area of ​​the plurality of second adhesive-containing portions accounts for 50%-90% of the total area of ​​the middle portion of the bending zone.

10. A display module, characterized in that: The display module comprises: Cover plate; A protective film, wherein the protective film is the protective film according to any one of claims 1 to 9, and the protective film is bonded to the cover plate; Wherein, the adhesive containing portion of the first adhesive layer is filled with a second adhesive, and the adhesive force of the second adhesive is greater than the adhesive force of the first adhesive layer.

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