Optical adhesive, display panel and preparation method of optical adhesive

Abstract

The application relates to an optical adhesive, a display panel and a preparation method of the optical adhesive. The optical adhesive comprises a first subsegment and a second subsegment connected with each other, and the optical adhesive is configured to be bent relative to a first virtual straight line. The first virtual straight line is located in the first subsegment in the orthographic projection of the optical adhesive. Two second subsegments are connected to two sides of the first subsegment in a first direction, and the edges of the second subsegments away from the first subsegment coincide with the edges of the optical adhesive. The first direction intersects with the extension direction of the first virtual straight line. The Young's modulus of the first subsegment is M1, and M1 is less than or equal to 30 kpa. The Young's modulus of the second subsegment is M2, and M2 is greater than or equal to 50 kpa. The optical adhesive, the display panel and the preparation method of the optical adhesive provided in the application have good performance.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an optical adhesive, a display panel, and a method for preparing the optical adhesive. Background Technology

[0002] Display panels are an indispensable key component in modern electronic devices, and are widely used in various fields such as consumer electronics, industrial equipment, automotive electronics, and medical devices.

[0003] Foldable display panels, due to their ability to be bent and fold, can balance large-area display with small-volume storage. During the bending and folding process, the performance of the foldable display panel must be maintained to ensure optimal display quality. Summary of the Invention

[0004] The optical adhesive, display panel, and preparation method of the optical adhesive provided in this application have excellent performance.

[0005] In a first aspect, embodiments of this application provide an optical adhesive comprising interconnected first and second segments. The optical adhesive is configured to bend relative to a first virtual straight line, the orthographic projection of which lies within the first segment. Two second segments are respectively connected to both sides of the first segment in a first direction, the edges of the second segments away from the first segment coinciding with the edges of the optical adhesive, and the first direction intersecting the extension direction of the first virtual straight line. The Young's modulus of the first segment is M1, where M1 ≤ 30 kPa, and the Young's modulus of the second segment is M2, where M2 ≥ 50 kPa.

[0006] Secondly, embodiments of this application provide a display panel including the optical adhesive provided in the first aspect of this application.

[0007] Thirdly, embodiments of this application provide a method for preparing an optical adhesive, comprising: S10, forming a first gel and a second gel, wherein the Young's modulus of the first gel is less than that of the second gel; S20. The first adhesive and the second adhesive are loaded into a coating device. The coating device includes a first coating head and a second coating head that are independent of each other. The first coating head is used to coat the first adhesive and the second coating head is used to coat the second adhesive. S30, Forming a coating layer, with the first coating head and the second coating head applying the coating in sections along the first direction, and the first adhesive material and the second adhesive material arranged side by side along the first direction; S40. An optical adhesive is formed. The first adhesive material is cured to form a first segment, and the second adhesive material is cured to form a second segment. The first segment and the second segment form an optical adhesive.

[0008] According to the optical adhesive, display panel, and preparation method of the optical adhesive provided in this application, the optical adhesive is applied to a foldable display panel, and the optical adhesive is configured to be bent relative to a first virtual straight line. The optical adhesive includes a first sub-segment and two second sub-segments connected to both sides of the first sub-segment along a first direction. The orthographic projection of the first virtual straight line onto the optical adhesive is located inside the first sub-segment, and the first direction intersects the extension direction of the first virtual straight line. When the optical adhesive is applied to the foldable display panel, the first sub-segment corresponds to the bent portion of the foldable display panel, and the two second sub-segments correspond to the first flat portion and the second flat portion of the foldable display panel, respectively. By reducing the Young's modulus of the first sub-segment, strain can be relatively easily generated at the first sub-segment, which can have a good absorption effect on bending stress, and the deformation recovery ability of the first sub-segment can be relatively improved, thereby reducing the probability of creases occurring at the first sub-segment. By increasing the Young's modulus of the second sub-segments, the ability of the second sub-segment to generate strain can be reduced, which can ensure the shape stability of the second sub-segment itself, thereby improving the positional stability between the second sub-segment and adjacent film layers. Based on the connection between the second sub-segment and the first sub-segment, the second sub-segment has good positional stability and can provide good limiting stability for the first sub-segment, thereby improving the overall structural stability of the optical adhesive and enhancing the performance stability of the folding and unfolding of the foldable display panel, thus ensuring the display effect of the foldable display panel. Attached Figure Description

[0009] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0010] Figure 1 A schematic diagram of a display panel in an unfolded state, provided for some embodiments of this application; Figure 2 This application provides a schematic diagram of the structure of a display panel in a folded state, based on some embodiments of the present application. Figure 3 A first structural schematic diagram of an optical adhesive provided for some embodiments of this application; Figure 4 This is a schematic diagram of a second structure of an optical adhesive provided in some embodiments of this application; Figure 5 This application provides a schematic diagram of the structure of a display panel according to some embodiments; Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure at point AA; Figure 7 for Figure 5 Schematic diagram of the first sectional view at point BB; Figure 8 for Figure 5 Schematic diagram of the second sectional view at point BB; Figure 9 for Figure 5 Schematic diagram of the third sectional view at point BB; Figure 10 for Figure 5 Schematic diagram of the fourth sectional view at point BB; Figure 11 for Figure 5 Schematic diagram of the fifth sectional view at point BB; Figure 12 for Figure 5 A schematic diagram of the sixth sectional view at point BB; Figure 13 This is a schematic flowchart illustrating a method for preparing an optical adhesive according to some embodiments of this application.

[0011] Marker explanation: 10. Optical adhesive; 11. First segment; 12. Second segment; 13. Third segment; L1, the first virtual line; 200. Display panel; 20. Substrate; 30. Array circuit layer; 40. Light-emitting functional layer; 41. Light-emitting structure; 50. Encapsulation layer; 60. Cover plate; 61. First sub-area; 62. Second sub-area; 70. First functional layer; 71. First routing area; 711. First routing section; 72. Second routing area; 721. Second routing section; 80. First electrode layer; 101. First adhesive layer; 102. Second adhesive layer; M1, first surface; M11, first sub-surface; M12, second sub-surface; B1, Bending section; B2, First flat section; B3, Second flat section; X, first direction; Z, thickness direction.

[0012] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0013] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0014] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0015] Foldable display panels offer a balance between large-area display and compact storage. When unfolded, they provide a large display area for easy viewing, while when folded, they have a small storage volume for easy portability. In foldable display panels, optical adhesive acts as a flexible interlayer, using deformation to coordinate displacement differences between adjacent layers, thus ensuring the folding performance of the display panel.

[0016] In view of this, firstly, please refer to Figure 1 , Figure 2 and Figure 3 This application provides an optical adhesive 10, including a first segment 11 and a second segment 12 connected to each other. The optical adhesive 10 is configured to bend relative to a first virtual straight line L1, and the orthographic projection of the first virtual straight line L1 onto the optical adhesive 10 lies within the first segment 11. Two second segments 12 are respectively connected to both sides of the first segment 11 in a first direction X. The edges of the second segments 12 away from the first segment 11 coincide with the edges of the optical adhesive 10. The first direction X intersects the extension direction of the first virtual straight line L1. The Young's modulus of the first segment 11 is M1, where M1 ≤ 30 kPa, and the Young's modulus of the second segment 12 is M2, where M2 ≥ 50 kPa.

[0017] The optical adhesive 10 provided in this embodiment is applied to a foldable display panel 200. Specifically, the foldable display panel 200 includes a bent portion B1 and a first flat portion B2 and a second flat portion B3 located on both sides of the bent portion B1. When the foldable display panel 200 is in the unfolded state, the first flat portion B2 and the second flat portion B3 are located on both sides of the bent portion B1 along the first direction X, and there is no contact between the first flat portion B2 and the second flat portion B3. Correspondingly, the optical adhesive 10 is also in the unfolded state in the foldable display panel 200. When the foldable display panel 200 is in the folded state, the first flat portion B2 and the second flat portion B3 are stacked on top of each other and in contact with each other. Correspondingly, the optical adhesive 10 is also in the folded state in the foldable display panel 200. It can be understood that the optical adhesive 10 is a single layer in the foldable display panel 200, and the optical adhesive 10 unfolds and folds accordingly during the transition between the unfolded and folded states of the foldable display panel 200.

[0018] Specifically, the optical adhesive 10 is configured to be bent relative to the first virtual straight line L1. Taking the optical adhesive 10 as a rectangular structure as an example, the optical adhesive 10 has a length direction and a width direction. The first virtual straight line L1 can be the center line of the optical adhesive 10 along the length direction, and the optical adhesive 10 is folded along the length direction; or, the first virtual straight line L1 can be the center line of the optical adhesive 10 along the width direction, and the optical adhesive 10 is folded along the width direction.

[0019] The optical adhesive 10 includes a first segment 11 and two second segments 12 connected to both sides of the first segment 11 along a first direction X. The orthographic projection of a first virtual straight line L1 onto the optical adhesive 10 is located inside the first segment 11, and the first direction X intersects the extension direction of the first virtual straight line L1. When the optical adhesive 10 is applied to the foldable display panel 200, the first segment 11 corresponds to the bent portion B1 of the foldable display panel 200, and the two second segments 12 correspond to the first flat portion B2 and the second flat portion B3 of the foldable display panel 200, respectively.

[0020] In related technologies, the optical adhesive 10 is integrally disposed within the foldable display panel 200, and the Young's modulus of the optical adhesive 10 remains constant across different locations. The Young's modulus of the portion of the optical adhesive 10 corresponding to the bending portion B1 is the same as that of the portion corresponding to the flat portion. However, during the transition between the unfolded and folded states of the foldable display panel 200, the portion of the optical adhesive 10 corresponding to the bending portion B1 experiences relatively larger strain, while the portion corresponding to the flat portion experiences smaller strain. Consequently, the performance requirements for the optical adhesive 10 differ at different locations. The homogeneous modulus of the optical adhesive 10 in related technologies is insufficient to meet these performance requirements at different locations, making it difficult to guarantee the performance of the foldable display panel 200.

[0021] The applicant's research revealed that in related technologies, the optical adhesive 10 employs a homogeneous modulus setting, typically with the Young's modulus of the entire layer set to 40 kPa. The strain occurring in the portion of the optical adhesive 10 corresponding to the bend B1 is relatively large. In this portion, performance requirements for stress absorption and greater deformation recovery are prioritized to reduce the probability of creases forming at the bend B1. However, a Young's modulus of 40 kPa for the optical adhesive 10 does not provide good stress absorption, resulting in weak deformation recovery at this location. Conversely, since the strain occurring in the portion of the optical adhesive 10 corresponding to the flat portion is smaller, performance requirements for constrained creep and smaller deformation are prioritized to reduce the probability of misalignment between the portion of the optical adhesive 10 corresponding to the flat portion and adjacent film layers. A Young's modulus of 40 kPa for the optical adhesive 10 easily causes material flow displacement, leading to misalignment between the optical adhesive 10 and adjacent film layers. When the portion of the optical adhesive 10 corresponding to the flat part is misaligned, it will affect the shape and position of the entire layer of optical adhesive 10, thereby affecting the stability of the folding and unfolding performance of the foldable display panel 200, and consequently affecting the display effect of the foldable display panel 200.

[0022] In the optical adhesive 10 provided in this embodiment, the first segment 11 corresponds to the bent portion B1 of the folded display panel 200. The first segment 11 experiences significant bending stress and strain during folding and unfolding. Lowering the Young's modulus of the first segment 11 makes it easier for strain to occur at this location, thus providing good stress absorption and improving its deformation recovery ability, thereby reducing the probability of creases forming at the first segment 11. For example, the Young's modulus of the first segment 11 can be set to no more than 30 kPa to ensure good deformation capacity and thus good stress absorption.

[0023] In the optical adhesive 10 provided in this embodiment, the second segment 12 corresponds to the flat portion of the foldable display panel 200. The second segment 12 experiences relatively low bending stress and strain during folding and unfolding. The second segment 12 is primarily subjected to the tensile force along the first direction X exerted by the first segment 11 during deformation. Increasing the Young's modulus of the second segment 12 reduces its strain capacity, ensuring its shape stability and improving its positional stability with adjacent film layers. Based on the connection between the second segment 12 and the first segment 11, the second segment 12 exhibits good positional stability and provides good limiting stability for the first segment 11, thereby improving the overall structural stability of the optical adhesive 10. This enhances the folding and unfolding performance stability of the foldable display panel 200, ensuring its display effect. For example, the Young's modulus of the second segment 12 can be set to a form exceeding 50 kPa to give the second segment 12 good self-shape stability, thereby giving it good resistance to deformation and creep.

[0024] Furthermore, the edge of the second segment 12, away from the first segment 11, is aligned with the edge of the optical adhesive 10. In other words, the second segment 12 is located at the end edge of the entire structure of the optical adhesive 10. When the optical adhesive 10 is applied to the foldable display panel 200, the second segment 12 exhibits good structural shape stability at the edge of the optical adhesive 10, while maintaining good positional stability with adjacent film layers. The second segment 12 can exert a good tensile force on the entire structure of the optical adhesive 10 at its edge. When the internal region of the optical adhesive 10 deforms, the positional stability of the second segment 12 confines the entire structure of the optical adhesive 10 within a relatively fixed area, facilitating deformation and recovery of the internal region of the optical adhesive 10. This ensures the stability of the folding and unfolding performance of the foldable display panel 200, thereby guaranteeing the display effect of the foldable display panel 200.

[0025] In summary, in this embodiment, the optical adhesive 10 is applied to the foldable display panel 200, and the optical adhesive 10 is configured to be bent relative to the first virtual straight line L1. The optical adhesive 10 includes a first sub-segment 11 and two second sub-segments 12 connected to both sides of the first sub-segment 11 along the first direction X. The orthographic projection of the first virtual straight line L1 onto the optical adhesive 10 is located inside the first sub-segment 11, and the first direction X intersects the extension direction of the first virtual straight line L1. When the optical adhesive 10 is applied to the foldable display panel 200, the first sub-segment 11 corresponds to the bent portion B1 of the foldable display panel 200, and the two second sub-segments 12 correspond to the first flat portion B2 and the second flat portion B3 of the foldable display panel 200, respectively. By reducing the Young's modulus of the first sub-segment 11, strain can occur relatively easily at the first sub-segment 11, which can have a good absorption effect on bending stress, and the deformation recovery ability of the first sub-segment 11 is relatively improved, thereby reducing the probability of creases occurring at the first sub-segment 11. Increasing the Young's modulus of the second segment 12 reduces its strain resistance, ensuring its shape stability and improving its positional stability with adjacent film layers. Based on the connection between the second segment 12 and the first segment 11, the second segment 12 exhibits good positional stability, providing excellent restraint stability for the first segment 11. This enhances the overall structural stability of the optical adhesive 10, thereby improving the folding and unfolding performance stability of the foldable display panel 200 and ensuring its display effect.

[0026] In some embodiments, please refer to Figure 1 , Figure 2 and Figure 4 The optical adhesive 10 also includes a third segment 13, which is connected between the first segment 11 and the second segment 12 along the first direction X. The Young's modulus of the third segment 13 is not less than the Young's modulus of the first segment 11, and the Young's modulus of the third segment 13 is not greater than the Young's modulus of the second segment 12.

[0027] The optical adhesive 10 also includes a third sub-segment 13 located between the first sub-segment 11 and the second sub-segment 12. It is understood that the first sub-segment 11 is the central sub-segment of the optical adhesive 10, the second sub-segment 12 is the edge sub-segment of the optical adhesive 10, and the third sub-segment 13 is located between the first sub-segment 11 and the second sub-segment 12. The second sub-segment 12, the third sub-segment 13, the first sub-segment 11, the third sub-segment 13, and the second sub-segment 12 are sequentially arranged along a first direction X. When the optical adhesive 10 is applied to the foldable display panel 200, the first sub-segment 11 corresponds to the bent portion B1 of the foldable display panel 200, and the third sub-segment 13 and the second sub-segment 12 correspond to the flat portion of the foldable display panel 200. The third sub-segment 13 is positioned closer to the first sub-segment 11 than the second sub-segment 12.

[0028] When the optical adhesive 10 is folded and unfolded along with the foldable display panel 200, the first segment 11 corresponds to the bending part B1 and is subjected to greater bending stress. Correspondingly, the third segment 13 is between the first segment 11 and the second segment 12. When the first segment 11 is bent and deformed, it will first generate a tensile force on the third segment 13, and then transfer the tensile force to the second segment 12. The third segment 13 serves as a transition between the first segment 11 and the second segment 12. It serves both to alleviate the deformation of the optical adhesive 10 between the first segment 11 and the second segment 12 and to transfer the optical adhesive 10 between the second segment 12 and the first segment 11. The Young's modulus of the third segment 13 is set to be no less than the Young's modulus of the first segment 11 and no greater than the Young's modulus of the second segment 12. On the one hand, this allows the deformation capacity of the third segment 13 to be between that of the first segment 11 and the second segment 12. When the first segment 11 deforms, based on the difference in modulus between the third segment 13 and the first segment 11, the deformation capacity of the third segment 13 is weaker than that of the first segment 11. This can alleviate the deformation transfer from the first segment 11 to the second segment 12 to a certain extent, forming a buffer deformation segment between the first segment 11 and the second segment 12. This creates a suitable stress-strain gradient change within the optical adhesive 10, ensuring the structural stability of the optical adhesive 10. On the other hand, the structural stability of the third segment 13 can be between that of the second segment 12 and the first segment 11. When the second segment 12 is subjected to limiting tension on the first segment 11, based on the difference in modulus between the third segment 13 and the second segment 12, the structural stability of the third segment 13 is weaker than that of the second segment 12. This can alleviate the transmission of the limiting effect between the second segment 12 and the first segment 11 to a certain extent, forming a buffer limiting segment between the first segment 11 and the second segment 12. This creates a suitable stress-strain gradient change within the optical adhesive 10, ensuring the structural stability of the optical adhesive 10. For example, the Young's modulus of the third segment 13 is set to be greater than 30 kPa and not more than 50 kPa, so that the third segment 13 can simultaneously alleviate the deformation of the optical adhesive 10 between the first segment 11 and the second segment 12 and transmit the fixing effect of the optical adhesive 10 between the second segment 12 and the first segment 11.

[0029] In some embodiments, please refer to Figure 1 , Figure 2 and Figure 4 The Young's modulus of the first sub-segment 11 remains consistent across different regions along the first direction X, and the Young's modulus of the second sub-segment 12 remains consistent across different regions along the first direction X. Along the first direction X, from the first sub-segment 11 to the second sub-segment 12, the Young's modulus of the third sub-segment 13 gradually increases.

[0030] In the optical adhesive 10 provided in this embodiment, the first segment 11 corresponds to the bent portion B1 of the foldable display panel 200. The first segment 11 experiences significant bending stress and bending strain during folding and unfolding. It is understood that the first segment 11 has a certain extension dimension in the first direction X, and the bent portion B1 in the foldable display panel 200 also has a certain extension dimension in the first direction X. The edge of the first segment 11 in the first direction X extends beyond the extension dimension of the bent portion B1 in the first direction X, so that the first segment 11 can cover the bent portion B1. When the first segment 11 in the optical adhesive 10 deforms along with the bent portion B1, the first segment 11 can effectively absorb the stress generated by bending, and the first segment 11 has good deformation recovery ability, thereby reducing the probability of creases occurring at the first segment 11.

[0031] In the optical adhesive 10 provided in this embodiment, the second segment 12 corresponds to the flat portion of the foldable display panel 200. The second segment 12 experiences relatively small bending stress and bending strain during folding and unfolding. The second segment 12 is mainly subjected to the tensile force of the first segment 11 along the first direction X during deformation. It is understood that the second segment 12 has a certain extension dimension in the first direction X. In order to ensure the shape stability of the second segment 12, the second segment 12 needs a stable connection area with the adjacent film layer. The Young's modulus of the second segment 12 in different regions of its extension direction is set to a consistent form to ensure the shape stability of the second segment 12 itself, while also ensuring the stability of the limiting force of the second segment 12 on the first segment 11.

[0032] In the optical adhesive 10 provided in this embodiment, the third segment 13 serves as a transition between the first segment 11 and the second segment 12. It simultaneously alleviates deformation of the optical adhesive 10 between the first segment 11 and the second segment 12, and transfers the fixation of the optical adhesive 10 between the second segment 12 and the first segment 11. By setting the Young's modulus of the third segment 13 to gradually increase along the first direction X from the first segment 11 to the second segment 12, the third segment 13 can have different Young's moduli at its two ends along the extension direction. The Young's modulus of the end of the third segment 13 facing the first segment 11 is smaller, approaching the Young's modulus of the first segment 11; the Young's modulus of the end of the third segment 13 facing the second segment 12 is larger, approaching the Young's modulus of the second segment 12. This arrangement avoids abrupt changes in modulus within the optical adhesive 10, thereby preventing stress abrupt changes within the optical adhesive 10 and ensuring the structural stability of the optical adhesive 10.

[0033] In some embodiments, please refer to Figure 1 , Figure 2 and Figure 4 The extension dimension of the first sub-segment 11 in the first direction X is not less than the extension dimension of the second sub-segment 12 in the first direction X. And / or, the extension dimension of the first sub-segment 11 in the first direction X is not less than the extension dimension of the third sub-segment 13 in the first direction X.

[0034] As mentioned above, the first segment 11 has a certain extension dimension in the first direction X, and the bent portion B1 in the foldable display panel 200 also has a certain extension dimension in the first direction X. The edge of the first segment 11 in the first direction X extends beyond the extension dimension of the bent portion B1 in the first direction X, so that the first segment 11 can cover the bent portion B1. In the optical adhesive 10, the extension direction of the first segment 11 can be set to be no less than the extension dimension of the second segment 12 in the first direction X to ensure the stress absorption function of the first segment 11. Furthermore, the extension direction of the first segment 11 can also be set to be no less than the extension dimension of the third segment 13 in the first direction X to ensure the stress absorption function of the first segment 11.

[0035] Optionally, the extension dimension of the first segment 11 in the first direction X can be set to be equal to the extension dimension of the second segment 12 in the first direction X, and the extension dimension of the first segment 11 in the first direction X can be set to be equal to the extension dimension of the third segment 13 in the first direction X. The second segment 12, the third segment 13, the first segment 11, the third segment 13, and the second segment 12 have equal extension dimensions along the first direction X to facilitate the preparation and molding of the optical adhesive 10.

[0036] In some embodiments, please refer to Figure 3 and Figure 4 The Young's modulus of the first sub-segment 11 is M1, where 20 kPa ≤ M1 ≤ 30 kPa. The Young's modulus of the second sub-segment 12 is M2, where 50 kPa ≤ M2 ≤ 60 kPa. The Young's modulus of the third sub-segment 13 is M3, where 30 kPa ≤ M3 ≤ 50 kPa.

[0037] The first segment 11 has good deformability, thus possessing good stress absorption capacity. The Young's modulus of the first segment 11 is set to not exceed 30 kPa, but can be set to exceed 20 kPa to ensure suitable strength and thus good supporting stability in adjacent layer structures. The second segment 12 has good shape stability, thus possessing good resistance to deformation and creep. The Young's modulus of the second segment 12 can be set to exceed 50 kPa, while the Young's modulus of the first segment 11 can be set to not exceed 60 kPa to ensure suitable strength and thus good supporting stability in adjacent layer structures.

[0038] The Young's modulus of the third segment 13 is set to be no less than that of the first segment 11 and no greater than that of the second segment 12. The Young's modulus of the third segment 13 is set to be greater than 30 kPa and no more than 50 kPa, so that the third segment 13 can take into account both the role of alleviating the deformation of the optical adhesive 10 between the first segment 11 and the second segment 12 and the role of transferring the optical adhesive 10 to fix it between the second segment 12 and the first segment 11.

[0039] In some embodiments, please refer to Figure 3 and Figure 4 The first segment 11 comprises a polyurethane block copolymer, wherein the mass percentage of the polyurethane block copolymer in the first segment 11 is B1, and 8 wt% ≤ B1 ≤ 12 wt%. And / or, the second segment 12 comprises nano-silica, wherein the mass percentage of the nano-silica in the second segment 12 is B2, and 12 wt% ≤ B2 ≤ 18 wt%.

[0040] In this embodiment, the Young's modulus of the first segment 11 is reduced. The first segment 11 can be a polyurethane block copolymer, and the mass percentage of the polyurethane block copolymer in the first segment 11 is set between 8 wt% and 12 wt%. The polyurethane block copolymer can improve the slippage efficiency of the molecular chains during folding and improve the stress absorption capacity of the first segment 11. The Young's modulus of the second segment 12 is increased. The second segment 12 includes nano-silica, and the mass percentage of the nano-silica in the second segment 12 is set between 12 wt% and 18 wt%. The nano-silica can reduce the ability of the second segment 12 to undergo strain and ensure the shape stability of the second segment 12.

[0041] Secondly, please refer to Figure 5 , Figure 6 and Figure 7 This application provides a display panel 200, including the optical adhesive 10 provided in any embodiment of the first aspect of this application. The display panel 200 includes all the technical features of the optical adhesive 10 and has all the technical effects of the optical adhesive 10, which will not be repeated here.

[0042] In some embodiments, please refer to Figure 5 and Figure 6The display panel 200 typically includes a substrate 20 and an array circuit layer 30 disposed on one side of the substrate 20. The substrate 20 is a structure in the display panel 200 used to support other film layers. The array circuit layer 30 is disposed on one side of the substrate 20 along the thickness direction Z. The array circuit layer 30 includes multiple film layer structures. For example, the array circuit layer 30 may include stacked semiconductor layers, multiple conductor layers, and insulating layers located between adjacent different conductor layers or between adjacent conductor layers and semiconductor layers. The specific composition of the film layer structures inside the array circuit layer 30 is not limited in the embodiments of this application. The multiple film layer structures inside the array circuit layer 30 and the multiple film layer structures located outside the array circuit layer 30 are all stacked along the thickness direction Z of the substrate 20. The thickness directions Z of different film layer structures, the thickness direction Z of the display panel 200, and the thickness direction Z of the substrate 20 can be arranged parallel to each other. For ease of understanding, the thickness directions Z of different film layer structures, the thickness direction Z of the display panel 200, and the thickness direction Z of the substrate 20 are all shown in the same direction in the accompanying drawings.

[0043] The display panel 200 further includes a light-emitting functional layer 40 disposed on the side of the array circuit layer 30 facing away from the substrate 20, the light-emitting functional layer 40 including a plurality of light-emitting structures 41. The display panel 200 also includes a first electrode layer 80 disposed on the side of the light-emitting functional layer 40 facing away from the substrate 20, the first electrode layer 80 covering the plurality of light-emitting structures 41. The semiconductor layer, a plurality of conductor layers, and an insulating layer located between adjacent different conductor layers or between adjacent conductor layers and semiconductor layers stacked in the array circuit layer 30 form a corresponding array circuit. The light-emitting structures 41 and the first electrode layer 80 are electrically connected to the array circuit, and the first electrode layer 80 may be a cathode layer. The integrated circuit in the display panel 200 transmits relevant signals to the light-emitting structures 41 and the first electrode layer 80 through the array circuit to control the light emission of the light-emitting structures 41 and realize the display effect of the display panel 200.

[0044] The display panel 200 also includes an encapsulation layer 50 disposed on the side of the first electrode layer away from the substrate 20. The encapsulation layer 50 is a film layer in the display panel 200 used to realize the encapsulation function. The encapsulation layer 50 can effectively block water and oxygen from entering the light-emitting functional layer 40 in the external environment, thereby improving the reliability and lifespan of the display panel 200.

[0045] In some embodiments, please refer to Figure 5 , Figure 7 and Figure 8The display panel 200 also includes a cover plate 60 disposed on one side of the optical adhesive 10 along its thickness direction Z, the thickness direction Z intersecting with the first direction X. The cover plate 60 includes a first sub-region 61 and second sub-regions 62 located on both sides of the first sub-region 61 along the first direction X. The first sub-region 61 is correspondingly disposed to the first sub-segment 11 in the thickness direction Z, and at least a portion of the structure of the second sub-region 62 is correspondingly disposed to the second sub-segment 12 in the thickness direction Z. The thickness dimension of the cover plate 60 at the second sub-region 62 is not greater than the thickness dimension of the cover plate 60 at the first sub-region 61.

[0046] In this embodiment, the optical adhesive 10 can be disposed on the side of the encapsulation layer 50 opposite to the substrate 20. The display panel 200 also includes a cover plate 60 disposed on the side of the optical adhesive 10 opposite to the substrate 20. The cover plate 60 can cover and protect the remaining structures in the display panel 200. In the foldable display panel 200, the cover plate 60 can also switch between a folded state and an unfolded state.

[0047] The cover plate 60 includes a first sub-region 61 and second sub-regions 62 located on both sides of the first sub-region 61 along a first direction X. The cover plate 60 is folded at the first sub-region 61. In related technologies, considering that the cover plate 60 needs to be bent at the first sub-region 61, the cover plate 60 needs to be thinned accordingly at the first sub-region 61. When the cover plate 60 switches between the folded and unfolded states, the bending stress and bending strain within the coverage area of ​​the first sub-region 61 are relatively large. Due to frequent bending within the overall area of ​​the cover plate 60, the first sub-region 61 is a relatively weak point in terms of strength. In addition, since the cover plate 60 in related technologies is usually thinned at the first sub-region 61, the foldable display panel 200 often breaks at the crease.

[0048] In this embodiment, the first sub-region 61 in the cover plate 60 corresponds to the first segment 11 in the optical adhesive 10, and the second sub-region 62 in the cover plate 60 corresponds to the second segment 12 in the optical adhesive 10. The first segment 11 in the optical adhesive 10 and the first sub-region 61 in the cover plate 60 deform together. By reducing the Young's modulus of the first segment 11 in the optical adhesive 10, the optical adhesive 10 can have a relatively high deformation capacity during the deformation process of the first segment 11 in the optical adhesive 10 and the first sub-region 61 in the cover plate 60. Correspondingly, the first sub-region 61 in the cover plate 60 can have a relatively low deformation capacity, and the optical adhesive 10 can compensate for the deformation capacity of the cover plate 60 to a certain extent.

[0049] When the first sub-region 61 of the cover plate 60 has a relatively low deformation capacity, the strength of the cover plate 60 at the first sub-region 61 can be considered. The thickness of the cover plate 60 at the first sub-region 61 can be appropriately increased to improve its strength and reduce the probability of breakage at that location. Specifically, the thickness of the cover plate 60 at the first sub-region 61 can be equal to its thickness at the second sub-region 62 to facilitate the fabrication of the cover plate 60. Alternatively, the thickness of the cover plate 60 at the first sub-region 61 can be set to be greater than its thickness at the second sub-region 62 to further improve its strength at the first sub-region 61, thereby increasing its strength during deformation.

[0050] In some embodiments, please refer to Figure 5 , Figure 7 and Figure 9 The cover plate 60 includes a first surface M1 facing the optical adhesive 10. The first surface M1 includes a first sub-surface M11 and second sub-surfaces M12 located on both sides of the first sub-surface M11 along a first direction X. The first sub-surface M11 is disposed corresponding to a first sub-segment 11 in the thickness direction Z, and at least a portion of the structure of the second sub-surface M12 is disposed corresponding to the second sub-segment 12 in the thickness direction Z. The surface roughness of the first sub-surface M11 is greater than the surface roughness of the second sub-surface M12.

[0051] When the optical adhesive 10 is disposed between the cover plate 60 and the encapsulation layer 50, the cover plate 60 includes a first surface M1 facing the optical adhesive 10, the optical adhesive 10 is connected to the first surface M1 of the cover plate 60, and the optical adhesive 10 covers the first surface M1 in the thickness direction Z. The first surface M1 includes a first sub-surface M11 and a second sub-surface M12 located on both sides of the first sub-surface M11 along the first direction X. A first segment 11 in the optical adhesive 10 is in contact with the first sub-surface M11 in the first surface M1, and a second segment 12 in the optical adhesive 10 is in contact with the second sub-surface M12 in the first surface M1.

[0052] Based on the reduced Young's modulus of the first segment 11 in the optical adhesive 10, the first segment 11 has a relatively large deformation capacity. To improve the relative positional stability between the first segment 11 and the first sub-surface M11, the deformation of the first segment 11 is limited as much as possible within its own extension range. The surface roughness of the first sub-surface M11 is increased to improve the relative positional stability between the first segment 11 and the first sub-surface M11. Specifically, the surface roughness of the first sub-surface M11 can be set to be greater than that of the second sub-surface M12, so that the connecting force between the first segment 11 and the first sub-surface M11 is relatively higher than the connecting force between the second segment 12 and the second sub-surface M12, thereby ensuring the relative positional stability between the first segment 11 and the first sub-surface M11.

[0053] In some embodiments, please refer to Figure 5 , Figure 6 and Figure 10 The display panel 200 further includes a first functional layer 70 disposed on one side of the optical adhesive 10 along its thickness direction Z. The first functional layer 70 includes a first wiring area 71 and second wiring areas 72 located on both sides of the first wiring area 71 along a first direction X. The first wiring area 71 is disposed corresponding to a first sub-segment 11 in the thickness direction Z, and at least a portion of the structure of the second wiring area 72 is disposed corresponding to a second sub-segment 12 in the thickness direction Z. The first wiring area 71 includes a plurality of spaced-apart first wiring portions 711, and the second wiring area 72 includes a plurality of spaced-apart second wiring portions 721. The spacing between two adjacent second wiring portions 721 is not greater than the spacing between two adjacent first wiring portions 711, and / or, the width of the second wiring portion 721 is not greater than the width of the first wiring portion 711.

[0054] The display panel 200 also includes a first functional layer 70 disposed adjacent to the optical adhesive 10. The first functional layer 70 is used to implement specific functions in the display panel 200. For example, the first functional layer 70 can be a touch layer, including multiple functional traces configured as touch traces to implement the touch function of the display panel 200. Optionally, the first functional layer 70 can also be one or more conductor layers in the array circuit layer 30, used to implement the display driving function of the display panel 200. In the foldable display panel 200, the first functional layer 70 can also switch between a folded state and an unfolded state. The optical adhesive 10 is disposed adjacent to the first functional layer 70, which can absorb and compensate for deformation of the first functional layer 70.

[0055] The first functional layer 70 includes a first routing area 71 and second routing areas 72 located on both sides of the first routing area 71 along a first direction X. The first routing area 71 includes a plurality of spaced-apart first routing portions 711, and the second routing area 72 includes a plurality of spaced-apart second routing portions 721. It is understood that the first routing portions 711 and the second routing portions 721 jointly implement the function of the first functional layer 70. The first functional layer 70 is folded at the first routing area 71. In related technologies, considering that the first functional layer 70 needs to be bent and folded at the first routing area 71, the routing width of the first routing portions 711 in the first routing area 71 is usually reduced, and the routing spacing between adjacent first routing portions 711 in the first routing area 71 is increased to meet the bending performance requirements of the first routing area 71. During the switching between the folded and unfolded states of the first functional layer 70, the bending stress and bending strain within the coverage area of ​​the first wiring area 71 are relatively large. In addition, the width of the first wiring portion 711 is relatively small, and the first wiring portion 711 often breaks.

[0056] In this embodiment, the first trace area 71 in the first functional layer 70 corresponds to the first segment 11 in the optical adhesive 10, and the second trace area 72 in the first functional layer 70 corresponds to the second segment 12 in the optical adhesive 10. The first segment 11 in the optical adhesive 10 deforms together with the first trace area 71 in the first functional layer 70. By reducing the Young's modulus of the first segment 11 in the optical adhesive 10, the optical adhesive 10 has a relatively high deformation capacity during the deformation process of the first segment 11 in the optical adhesive 10 and the first trace area 71 in the first functional layer 70. Correspondingly, the first trace area 71 in the first functional layer 70 can have a relatively low deformation capacity, and the optical adhesive 10 can compensate for the deformation capacity of the first functional layer 70 to a certain extent.

[0057] When the first trace area 71 in the first functional layer 70 has relatively low deformation capacity, the strength of the first trace portion 711 can be considered by appropriately increasing its width to improve its strength and reduce the probability of breakage. Simultaneously, this also reduces the impedance of the first trace portion 711, facilitating signal transmission. Specifically, the width of the first trace portion 711 can be set to be the same as the width of the second trace portion 712 to facilitate the fabrication of the first functional layer 70. Figure 10The diagram shows a case where the width of the first trace portion 711 is equal to the width of the second trace portion 721. Alternatively, the width of the first trace portion 711 can be set to be greater than the width of the second trace portion 721 to further improve the strength of the first trace portion 711 and reduce the probability of breakage.

[0058] Correspondingly, when the first wiring area 71 in the first functional layer 70 can have a relatively low deformation capacity, when the width of the first wiring portion 711 is appropriately increased, the spacing between adjacent first wiring portions 711 will be reduced to a certain extent. In order to ensure the bending performance of the first wiring area 71, when the width of the first wiring portion 711 is set to be equal to the width of the second wiring portion 721, the spacing between adjacent first wiring portions 711 can be set to be equal to the spacing between adjacent second wiring portions 721, based on the same number of first wiring portions 711 and second wiring portions 721. Figure 10 The diagram shows a case where the width of the first wiring portion 711 is equal to the width of the second wiring portion 721, and the spacing between adjacent first wiring portions 711 is equal to the spacing between adjacent second wiring portions 721.

[0059] When the width of the first wiring portion 711 is greater than the width of the second wiring portion 721, the same number of first wiring portions 711 and second wiring portions 721 will result in the spacing between adjacent first wiring portions 711 being smaller than the spacing between adjacent second wiring portions 721, affecting the bending performance of the first wiring area 71. By widening the first wiring portions 711, the spacing between adjacent first wiring portions 711 can be increased by reducing the number of first wiring portions 711, so that the spacing between two adjacent second wiring portions 721 is no greater than the spacing between two adjacent first wiring portions 711, thus ensuring the bending performance of the first wiring area 71.

[0060] In some embodiments, please refer to Figure 5 , Figure 6 and Figure 11 The optical adhesive 10 includes a first adhesive layer 101 and a second adhesive layer 102. The display panel 200 also includes a first functional layer 70 and a cover plate 60. The first adhesive layer 101, the first functional layer 70, the second adhesive layer 102, and the cover plate 60 are stacked sequentially along the thickness direction Z. The extension dimension of the first segment 11 in the first adhesive layer 101 in the first direction X is greater than the extension dimension of the first segment 11 in the second adhesive layer 102 in the first direction X.

[0061] The display panel 200 includes a multi-layer structure. Multiple layers of optical adhesive 10 can be disposed within the display panel 200, spaced apart, to alleviate and absorb deformation of the multi-layer structure. Specifically, the optical adhesive 10 includes a first adhesive layer 101 and a second adhesive layer 102, which are spaced apart within the display panel 200. The display panel 200 also includes a first functional layer 70 and a cover plate 60. The first adhesive layer 101, the first functional layer 70, the second adhesive layer 102, and the cover plate 60 are sequentially stacked along the thickness direction Z. The first adhesive layer 101 and the second adhesive layer 102 can alleviate and absorb deformation and bending of the first functional layer 70 and the cover plate 60.

[0062] During the folding process of the display panel 200, the folding radii of the cover plate 60, the second adhesive layer 102, the first functional layer 70, and the first adhesive layer 101 increase sequentially. In order to facilitate the folding deformation of different layer structures, the extension dimension of the first sub-segment 11 in the first adhesive layer 101 is set to be greater than the extension dimension of the first sub-segment 11 in the second adhesive layer 102, so as to adapt to the relatively large folding diameter and relatively large deformation of the first adhesive layer 101, so as to ensure the folding performance of the multi-layer structure in the display panel 200.

[0063] In some embodiments, please refer to Figure 5 , Figure 6 and Figure 12 The optical adhesive 10 also includes a third segment 13, which connects the first segment 11 and the second segment 12 along the first direction X. The Young's modulus of the third segment 13 is not less than the Young's modulus of the first segment 11, and the Young's modulus of the third segment 13 is not greater than the Young's modulus of the second segment 12. The display panel 200 also includes a cover plate 60 disposed on one side of the optical adhesive 10 along its thickness direction Z. The edge of the cover plate 60 in the first direction X coincides with the edge of the second segment 12 away from the first segment 11.

[0064] The optical adhesive 10 also includes a third sub-segment 13 located between the first sub-segment 11 and the second sub-segment 12. It can be understood that the first sub-segment 11 is the central sub-segment of the optical adhesive 10, the second sub-segment 12 is the edge sub-segment of the optical adhesive 10, and the third sub-segment 13 is located between the first sub-segment 11 and the second sub-segment 12. The second sub-segment 12, the third sub-segment 13, the first sub-segment 11, the third sub-segment 13, and the second sub-segment 12 are sequentially arranged along the first direction X. When the optical adhesive 10 is connected to the cover plate 60, the first sub-segment 11 corresponds to the first sub-region 61 of the cover plate 60, the third sub-segment 13 and the second sub-segment 12 correspond to the second sub-region 62 of the cover plate 60, and the edge of the cover plate 60 coincides with the edge of the second sub-segment 12 away from the first sub-segment 11.

[0065] When the optical adhesive 10 is folded and unfolded along with the cover plate 60, the first segment 11 corresponds to the bent part B1, and it is subjected to greater bending stress. Correspondingly, the third segment 13 is between the first segment 11 and the second segment 12. When the first segment 11 is bent and deformed, it will first generate a tensile force on the third segment 13, and then transfer the tensile force to the second segment 12. The third segment 13 serves as a transition between the first segment 11 and the second segment 12. It serves both to alleviate the deformation of the optical adhesive 10 between the first segment 11 and the second segment 12 and to transfer the optical adhesive 10 between the second segment 12 and the first segment 11. The Young's modulus of the third segment 13 is set to be no less than the Young's modulus of the first segment 11 and no greater than the Young's modulus of the second segment 12. On the one hand, this allows the deformation capacity of the third segment 13 to be between that of the first segment 11 and the second segment 12. When the first segment 11 deforms, based on the difference in modulus between the third segment 13 and the first segment 11, the deformation capacity of the third segment 13 is weaker than that of the first segment 11. This can alleviate the deformation transfer from the first segment 11 to the second segment 12 to a certain extent, forming a buffer deformation segment between the first segment 11 and the second segment 12. This creates a suitable stress-strain gradient change within the optical adhesive 10, ensuring the structural stability of the optical adhesive 10. On the other hand, it can also make the structural stability of the third segment 13 between that of the second segment 12 and the first segment 11. When the second segment 12 limits the stretching of the first segment 11, based on the difference in modulus between the third segment 13 and the second segment 12, the structural stability of the third segment 13 is weaker than that of the second segment 12. This can alleviate the transmission of the limiting effect between the second segment 12 and the first segment 11 to a certain extent, forming a buffer limiting segment between the first segment 11 and the second segment 12, and forming a suitable gradient change of stress and strain inside the optical adhesive 10 to ensure the structural stability of the optical adhesive 10.

[0066] Thirdly, please refer to Figure 13 This application provides a method for preparing optical adhesive 10, comprising: S10, forming a first gel and a second gel, wherein the Young's modulus of the first gel is less than that of the second gel; S20. The first adhesive and the second adhesive are loaded into a coating device. The coating device includes a first coating head and a second coating head that are independent of each other. The first coating head is used to coat the first adhesive and the second coating head is used to coat the second adhesive. S30, Forming a coating layer, with the first coating head and the second coating head coating in sections along the first direction X, and the first adhesive and the second adhesive arranged side by side along the first direction X; S40, optical adhesive 10 is formed, the first adhesive material is cured to form the first segment 11, the second adhesive material is cured to form the second segment 12, and the first segment 11 and the second segment 12 form optical adhesive 10.

[0067] In S10, the first and second gel-like materials are formed. The Young's modulus of the first gel-like material is M1, where M1 ≤ 30 kPa. This material is relatively prone to strain and exhibits good stress absorption. The Young's modulus of the second gel-like material is M2, where M2 ≥ 50 kPa. This material is relatively less prone to strain and maintains good shape stability. The first gel-like material includes a polyurethane block copolymer, with the polyurethane block copolymer comprising B1 by mass, where 8 wt% ≤ B1 ≤ 12 wt%. The second gel-like material includes nano-silica, with nano-silica comprising B2 by mass, where 12 wt% ≤ B2 ≤ 18 wt%. In step S20, the first and second adhesive materials are loaded into a coating apparatus. The coating apparatus includes a first coating head and a second coating head that are independent of each other. It is understood that the first coating head and the second coating head can coat different materials simultaneously without interfering with each other. The first coating head is used to coat the first adhesive material, and the second coating head is used to coat the second adhesive material.

[0068] In step S30, forming the adhesive layer, the first coating head and the second coating head correspond to two different coating areas, which are arranged side by side along the first direction X. After the first coating head completes coating the first adhesive material and the second coating head completes coating the second adhesive material, the first and second adhesive materials are arranged side by side along the first direction X. The coating size of the first coating head corresponds to the forming size of the subsequent first segment 11, and the coating size of the second coating head corresponds to the forming size of the subsequent second segment 12.

[0069] In step S40, forming the optical adhesive 10, a first adhesive material cures to form a first segment 11, and a second adhesive material cures to form a second segment 12. The Young's modulus of the first segment 11 does not exceed 30 kPa, so that the first segment 11 has good deformability and thus good stress absorption capacity. The Young's modulus of the second segment 12 exceeds 50 kPa, so that the second segment 12 has good shape stability and thus good resistance to deformation and creep. The first segment 11 and the second segment 12 are interconnected to form the optical adhesive 10.

[0070] In some embodiments, S10, forming the first and second gels, further includes forming a third gel, wherein the Young's modulus of the third gel is not less than the Young's modulus of the first gel and the Young's modulus of the third gel is not greater than the Young's modulus of the second gel.

[0071] In step S20, the first and second adhesive materials are loaded into the coating apparatus, and a third adhesive material is also loaded into the coating apparatus. The coating apparatus includes a third coating head independent of the first and second coating heads, and the third coating head is used for the third adhesive material.

[0072] In S30, during the formation of the coating layer, the third coating head coats the third adhesive material between the first adhesive material and the second adhesive material along the first direction X.

[0073] In S40, during the formation of optical adhesive 10, the third adhesive material is cured to form the third segment 13. The first segment 11, the third segment 13, and the second segment 12 form optical adhesive 10. The first adhesive material is cured by irradiating it with ultraviolet light to form the first segment 11. The second adhesive material is cured by irradiating it with ultraviolet light to form the second segment 12. The third adhesive material is cured by irradiating it with ultraviolet light to form the third segment 13. The intensity of ultraviolet light irradiating the first gel is less than that irradiating the second gel. Along the first direction X from the side of the first gel pointing towards the second gel, the intensity of ultraviolet light irradiating the third gel gradually increases.

[0074] In S10, the formation of the first and second gel materials also includes the formation of a third gel material, the Young's modulus of which is between that of the first and second gel materials. In S20, the first and second gel materials are loaded into a coating apparatus, and the third gel material is also loaded into the coating apparatus, allowing the third, first, and second gel materials to be coated simultaneously and independently. In S30, the formation of the coating adhesive layer involves the first, third, and second coating heads corresponding to three different coating areas, which are arranged side-by-side along the first direction X. After the first coating head has finished coating the first gel material, the third coating head has finished coating the third gel material, and the second coating head has finished coating the second gel material, the first, third, and second gel materials are arranged side-by-side along the first direction X.

[0075] In step S40, forming the optical adhesive 10, the adhesive material is cured and shaped by ultraviolet light irradiation. The intensity of the ultraviolet light irradiation can be easily controlled by zonal adjustment to form segments with different Young's moduli. The first adhesive material is cured by ultraviolet light irradiation to form a first segment 11. The Young's modulus of the first segment 11 remains consistent across different regions in the first direction X, and the ultraviolet light intensity irradiating the first adhesive material is consistent. The second adhesive material is cured by ultraviolet light irradiation to form a second segment 12. The Young's modulus of the second segment 12 remains consistent across different regions in the first direction X, and the ultraviolet light intensity irradiating the second adhesive material is consistent. Along the first direction X, from the first segment 11 towards the second segment 12, the Young's modulus of the third segment 13 gradually increases. The ultraviolet light intensity irradiated onto the third adhesive material can gradually increase along the first direction X from the first adhesive material towards the second adhesive material, thus curing to obtain a third segment 13 with a gradually increasing Young's modulus. For example, the intensity of ultraviolet light irradiating the first gelatinous material is 300 mJ / cm. 2 -400mJ / cm 2 Between these points, the intensity of ultraviolet light irradiating the third colloidal substance was 400 mJ / cm. 2 -450mJ / cm 2 Between these times, the intensity of ultraviolet light irradiating the second colloidal substance was 450 mJ / cm. 2 -550mJ / cm 2 Between. By combining the first sub-segment 11, the third sub-segment 13 and the second sub-segment 12, it is possible to avoid the formation of a sudden change in modulus inside the optical adhesive 10, thereby avoiding the occurrence of a sudden change in stress inside the optical adhesive 10 and ensuring the structural stability of the optical adhesive 10.

[0076] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An optical adhesive, characterized in that, include: In the first sub-segment, the optical adhesive is configured to bend relative to a first virtual straight line, the orthographic projection of which is located within the first sub-segment; The second sub-segment is connected to the first sub-segment on both sides in the first direction. The edge of the second sub-segment away from the first sub-segment coincides with the edge of the optical adhesive. The first direction intersects the extension direction of the first virtual straight line. Wherein, the Young's modulus of the first sub-segment is M1, M1≤30 kPa, and the Young's modulus of the second sub-segment is M2, M2≥50 kPa.

2. The optical adhesive according to claim 1, characterized in that, It also includes a third sub-segment, which is connected between the first sub-segment and the second sub-segment along the first direction; The Young's modulus of the third segment is not less than the Young's modulus of the first segment, and the Young's modulus of the third segment is not greater than the Young's modulus of the second segment.

3. The optical adhesive according to claim 2, characterized in that, The Young's modulus of the first sub-segment remains consistent in different regions along the first direction, and the Young's modulus of the second sub-segment remains consistent in different regions along the first direction; Along the first direction from the first sub-segment to the second sub-segment, the Young's modulus of the third sub-segment gradually increases.

4. The optical adhesive according to claim 2, characterized in that, The extension dimension of the first sub-segment in the first direction is not less than the extension dimension of the second sub-segment in the first direction; And / or, the extension dimension of the first sub-segment in the first direction is not less than the extension dimension of the third sub-segment in the first direction.

5. The optical adhesive according to claim 2, characterized in that, The Young's modulus of the first segment is M1, 20 kPa ≤ M1 ≤ 30 kPa; The Young's modulus of the second segment is M2, 50 kPa ≤ M2 ≤ 60 kPa; The Young's modulus of the third segment is M3, where 30 kPa ≤ M3 ≤ 50 kPa.

6. The optical adhesive according to claim 1, characterized in that, The first segment comprises a polyurethane block copolymer, wherein the mass percentage of the polyurethane block copolymer in the first segment is B1, and 8 wt% ≤ B1 ≤ 12 wt%; And / or, the second segment includes nano-silica, wherein the mass percentage of nano-silica in the second segment is B2, 12 wt% ≤ B2 ≤ 18 wt%.

7. A display panel, characterized in that, Includes the optical adhesive as described in any one of claims 1-6.

8. The display panel according to claim 7, characterized in that, It also includes a cover plate disposed on one side of the optical adhesive along its thickness direction, the thickness direction intersecting the first direction; the cover plate includes a first sub-region and a second sub-region located on both sides of the first sub-region along the first direction, the first sub-region being disposed corresponding to the first sub-segment in the thickness direction, and at least a portion of the structure of the second sub-region being disposed corresponding to the second sub-segment in the thickness direction; The thickness of the cover plate in the second sub-region is not greater than the thickness of the cover plate in the first sub-region.

9. The display panel according to claim 8, characterized in that, The cover plate includes a first surface facing the optical adhesive, the first surface including a first sub-surface and a second sub-surface located on both sides of the first sub-surface along the first direction, the first sub-surface being disposed corresponding to the first sub-segment in the thickness direction, and at least a portion of the structure of the second sub-surface being disposed corresponding to the second sub-segment in the thickness direction; The surface roughness of the first sub-face is greater than that of the second sub-face.

10. The display panel according to claim 7, characterized in that, It also includes a first functional layer disposed on one side of the optical adhesive along its thickness direction. The first functional layer includes a first trace area and a second trace area located on both sides of the first trace area along the first direction. The first trace area is disposed corresponding to the first sub-segment in the thickness direction, and at least a portion of the structure of the second trace area is disposed corresponding to the second sub-segment in the thickness direction. The first wiring area includes a plurality of first wiring sections arranged at intervals, and the second wiring area includes a plurality of second wiring sections arranged at intervals. The spacing between two adjacent second wiring portions is not greater than the spacing between two adjacent first wiring portions, and / or the width of the second wiring portion is not greater than the width of the first wiring portion.

11. The display panel according to claim 7, characterized in that, The optical adhesive includes a first adhesive layer and a second adhesive layer, and the display panel further includes a first functional layer and a cover plate. The first adhesive layer, the first functional layer, the second adhesive layer and the cover plate are stacked sequentially along the thickness direction. The first segment in the first adhesive layer has a greater extension dimension in the first direction than the first segment in the second adhesive layer has in the first direction.

12. The display panel according to claim 7, characterized in that, The optical adhesive further includes a third segment, which is connected between the first segment and the second segment along the first direction. The Young's modulus of the third segment is not less than the Young's modulus of the first segment, and the Young's modulus of the third segment is not greater than the Young's modulus of the second segment. The display panel further includes a cover plate disposed on one side of the optical adhesive along its thickness direction, wherein the edge of the cover plate in the first direction coincides with the edge of the second sub-segment away from the first sub-segment.

13. A method for preparing an optical adhesive, characterized in that, include: A first gelatinous substance and a second gelatinous substance are formed, wherein the Young's modulus of the first gelatinous substance is less than that of the second gelatinous substance; The first gel and the second gel are loaded into a coating device, which includes a first coating head and a second coating head that are independent of each other. The first coating head is used to coat the first gel and the second coating head is used to coat the second gel. A coating layer is formed, wherein the first coating head and the second coating head apply the coating in sections along a first direction, and the first adhesive material and the second adhesive material are arranged side by side along the first direction; An optical adhesive is formed, the first adhesive material is cured to form the first segment, the second adhesive material is cured to form the second segment, and the first segment and the second segment form the optical adhesive.

14. The method for preparing the optical adhesive according to claim 13, characterized in that, The formation of the first and second gels also includes the formation of a third gel, wherein the Young's modulus of the third gel is not less than the Young's modulus of the first gel and the Young's modulus of the third gel is not greater than the Young's modulus of the second gel. The process of loading the first and second adhesive materials into the coating equipment further includes loading the third adhesive material into the coating equipment. The coating equipment includes a third coating head independent of the first and second coating heads, and the third coating head is used to coat the third adhesive material. In the formation of the adhesive coating layer, the third coating head coats the third adhesive between the first adhesive and the second adhesive along the first direction; In the formation of the optical adhesive layer, the third adhesive material is cured to form a third segment, and the first segment, the third segment, and the second segment form the optical adhesive. The first adhesive material is cured by irradiating it with ultraviolet light to form a first segment, the second adhesive material is cured by irradiating it with ultraviolet light to form a second segment, and the third adhesive material is cured by irradiating it with ultraviolet light to form a third segment. The intensity of ultraviolet light irradiating the first gel is less than the intensity of ultraviolet light irradiating the second gel. Along the first direction from the first gel to the side of the second gel, the intensity of ultraviolet light irradiating the third gel gradually increases.

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