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CN-117445521-B - Flexible cover plate, preparation method thereof and display device

CN117445521BCN 117445521 BCN117445521 BCN 117445521BCN-117445521-B

Abstract

The application provides a flexible cover plate, a preparation method thereof and a display device, wherein the flexible cover plate comprises at least two substrate layers, and the elastic modulus of the substrate layer close to the bending inner side of the flexible cover plate is larger than that of the substrate layer far away from the bending inner side of the flexible cover plate, so that the bending performance of the substrate layer far away from the bending inner side of the flexible cover plate is better than that of the substrate layer close to the bending inner side of the flexible cover plate, the surface hardness and the impact resistance of the substrate layer close to the bending inner side of the flexible cover plate are better than those of the substrate layer far away from the bending inner side of the flexible cover plate, and when the flexible cover plate is attached to the display panel, the substrate layer with relatively lower elastic modulus in the flexible cover plate is arranged at the bending outer side of the display device, and the substrate layer with relatively higher elastic modulus is arranged at the bending inner side of the display device, so that the bending performance and the surface hardness of a display device are considered.

Inventors

  • CHEN YONGSHENG

Assignees

  • 武汉华星光电半导体显示技术有限公司

Dates

Publication Date
20260512
Application Date
20230217

Claims (14)

  1. 1. The flexible cover plate is characterized by comprising at least two base material layers, wherein in the two adjacent base material layers, the elastic modulus of the base material layer close to the inner side of the flexible cover plate is larger than that of the base material layer far away from the inner side of the flexible cover plate, the repeated structural units of the corresponding materials of the base material layers are the same, and the polymerization degree of the corresponding materials of the base material layer close to the inner side of the flexible cover plate is larger than that of the corresponding materials of the base material layer far away from the inner side of the flexible cover plate.
  2. 2. The flexible cover sheet of claim 1, wherein, of the two adjacent substrate layers, the substrate layer adjacent to the inside of the bend of the flexible cover sheet is in direct contact with the substrate layer further from the inside of the bend of the flexible cover sheet.
  3. 3. The flexible cover sheet according to claim 1, wherein when the bending direction of the flexible cover sheet is inward, the flexible cover sheet further includes a hardened layer, the hardened layer is disposed on a side of the substrate layer near the inside of the bend of the flexible cover sheet, and an elastic modulus of the hardened layer is greater than an elastic modulus of the substrate layer near the inside of the bend of the flexible cover sheet.
  4. 4. The flexible cover sheet according to claim 1, wherein when the bending direction of the flexible cover sheet is an outward bending, the flexible cover sheet further comprises a hardening layer, the hardening layer is disposed on a side of the substrate layer away from the bending inner side of the flexible cover sheet, which is away from the bending inner side of the flexible cover sheet, and the elastic modulus of the hardening layer is greater than the elastic modulus of the substrate layer near the bending inner side of the flexible cover sheet.
  5. 5. The flexible cover sheet of claim 1, wherein the elastic modulus of the plurality of substrate layers increases in a direction from the outside of the bend of the flexible cover sheet to the inside of the bend of the flexible cover sheet when the flexible cover sheet is in the bent state.
  6. 6. The flexible cover sheet of claim 5, wherein the adjacent substrate layers have a difference in modulus of elasticity in the range of less than or equal to 100 megapascals.
  7. 7. The flexible cover sheet of claim 1, wherein the substrate layer distal to the flexible cover sheet has a modulus of elasticity greater than or equal to 4 gigapascals of the inside of the bend.
  8. 8. The flexible cover sheet of claim 1, wherein the substrate layer has a thickness of greater than or equal to 10 microns.
  9. 9. The flexible cover sheet of claim 1, wherein the flexible cover sheet has a thickness in the range of 20 microns to 200 microns.
  10. 10. A method for producing a flexible cover sheet according to any one of claims 1 to 9, comprising: putting polyethylene terephthalate particles with different molecular weights into different feed inlets, and enabling the polyethylene terephthalate particles with different molecular weights to flow into the same casting plate from different flow channels after being melted; and stretching and cooling the melted polyethylene terephthalate to obtain the flexible cover plate.
  11. 11. The method of making a flexible cover sheet according to claim 10 wherein the substrate layer proximate the inside of the bend of the flexible cover sheet has an average molecular weight greater than the average molecular weight of the substrate layer distal the inside of the bend of the flexible cover sheet.
  12. 12. A display device, comprising: a display panel; The flexible cover plate can be bent along a bending line, the flexible cover plate is arranged on one side of the display panel, the flexible cover plate comprises at least two layers of substrate layers, the elastic modulus of the substrate layer close to the bending inner side of the flexible cover plate is larger than that of the substrate layer far away from the bending inner side of the flexible cover plate in two adjacent substrate layers, and the repeated structural units of the corresponding materials of the substrate layers are the same; And the bonding layer is arranged between the display panel and the flexible cover plate.
  13. 13. The display device according to claim 12, wherein the base material layer far from the inside of the bend of the flexible cover plate is disposed between the display panel and the base material layer near the inside of the bend of the flexible cover plate when the bending direction of the display device is inward.
  14. 14. The display device according to claim 12, wherein the base material layer near the inside of the bend of the flexible cover plate is disposed between the display panel and the base material layer far from the inside of the bend of the flexible cover plate when the bending direction of the display device is an outside bend.

Description

Flexible cover plate, preparation method thereof and display device Technical Field The application relates to the technical field of display, in particular to a flexible cover plate, a preparation method thereof and a display device. Background Organic Light-Emitting Diode (OLED) display devices are widely used due to their high Light emission luminance, wide viewing angle, fast response speed, ultra-thin, light weight, and realizable flexibility. In order to achieve flexibility of the OLED display device, in addition to adopting a flexible design for the display panel, a flexible cover plate needs to be selected as the cover plate of the OLED display device. The conventional flexible cover plate comprises an organic substrate layer and a hardening coating, when the thickness of the flexible cover plate is low, the bending performance of the flexible cover plate is good, but the surface hardness and the impact resistance are poor, when the thickness of the flexible cover plate is high, the surface hardness and the impact resistance of the flexible cover plate are good, but the bending performance of the flexible cover plate is poor, so that each film layer in the flexible cover plate is broken due to overlarge internal stress in the repeated bending process. Therefore, the existing flexible cover plate has the technical problem that the bending performance and the surface hardness cannot be simultaneously achieved. Disclosure of Invention The embodiment of the application provides a flexible cover plate, a preparation method thereof and a display device, which are used for solving the technical problem that the bending performance and the surface hardness of the conventional flexible cover plate cannot be considered. The embodiment of the application provides a flexible cover plate, which can be bent along a bending line, and comprises at least two substrate layers, wherein in the adjacent two substrate layers, the elastic modulus of the substrate layer close to the bending inner side of the flexible cover plate is larger than that of the substrate layer far away from the bending inner side of the flexible cover plate, and the repeated structural units of corresponding materials of the substrate layers are the same. In some embodiments, the degree of polymerization of the substrate layer counterpart material proximate to the inside of the bend of the flexible cover sheet is greater than the degree of polymerization of the substrate layer counterpart material distal to the inside of the bend of the flexible cover sheet. In some embodiments, of the two adjacent substrate layers, the substrate layer proximate to the inside of the bend of the flexible cover sheet is in direct contact with the substrate layer distal to the inside of the bend of the flexible cover sheet. In some embodiments, when the bending direction of the flexible cover plate is inward, the flexible cover plate further includes a hardening layer, the hardening layer is disposed on a side of the substrate layer near the bending inner side of the flexible cover plate, and an elastic modulus of the hardening layer is greater than an elastic modulus of the substrate layer near the bending inner side of the flexible cover plate. In some embodiments, when the bending direction of the flexible cover plate is outward, the flexible cover plate further includes a hardening layer, the hardening layer is disposed on a side of the substrate layer away from the bending inner side of the flexible cover plate, the side of the substrate layer away from the bending inner side of the flexible cover plate, and the elastic modulus of the hardening layer is greater than the elastic modulus of the substrate layer close to the bending inner side of the flexible cover plate. In some embodiments, when the flexible cover plate is in a bent state, the elastic modulus of the substrate layers increases in multiple layers along the direction from the outside of the bend of the flexible cover plate to the inside of the bend of the flexible cover plate. In some embodiments, the difference in elastic modulus of adjacent substrate layers ranges from less than or equal to 100 megapascals. In some embodiments, the elastic modulus of the substrate layer distal to the folded inner side of the flexible cover sheet is greater than or equal to 4 gigapascals. In some embodiments, the substrate layer has a thickness greater than or equal to 10 microns. In some embodiments, the flexible cover plate has a thickness in the range of 20 microns to 200 microns. Meanwhile, an embodiment of the present application provides a method for preparing a flexible cover plate, where the method for preparing a flexible cover plate according to any one of the above embodiments includes: putting polyethylene terephthalate particles with different molecular weights into different feed inlets, and enabling the polyethylene terephthalate particles with different molecular weights to flow into the same casti