Protective film for display screen and display device

Abstract

The invention provides a protective film for a display screen and a display device. The protective film comprises: a protective film substrate; the adhesive layer is located on one side of the protective film base material, the adhesive layer comprises a main body adhesive material and polymer spheres, the polymer spheres are dispersed in the main body adhesive material, and the polymer spheres can expand with heat and contract with cold. Therefore, the adhesive layer has better adhesive property at normal temperature, so that the protective film can be firmly attached to the display screen, and the effect of protecting the display screen is achieved; under the heating condition, the polymer sphere expands to reduce the contact area between the main body adhesive material and the protective film base material, so that the viscosity of the adhesive layer is reduced, the difficulty of tearing the protective film is obviously reduced, adhesive pulling and adhesive residue are not easily generated in the film tearing process, and after the temperature is reduced to normal temperature, the polymer sphere shrinks, the viscosity of the adhesive layer can be recovered, and the service life of the protective film is prolonged. And the film can be attached to the display screen again.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a protective film for a display screen and a display device. Background Art

[0002] At present, compared with candy-bar phones, the car-mounted curved module is larger in size and heavier in weight. When using conventional low-viscosity protective film, it is easy to fall off during transportation in the factory due to the excessive weight. Therefore, high-viscosity protective film is needed for protection during the production or transportation of large-size screens. The use of high-viscosity protective film can completely conform to the surface of CG (Cover Glass), which plays a good protective role. Usually, in order to protect the CG, the protective film will be applied after the CG is applied, and there will be a series of subsequent processes such as optical compensation, appearance inspection, and functional inspection; these processes require tearing off the protective film. The adhesive material of the high-viscosity protective film is very sticky, which makes it difficult to tear off the high-viscosity protective film. The tearing process is prone to glue pulling and residual glue, making it impossible to reuse. At the same time, due to its large size and high viscosity, the stress at the starting point of the tearing process is too high, which can easily cause the protective film to tear. In addition, the adhesive surface is easily sticky and dirty after multiple tearing, resulting in reduced viscosity, making it difficult to attach later and impossible to produce corresponding production. Currently, factories usually replace the film before shipment, which means that each module needs to use two protective films, which greatly increases the cost.

[0003] Therefore, current display screen protective films and display devices still need to be improved. Summary of the Invention

[0004] The present invention aims to alleviate or even solve one of the technical problems in the related art at least to a certain extent.

[0005] In one aspect of the present invention, the present invention proposes a protective film for a display screen. In some embodiments of the present invention, the protective film includes: a protective film substrate; an adhesive layer, the adhesive layer is located on one side of the protective film substrate, the adhesive layer includes a main adhesive material and polymer spheres, the polymer spheres are dispersed in the main adhesive material, and the polymer spheres can expand and contract with heat and cold. As a result, the adhesive layer has good bonding properties at room temperature, so that the protective film can be firmly attached to the display screen, playing a role in protecting the display screen; under heating conditions, the polymer spheres will expand, reducing the contact area between the main adhesive material and the protective film substrate, thereby reducing the viscosity of the adhesive layer, making it significantly easier to tear off the protective film, and it is not easy to produce glue pulling and residual glue during the tearing process. After the temperature drops to room temperature, the polymer spheres will shrink, and the viscosity of the adhesive layer can be restored, and it can be attached to the display screen again.

[0006] In some embodiments of the present invention, the polymer sphere includes a shell and an organic material encapsulated within the shell. The shell comprises an acrylic polymer, the organic material has a boiling point of 60°C or less, and is liquid at room temperature. As a result, the organic material within the shell can transition from liquid to gaseous state under heating, allowing the shell to undergo elastic deformation. As the organic material expands or contracts with heat, the shell can expand or contract with the state of the organic material within, thereby varying the bond strength between the adhesive layer and the display screen as needed.

[0007] In some embodiments of the present invention, the organic matter includes ethers.

[0008] In some embodiments of the present invention, the main adhesive material includes at least one of acrylic adhesive, polyurethane, and silicone. These materials have good adhesive properties, which are conducive to firmly adhering the protective film to the display screen.

[0009] In some embodiments of the present invention, the mass ratio of the main adhesive material to the polymer spheres is 7:3 to 8:2. This helps improve the adhesive layer's bonding performance at room temperature; under heated conditions, the adhesive layer's bonding strength to the display screen decreases significantly, facilitating film removal.

[0010] In some embodiments of the present invention, the adhesive layer is rectangular or chamfered.

[0011] In some embodiments of the present invention, the adhesive layer is attached near an edge of the protective film substrate.

[0012] In some embodiments of the present invention, the longest side of the adhesive layer is ≥20 mm.

[0013] In some embodiments of the present invention, the thickness of the adhesive layer is ≥25 μm.

[0014] In some embodiments of the present invention, the peeling force of the adhesive layer at room temperature is ≥100 gf / inch.

[0015] In some embodiments of the present invention, the protective film substrate includes at least one of polyethylene terephthalate and polyimide.

[0016] In some embodiments of the present invention, the thickness of the protective film substrate is ≥50 μm.

[0017] In another aspect, the present invention provides a display device. In some embodiments, the display device includes a display screen and the aforementioned protective film, with the adhesive layer of the protective film attached to the display surface of the display screen. Thus, the display device possesses all the features and advantages of the aforementioned protective film, which will not be further elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a protective film according to an embodiment of the present invention is shown;

[0019] Figure 2 A schematic structural diagram of a protective film according to another embodiment of the present invention is shown;

[0020] Figure 3 A schematic structural diagram of a protective film according to another embodiment of the present invention is shown;

[0021] Figure 4 It shows a schematic structural diagram of a glue layer according to one embodiment of the present invention;

[0022] Figure 5 A schematic structural diagram of a polymer sphere according to an embodiment of the present invention is shown;

[0023] Figure 6 It shows a schematic structural diagram of a glue layer according to one embodiment of the present invention;

[0024] Figure 7 Shows the schematic diagram of the structure of the adhesive layer and the object being adhered at room temperature;

[0025] Figure 8 Shows the schematic diagram of the structure of the adhesive layer and the object being adhered under high temperature conditions;

[0026] Figure 9 shows a schematic planar structural diagram of a protective film according to one embodiment of the present invention;

[0027] Figure 10 shows a schematic planar structural diagram of a protective film according to another embodiment of the present invention;

[0028] Figure 11 FIG. 1 is a schematic structural diagram of a display device according to an embodiment of the present invention.

[0029] Description of reference numerals:

[0030] 100: protective film; 110: protective film substrate; 120: adhesive layer; 121: main adhesive material; 122: polymer sphere; 130: film tearing handle; 200: display screen; 1: object to be adhered; 2: heat source; 3: shell; 4: organic matter; 5: main cross-linking chain; 6: photoinitiator; 7: antistatic ion. DETAILED DESCRIPTION

[0031] The following embodiments of the present invention are described in detail. The embodiments described below are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in the art or in the product specifications shall be followed.

[0032] In one aspect of the present invention, a protective film for a display screen is provided. Figures 1 to 6 In some embodiments of the present invention, the protective film 100 may include a protective film substrate 110 and an adhesive layer 120, wherein the adhesive layer 120 is located on one side of the protective film substrate 110. Figure 4 The adhesive layer may include a main adhesive material 121 and polymer spheres 122. The polymer spheres 122 are dispersed in the main adhesive material 121, and the polymer spheres 122 can expand and contract with heat and cold. As a result, the polymer spheres in the adhesive layer can expand and contract with heat. At room temperature, the volume of the polymer spheres is relatively small. When the protective film is attached to the display screen, there is a strong bonding effect between the main adhesive material and the display screen. The adhesive layer can be firmly attached to the display screen, which plays a good role in protecting the display screen. During transportation, the display screen is not easy to fall off. Under heating conditions, the volume of the polymer spheres increases, and the bonding force between the adhesive layer and the display screen decreases. The protective film can be torn off from the display screen with a small external force. In addition, it is not easy to cause problems such as glue pulling and residual glue. After repeated tearing, the surface of the adhesive layer is not easy to get dirty. After the temperature drops to room temperature, the adhesive layer can maintain good adhesion.

[0033] In some embodiments of the present invention, reference Figure 1 , the adhesive layer 120 can be attached to the edge of the protective film substrate 110. In other embodiments of the present invention, refer to Figure 2 , the adhesive layer 120 can cover most of the surface of the protective film substrate 110. In other embodiments of the present invention, refer to Figure 3 , the adhesive layer 120 can cover one surface of the protective film substrate 110 .

[0034] In some embodiments of the present invention, reference Figure 5 and Figure 6 The polymer sphere 122 may include a shell 3 and an organic substance 4 encapsulated in the shell. The shell 3 may include an acrylic polymer. The boiling point of the organic substance 4 is less than or equal to 60°C, and the organic substance is liquid at room temperature. As a result, the organic substance in the shell remains liquid at room temperature, and the volume of the polymer sphere is relatively small. The shell can be elastically deformed. After the temperature rises to the boiling point of the organic substance, the organic substance becomes gaseous. The shell can expand as the volume of the internal organic substance increases, and the volume of the polymer sphere increases. When the film needs to be torn off, the adhesive layer can be heated to the boiling point of the organic substance. The temperature does not need to be too high. The polymer sphere expands, and the bonding strength between the adhesive layer and the display screen will be significantly reduced, making it easier to tear off the protective film.

[0035] It should be noted that, in the present invention, normal temperature may refer to 20°C to 25°C.

[0036] In some embodiments of the present invention, the organic matter 4 within the housing 3 may include ethers. Ethers have a low boiling point and can be gaseous at temperatures between 50°C and 60°C. This causes the polymer spheres 122 to transform from liquid to gas under heating conditions, expanding in volume. This increases the volume of the housing 3, thereby reducing the bond strength between the adhesive layer 120 and the display screen. This makes it easier to peel the protective film 100 from the display screen, reducing the risk of adhesive residue or adhesive pull-off.

[0037] In some embodiments of the present invention, at room temperature, the diameter of the polymer sphere may be less than or equal to 5 microns.

[0038] In some embodiments, the diameter of the polymer spheres may increase by 0.5 to 1 times from room temperature to high temperature.

[0039] In some embodiments of the present invention, the main adhesive material 121 may be a pressure-sensitive adhesive.

[0040] In some embodiments of the present invention, the main adhesive material 121 may include at least one of acrylic adhesive, polyurethane, and silicone. In some specific embodiments of the present invention, the main adhesive material 121 may include acrylic adhesive, polyurethane, or silicone. In other specific embodiments of the present invention, the main adhesive material 121 may include two or three of acrylic adhesive, polyurethane, and silicone. These adhesive materials have a certain degree of viscosity and can adhere to the surface of the display screen at room temperature, thereby protecting the display screen.

[0041] In some specific embodiments of the present invention, the shell of the polymer sphere may include an acrylic polymer, and the main adhesive material in the adhesive layer may include acrylic adhesive. The polymer sphere has good compatibility with the adhesive layer, which facilitates adjustment of the mass ratio of the main adhesive material and the polymer sphere in the adhesive layer, thereby preparing the adhesive layer as needed.

[0042] In some embodiments of the present invention, the internal molecular structure of the adhesive layer 120 can be referred to Figure 6 The adhesive layer 120 may include a main adhesive material 121 and polymer spheres 122 . The polymer spheres 122 are dispersed in the main adhesive material 121 . The main adhesive material 121 may include a main cross-linking chain 5 , a photoinitiator 6 and an antistatic ion 7 .

[0043] In some embodiments of the present invention, the main cross-linking chain 5 may include one or more of an acrylic main cross-linking chain, a polyurethane main cross-linking chain, and a silicone main cross-linking chain.

[0044] In some specific embodiments of the present invention, the main cross-linked chain 5 may be an acrylic acid main cross-linked chain.

[0045] In some embodiments of the present invention, the photoinitiator 6 may include initiators such as benzoin derivatives and hydroxyketones.

[0046] In some embodiments of the present invention, the antistatic ions 7 may include fluoride ions. Fluoride ions can have a certain degree of antistatic effect. Adding fluoride ions to the adhesive layer can improve the antistatic effect of the adhesive layer, making the protective film more suitable for use as a protective film for display devices.

[0047] The adhesive layer can change its viscosity at different temperatures. The following is a detailed description of the state changes between the adhesive layer and the object being adhered, combined with the accompanying drawings. Figure 7 Under normal temperature conditions, the multiple polymer spheres 122 in the adhesive layer are evenly dispersed in the main adhesive material 121, the organic matter in the polymer spheres 122 remains liquid, the volume of the polymer spheres is small, and the adhesive layer 120 can be firmly bonded to the object 1. Figure 8 Heat source 2 is used to heat adhesive layer 120, for example, to a specific temperature (e.g., approximately 50°C to 60°C). The organic matter in polymer spheres 122 transforms from liquid to gas, causing the volume to expand. The shell undergoes elastic deformation, increasing its volume. The volume occupied by the polymer spheres in the adhesive layer increases, causing the contact area between the adhesive layer and the surface of the adhered object 1 to decrease or even separate. This reduces the bonding strength between the adhesive layer and the adhered object, making it easier to remove from the adhered object 1. After cooling from a higher temperature to room temperature, the organic matter in the shell transforms from gas to liquid. The shell volume decreases as the organic matter changes state, and the polymer spheres return to their original size. The adhesive layer can regain its high viscosity and be reattached to the adhered object, maintaining a strong bond.

[0048] The protective film can be pasted on a display screen, with the adhesive layer located between the protective film substrate and the display screen. Under normal temperature conditions, the polymer spheres are relatively small in size, and the bonding strength between the adhesive layer and the display screen is relatively high. During factory transfer or other transportation processes, the protective film can protect the display screen. When performing appearance inspections and lighting inspections, the protective film needs to be torn off. The adhesive layer can be heated by a heat source. At this time, the polymer spheres in the adhesive layer will expand in volume under heating conditions, and the bonding strength between the adhesive layer and the display screen will decrease, making it easier to tear the adhesive layer off the display screen. Furthermore, it is less likely to cause glue pull or residual glue, and it is less likely to get dirty after multiple tearings. After cooling from high temperature to low temperature, the viscosity can be restored. This design can increase the number of times the protective film can be reused, and can also reduce the risk of getting dirty, thereby enabling a film to be used from production to shipment without the need to change the film before leaving the factory, thereby reducing costs.

[0049] In some embodiments of the present invention, the mass ratio of the main adhesive material 121 to the polymer spheres 122 in the adhesive layer 120 can be 7:3 to 8:2. For example, the mass ratio of the main adhesive material 121 to the polymer spheres 122 can be 7:3, 7.2:2.8, 7.5:2.5, 7.8:2.2, or 8:2. As a result, at room temperature, the adhesive layer has high bonding properties and can firmly adhere to the display screen, thereby allowing the protective film to better protect the display screen.

[0050] In some embodiments of the present invention, the polymer spheres can be directly mixed with the raw materials forming the main adhesive material during the preparation process of the main adhesive material. For example, the raw materials of acrylic adhesive (such as acrylic polymer monomers, photoinitiators, antistatic materials, etc.), polyurethane raw materials or silicone raw materials can be mixed with the polymer spheres in a mass ratio of 7:3 to 8:2. After curing, an adhesive layer with strong bonding effect at room temperature is formed.

[0051] In some embodiments of the present invention, the peeling force of the adhesive layer 120 at room temperature may be ≥100 gf / inch (gram-force / inch).

[0052] In some embodiments of the present invention, the peeling force of the adhesive layer 120 at room temperature can be 100 gf / inch or greater than 100 gf / inch. Under heating conditions (for example, heated to 50°C to 60°C), the peeling force of the adhesive layer 120 can be reduced to ≤3 gf / inch, making it easier to tear off.

[0053] In the present invention, the peeling force of the adhesive layer can be tested using methods commonly used in the art. In some embodiments, a 25 mm wide and 100 mm long adhesive layer sample can be used to test the peeling force.

[0054] In some embodiments of the present invention, reference Figure 9 and Figure 10 The protective film may further include a tearing handle 130 , thereby making it convenient to apply force to the tearing handle 130 to tear off the protective film when needed.

[0055] In some specific embodiments of the present invention, reference Figure 9 and Figure 10 The protective film may have a tear-off handle 130. In other specific embodiments of the present invention, the protective film may have two tear-off handles 130. The present invention does not specifically limit the specific material and size of the tear-off handles. Those skilled in the art can select the material of the tear-off handles for the protective film and adjust the size of the tear-off handles as needed.

[0056] In some embodiments of the present invention, reference Figure 9 and Figure 10, the adhesive layer 120 can be attached to the edge of the protective film substrate 110. Therefore, the protective film adopts a hollow pasting method, and the horizontal edge of the adhesive layer 120 (with the edge of the protective film substrate 110) is Figure 9 and Figure 10 The middle tear film handle 130 (an edge parallel to the long side) is attached to the upper and lower edges of the protective film substrate 110, and the vertical edge of the adhesive layer 120 (an edge perpendicular to the horizontal edge) is attached to the left and right edges of the protective film substrate 110. With this design, the protective film body only has a substrate and no adhesive layer, which can minimize the contact area between the protective film and the display screen, thereby reducing the probability of residual adhesive and adhesive pulling. The smaller area of the adhesive layer can further reduce the risk of stickiness and dirt.

[0057] In some embodiments of the present invention, reference Figure 9 The adhesive layer 120 can be chamfered. The protective film 100 can include four adhesive layers 120, each located near the edge of the four corners of the protective film substrate 110. The chamfered adhesive layer 120 can provide a bonding effect and reduce the probability of adhesive pulling and residual adhesive during tearing.

[0058] In some embodiments of the present invention, reference Figure 10 The adhesive layer 120 may be rectangular. The adhesive layer 120 may be rectangular. A rectangular adhesive layer may have a better bonding effect. In some specific embodiments, the adhesive layer 120 may be square.

[0059] In some specific embodiments of the present invention, reference Figure 9 and Figure 10 The longest side L of the adhesive layer 120 can be ≥ 20 mm. For example, the longest side L of the adhesive layer 120 can be 20 mm, 22 mm, 23 mm, 25 mm, etc. Thus, the adhesive layer can firmly bond the protective film substrate and the display screen, so that the protective film can protect the display screen at room temperature.

[0060] In some embodiments of the present invention, the thickness of the adhesive layer 120 may be ≥ 25 μm. For example, the thickness of the adhesive layer 120 may be 25 μm, 26 μm, 28 μm, 30 μm, etc. When the thickness of the adhesive layer is within the above range, it is beneficial to improve the bonding strength between the adhesive layer and the display screen, thereby further improving the protective effect of the protective film.

[0061] In some embodiments of the present invention, the protective film substrate 110 may comprise at least one of polyethylene terephthalate (PET) and polyimide (PI). In some specific embodiments, the protective film substrate 110 may be a PET film layer. In other specific embodiments, the protective film substrate 110 may be a PI film layer. These materials are relatively inexpensive and provide good protection.

[0062] In some embodiments of the present invention, the thickness of the protective film substrate 110 may be ≥ 50 μm. For example, the thickness of the protective film substrate 110 may be 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, etc. A thickness of the protective film substrate within the above range is beneficial to improving the protective effect of the protective film.

[0063] In general, the protective film proposed by the present invention can play a role in protecting the display screen during factory transshipment or other transportation processes; and, by heating, the bonding strength between the adhesive layer and the display screen can be reduced, making it easy to tear the protective film from the display screen. During the film tearing process, it is not easy to produce glue pulling, residual glue, etc., and the stress at the starting point of the film tearing is not too large, thereby reducing the risk of the protective film tearing. The protective film can achieve the effect of increasing viscosity and reducing viscosity. It is not easy to produce glue pulling, residual glue, and tearing problems after multiple film tearing. It can be reused. There is no need to replace the protective film when the display device is shipped, which is conducive to reducing costs. The protective film can be used to protect larger-sized vehicle-mounted display screens, and is particularly suitable for protecting vehicle-mounted curved display screens.

[0064] In another aspect of the present invention, the present invention provides a display device. Figure 11 The display device includes a display screen 200 and the aforementioned protective film 100, and the adhesive layer 120 of the protective film 100 is attached to the display surface of the display screen 200. Therefore, the display device has all the features and advantages of the aforementioned protective film, which will not be repeated here.

[0065] In some embodiments, the display device may include a display backplane, a light-emitting component, an encapsulation layer, and the like.

[0066] In some embodiments, the display device may include a polarizer, and the protective film may be attached to the polarizer.

[0067] In some embodiments, the display device may include a cover plate, which may be a glass cover plate, a transparent polyimide (CPI) cover plate, UFG (Ultra Flexible Glass), etc. In some embodiments, the display device may include a cover plate, and the protective film may be attached to the cover plate.

[0068] In some embodiments of the present invention, the display screen 200 may be a flat display screen, and the adhesive layer may be attached to the entire light emitting surface of the flat display screen.

[0069] In other embodiments of the present invention, the protective film may have four adhesive layers, and the adhesive layers may be attached to the four corners of the flat display screen. The adhesive layers may be rectangular or chamfered.

[0070] In some embodiments of the present invention, reference Figure 11Display screen 200 may be a curved display screen. In some specific embodiments, adhesive layer 120 may be attached to the flat portion of the curved display screen. In other specific embodiments of the present invention, adhesive layer 120 may be attached to the interface between the curved and flat portions of the curved display screen. In other specific embodiments of the present invention, adhesive layer 120 may be attached to the curved portion of the curved screen. In the present invention, the adhesive layer of the protective film can be well adhered to the curved portion, thereby achieving the purpose of protecting the display screen.

[0071] In some embodiments, the size of the curved display screen can be a 16-inch display screen, and the protective film can have four adhesive layers, each with a longest side ≥ 20 mm, which are respectively attached to the four corners of the flat part of the curved display screen, and can be attached to the flat part.

[0072] For display screens larger than 16 inches, the size of the adhesive layer can be appropriately increased to meet the needs of protecting large-size display screens.

[0073] In some embodiments of the present invention, the protective film can be used to protect the display device. There are no special requirements for the specific type of the above-mentioned display device. Those skilled in the art can flexibly choose according to actual needs. For example, it can be a display device such as a mobile phone, iPad, notebook, etc. Those skilled in the art will understand that the display device may include a display screen, and the protective film can be attached to the light-emitting surface of the display screen. In some embodiments of the present invention, in addition to the display screen and the protective film, the display device also has the necessary structures and components of a conventional display device. Taking a mobile phone as an example, in addition to the display screen and the protective film mentioned above, the display device also includes the necessary structures and components such as the battery back cover, the middle frame, the touch panel, the audio module, and the mainboard.

[0074] The present application will be described below by specific examples, and it will be appreciated by those skilled in the art that the following specific examples are merely for illustrative purposes and are not intended to limit the scope of the present application in any way. In addition, in the following examples, unless otherwise specified, the materials and equipment employed are all commercially available. If, in the following examples, specific processing conditions and treatment methods are not clearly described, then conditions and methods well known in the art may be used to process.

[0075] Example 1

[0076] The raw materials of acrylic adhesive and polymer spheres (commercially available) are mixed in a mass ratio of 7:3. After curing, an adhesive layer with strong bonding effect at room temperature is formed.

[0077] In Example 1, the protective film includes a protective film substrate and the above-mentioned adhesive layer. The protective film substrate is PET with a thickness of 50 μm, and the adhesive layer has a thickness of 25 μm.

[0078] Comparative Example 1

[0079] The difference from Example 1 is that no polymer spheres are added to the glue layer in Comparative Example 1.

[0080] Testing the peel force of the adhesive layers of Example 1 and Comparative Example 1 revealed that at 20°C, both exhibited peel forces exceeding 100 gf / inch. When heated to 60°C, the peel force of the protective film of Comparative Example 1 was higher, with a contamination rate of approximately 20%. However, the adhesive layer of Example 1 exhibited lower peel force after heating, with a contamination rate of less than 1%. This demonstrates that the addition of polymer spheres makes the protective film easier to peel under heated conditions and less susceptible to contamination.

[0081] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0082] In the description of this specification, the reference terms "one embodiment", "another embodiment", "some embodiments", "some specific embodiments" or "some other specific embodiments" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0083] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A protective film for a display screen, characterized in that: include: Protective film substrate; The adhesive layer is located on one side of the protective film substrate. The adhesive layer includes a main adhesive material and polymer spheres. The polymer spheres are dispersed in the main adhesive material and can expand and contract with heat and cold.

2. The protective film according to claim 1, wherein The polymer sphere includes a shell and an organic substance coated in the shell. The shell includes an acrylic polymer. The boiling point of the organic substance is less than or equal to 60° C., and the organic substance is liquid at room temperature.

3. The protective film according to claim 2, characterized in that The organic matter includes ethers.

4. The protective film according to claim 1, wherein The main adhesive material includes at least one of acrylic adhesive, polyurethane, and silicone.

5. The protective film according to claim 1, wherein The mass ratio of the main adhesive material to the polymer spheres is 7:3 to 8:

2.

6. The protective film according to claim 1, wherein The adhesive layer is rectangular or chamfered; And / or, the adhesive layer is attached near the edge of the protective film substrate.

7. The protective film according to claim 1, wherein The longest side of the adhesive layer is ≥20mm; And / or, the thickness of the adhesive layer is ≥25 μm.

8. The protective film according to any one of claims 1 to 7, wherein The peeling force of the adhesive layer at room temperature is ≥100 gf / inch.

9. The protective film according to any one of claims 1 to 7, wherein The protective film substrate includes at least one of polyethylene terephthalate and polyimide; And / or, the thickness of the protective film substrate is ≥50 μm.

10. A display device, characterized in that: The invention comprises a display screen and the protective film according to any one of claims 1 to 9, wherein the adhesive layer of the protective film is attached to the display surface of the display screen.

Images