Optical film and performance qualitative evaluation method thereof

Abstract

The invention relates to an optical film and a performance qualitative evaluation method thereof.The optical film comprises a PMMA film and a primer layer which are arranged in a stacked mode, the primer layer is further provided with a first printing area and a second printing area, and the first printing area and the second printing area are both arranged in the extending direction of the primer layer and located on the edges of the two sides of the primer layer in parallel; a first detection area which is adjacent to and parallel to the first printing area is arranged on the primer layer, and / or a second detection area which is adjacent to and parallel to the second printing area is arranged on the primer layer, and the thickness of the first detection area and the thickness of the second detection area are 10-15 nm smaller than the minimum value of the preset thickness range of the primer layer. The arrangement of the first detection area and / or the second detection area is beneficial for simply and conveniently qualitatively evaluating the thickness of the primer layer, so that whether the performance of the optical film reaches the standard or not is judged, and the detection cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and in particular to an optical film and a method for qualitatively evaluating its performance. Background Art

[0002] In modern industrial production and application, polymethyl methacrylate (PMMA) films are widely used in display screens, optical lenses, decorative materials, and many other fields due to their excellent optical properties, weather resistance, and processing capabilities. To facilitate subsequent processing, a primer layer is typically applied to the PMMA film, which acts as a bond between the film and other materials. The thickness of the primer layer directly affects the bonding between the PMMA film and other materials. Different primer thicknesses are designed for different materials. Insufficient primer thickness can significantly reduce the adhesion between the PMMA film and other materials, affecting the product's stability, durability, and service life.

[0003] Current online monitoring technology for the thickness of primer layers applied to PMMA films is complex and expensive. Offline measurement methods require sampling and sending the samples to specialized testing departments for measurement using high-precision methods such as electron microscopy. This process is time-consuming and requires complex sample pre-treatment, significantly impacting production efficiency and posing significant challenges to the continuity and timeliness of the production process.

[0004] Therefore, it is very necessary to develop a convenient and time-saving method to monitor the thickness of primer film. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides an optical film and a method for qualitatively evaluating its performance.

[0006] To achieve the above-mentioned purpose, the present application provides an optical film, including a PMMA film and a primer layer arranged on the PMMA film, the primer layer also being provided with a first printing area and a second printing area, the first printing area and the second printing area being arranged along the extension direction of the primer layer, and being respectively parallel to the two side edges of the primer layer, a first detection area adjacent to and parallel to the first printing area is arranged on the primer layer, and / or a second detection area adjacent to and parallel to the second printing area is arranged on the primer layer, the thickness of the first detection area and the second detection area being 10nm to 15nm smaller than the minimum value of the preset thickness range of the primer layer.

[0007] As a further improvement of the present application, the width of the first detection zone is 5 mm to 10 mm, and the width of the second detection zone is 5 mm to 10 mm.

[0008] As a further improvement of the present application, the horizontal distance between the first detection area and the first printing area is 1 mm to 5 mm, and the horizontal distance between the second detection area and the second printing area is 1 mm to 5 mm.

[0009] As a further improvement of the present application, the width of the printing area accounts for 1% to 5% of the width of the PMMA film.

[0010] As a further improvement of the present application, the width of the first printing area is the same as the width of the second printing area.

[0011] As a further improvement of the present application, the thickness of the PMMA film is 20 μm to 80 μm.

[0012] As a further improvement of the present application, the thickness of the primer layer is 280nm to 600nm.

[0013] As a further improvement of the present application, the primer layer is prepared from water-based polyurethane.

[0014] As a further improvement of the present application, the first printing area, the second printing area, the first detection area and the second detection area are all processed by laser irradiation of the primer layer.

[0015] To achieve the above objectives, the present application also provides a method for evaluating the performance of an optical film based on the above-mentioned optical film, comprising the following steps: S1. Take the optical film to be tested, lay it flat with the primer layer facing upwards; S2, adding a mixture of 50% toluene / anhydrous ethanol dropwise to the first inspection area and / or the second inspection area of the optical film to be inspected, and letting it stand for 30 seconds; S3, removing residual toluene from the first detection area and / or the second detection area; S4. Result Determination: Visually observe the surface morphology of the first and / or second inspection areas to determine whether the thickness of the optical film's base layer meets the requirements, thereby determining the performance of the optical film. If the surface of the first and / or second inspection areas is smooth, without any sag or cracks, the actual thickness of the primer layer of the optical film under test is greater than the preset thickness, and the optical film's performance is acceptable. If the surface of the first and / or second inspection areas is rough, with obvious depressions or holes, the actual thickness of the primer layer of the optical film under test is less than the preset thickness, and the optical film's performance is unacceptable.

[0016] The beneficial effect of the present application is that it provides an optical film, which includes a PMMA film and a primer layer provided on the PMMA film, wherein the primer layer is further processed with a printing area, the printing area being arranged parallel to the extension direction of the primer layer and located at both side edges of the printing layer, and a detection area is further processed on the primer layer adjacent to the printing area on at least one side edge. The above structure is conducive to qualitatively detecting whether the thickness of the primer layer meets the minimum value of the optical film primer layer thickness required by the customer during the production process of the optical film, so as to facilitate the determination of whether the optical film required by the customer has been produced. The provision of the detection area simplifies the primer layer thickness detection procedure and improves the production efficiency of the optical film. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the top view structure of the optical film; Figure 2 is a schematic diagram of the cross-sectional structure of the optical film sample of Example 1; Figure 3 Schematic diagram of the cross-sectional structure of the optical film sample of Example 2.

[0018] In the figure: 10, optical film; 20, primer layer; 30, PMMA film; 1, first printing area; 2, first detection area. DETAILED DESCRIPTION

[0019] As can be seen from the background technology, in order to facilitate the subsequent processing of PMMA film, a primer layer is generally coated on the PMMA film, and the primer layer is used to bond with other materials. The thickness of the primer layer directly affects the bonding performance between the PMMA film and other materials. If the thickness of the primer layer is insufficient, the bonding strength between the PMMA film and other materials will be significantly reduced, thereby affecting the stability, durability and service life of the product.

[0020] According to different customer needs, the thickness of the primer layer applied to the PMMA film is generally set to 280nm~600nm. Common coating methods include wire rod coating, extrusion coating, micro-dimpled coating, etc. Among them: The specific steps of wire rod coating are as follows: 1) Fix the PMMA film substrate to be coated on the workbench; 2) Select the appropriate type of wire rod coater according to the required primer layer thickness; 3) Place the water-based polyurethane primer approximately 1 cm below the coating rod, and the amount to be used should be determined according to the area and thickness to be coated; 4) Hold both ends of the coating rod with both hands and pull the coating rod from one end of the substrate to the other at a constant speed and pressure. Do not rotate the coating rod during the operation to ensure that the paint is evenly coated on the substrate surface and dry.

[0021] The specific steps of extrusion coating are as follows: 1) Install the PMMA film on the unwinding device of the extrusion coater and adjust the tension. At the same time, pour the water-based polyurethane primer into the barrel and adjust the flow rate by controlling the valve to ensure that the paint can be evenly delivered to the coating area; 2) Turn on the power and drive device of the equipment to make the coating roller, pressure roller, etc. start to rotate, and start the extrusion screw at the same time to extrude the paint out of the barrel and evenly coat the surface of the PMMA film; 3) After coating is completed, the solvent in the primer layer is removed through the drying device, so that the primer layer is solidified on the surface of the PMMA film.

[0022] The specific steps of micro-gravure coating are as follows: 1) Install and debug the gravure roller and the matching roller so that the distance and pressure between them meet the process requirements. According to the characteristics of the PMMA film and the thickness requirements of the primer layer, select a suitable gravure roller, and the pattern or groove on its surface should match the primer layer to be coated; 2) Stir the water-based polyurethane primer thoroughly to achieve a uniform state, and then pour the coating into the feed trough so that part of the surface of the gravure roller is immersed in the coating; 3) Start the equipment and make the gravure roller start to rotate. As the gravure roller rotates, The pattern or groove on its surface will bring up a certain amount of paint from the feed trough. After the scraper is scraped and measured, the excess paint on the surface of the gravure roller is scraped off, leaving only the paint in the pattern or groove. Under the action of the traction device, the PMMA film runs in the reverse direction and contacts lightly with the rotating gravure roller. The paint forms a wetting line at the contact point and is transferred from the groove of the gravure roller to the surface of the PMMA film under the action of surface tension and adhesion, forming a uniform primer layer. 4) The coated PMMA film passes through the drying device, and the primer layer gradually solidifies.

[0023] None of the three coating methods mentioned above can achieve the desired primer thickness in one go. All require real-time monitoring and adjustment of the primer thickness. For example, if a customer requires a primer film with a thickness of 300±10nm, the applied thickness may be 270nm. This means the primer film thickness does not meet the requirements, resulting in poor bonding performance with other materials. Therefore, the coating amount must be increased to achieve a primer film thickness of 300±10nm.

[0024] To solve the above problems, the present application provides an optical film, which is provided with a first detection area and / or a second detection area, which can conveniently qualitatively detect the thickness of the primer layer of the optical film and facilitate real-time adjustment of the coating thickness of the primer layer.

[0025] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following describes the specific embodiments of the present invention in a clear and complete manner. It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0026] The present application provides an optical film 10, comprising a PMMA film 30 and a primer layer 20 disposed on the PMMA film 30. The primer layer 20 is further provided with a first printing area 1 and a second printing area. The first printing area 1 and the second printing area are both disposed along the extension direction of the primer layer 20 and are respectively located parallel to the two side edges of the primer layer 20. A first detection area 2 parallel to the first printing area 1 is disposed adjacent to the first printing area 1 on the primer layer 20, and / or a second detection area parallel to the second printing area is disposed adjacent to the second printing area on the primer layer 20. The thickness of the first detection area 2 and the second detection area is 10 nm to 15 nm less than the minimum value of the preset thickness range of the primer layer 20. The preset thickness range of the primer layer 20 is the thickness range of the primer layer 20 required by the customer, which is generally 280 nm to 600 nm. The thickness of the PMMA film 30 is 20 μm to 80 μm.

[0027] Based on the above technical solution, the functions of the first printing area 1 and the second printing area are, on the one hand, to suppress the occurrence of poor appearance caused by winding deviation or looseness, adhesion, uneven thickness, etc. when winding the optical film; on the other hand, the first printing area 1 and the second printing area are used for positioning, which makes it easier for production line personnel to find the first detection area 2 and / or the second detection area and take samples for testing.

[0028] In an optional embodiment, the combined width of the first and second printing areas 1 and 1% to 5% of the width of the PMMA film 10. Preferably, the width of the first and second printing areas 1 and 1% are the same. It should be noted that in conventional production, the width of the PMMA film 10 is generally greater than 2 meters.

[0029] In an optional embodiment, the width of the first detection zone 2 is 5 mm to 10 mm, and the width of the second detection zone is 5 mm to 10 mm.

[0030] In an optional embodiment, the horizontal distance between the first detection area 2 and the first printing area 1 is 1 mm to 5 mm, and the horizontal distance between the second detection area and the second printing area is 1 mm to 5 mm.

[0031] In an alternative embodiment, reference Figure 1 、 Figure 2 and Figure 3 The present application provides an optical film 10 according to an embodiment, comprising a PMMA film 30 and a primer layer 20 disposed on the PMMA film 30. The primer layer 20 further comprises a first printing area 1 and a second printing area. The first printing area 1 and the second printing area are both disposed along the extension direction of the primer layer 20 and are respectively located parallel to the two side edges of the primer layer 20. A first detection area 2 is disposed on the primer layer 20, adjacent to the first printing area 1 and parallel to the first printing area 1. Specifically: Figure 1 Schematic diagram of the top view structure of the optical film; Figure 2 is a schematic diagram of the cross-sectional structure of the optical film sample of Example 1; Figure 3 Schematic diagram of the cross-sectional structure of the optical film sample of Example 2.

[0032] The present application also provides a method for preparing the optical film 10 described above, comprising the following steps: A1. Prepare a PMMA film 30 using PMMA resin. Specifically, the PMMA film 30 is prepared using a solution casting method, a resin melt extrusion method, or the like. For example, using the resin melt extrusion method, the PMMA resin is first melted and extruded, cooled, and then longitudinally stretched at high temperature to form the PMMA film 30. A2. Applying a primer coating liquid, curing it, and laterally stretching it at high temperature to form a primer layer 20. Specifically, the primer coating liquid is applied to the PMMA film 30 by a wire rod coating, extrusion coating, micro-dimpled coating, roller coating, knife coating, D-BAR coating, or the like, curing it, and laterally stretching it at high temperature to form the primer layer 20. The thickness of the primer layer 20 is a preset thickness, which is the thickness of the primer layer 20 required by the customer and can be between 280 nm and 600 nm. Preferably, the primer coating liquid is water-based polyurethane. A3. Use laser irradiation to form the primer layer 20 parallel to the edges of both sides along the extension direction of the PMMA film 30 to form the first printing area 1, the second printing area, and the first detection area 2 and / or the second detection area. Specifically, the first printing area 1 and the second printing area are formed simultaneously. The first detection area 2 and / or the second detection area can be formed simultaneously with the first printing area 1 and the second printing area, or they can be formed at different times. The first laser device for forming the first printing area 1 and the second printing area can be set on the side adjacent to the primer layer 20, or on the side of the PMMA film 10 away from the primer layer 20, or on both sides. The second laser device for forming the first detection area 2 and / or the second detection area is set on the side adjacent to the primer layer 20.

[0033] More specifically, there is no limitation on the type of laser emitted by the first laser device or the second laser device, and it can be an ArF excimer laser, a KrF excimer laser, a XeCl excimer laser, a semiconductor laser, a fiber laser or a carbon dioxide laser, etc. Carbon dioxide laser is preferred, as carbon dioxide laser has higher production efficiency. The laser irradiation power emitted by the first laser device forming the first printing area 1 and the second printing area is preferably in the range of 1 to 20 W, more preferably in the range of 5 to 15 W; the laser irradiation power emitted by the second laser device forming the first detection area 2 and / or the second detection area is preferably in the range of 1 to 20 W, more preferably in the range of 5 to 15 W. The laser irradiation power emitted by the first laser device and the laser irradiation power emitted by the second laser device are both controlled at more than 1 W, which can prevent insufficient laser irradiation power, so that the surface of the primer layer 20 can be fully scratched. On the other hand, the laser irradiation power emitted by the first laser device and the laser irradiation power emitted by the second laser device are both controlled below 20W, which can prevent the formation of through holes in the primer layer 20 during the laser irradiation process, and at the same time avoid thermal effects on the peripheral part of the primer layer 20 irradiated by the laser, thereby preventing the expansion of the micro-processing width and the inability to obtain an ideal micro-pattern.

[0034] Specifically, in the technical solution of the present application, the size of the recess is controlled by controlling the focusing diameter of the laser irradiation.

[0035] In an optional embodiment, the present application further provides a method for evaluating the performance of an optical film based on the optical film 10 described above, comprising the following steps: S1. Take the optical film 10 to be tested, lay it flat with the primer layer 20 facing upwards; S2, adding a mixture of 50% toluene / anhydrous ethanol to the first detection area 2 and / or the second detection area of the optical film 10 to be detected, and letting it stand for 30 seconds; S3, removing the residual toluene in the first detection area 2 and / or the second detection area; further, blowing or wiping the residual liquid in the first detection area 2 and / or the second detection area dry, preferably, using nitrogen to blow dry; S4. Result Determination: Visually observe the surface morphology of the first test area 2 and / or the second test area to determine whether the thickness of the optical film's base layer meets the requirements, and then determine the performance of the optical film. If the surface of the first test area 2 and / or the second test area is smooth, without any depressions or cracks, the actual thickness of the primer layer 20 of the optical film 10 to be tested is greater than the preset thickness, and the performance of the optical film 10 is acceptable. If the surface of the first test area 2 and / or the second test area is rough, with obvious depressions or holes, the actual thickness of the primer layer 20 of the optical film 10 to be tested is less than the preset thickness, and the performance of the optical film 10 is unacceptable.

[0036] The principle of optical film performance evaluation is as follows: if the thickness of the first detection area 2 and / or the second detection area is greater than the minimum value of the preset thickness range of the primer layer, the PMMA film at the position of the first detection area 2 and / or the second detection area will not be exposed, and toluene will not corrode the PMMA film. Therefore, the surface of the first detection area 2 and / or the second detection area is smooth, without collapse or cracks; if the thickness of the first detection area 2 and / or the second detection area is less than the minimum value of the preset thickness range of the primer layer, the PMMA film at the position of the first detection area 2 and / or the second detection area will be exposed, and toluene will corrode the PMMA film. Therefore, the surface of the first detection area 2 and / or the second detection area is rough, with obvious depressions and holes.

[0037] In order to better understand the technical solution of this application, the following examples are also provided: Example 1 The optical film to be produced by Customer A includes a PMMA film and a primer layer disposed on the PMMA film. The primer layer is further provided with a first printing area and a second printing area. The first printing area and the second printing area are both disposed along the extension direction of the primer layer and are respectively located parallel to the two side edges of the primer layer. A first detection area parallel to the first printing area is disposed adjacent to the first printing area on the primer layer, and a second detection area parallel to the second printing area is disposed adjacent to the second printing area on the primer layer. The thickness of the first detection area and the second detection area is 10 nm less than the minimum value of the preset thickness range of the primer layer. The preset thickness requirement for the primer layer is 300 ± 10 nm, the thickness of the PMMA film is 20 μm, the width of the first detection area is 8 mm, the width of the second detection area is 8 mm, the horizontal distance between the first detection area and the first printing area is 3 mm, the horizontal distance between the second detection area and the second printing area is 3 mm, the width of the first printing area is 10 mm, the width of the second printing area is 10 mm, the thickness of the first detection area is 280 nm, and the thickness of the second detection area is 280 nm.

[0038] Prepare the optical film required by the above customer according to the regulations. The specific steps are as follows: First, the PMMA resin is melted and extruded by a resin melt extrusion method, cooled, and then longitudinally stretched at high temperature to form a PMMA film; Secondly, according to experience, a suitable amount of waterborne polyurethane is evenly applied to the PMMA film using a roller coating method, cured, and laterally extended at high temperature to form a primer layer; Finally, laser irradiation is performed on the primer layer located parallel to the side edges along the extension direction of the PMMA film to form a first printing area, a second printing area, and a first detection area and a second detection area. The parameters of the first laser device are set so that the widths of the first printing area and the second printing area are both 10 mm, and the parameters of the second laser device are set so that the widths of the first detection area and the second detection area are both 8 mm. At the same time, the positions of the irradiation laser heads of the first laser device and the second laser device are set so that the horizontal distance between the first detection area and the first printing area is 3 mm, and the horizontal distance between the second detection area and the second printing area is 3 mm. At the same time, the first printing area and the second printing area are respectively located parallel to the side edges of the PMMA film along the extension direction of the PMMA film.

[0039] After a period of initial production, take an optical film sample from the production line every 10 meters, and take at least 3 consecutive samples. Each optical film sample includes a first test area or a second test area with a length of 2cm. The samples are tested. The specific steps are as follows: S1. Take the optical film to be tested, make the primer layer face up, and lay it flat; S2, adding 20 μL of a 50% toluene / anhydrous ethanol mixture to the first detection area and the second detection area of the optical film to be detected, respectively, and letting it stand for 30 seconds; S3. Remove residual toluene from the first detection area and / or the second detection area and blow dry with nitrogen; S4. Result determination: Observe the surface of the first test area or the second test area with the naked eye. If the surface of the first test area or the second test area is smooth, without collapse or cracks, and the actual thickness of the primer layer of the optical film to be tested is greater than the preset minimum thickness, the thickness of the primer layer of the optical film batch is qualified and production can continue. The cross-sectional structure diagram of the optical film sample of this embodiment is shown in FIG. Figure 2 shown.

[0040] Example 2 The optical film to be produced by Customer B includes a PMMA film and a primer layer disposed on the PMMA film. The primer layer further includes a first printing area and a second printing area. The first printing area and the second printing area are both disposed along the extension direction of the primer layer and are respectively located parallel to the edges of the primer layer. A first detection area parallel to the first printing area is disposed adjacent to the first printing area on the primer layer, and a second detection area parallel to the second printing area is disposed adjacent to the second printing area on the primer layer. The thickness of the first detection area and the second detection area is 15 nm less than the minimum value of the preset thickness range of the primer layer. The preset thickness requirement for the primer layer is 400 ± 10 nm, the thickness of the PMMA film is 50 μm, the width of the first detection area is 10 mm, the width of the second detection area is 10 mm, the horizontal distance between the first detection area and the first printing area is 5 mm, the horizontal distance between the second detection area and the second printing area is 5 mm, the width of the first printing area is 10 mm, the width of the second printing area is 10 mm, the thickness of the first detection area is 380 nm, and the thickness of the second detection area is 380 nm.

[0041] Prepare the optical film required by the above customer according to the regulations. The specific steps are as follows: First, the PMMA resin is melted and extruded by a resin melt extrusion method, cooled, and then longitudinally stretched at high temperature to form a PMMA film; Secondly, according to experience, a suitable amount of waterborne polyurethane is evenly applied to the PMMA film using a roller coating method, cured, and laterally extended at high temperature to form a primer layer; Finally, laser irradiation is performed on the primer layer located parallel to the edges of the PMMA film along its extension direction to form a first printing area, a second printing area, a first detection area, and a second detection area. The parameters of the first laser device are set so that the widths of the first printing area and the second printing area are both 10 mm, and the parameters of the second laser device are set so that the widths of the first detection area and the second detection area are both 10 mm. Furthermore, the positions of the irradiation laser heads of the first and second laser devices are set so that the horizontal distance between the first detection area and the first printing area is 5 mm, and the horizontal distance between the second detection area and the second printing area is 5 mm. Furthermore, the first printing area and the second printing area are located parallel to the edges of the PMMA film along its extension direction.

[0042] After a period of initial production, take an optical film sample from the production line every 10 meters, and take at least 3 consecutive samples. Each optical film sample includes a first test area or a second test area with a length of 2cm. The samples are tested. The specific steps are as follows: S1. Take the optical film to be tested, make the primer layer face up, and lay it flat; S2, adding 20 μL of a 50% toluene / anhydrous ethanol mixture to the first detection area and the second detection area of the optical film to be detected, respectively, and letting it stand for 30 seconds; S3. Remove residual toluene from the first detection area and / or the second detection area and blow dry with nitrogen; S4. Result determination: Observe the surface of the first test area or the second test area with the naked eye. If the surface of the first test area or the second test area is rough, with obvious depressions and holes, the actual thickness of the primer layer of the optical film to be tested is less than the minimum value of the preset thickness. The thickness requirement of the primer film of the optical film does not meet the standard, and the coating dosage of the water-based polyurethane needs to be increased appropriately. After increasing the dosage, produce for a period of time, and repeat the above-mentioned sampling and testing steps until the surface of the first test area or the second test area is smooth, without collapse or cracks, and the thickness requirement of the primer film of the optical film meets the standard. The schematic diagram of the cross-sectional structure of the optical film sample of this embodiment is shown in FIG. Figure 3 shown.

[0043] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. An optical film, characterized in that: It includes a PMMA film and a primer layer arranged on the PMMA film, the primer layer is further provided with a first printing area and a second printing area, the first printing area and the second printing area are both arranged along the extension direction of the primer layer, and are respectively parallel to the two side edges of the primer layer, a first detection area adjacent to and parallel to the first printing area is arranged on the primer layer, and / or a second detection area adjacent to and parallel to the second printing area is arranged on the primer layer, the thickness of the first detection area and the second detection area is 10nm to 15nm smaller than the minimum value of the preset thickness range of the primer layer.

2. The optical film according to claim 1, wherein The width of the first detection area is 5 mm to 10 mm, and the width of the second detection area is 5 mm to 10 mm.

3. The optical film according to claim 1, wherein The horizontal distance between the first detection area and the first printing area is 1 mm to 5 mm, and the horizontal distance between the second detection area and the second printing area is 1 mm to 5 mm.

4. The optical film according to claim 1, wherein The total width of the first printing area and the second printing area accounts for 1% to 5% of the width of the PMMA film.

5. The optical film according to claim 4, wherein The width of the first printing area is the same as the width of the second printing area.

6. The optical film according to claim 1, wherein The PMMA film has a thickness of 20 μm to 80 μm.

7. The optical film according to any one of claims 1 to 6, characterized in that: The thickness of the primer layer is 280nm to 600nm.

8. The optical film according to claim 7, wherein The primer layer is prepared from waterborne polyurethane.

9. The optical film according to claim 8, wherein The first printing area, the second printing area, the first detection area and the second detection area are all processed by laser irradiation of the primer layer.

10. A method for evaluating optical film performance based on the optical film according to any one of claims 1 to 9, characterized in that: The steps include: S1. Take the optical film to be tested, lay it flat with the primer layer facing upwards; S2, adding a mixture of 50% toluene / anhydrous ethanol dropwise to the first inspection area and / or the second inspection area of the optical film to be inspected, and letting it stand for 30 seconds; S3, removing residual toluene from the first detection area and / or the second detection area; S4. Result determination: Observe the surface morphology of the first detection area and / or the second detection area with the naked eye to determine whether the bottom layer thickness of the optical film meets the requirements, and then determine the performance of the optical film.

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