Protective film, processing method of protective film and display equipment

Abstract

The invention discloses a protective film, a processing method of the protective film and display equipment, and belongs to the technical field of optical elements. The disclosed display device comprises: a protective film, the protective film comprising: a transparent base layer, the transparent base layer being a polyester layer, and the in-plane retardation of the transparent base layer being not greater than 400 nm; the anti-dazzle part comprises a transparent adhesive layer and a plurality of particles, the transparent adhesive layer and the transparent base layer are the same in thickness direction, the transparent adhesive layer is stacked on one side of the transparent base layer in the thickness direction, each particle is embedded in the transparent adhesive layer, and at least part of the particles protrude out of the side, away from the transparent base layer, of the transparent adhesive layer; and the anti-dazzle layer and one surface, deviating from the transparent base layer, of the transparent adhesive layer form an anti-dazzle surface, and the anti-dazzle surface can enable light to generate diffuse reflection. Wherein the value range of the ten-point average roughness of the anti-dazzle surface is 0.5 [mu] m to 1m. The protective film has relatively good moisture resistance and heat resistance, is relatively low in cost and has relatively good anti-dazzle performance.

Description

Technical Field

[0001] The present application belongs to the technical field of optical elements, and specifically relates to a protective film, a processing method of the protective film, and a display device. Background Art

[0002] Polarizing elements are an indispensable part of display devices. In order to prevent polarizing elements from being damaged by finger contact, their surface is usually covered with a protective film.

[0003] In recent years, with the booming global trade and the rising demand for export shipping, higher requirements have been placed on the moisture resistance and heat resistance of protective films. However, the transparent base layer of traditional protective films is generally a cellulose ester layer, and the moisture resistance and heat resistance of cellulose ester materials are poor, resulting in poor moisture resistance and heat resistance of the protective film.

[0004] Therefore, how to provide a protective film with good moisture resistance and heat resistance has become a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a protective film, a processing method of the protective film and a display device, which can solve the problem of poor moisture resistance and heat resistance of the protective film in the related art.

[0006] In a first aspect, a protective film is provided in an embodiment of the present application, comprising: A transparent base layer, wherein the transparent base layer is a polyester layer, and the in-plane retardation of the transparent base layer is not greater than 400 nm; The anti-glare portion comprises a transparent adhesive layer and a plurality of particles, wherein the transparent adhesive layer and the transparent base layer have the same thickness direction, and the transparent adhesive layer is stacked on one side of the transparent base layer in the thickness direction, each of the particles is embedded in the transparent adhesive layer, and at least part of the particles protrude from a side of the transparent adhesive layer away from the transparent base layer, and together with a side of the transparent adhesive layer away from the transparent base layer, form an anti-glare surface, and the anti-glare surface can cause light to produce diffuse reflection; The ten-point average roughness of the anti-glare surface ranges from 0.5 μm to 1 μm.

[0007] In a second aspect, an embodiment of the present application provides a method for processing the protective film as described above, which comprises the following steps: Applying a coating liquid on one side of the transparent base layer in the thickness direction, wherein the coating liquid is at least a mixture of a transparent adhesive liquid and the particles; The transparent adhesive liquid is solidified for a preset time, so that the particles sink a preset distance along the thickness direction of the transparent adhesive layer, and the transparent adhesive liquid forms the transparent adhesive layer.

[0008] In a third aspect, an embodiment of the present application further provides a display device, which includes the protective film described above.

[0009] In the embodiment of the present application, the transparent base layer is a polyester layer. Compared with the cellulose ester material, the polyester material has better moisture resistance and heat resistance, and the cost of the polyester layer is lower, so that the moisture resistance and heat resistance of the protective film are better, and the cost of the protective film is lower. In addition, in the embodiment of the present application, the in-plane delay of the transparent base layer is not more than 400nm, so that it is not easy to produce in-plane birefringence, thereby reducing the probability of the occurrence of rainbow patterns, and thus improving the display effect of the display device. Furthermore, using the scheme in the embodiment of the present application, the protective film also includes an anti-glare portion, and the anti-glare portion includes a transparent adhesive layer and a plurality of particles, at least some of the particles protrude from the side of the transparent adhesive layer away from the transparent base layer, and together with the side of the transparent adhesive layer away from the transparent base layer, form an anti-glare surface, the anti-glare surface can cause light to produce diffuse reflection, and the ten-point average roughness of the anti-glare surface ranges from 0.5μm to 1µm. With this arrangement, the protective film has good anti-glare performance, which helps to improve the visual comfort of the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the structure of the protective film disclosed in the embodiment of the present application; Figure 2 A two-dimensional height map of the anti-glare surface disclosed in the embodiment of the present application; Figure 3 This is the particle distribution diagram corresponding to Example 1 of the present application; Figure 4 The concave-convex pattern of the anti-glare surface corresponding to the first embodiment of the present application; Figure 5 This is the particle distribution diagram corresponding to Example 2 of the present application; Figure 6 The concave-convex pattern of the anti-glare surface corresponding to the second embodiment of the present application; Figure 7 This is the particle distribution diagram corresponding to Example 3 of the present application; Figure 8 The concave-convex pattern of the anti-glare surface corresponding to the third embodiment of the present application; Fig. 9 This is the particle distribution diagram corresponding to Example 4 of the present application; Fig.10 The concave-convex pattern of the anti-glare surface corresponding to the fourth embodiment of the present application; Fig.11 This is the particle distribution diagram corresponding to Example 5 of the present application; Fig.12 The concave-convex pattern of the anti-glare surface corresponding to the fifth embodiment of the present application; Fig.13 This is the particle distribution diagram corresponding to Example 6 of the present application; Fig.14 The concave-convex pattern of the anti-glare surface corresponding to the sixth embodiment of the present application; Fig.15 This is the particle distribution diagram corresponding to Example 7 of the present application; Fig.16 The concave-convex pattern of the anti-glare surface corresponding to the seventh embodiment of the present application; Fig.17 This is the particle distribution diagram corresponding to Example 8 of the present application; Fig.18 This is the concave-convex pattern of the anti-glare surface corresponding to the eighth embodiment of the present application.

[0011] Description of reference numerals: 100-transparent base layer; 210-transparent adhesive layer, 220-microparticles, 230-anti-glare surface; 300-projection surface. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0013] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0014] The protective film provided in the embodiment of the present application is described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0015] Please refer to Figures 1 to 18 As shown, a protective film is provided in an embodiment of the present application, which includes: a transparent base layer 100 and an anti-glare portion.

[0016] Specifically, the transparent base layer 100 is a polyester layer, and the in-plane retardation of the transparent base layer 100 is not greater than 400 nm, so as to control the in-plane retardation of the transparent base layer 100 within a smaller range. Optionally, the transparent base layer 100 is, for example, a polyethylene terephthalate layer, and the in-plane retardation ranges from, for example, 100 nm to 200 nm.

[0017] The anti-glare part includes a transparent adhesive layer 210 and a plurality of particles 220. The specific number of the particles 220 depends on the actual situation. The transparent adhesive layer 210 and the transparent base layer 100 have the same thickness direction. Figure 1 The transparent adhesive layer 210 is stacked on one side of the transparent base layer 100 in the thickness direction in the direction indicated by the arrow line A.

[0018] Each particle 220 is embedded in the transparent adhesive layer 210 . Here, “embedded” may mean that the particle 220 is embedded in the transparent adhesive layer 210 as a whole, or that a part of the particle 220 is embedded in the transparent adhesive layer 210 and the other part is located outside the anti-glare portion.

[0019] At least part of the particles 220 protrude from the side of the transparent adhesive layer 210 away from the transparent base layer 100, and together with the side of the transparent adhesive layer 210 away from the transparent base layer 100, form an anti-glare surface 230, the anti-glare surface 230 can make light diffusely reflect, and the ten-point average roughness of the anti-glare surface 230 is, for example, in the range of 0.5μm to 1µm. Further, the ten-point average roughness of the anti-glare surface 230 is, for example, in the range of 0.5μm to 0.85µm, more specifically, for example, 0.5μm, 0.7μm or 0.85μm.

[0020] It should be noted that the ten-point average roughness is calculated according to the standard specified in JIS B0601 1994. Specifically, the ten-point average roughness refers to the sum of the average values ​​of the five maximum peak heights (the first five peak heights in descending order) and the average values ​​of the five maximum valley depths (the first five valley depths in descending order) within the sampling length.

[0021] In the embodiment of the present application, the transparent base layer 100 is a polyester layer. Compared with cellulose ester materials, polyester materials have better moisture resistance and heat resistance, and the cost of polyester layers is lower, so that the moisture resistance and heat resistance of the protective film are better and the cost of the protective film is lower.

[0022] In addition, in the embodiment of the present application, the in-plane delay of the transparent base layer 100 is not greater than 400 nm. In this way, in-plane birefringence is not easily generated, thereby reducing the probability of the occurrence of rainbow patterns and further improving the display effect of the display device.

[0023] Furthermore, using the solution in the embodiment of the present application, the protective film also includes an anti-glare portion, which includes a transparent adhesive layer 210 and a plurality of particles 220, at least some of the particles 220 protrude from the side of the transparent adhesive layer 210 away from the transparent base layer 100, and together with the side of the transparent adhesive layer 210 away from the transparent base layer 100, form an anti-glare surface 230, the anti-glare surface 230 can cause light to produce diffuse reflection, and the ten-point average roughness of the anti-glare surface 230 has a value range of, for example, 0.5μm~1µm. With this arrangement, the protective film has a better anti-glare effect, which helps to improve the visual comfort of the user.

[0024] In another embodiment, the total haze of the protective film is in the range of, for example, 2% to 60%, optionally, for example, 2%, 30% or 60%, and the percentage of the internal haze of the protective film to the total haze, referred to as the internal haze ratio, is in the range of, for example, 10% to 50%, optionally, for example, 10%, 25% or 50%. Both the total haze and the internal haze are measured according to the standards specified in JIS K-7136, wherein the total haze is the sum of the internal haze and the external haze, the internal haze mainly reflects the scattering effect of the internal part of the protective film on light, and the external haze mainly reflects the scattering effect of the anti-glare surface 230 on light.

[0025] In this embodiment, the ratio of inner haze to outer haze is relatively appropriate, so that the protective film can have better clarity while reducing glare.

[0026] In other optional embodiments, the total haze value range of the protective film may also be less than 2% or greater than 60%. Similarly, the internal haze ratio of the protective film may also be less than 10% or greater than 50%.

[0027] Further, as a specific implementation, in a plane perpendicular to the thickness direction of the transparent adhesive layer 210, the number of particles 220 in every 0.01 square millimeter ranges from 5,000 to 80,000, that is, the number of particles 220 in a square area of ​​100 microns by 100 microns ranges from 5,000 to 80,000, further, for example, from 8,000 to 75,000, more specifically, for example, 5,000, 40,000 or 80,000. The particles 220 are spherical structures, and at least some of the particles 220 have different diameters. The median of the diameter of each particle 220 ranges from 1 μm to 5 μm, further, for example, from 2 μm to 4 μm, more specifically, for example, 2 μm, 3 μm or 4 μm. The difference between the thickness of the transparent adhesive layer 210 and the median diameter of each particle 220 is, for example, in the range of 0 μm to 2 μm, and optionally, is, for example, 0 μm, 1 μm or 2 μm. In this way, the diameter of the particle 220 and the thickness of the transparent adhesive layer 210 are matched, so that the protective film has better optical properties.

[0028] In addition, when the diameter of each particle 220 and the difference between the thickness of the transparent adhesive layer 210 and the median of the diameter of each particle 220 are determined, the thickness of the transparent adhesive layer 210 is determined accordingly. In the actual processing process, for example, the diameter of each particle 220 is first determined, and then the thickness of the transparent adhesive layer 210 is obtained based on the difference between the thickness of the transparent adhesive layer 210 and the median of the diameter of each particle 220.

[0029] In other optional embodiments, in a plane perpendicular to the thickness direction of the transparent adhesive layer 210, the number of particles 220 in every 0.01 square millimeter may also be less than 5000 or greater than 80000. Similarly, the median diameter of each particle 220 may be, for example, less than 1 μm or 5 μm, the difference between the thickness of the transparent adhesive layer 210 and the median diameter of each particle 220 may be greater than 2 μm, and the diameters of each particle 220 may be equal.

[0030] It should be noted that, in the embodiment of the present application, there is no limitation on the specific size of the diameter of each particle 220 , and the diameter can be designed according to actual needs.

[0031] Further, as a specific implementation, the refractive index of the transparent adhesive layer 210 is in the range of, for example, 1.4 to 1.6, further, for example, 1.48 to 1.54, more specifically, for example, 1.48, 1.5 or 1.54. The difference in refractive index between the transparent adhesive layer 210 and the microparticles 220 is in the range of, for example, 0 to 0.05, further, for example, 0.01 to 0.03, more specifically, for example, 0.01, 0.02 or 0.03. The refractive index of the transparent base layer 100 is in the range of, for example, 1.49 to 1.51, optionally, for example, 1.49, 1.5 or 1.51. With such a configuration, the refractive index difference among the transparent adhesive layer 210, the particles 220 and the transparent base layer 100 is relatively small, so that the reflection and scattering of light at the interface between the transparent adhesive layer 210 and the particles 220 and at the interface between the transparent adhesive layer 210 and the transparent base layer 100 will be reduced, which helps to reduce the loss of light and thus improve the transmittance of light.

[0032] In other optional embodiments, the refractive index of the transparent adhesive layer 210 may be less than 1.4 or greater than 1.6. Similarly, the difference between the refractive indices of the transparent adhesive layer 210 and the particles 220 may be greater than 0.05, and the refractive index of the transparent base layer 100 may be less than 1.49 or greater than 1.51.

[0033] In another embodiment, the average tilt angle θ of the anti-glare surface 230 is, for example, in a range of 0.1° to 25°. The average tilt angle θ can reflect the degree to which the particles 220 protruding from the side of the transparent adhesive layer 210 away from the transparent base layer 100 protrude from the transparent adhesive layer 210, and the larger the average tilt angle θ, the higher the height of the particles 220 protruding from the transparent adhesive layer 210, and the better the diffuse reflection effect of the light. In actual use, by reasonably designing the average tilt angle θ, different anti-glare requirements can be met.

[0034] Optionally, the average tilt angle θ satisfies the following relationship, for example: , Wherein, n is a positive integer, and k1, k2, k3 and kn are slopes obtained by taking the modulus of the gradient vector formed by the particle 220 protruding from the transparent adhesive layer 210 .

[0035] Specifically, for example, the topography of the anti-glare surface 230 is first measured to obtain a two-dimensional height map, and then the gradient of the two-dimensional height map is calculated. The gradient, for example, refers to Figure 2 H1, H2 or H3 in the equation, and modulo the gradient vector to obtain the slope k, then convert the slope k into an inclination angle, and finally calculate the average of the inclination angles to obtain the average inclination angle θ. More specifically, refer to Figure 2 As shown, k1 satisfies the following relationship: , Among them, reference Figure 2 As shown, H1 is the gradient of the position corresponding to point C, that is, the distance between point C and the projection surface 300, H2 is the gradient of the position corresponding to point D, that is, the distance between point D and the projection surface 300, points C and D are both points on the anti-glare surface 230, L is the distance between the projection of point C on the projection surface 300 and the projection of point D on the projection surface 300, and the projection surface 300 is, for example, perpendicular to the thickness direction of the transparent adhesive layer 210.

[0036] Further, the value range of the average tilt angle θ is, for example, 0.3° to 0.22°, specifically, for example, 0.3°, 11° or 22°.

[0037] In other optional embodiments, the average inclination angle θ of the anti-glare surface 230 may also be less than 0.1° or greater than 25°.

[0038] In another embodiment, at least some of the particles 220 are located at different positions in the thickness direction of the transparent adhesive layer 210 , and some of the particles 220 are located inside the transparent adhesive layer 210 to meet corresponding internal haze requirements.

[0039] In other optional embodiments, each particle 220 may protrude from a side of the transparent adhesive layer 210 facing away from the transparent base layer 100 .

[0040] In another embodiment, the particles 220 are, for example, organic particles or inorganic particles. The refractive index of organic particles and inorganic particles is different, and inorganic particles can block light, while organic particles have good light transmittance. Therefore, by making the particles 220 organic particles or inorganic particles, different optical requirements can be met respectively.

[0041] In actual use, each particle 220 may be an organic particle, or each particle 220 may be an inorganic particle, or a portion of the particles 220 may be organic particles, and another portion of the particles 220 may be inorganic particles.

[0042] Optionally, the inorganic particles are made of silicon dioxide, for example. The organic particles are made of at least one of acrylic resin, polystyrene resin, styrene-acrylic acid copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride resin and polyvinyl fluoride resin. More specifically, the organic particles are styrene-acrylic acid copolymer particles, for example.

[0043] In another embodiment, the material of the transparent adhesive layer 210 includes a curable resin, and the curable resin includes an acrylate functional group. The presence of the acrylate functional group makes the transparent adhesive layer 210 have a higher hardness, thereby making the hardness of the protective film higher, which is conducive to extending the service life of the protective film.

[0044] Optionally, the curable resin is, for example, a UV (Ultraviolet) curable resin. Further, the curable resin is, for example, a polyester resin, a polyether resin, an acrylic resin, an epoxy resin, a polyurethane resin, an alkyd resin, a spiroacetal resin, a polybutadiene resin, a polythiol polyene resin or a polyol having a relatively low molecular weight. Further, for example, monofunctional monomers and multifunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene or N-vinylpyrrolidone, more specifically, for example, polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate or neopentyl glycol di(meth)acrylate.

[0045] In other optional embodiments, the transparent adhesive layer 210 may not include an acrylate functional group.

[0046] The present application also provides a method for processing the protective film as described above, which comprises the following steps: Applying a coating liquid on one side of the transparent base layer 100 in the thickness direction, the coating liquid is at least a mixture of a transparent adhesive liquid and particles 220, and the thickness direction of the transparent adhesive liquid is, for example, the same as the thickness direction of the transparent base layer 100; The transparent adhesive liquid is cured for a preset time (the curing method may be a thermal curing method, or a method of first thermal curing and then UV curing), so that the particles 220 sink a preset distance along the thickness direction of the transparent adhesive layer 210, and the transparent adhesive liquid forms the transparent adhesive layer 210. In other words, by adjusting the curing time of the transparent adhesive liquid, the distribution state of the particles 220 in the transparent adhesive layer 210 can be adjusted.

[0047] It should be noted that, in the initial state, the particles 220, for example, float on the top of the transparent adhesive liquid. During the curing process, under the action of gravity, the particles 220 will sink, and the sinking speeds of particles 220 of different weights are different. When the curing is completed, the position of the particles 220 is fixed, thereby obtaining the desired anti-glare portion. In addition, the transparent adhesive liquid, for example, includes transparent glue and solvent, the transparent glue is dissolved in the solvent, and when the transparent glue liquid is cured, the solvent is basically evaporated. Furthermore, the thickness of the coating liquid will become thinner after the solvent evaporates. For example, under the combined effect of the evaporation of the solvent and the sinking of the particles 220 themselves, at least part of the particles 220 protrude from the side of the transparent adhesive layer 210 away from the transparent base layer 100.

[0048] In actual use, for example, a disperser, a paint oscillator, a magnetic stirrer, a bead mill, a kneader or a mixer is used to mix the transparent adhesive and the particles 220 to obtain a coating liquid. For example, the coating liquid is applied to the transparent base layer 100 by spin coating, dipping, spraying, die coating, rod coating, roller coating, screen printing or drop coating. For example, the transparent adhesive is solidified by blowing air on the surface of the coating liquid in an oven, and the transparent base layer 100 coated with the coating liquid passes through the oven at a preset speed, thereby achieving the solidification of the coating liquid. More specifically, for example, a roll-to-roll production process is used to process the protective film in the embodiment of the present application. Optionally, the curing time of the transparent adhesive is adjusted, for example, by adjusting the coating liquid temperature, the blowing temperature, the blowing wind speed, the blowing angle, the speed at which the transparent base layer 100 passes through the oven, and the solvent concentration.

[0049] In addition, in addition to adjusting the curing time of the transparent adhesive liquid, the distribution state of the particles 220 in the transparent adhesive layer 210 may also be adjusted by adjusting the number of the particles 220 .

[0050] A display device is also provided in an embodiment of the present application, which includes the protective film described above. Optionally, the display device is, for example, a display screen, and the display screen includes, for example, a polarizing element, and the protective film is, for example, attached to the light-emitting side of the polarizing element, that is, the protective film serves as an outer protective film of the polarizing element, and the polarizing element includes, for example, a first polarizer and a second polarizer, the absorption axes of the first polarizer and the second polarizer are perpendicular to each other, the second polarizer is, for example, arranged on the light-emitting side of the first polarizer, and the protective film is, for example, arranged on the side of the second polarizer away from the first polarizer, that is, the protective film is arranged on the light-emitting side of the second polarizer.

[0051] The protective film provided in the embodiments of the present application is described in detail below in combination with eight specific embodiments and three comparative examples. The detailed parameters of embodiments 1 to 8 and comparative examples 1 to 3 are shown in Table 1 below. Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 as well as Fig.17 These are the particle distribution diagrams corresponding to Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7 and Example 8, respectively. Figure 4 , Figure 6 , Figure 8 , Fig.10 , Fig.12 , Fig.14 , Fig.16 as well as Fig.18 The concave-convex patterns of the anti-glare surface 230 correspond to the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, the sixth embodiment, the seventh embodiment and the eighth embodiment, respectively. Specifically, the concave-convex pattern of the anti-glare surface 230 refers, for example, to a schematic diagram of the anti-glare surface 230 when looking down at the anti-glare surface 230 in the thickness direction of the transparent base layer 100, and in the concave-convex pattern of the anti-glare surface 230, each circular area represents a particle 220, and in the particle distribution pattern, each circular ring represents a particle 220, and the viewing angle of the particle distribution pattern is, for example, the same as the viewing angle of the concave-convex pattern of the anti-glare surface 230.

[0052] Table 1 Detailed parameters of Examples 1 to 8 and Comparative Examples 1 to 3

[0053] In the first to fifth embodiments, the in-plane retardation Re of the transparent base layer 100 is in the range of, for example, 100 nm to 200 nm, the sum of the thicknesses of the transparent adhesive layer 210 and the transparent base layer 100 is in the range of 25 μm to 45 μm, the refractive index of the transparent adhesive layer 210 is 1.51, the refractive index of the particles 220 is 1.49, the particles 220 are spherical structures, the median R of the diameter of each particle 220 is 3 μm, the thickness M of the transparent adhesive layer 210 is in the range of 4 μm to 5 μm, and the thickness M of the transparent adhesive layer 210 is proportional to the diameter of each particle 220. The value range of the difference MR of the median R is, for example, 1μm~2um, the value range of the ten-point average roughness Rz of the anti-glare surface 230 is, for example, 0.501μm~0.557um, the value range of the average inclination angle θ of the anti-glare surface 230 is, for example, 0.339°~5.725°, and the value range of the number of particles 220 per 0.01 square millimeter in the plane perpendicular to the thickness direction of the transparent adhesive layer 210 is, for example, 8000~58000. The total haze of the protective film finally obtained in Examples 1 to 5 is less than 25%.

[0054] In the sixth to eighth embodiments, the in-plane retardation Re of the transparent base layer 100 is in the range of, for example, 350 nm to 400 nm, the sum of the thicknesses of the transparent adhesive layer 210 and the transparent base layer 100 is in the range of 60 μm, the refractive index of the transparent adhesive layer 210 is 1.51, the refractive index of the particles 220 is 1.49, the particles 220 are spherical structures, the median R of the diameter of each particle 220 is 3 μm, the thickness M of the transparent adhesive layer 210 is in the range of 3 μm to 3.5 μm, and the difference M between the thickness M of the transparent adhesive layer 210 and the median R of the diameter of each particle 220 is 1 μm to 1 μm. The value range of R is, for example, 0μm~0.5um, the value range of the ten-point average roughness Rz of the anti-glare surface 230 is, for example, 0.549μm~0.843um, the value range of the average inclination angle θ of the anti-glare surface 230 is, for example, 8.619°~21.89°, and the value range of the number of particles 220 per 0.01 square millimeter in the plane perpendicular to the thickness direction of the transparent adhesive layer 210 is, for example, 58000~75000. The total haze of the protective film finally obtained in Examples 1 to 5 is greater than or equal to 25%, and less than 60%.

[0055] The difference between Comparative Example 1 and Examples 1 to 5 is that in Comparative Example 1, the in-plane delay Re of the transparent base layer 100 is 500nm, the sum of the thicknesses of the transparent adhesive layer 210 and the transparent base layer 100 is 80um, the thickness of the transparent adhesive layer 210 is 3.6µm, the ten-point average roughness Rz of the anti-glare surface 230 has a value range of 0.278, the average inclination angle θ of the anti-glare surface 230 is 0.402°, and in a plane perpendicular to the thickness direction of the transparent adhesive layer 210, the number of particles 220 per 0.01 square millimeter is 16,000.

[0056] Compared with the protective films obtained in Examples 1 to 5, the protective film obtained in Comparative Example 1 has more obvious iridescence and worse anti-glare performance.

[0057] The difference between Comparative Example 2 and Examples 1 to 5 is that in Comparative Example 2, the in-plane delay Re of the transparent base layer 100 is 1000nm, the sum of the thicknesses of the transparent adhesive layer 210 and the transparent base layer 100 is 80um, the thickness of the transparent adhesive layer 210 is 3.6µm, the ten-point average roughness Rz of the anti-glare surface 230 ranges from 0.336μm, the average inclination angle θ of the anti-glare surface 230 is 0.467°, and the number of particles 220 per 0.01 square millimeter in a plane perpendicular to the thickness direction of the transparent adhesive layer 210 is 16,000.

[0058] Compared with the protective films obtained in Examples 1 to 5, the protective film obtained in Comparative Example 2 also has more obvious iridescence and worse anti-glare performance.

[0059] The difference between Comparative Example 3 and Examples 1 to 5 is that the transparent base layer 100 is a triacetyl cellulose layer, the in-plane retardation Re of the transparent base layer 100 is 5 nm, the sum of the thicknesses of the transparent adhesive layer 210 and the transparent base layer 100 is 60 um, the thickness of the transparent adhesive layer 210 is 3.3 µm, the ten-point average roughness Rz of the anti-glare surface 230 is 0.242 um, the average inclination angle θ is 1.071°, and in a plane perpendicular to the thickness direction of the transparent adhesive layer 210, the number of particles 220 per 0.01 square millimeter is 26,000.

[0060] Compared with the protective films obtained in Examples 1 to 5, the iris patterns of the protective film obtained in Comparative Example 3 are similar to those of the protective films obtained in Examples 1 to 5, but the anti-glare performance of the protective film obtained in Comparative Example 3 is worse.

[0061] The evaluation method of the pellicle membranes obtained in Examples 1 to 8 and Comparative Examples 1 to 3 is as follows: When evaluating the rainbow pattern, a protective film is set on the light-emitting side of the second polarizer mentioned above, and the slow axis of the transparent base layer 100 is set at a 45-degree angle with the absorption axis of the second polarizer. In this case, the rainbow pattern is more obvious and easy for the human eye to distinguish. After that, the image displayed by the display device is observed visually and through the third polarizer in different directions. The absorption axis of the third polarizer is, for example, perpendicular to the absorption axis of the second polarizer. The number of observers is, for example, 10. The most evaluations given by all observers are taken as the observation results. In the observation results, "○" indicates that the observer did not observe the rainbow pattern, "△" indicates that the observer observed lighter rainbow patterns, and "╳" indicates that the observer observed more obvious rainbow patterns. Specifically, for example, if 7 observers believe that no rainbow pattern is observed and 3 observers believe that lighter rainbow patterns are observed, it is determined that no rainbow pattern is observed, and accordingly, the observation result is recorded as "○".

[0062] When evaluating the anti-glare properties of the protective film, the protective film is attached to a black plastic plate, and the observer observes the reflected image of the protective film when irradiated with a three-wavelength fluorescent lamp with the naked eye, and evaluates according to the following criteria: ○: The outline of the fluorescent lamp is not observed at all; △: The outline of the fluorescent lamp is blurred; ×: The outline of the fluorescent lamp can be observed relatively clearly.

[0063] Similarly, when evaluating the anti-glare property of the protective film, the number of observers is, for example, 10, and the highest evaluation given by all observers is used as the observation result. In addition, the better the anti-glare property of the protective film, the better the clarity of the outline of the fluorescent lamp observed by the observer.

[0064] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A protective film, characterized in that: include: A transparent base layer (100), the transparent base layer (100) being a polyester layer, and the in-plane retardation of the transparent base layer (100) being no greater than 400 nm; An anti-glare portion, comprising a transparent adhesive layer (210) and a plurality of particles (220), wherein the transparent adhesive layer (210) and the transparent base layer (100) have the same thickness direction, and the transparent adhesive layer (210) is stacked on one side of the transparent base layer (100) in the thickness direction, each of the particles (220) is embedded in the transparent adhesive layer (210), and at least part of the particles (220) protrude from a side of the transparent adhesive layer (210) facing away from the transparent base layer (100), and together with a side of the transparent adhesive layer (210) facing away from the transparent base layer (100), form an anti-glare surface (230), and the anti-glare surface (230) can cause light to generate diffuse reflection; The ten-point average roughness of the anti-glare surface (230) ranges from 0.5 μm to 1 μm.

2. The protective film according to claim 1, characterized in that: The total haze of the protective film is in the range of 2% to 60%, and the percentage of the internal haze of the protective film to the total haze is in the range of 10% to 50%.

3. The protective film according to claim 2, characterized in that: In a plane perpendicular to the thickness direction of the transparent adhesive layer (210), the number of the particles (220) per 0.01 square millimeter is in a range of 5,000 to 80,000; the particles (220) are spherical structures, at least some of the particles (220) have different diameters, the median of the diameter of each particle (220) is in a range of 1 μm to 5 µm, and the difference between the thickness of the transparent adhesive layer (210) and the median of the diameter of each particle (220) is in a range of 0 μm to 2 µm.

4. The protective film according to claim 2, characterized in that: The refractive index of the transparent adhesive layer (210) is in the range of 1.4 to 1.6, the difference between the refractive indices of the transparent adhesive layer (210) and the particles (220) is in the range of 0 to 0.05, and the refractive index of the transparent base layer (100) is in the range of 1.49 to 1.

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5. The protective film according to claim 1, characterized in that: The average inclination angle θ of the anti-glare surface (230) has a value range of 0.1° to 25°; And / or, the average inclination angle θ of the anti-glare surface (230) satisfies the following relationship: ， Wherein, n is a positive integer, and k1, k2, k3, and kn are all slopes obtained by taking the modulus of the gradient vector formed by the protrusion of the particle (220) from the transparent adhesive layer (210).

6. The protective film according to claim 1, characterized in that: At least some of the particles (220) are located at different positions in the thickness direction of the transparent adhesive layer (210), and some of the particles (220) are located inside the transparent adhesive layer (210).

7. The protective film according to claim 1, characterized in that: The particles (220) are organic particles or inorganic particles.

8. The protective film according to claim 1, characterized in that: The material of the transparent adhesive layer (210) includes a curable resin, and the curable resin contains an acrylate functional group.

9. A method for processing a protective film according to any one of claims 1 to 8, characterized in that: The following steps are involved: Applying a coating liquid on one side of the transparent base layer (100) in the thickness direction, the coating liquid being at least a mixture of a transparent adhesive liquid and the particles (220); The transparent adhesive liquid is solidified for a preset time, so that the particles (220) sink a preset distance along the thickness direction of the transparent adhesive layer (210), and the transparent adhesive liquid forms the transparent adhesive layer (210).

10. A display device, characterized in that: Comprising the protective film as described in any one of claims 1-8.

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