Anti-glare polarizing film based on adaptive control of coating thickness and preparation method thereof

Abstract

The present application relates to the technical field of anti-glare polarizing film preparation, and particularly relates to an anti-glare polarizing film based on self-adaptive control of coating thickness and a preparation method thereof, which comprises the following steps: cleaning and surface activating a PC compensation film, and coating an anti-glare coating liquid containing organic anti-glare particles; collecting a transmission image of a coating area, determining a coating abnormal area based on a relative deviation of average transmission intensity of the coating area and a plurality of detection units, and correcting the thickness of the coating abnormal area to obtain a corrected wet film; performing interface migration on the organic anti-glare particles in the corrected wet film, and determining a particle protrusion height to obtain a to-be-solidified coating layer; limiting particle continuous migration through pre-solidification, and completing coating setting through stepwise heating and heat preservation and exhaust to obtain an anti-glare polarizing film. The present application can reduce the influence of local coating thickness fluctuation on the protrusion height of the organic anti-glare particles, and improve the consistency of the surface microstructure and optical performance of the anti-glare polarizing film.

Description

Technical Field

[0001] This invention relates to the field of anti-glare polarizing film preparation technology, and in particular to an anti-glare polarizing film based on adaptive control of coating thickness and its preparation method. Background Technology

[0002] Anti-glare polarizing films are commonly used in display devices. By creating an anti-glare coating with a microscopic uneven structure on the surface of the polarizing film, incident light is scattered at the coating surface, reducing glare caused by specular reflection. Existing anti-glare coatings typically involve dispersing organic or inorganic anti-glare particles in a curable resin system, applying the resulting anti-glare coating liquid to the surface of a transparent film, and then drying and curing to form the anti-glare layer. The particle size of the anti-glare particles, the coating thickness, and the degree of particle embedding within the coating affect the microstructure of the coating surface, further influencing anti-glare performance and light transmittance. Existing anti-glare film technologies also adjust the anti-glare effect by controlling the particle size and coating thickness.

[0003] Chinese Patent Application Publication No. CN111100314A discloses a method for preparing an anti-glare curing film for polarizers. The curing film comprises, from top to bottom, a second anti-glare layer, a first anti-glare layer, and a transparent support. The preparation is carried out according to the following steps: coating the first anti-glare layer onto the transparent support, coating the second anti-glare layer onto the surface of the first anti-glare layer, and drying and curing to form the anti-glare curing film for polarizers. This invention provides a simple and efficient preparation method that can form an anti-glare curing film with excellent texture, superior anti-glare properties, and excellent resistance to flashing, thereby improving the display quality.

[0004] However, the method for preparing an anti-glare curing film for polarizers has the following problems:

[0005] 1. When the thickness of the wet film fluctuates locally during the coating process, existing methods are unable to identify and correct areas of abnormal thickness, causing the thickness deviation to continue into the subsequent film formation process;

[0006] 2. Using fixed drying and curing conditions makes it difficult to adapt to the differences in particle migration states under different wet film thicknesses, which can easily lead to inconsistent particle protrusion heights and affect the consistency of optical performance. Summary of the Invention

[0007] To address this issue, the present invention provides an anti-glare polarizing film based on adaptive coating thickness control and its preparation method, which overcomes the problem in the prior art that it is difficult to identify and correct abnormal thickness areas when the wet film thickness fluctuates, and that fixed particle migration conditions are still used, resulting in inconsistent particle protrusion heights.

[0008] To achieve the above objectives, the present invention provides a method for preparing an anti-glare polarizing film based on adaptive coating thickness control, comprising:

[0009] The surface of the PC compensation film is cleaned and chemically activated, and an anti-glare coating liquid containing organic anti-glare particles is prepared.

[0010] The coating area on the surface of the PC compensation film is determined, and the coating area is divided into several detection units arranged radially along the PC compensation film. The boundary between adjacent detection units is the detection unit boundary position. The anti-glare coating liquid is applied to the coating area to form an anti-glare wet film.

[0011] Acquire a transmission image of the coating area of ​​the anti-glare wet film, and determine the average transmission intensity of the coating area and the average transmission intensity of the detection unit;

[0012] Based on the average transmission intensity of the coating area and the average transmission intensity of the detection unit, the relative deviation of the detection unit relative to the average transmission intensity of the coating area is obtained, and the coating abnormal area is determined.

[0013] The thickness of the coating abnormal area is corrected, and based on the relative deviation of the average transmission intensity of the coating abnormal area after thickness correction, the thickness correction is completed, and a corrected wet film is obtained.

[0014] The organic anti-glare particles in the corrected wet film are subjected to interface migration treatment to determine the particle protrusion height, and a coating to be cured is obtained.

[0015] The coating to be cured is pre-cured to limit the continued migration of the organic anti-glare particles, resulting in a pre-cured wet film. The pre-cured wet film is then subjected to a stepped temperature setting process to obtain an anti-glare polarizing film.

[0016] Furthermore, the process of determining whether the PC compensation film surface has undergone chemical surface activation treatment includes:

[0017] Based on the activation state of the PC compensation film surface, determine whether the PC compensation film surface has completed chemical surface activation treatment;

[0018] Before applying the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the first wetting angle formed between the deionized water and the surface of the PC compensation film is collected.

[0019] Based on the fact that the first wetting angle is greater than the reference wetting angle, the surface of the PC compensation film is determined to be in the first activated state, and the surface of the PC compensation film is subjected to chemical surface activation treatment.

[0020] After removing the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the second wetting angle formed between the deionized water and the surface of the PC compensation film is collected.

[0021] Based on the fact that the second wetting angle is greater than the reference wetting angle, it is determined that the surface of the PC compensation film remains in the first activated state, and chemical surface activation treatment continues.

[0022] Based on the second wetting angle being less than or equal to the reference wetting angle, the surface of the PC compensation film is determined to be in a second activated state, and the chemical surface activation treatment of the PC compensation film surface is determined to be completed.

[0023] Furthermore, the process of determining the coating area on the surface of the PC compensation film includes:

[0024] A 365nm ultraviolet light was perpendicularly irradiated onto the surface of the PC compensation film at a distance of 20cm to acquire a first transmission image of the PC compensation film surface.

[0025] Based on the radial transmission intensity distribution gradient of the first transmission image, the boundary positions of several detection units on the surface of the PC compensation film are determined sequentially.

[0026] A detection unit is defined as the area between the boundary positions of adjacent detection units, and several detection units are arranged radially along the PC compensation film.

[0027] Furthermore, determining the boundary position of the detection unit includes:

[0028] Based on the transmission intensity distribution along the radial direction of the PC compensation film in the first transmission image, the gradient change value of the transmission intensity is obtained;

[0029] The detection unit boundary position is determined based on the gradient change value of the transmission intensity being greater than or equal to 5% of the average transmission intensity of the PC compensation film.

[0030] Based on the fact that the gradient change value of the transmission intensity is less than 5% of the average transmission intensity of the PC compensation film, the coating area is divided into equal widths with a radial interval of 10mm to 20mm, and the position between adjacent equal width areas is determined as the boundary position of the detection unit.

[0031] The average transmission intensity is the quotient obtained by summing the gray values ​​of all pixels in the region after the image is acquired using an industrial camera and dividing it by the total number of pixels in the region.

[0032] Furthermore, the process of identifying areas of coating abnormality includes:

[0033] Ultraviolet light with a wavelength of 365nm was placed on the uncoated side of the PC compensation film and vertically irradiated for 10s at a distance of 20cm from the uncoated side of the PC compensation film, and a second transmission image was obtained.

[0034] Based on the second transmission image, the average transmission intensity of the coating area is determined, and the average transmission intensity of each detection unit within the coating area is determined respectively.

[0035] Based on the relative deviation between the average transmission intensity of the coating area and the average transmission intensity of each detection unit, the coating abnormal area is determined.

[0036] The coating abnormality area includes a first coating abnormality area and a second coating abnormality area.

[0037] The first coating abnormality area is defined as the area where the average transmission intensity of the detection unit is less than the average transmission intensity of the coating area, and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%.

[0038] The second coating abnormality area is defined as the area where the average transmission intensity of the detection unit is greater than the average transmission intensity of the coating area, and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%.

[0039] The detection units with an absolute value of relative deviation greater than 30% are identified as coating defect areas, and the coating defect areas are recoated. The average transmission intensity and relative deviation of the coating defect areas are then re-determined.

[0040] Furthermore, the process of correcting the thickness of the coating abnormal area includes:

[0041] The first coating abnormal area is subjected to local vibration leveling treatment to obtain the first corrected coating area and determine the average transmission intensity of the first corrected coating area.

[0042] The second coating abnormal area is compensated for in thickness to obtain a second corrected coating area and the average transmission intensity of the second corrected coating area is determined.

[0043] Based on the average transmission intensity of the first and second corrected coating regions, the relative deviations of the two regions relative to the average transmission intensity of the coating region in the second transmission image are determined respectively.

[0044] When the absolute value of the relative deviation corresponding to the first correction coating area and the second correction coating area is less than or equal to 10%, the thickness correction is determined to be complete.

[0045] Furthermore, the local vibration leveling treatment involves using a point-contact ultrasonic probe to contact the uncoated surface of the PC compensation film, while keeping the central axis of the probe perpendicular to the surface of the PC compensation film. This allows the probe to move within the orthographic projection range of the first coating abnormality area onto the uncoated surface of the PC compensation film, thereby vibrating the first coating abnormality area. The thickness compensation involves applying a compensation coating liquid to the second coating abnormality area, allowing the compensation coating liquid to combine with the original anti-glare wet film within the second coating abnormality area.

[0046] The compensation coating liquid is the anti-glare coating liquid.

[0047] Furthermore, the interface migration process of the organic anti-glare particles includes:

[0048] Place the PC compensation film on a horizontal workbench with the coated surface of the PC compensation film facing upwards and let it stand for 5 to 10 minutes.

[0049] Determine the Spk of the coating area, and stop interface migration when the Spk is between 0.6 μm and 1.2 μm;

[0050] Spk represents the particle protrusion height of the organic anti-glare particles.

[0051] Furthermore, the stepped heating and shaping process includes:

[0052] The pre-cured wet film is subjected to a first-stage heating treatment at 5°C / min, heated to 50°C and held for 10 min, and exhaust treatment is carried out during the holding process;

[0053] The pre-cured wet film is subjected to a second stage of heating treatment at 5°C / min, heated to 70°C and held for 5 min, and exhaust treatment is carried out during the holding process;

[0054] After the second stage of heat preservation is completed, the exhaust device is turned off and heating is stopped. The film is allowed to cool down naturally to obtain the anti-glare polarizing film.

[0055] The exhaust device is turned off during the first and second stages of heating, and is only turned on during the heat preservation process, so that heating and exhaust alternate.

[0056] Furthermore, the anti-glare polarizing film includes a PC compensation film and an anti-glare coating formed on the surface of the PC compensation film;

[0057] The anti-glare coating comprises a curable resin, an anti-UV agent, a photoinitiator, and organic anti-glare particles. The curable resin comprises 100 parts by weight, the anti-UV agent comprises 1 part by weight, the photoinitiator comprises 3 parts by weight, and the organic anti-glare particles comprise 10 parts by weight. The curable resin is polyurethane acrylate, the anti-UV agent is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, the photoinitiator is 1-hydroxycyclohexylphenyl ketone, and the organic anti-glare particles are cross-linked polymethyl methacrylate microspheres with a median particle size D50 of 5 μm.

[0058] Compared with the prior art, the beneficial effects of the present invention are as follows: by cleaning and surface activating the PC compensation film, the wetting state of the anti-glare coating liquid on the film surface is improved; the thickness state of the anti-glare wet film and the coating abnormal areas are determined based on the transmission image; the thickness of the coating abnormal areas is corrected; and the interface migration process of the organic anti-glare particles is adjusted so that the organic anti-glare particles in different wet film thickness areas all form Spk within the target range. The migration of the organic anti-glare particles is restricted by pre-curing, and the particle protrusion height is maintained by step-heating shaping treatment, so as to reduce the influence of wet film thickness variation on the formation of anti-glare surface structure and improve the consistency of the optical performance of the anti-glare coating.

[0059] Furthermore, this invention improves the activation state of the PC compensation film surface through hydrolysis pretreatment and ultraviolet light surface activation treatment, and uses a reference wetting angle to determine whether the PC compensation film has reached a surface state suitable for the spread of the anti-glare coating liquid, reducing local shrinkage and coating defects caused by inconsistent surface states in different areas. In addition, by utilizing the ultraviolet absorption characteristics of the anti-UV reagent, the anti-UV reagent has both ultraviolet protection function and wet film thickness indication function, eliminating the need to add tracer components to the anti-glare coating liquid, and the transmission intensity distribution of the coating area can be determined based on the transmission image.

[0060] Furthermore, this invention irradiates the anti-glare wet film with ultraviolet light and acquires a second transmission image to obtain the average transmission intensity of the coating area. The average transmission intensity of each detection unit is compared with the average transmission intensity of the coating area, and the degree of deviation of each detection unit relative to the average transmission intensity of the coating area is determined based on the relative deviation. Since changes in the wet film thickness will cause changes in ultraviolet transmission intensity when the composition of the anti-glare coating liquid remains constant, the detection units with localized abnormal wet film thickness are identified based on the relative deviation, and the abnormal coating areas are determined, providing a basis for subsequent thickness correction.

[0061] Furthermore, this invention corrects the thickness and then re-acquires ultraviolet transmission images to determine the average transmission intensity of the first corrected coating area and the average transmission intensity of the second corrected coating area. This allows the subsequent adaptive interface migration processing of organic anti-glare particles to be based on the corrected average transmission intensity, reducing the impact of wet film thickness deviation on the particle protrusion height of organic anti-glare particles and providing a basis for forming similar particle protrusion heights in different coating areas.

[0062] Furthermore, this invention determines the particle protrusion height by correcting the Spk of the coating area, reducing the insufficient or excessive migration of organic anti-glare particles caused by using the same resting time for different areas. This allows the subsequent pre-curing treatment to correspond to the actual migration state of the organic anti-glare particles, enabling organic anti-glare particles in coating areas with different wet film thicknesses to form similar particle protrusion heights, thus reducing the impact of wet film thickness variations on the optical performance of the anti-glare polarizing film.

[0063] Furthermore, the present invention forms a pre-cured resin network through pre-curing treatment to fix the protrusion height of the organic anti-glare particles formed by interfacial migration, and performs a stepped heating treatment on the pre-cured film layer, venting at the constant temperature stages corresponding to 50℃ and 70℃ respectively, so that the residual solvent migrates from the interior of the film layer in stages and is discharged as the temperature rises, reducing the local shrinkage and surface morphology changes of the film layer caused by the concentrated escape of volatile components, thereby reducing the impact of the subsequent solvent removal process on the particle protrusion height and improving the consistency of the microstructure and optical properties of the anti-glare coating surface. Attached Figure Description

[0064] Figure 1 This is a flowchart illustrating the steps of a method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to an embodiment of the present invention.

[0065] Figure 2 This is a logic diagram for determining coating abnormality areas based on the relative deviation of transmission intensity in an embodiment of the present invention.

[0066] Figure 3 This is a logic diagram for thickness correction of coating abnormal areas in an embodiment of the present invention.

[0067] Figure 4 This is a schematic diagram of the interface migration and pre-curing of organic anti-glare particles in an embodiment of the present invention. Detailed Implementation

[0068] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the present invention.

[0069] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0070] Please see Figure 1 The diagram shows a flowchart of the steps in the preparation method of the anti-glare polarizing film based on adaptive coating thickness control according to an embodiment of the present invention. The preparation method of the anti-glare polarizing film based on adaptive coating thickness control according to an embodiment of the present invention includes:

[0071] Step S1: Clean and chemically activate the surface of the PC compensation film, and prepare an anti-glare coating liquid containing organic anti-glare particles.

[0072] Step S2: Determine the coating area on the surface of the PC compensation film, divide the coating area into several detection units arranged radially along the PC compensation film, with the boundary between adjacent detection units, and apply the anti-glare coating liquid to the coating area to form an anti-glare wet film.

[0073] Step S3: Acquire a transmission image of the coating area of ​​the anti-glare wet film, and determine the average transmission intensity of the coating area and the average transmission intensity of the detection unit.

[0074] Step S4: Based on the average transmission intensity of the coating area and the average transmission intensity of the detection unit, the relative deviation of the detection unit relative to the average transmission intensity of the coating area is obtained, and the detection units with an absolute value of the relative deviation greater than 10% and less than or equal to 30% are identified as coating abnormal areas.

[0075] Step S5: Perform thickness correction on the coating abnormal area, and determine the completion of thickness correction based on the relative deviation of the average transmission intensity of the coating abnormal area after thickness correction, to obtain a corrected wet film.

[0076] Step S6: Perform interface migration treatment on the organic anti-glare particles in the corrected wet film, determine the particle protrusion height, and obtain the coating to be cured;

[0077] Step S7: Pre-curing treatment is performed on the coating to be cured to limit the continued migration of the organic anti-glare particles, resulting in a pre-cured wet film. The pre-cured wet film is then subjected to a stepped temperature setting treatment to obtain an anti-glare polarizing film.

[0078] Specifically, in this embodiment of the invention, the wetting state of the anti-glare coating liquid on the film surface is improved by cleaning and surface activation treatment of the PC compensation film. Based on the transmission image, the thickness state of the anti-glare wet film and the abnormal coating areas are determined. The thickness of the abnormal coating areas is corrected, and the interfacial migration process of the organic anti-glare particles is adjusted so that the organic anti-glare particles in different wet film thickness areas form a particle protrusion height within the target range. The migration of the organic anti-glare particles is restricted by pre-curing, and the particle protrusion height is maintained by step-heating shaping treatment. This reduces the impact of wet film thickness changes on the formation of the anti-glare surface structure and improves the consistency of the optical performance of the anti-glare coating.

[0079] In this embodiment, the cleaning process for the surface of the PC compensation film includes:

[0080] An alkaline pretreatment solution was applied to the surface of the PC compensation membrane, and a hydrolysis pretreatment was performed for 10 minutes to remove low molecular weight oligomers from the surface of the PC compensation membrane.

[0081] The PC compensation membrane was repeatedly immersed in deionized water three times to remove the alkaline pretreatment solution.

[0082] In this embodiment, the alkaline pretreatment solution is prepared from deionized water, sodium bicarbonate and sodium carbonate, wherein the mass fraction of sodium bicarbonate is 5.0%, the mass fraction of sodium carbonate is 1% to 3.0%, and the pH value is 9.0 to 10.0.

[0083] In this embodiment, the process of activating the PC compensation film surface is as follows: applying an activation solution to the PC compensation film surface, irradiating the PC compensation film surface with ultraviolet light to activate the PC compensation film surface, and determining the activation state of the PC compensation film surface.

[0084] In this embodiment, the activation solution is an aqueous solution of hydrogen peroxide, and the mass fraction of hydrogen peroxide in the aqueous solution is 10%. The activation solution covers the surface of the PC compensation film to be activated in the form of a continuous liquid film, with an application rate of 10 μL / cm². 2 The UVS-28 ultraviolet lamp was used as the ultraviolet light source, with a wavelength of 254nm and an irradiation energy of 600mJ / cm². 2 The irradiation time is 15 minutes. The irradiation distance is 10 cm.

[0085] In this embodiment, after ultraviolet light irradiation, the surface of the PC compensation film is subjected to activation solution removal treatment. The activation solution removal treatment involves rinsing the activated surface of the PC compensation film three times with deionized water, with each rinse lasting 30 seconds, to remove residual hydrogen peroxide aqueous solution from the surface of the PC compensation film. After rinsing, the surface of the PC compensation film is purged with nitrogen gas at a pressure of 0.05 MPa to 0.10 MPa for 1 to 2 minutes until no visible droplets are visible on the surface of the PC compensation film.

[0086] In this embodiment, the process of determining whether the PC compensation film surface has completed chemical surface activation treatment includes:

[0087] Based on the activation state of the PC compensation film surface, determine whether the PC compensation film surface has completed chemical surface activation treatment;

[0088] Before applying the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the first wetting angle formed between the deionized water and the surface of the PC compensation film is collected.

[0089] Based on the fact that the first wetting angle is greater than the reference wetting angle, the surface of the PC compensation film is determined to be in the first activated state, and the surface of the PC compensation film is subjected to chemical surface activation treatment.

[0090] After removing the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the second wetting angle formed between the deionized water and the surface of the PC compensation film is collected.

[0091] Based on the fact that the second wetting angle is greater than the reference wetting angle, it is determined that the surface of the PC compensation film remains in the first activated state, and chemical surface activation treatment continues.

[0092] Based on the second wetting angle being less than or equal to the reference wetting angle, the surface of the PC compensation film is determined to be in a second activated state, and the chemical surface activation treatment of the PC compensation film surface is determined to be completed.

[0093] In this embodiment, based on the fact that the first wetting angle is less than or equal to the reference wetting angle, it is determined that the surface of the PC compensation film does not require chemical surface activation treatment.

[0094] It is understood that the wetting angle is the contact angle formed by deionized water on the PC compensation film surface, used to characterize the degree of wetting of deionized water on the PC compensation film surface and reflect the surface energy state of the PC compensation film surface. When the PC compensation film surface is irradiated with ultraviolet light, the hydrogen peroxide in the activation solution decomposes to generate hydroxyl radicals, causing oxidation of the PC compensation film surface and introducing oxygen-containing polar groups, which manifests as a decrease in the surface wetting angle.

[0095] In this embodiment, the first wetting angle, the second wetting angle, and the reference wetting angle are measured according to GB / T 30447-2013.

[0096] In this embodiment, the reference wetting angle is 60°. This value is determined by selecting PC compensation film samples from the same batch, of the same material, and with a thickness of 50 μm. Several PC compensation film samples of 10 cm × 10 cm size are cut, and the surfaces of these samples undergo the same cleaning treatment and are irradiated with the same amount of activating solution. The irradiation is performed using a wavelength of 254 nm and an energy of 600 mJ / cm². 2 The PC compensation film samples were surface activated by ultraviolet light. The irradiation distance and the relative position between the PC compensation film and the ultraviolet light source were the same. The ultraviolet light irradiation time was set to 0 min, 5 min, 10 min, 15 min, 20 min, and 30 min, respectively. After the surface activation treatment corresponding to each irradiation time was completed, measurements were performed according to GB / T 30447-2013. 2 μL of deionized water was dropped onto the surface of each PC compensation film sample as the wetting angle test solution, and the wetting angle was measured within 60 s after the droplet formed. Five different positions were selected for measurement of each PC compensation film sample, and the average value of the wetting angle at each position was taken as the wetting angle under the corresponding ultraviolet light irradiation time. The reference wetting angle was determined based on the wetting angle corresponding to different ultraviolet light irradiation times. When the wetting angle is greater than 60°, the decrease in wetting angle is greater than 5° every 5 minutes of irradiation; when the wetting angle decreases to 60° or below, the decrease in wetting angle is less than 5° every 5 minutes of irradiation, indicating that the effect of further increasing the UV irradiation time on reducing the wetting angle of the PC compensation film surface tends to stabilize. Therefore, 60° is determined as the reference wetting angle to distinguish the reference wetting angle between the first activation state and the second activation state.

[0097] Understandably, alkaline pretreatment can remove low-molecular-weight oligomers from the surface of the PC compensation film, reducing obstacles to subsequent activation treatment. The hydrogen peroxide aqueous solution decomposes under ultraviolet light irradiation to generate hydroxyl radicals, causing oxidation of the PC compensation film surface and introducing oxygen-containing polar groups. This increases the surface energy of the PC compensation film surface, resulting in a decrease in the wetting angle. Simultaneously, determining the surface activation state by comparing the wetting angle with a reference wetting angle reduces the influence of different initial surface states of the PC compensation film on the activation treatment results, ensuring the PC compensation film surface reaches a suitable state for subsequent anti-glare coating liquid spreading, thus improving the uniformity of subsequent coating.

[0098] In this embodiment, the preparation process of the anti-glare coating liquid includes:

[0099] Add curable resin, UV-resistant reagent, photoinitiator and solvent to a beaker and mix at 500 r / min and 25°C for 20 min to obtain a resin mixture containing the UV-resistant reagent.

[0100] Organic anti-glare particles were added to the resin mixture and mixed at 1000 r / min and 25°C for 30 min to obtain an anti-glare coating solution.

[0101] In this embodiment, the anti-glare coating liquid comprises a curable resin, an anti-UV agent, a photoinitiator, ethanol, and organic anti-glare particles. The curable resin comprises 100 parts by weight, the anti-UV agent comprises 1 part by weight, the photoinitiator comprises 3 parts by weight, the solvent comprises 120 parts by weight, and the organic anti-glare particles comprises 10 parts by weight. The curable resin is polyurethane acrylate, the anti-UV agent is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, the photoinitiator is 1-hydroxycyclohexylphenyl ketone, the solvent is ethanol, and the organic anti-glare particles are cross-linked polymethyl methacrylate microspheres with a median particle size D50 of 5 μm.

[0102] Specifically, the embodiments of the present invention improve the activation state of the PC compensation film surface through hydrolysis pretreatment and ultraviolet light surface activation treatment, and use the reference wetting angle to determine whether the PC compensation film has reached a surface state suitable for the spread of the anti-glare coating liquid, thereby reducing local shrinkage and coating defects caused by inconsistent surface states in different areas. Furthermore, by utilizing the ultraviolet absorption characteristics of the anti-UV reagent, the anti-UV reagent can have both ultraviolet protection function and wet film thickness indication function, without the need to add tracer components to the anti-glare coating liquid, and the transmission intensity distribution of the coating area can be determined based on the transmission image.

[0103] In this embodiment, the process of determining the coating area on the surface of the PC compensation film includes:

[0104] A 365nm ultraviolet light was perpendicularly irradiated onto the surface of the PC compensation film at a distance of 20cm to acquire a first transmission image of the PC compensation film surface.

[0105] Based on the radial transmission intensity distribution gradient of the first transmission image, the boundary positions of several detection units on the surface of the PC compensation film are determined sequentially.

[0106] A detection unit is defined as the area between the boundary positions of adjacent detection units, and several detection units are arranged radially along the PC compensation film.

[0107] In this embodiment, determining the boundary position of the detection unit includes:

[0108] Based on the transmission intensity distribution along the radial direction of the PC compensation film in the first transmission image, the gradient change value of the transmission intensity is obtained;

[0109] The detection unit boundary position is determined based on the gradient change value of the transmission intensity being greater than or equal to 5% of the average transmission intensity of the PC compensation film.

[0110] Based on the fact that the gradient change value of the transmission intensity is less than 5% of the average transmission intensity of the PC compensation film, the coating area is divided into equal widths with a radial interval of 10-20 mm, and the position between adjacent equal width areas is determined as the boundary position of the detection unit.

[0111] The average transmission intensity is the quotient obtained by summing the gray values ​​of all pixels in the region after the image is acquired using an industrial camera and dividing it by the total number of pixels in the region.

[0112] In this embodiment, the process of determining the average transmission intensity is as follows: after acquiring an image using an industrial camera, the gray values ​​of all pixels in the region are summed and divided by the total number of pixels in the region to obtain the quotient as the average transmission intensity.

[0113] In this embodiment, the determination of the 5% gradient change value of transmission intensity is based on using gradient change values ​​of 2%, 5%, 8%, and 10% as the criteria for determining the boundary position of the detection unit. The same first transmission image is divided into detection units, and the average relative deviation of the transmission intensity of each detection unit is determined based on the corresponding second transmission image. When using a 2% gradient change value as the boundary, a local coating area is further divided into two adjacent detection units with an area ratio of 1:1. The corresponding relative deviations are +17.4% and +18.6%, respectively, both meeting the criteria for determining a coating anomaly area greater than 10%, and both are determined to undergo thickness compensation processing. This indicates that the further division of this local area did not result in different coating anomaly identification results. When using a 5% gradient change value as the boundary, the local coating area with an initial relative deviation of +18.0% and the adjacent area with a relative deviation of +2.0% form independent detection units with an area ratio of 1:2. The relative deviation corresponding to the local coating area remains at +18.0%, reaching... The criteria for identifying coating anomalies are as follows: A region with an initial relative deviation of +18.0% and an adjacent region with a relative deviation of +2.0% are grouped into the same detection unit, with an area ratio of 1:2, and the merged relative deviation is reduced to +7.3%. A region with an initial relative deviation of +22.0% and an adjacent region with a relative deviation of +1.0% are grouped into the same detection unit, with an area ratio of 1:2, and the merged relative deviation is reduced to +8.0%. Neither of these criteria meets the requirement of a coating anomaly exceeding 10%. Therefore, when the gradient change value is too large, the difference in transmission intensity between local coating anomalies is reduced by the averaging effect of adjacent regions during the calculation of the average transmission intensity of the detection unit, thus reducing the ability to identify local coating anomalies. Therefore, 5% is determined as the threshold for the detection unit boundary.

[0114] Understandably, the first transmission image is used to characterize the radial transmission state distribution of the PC compensation film before the anti-glare coating liquid is applied, and to divide the detection units according to the location of transmission intensity changes, so as to determine the detection area of ​​the subsequent anti-glare wet film transmission state; the second transmission image is acquired after the anti-glare wet film is formed, and is used to determine the deviation direction and degree of each detection unit relative to the overall average transmission intensity of the coating area. Therefore, the first transmission image is used to divide the detection units, and the second transmission image is used to determine the coating abnormality area.

[0115] In this embodiment, the process of applying the anti-glare coating liquid to the coating area to form an anti-glare wet film is as follows: using a micro-gravure coating method, the anti-glare coating liquid is applied to the surface of the PC compensation film at a coating speed of 8m / min along the direction of the coating area.

[0116] Please see Figure 2 As shown, this is a logic diagram for determining coating abnormalities based on the relative deviation of transmission intensity in an embodiment of the present invention. In this embodiment, the process of determining coating abnormalities includes:

[0117] Ultraviolet light with a wavelength of 365nm was placed on the uncoated side of the PC compensation film and vertically irradiated for 10s at a distance of 20cm from the uncoated side of the PC compensation film, and a second transmission image was obtained.

[0118] Based on the second transmission image, the average transmission intensity of the coating area is determined, and the average transmission intensity of each detection unit within the coating area is determined respectively.

[0119] Based on the relative deviation between the average transmission intensity of the coating area and the average transmission intensity of the detection unit, the coating abnormality area is determined.

[0120] In this embodiment, the irradiance of the 365nm ultraviolet light is 2.0mW / cm². 2 The irradiance is the irradiance measured by an ultraviolet radiometer at a distance of 20 cm from the uncoated surface of the PC compensation film; the irradiance is 2.0 mW / cm². 2 The imaging energy corresponding to an irradiation time of 10 seconds is 20 mJ / cm². 2 It is far lower than the 300 mJ / cm² of the pre-cured treatment. 2 This is to avoid the anti-glare coating liquid from pre-curing due to ultraviolet light used for imaging, which could interfere with thickness recognition.

[0121] In this embodiment, the process of determining the average transmission intensity of the coating area is as follows: after acquiring the image using an industrial camera, the gray values ​​of all pixels in the entire coating area in the second transmission image are summed and divided by the total number of pixels in the coating area to obtain a quotient value; the average transmission intensity of each detection unit is the sum of the gray values ​​of all pixels in the corresponding detection unit and divided by the total number of pixels in the corresponding detection unit to obtain a quotient value.

[0122] In this embodiment, the first The relative deviation of the transmission intensity of the first detection unit is based on the first... The difference between the average transmission intensity of each detection unit and the average transmission intensity of the coating area is multiplied by 100% to determine the ratio of the difference to the average transmission intensity of the coating area.

[0123] In this embodiment, the coating abnormality area includes a first coating abnormality area and a second coating abnormality area.

[0124] In this embodiment, the first coating abnormality area is defined as the area where the average transmission intensity of the detection unit is less than the average transmission intensity of the coating area in the second transmission image and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%. The second coating abnormality area is defined as the area where the average transmission intensity of the detection unit is greater than the average transmission intensity of the coating area in the second transmission image and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%.

[0125] In this embodiment, detection units with an absolute value of relative deviation greater than 30% are identified as coating defect areas. The coating defect areas are then recoated, and the average transmission intensity and relative deviation of the coating defect areas are re-determined.

[0126] In this embodiment, the range of the relative deviation is determined as follows: Experimentally, when the absolute value of the relative deviation of the detection unit relative to the average transmission intensity of the coating area is less than or equal to 10%, the detection unit does not need local thickness correction; when the relative deviation is +8.6%, local thickness correction is sufficient to meet the condition that the relative deviation is less than or equal to 10%, therefore, the absolute value of the relative deviation being less than or equal to 10% is used as the criterion for not needing local thickness correction or completing thickness correction; when the absolute value of the relative deviation is greater than 10% and less than or equal to 30%, the corresponding area can reduce the relative deviation to less than or equal to 10% through local vibration leveling or thickness compensation processing. When the initial relative deviations are -11.6%, +12.5%, -30.0%, and +30.0%, respectively, after... After appropriate local vibration leveling or thickness compensation treatment, the relative deviations decreased to -3.2%, +3.1%, -6.8%, and +5.9%, respectively. Therefore, the range where the absolute value of the relative deviation is greater than 10% and less than or equal to 30% is defined as the local thickness correction range. When the absolute value of the relative deviation is greater than 30%, the relative deviation of the corresponding area is difficult to reduce to less than or equal to 10% after local vibration leveling or thickness compensation treatment. When the initial relative deviations are -32.8% and +36.5%, respectively, after corresponding treatment, the relative deviations are -14.6% and +17.2%, respectively, neither of which meets the thickness correction completion condition of relative deviation less than or equal to 10%. Therefore, the detection unit where the absolute value of the relative deviation is greater than 30% is defined as the coating defect area, and the coating defect area is re-coated.

[0127] Please see Figure 3 As shown, this is a logic diagram for thickness correction of coating abnormal areas according to an embodiment of the present invention. In this embodiment, the process of thickness correction of the coating abnormal areas includes:

[0128] The first coating abnormal area is subjected to local vibration leveling treatment to obtain the first corrected coating area and determine the average transmission intensity of the first corrected coating area.

[0129] The second coating abnormal area is compensated for in thickness to obtain a second corrected coating area and the average transmission intensity of the second corrected coating area is determined.

[0130] Based on the average transmission intensity of the first and second corrected coating regions, the relative deviations of the two regions relative to the average transmission intensity of the coating region in the second transmission image are determined respectively.

[0131] When the absolute value of the relative deviation corresponding to the first correction coating area and the second correction coating area is less than or equal to 10%, the thickness correction is determined to be complete.

[0132] In this embodiment, the local vibration leveling process involves using a point-contact ultrasonic probe to contact the uncoated surface of the PC compensation film, while keeping the central axis of the probe perpendicular to the surface of the PC compensation film. The probe is moved within the orthographic projection range of the first coating abnormality area onto the uncoated surface of the PC compensation film to vibrate the first coating abnormality area. The vibration frequency is 20–40 kHz, the amplitude is 1–5 μm, and the vibration time is 2 min.

[0133] In this embodiment, the thickness compensation is achieved by using a micro-gravure coating method, applying the compensation coating liquid to the second coating abnormal area at a speed of 5 m / min, so that the compensation coating liquid combines with the original anti-glare wet film in the second coating abnormal area.

[0134] In this embodiment, the compensation coating liquid is the anti-glare coating liquid.

[0135] It is understood that, with the composition of the anti-glare coating liquid and the ultraviolet irradiation conditions remaining constant, changes in the thickness of the anti-glare wet film will cause changes in the ultraviolet transmission intensity. When the thickness of the anti-glare wet film increases, the transmission intensity of ultraviolet light through the anti-glare wet film decreases; when the thickness of the anti-glare wet film decreases, the transmission intensity of ultraviolet light through the anti-glare wet film increases.

[0136] Specifically, in this embodiment of the invention, the anti-glare wet film is irradiated with ultraviolet light and a second transmission image is acquired to obtain the average transmission intensity of the coating area. The average transmission intensity of each detection unit is compared with the average transmission intensity of the coating area, and the deviation direction and degree of deviation of each detection unit relative to the average transmission intensity of the coating area are determined based on the relative deviation between the two. Since changes in the wet film thickness will cause changes in ultraviolet transmission intensity when the composition of the anti-glare coating liquid remains constant, the detection units with local wet film thickness abnormalities are identified based on the relative deviation, and the abnormal coating areas are determined, providing a regional basis for subsequent thickness correction.

[0137] Understandably, local vibration leveling treatment is applied to the first abnormal coating area to diffuse the locally accumulated anti-glare coating liquid into the surrounding area; thickness compensation is applied to the second abnormal coating area to allow the compensation coating liquid to combine with the original anti-glare wet film, thereby increasing the wet film thickness in the second abnormal coating area. After thickness correction is completed, the average transmission intensity of the first and second corrected coating areas is re-acquired to determine whether the local vibration leveling treatment and thickness compensation have restored the abnormal coating area to the allowable wet film thickness range, thus avoiding insufficient or excessive thickness correction from affecting the interface migration of subsequent organic anti-glare particles.

[0138] Specifically, this embodiment of the invention corrects the thickness and then re-acquires ultraviolet transmission images to determine the average transmission intensity of the first corrected coating area and the average transmission intensity of the second corrected coating area. This allows the subsequent adaptive interface migration processing of organic anti-glare particles to be based on the corrected average transmission intensity, reducing the impact of wet film thickness deviation on the particle protrusion height of organic anti-glare particles and providing a basis for forming similar particle protrusion heights in different coating areas.

[0139] Please see Figure 4 As shown, this is a schematic diagram of the interface migration and pre-curing of organic anti-glare particles according to an embodiment of the present invention. In this embodiment, the interface migration process of the organic anti-glare particles includes:

[0140] Place the PC compensation film on a horizontal workbench with the coated surface of the PC compensation film facing upwards and let it stand for 5 to 10 minutes.

[0141] Determine the Spk of the coating area, and stop interface migration when the Spk is between 0.6 μm and 1.2 μm;

[0142] Spk represents the particle protrusion height of the organic anti-glare particles.

[0143] In this embodiment, the method for determining the particle protrusion height includes:

[0144] The surface roughness of the coated area was measured using a surface roughness tester conforming to ISO 25178 to obtain surface roughness data.

[0145] Based on the surface roughness data, the particle protrusion height of the organic anti-glare particles is obtained.

[0146] In this embodiment, the particle protrusion height is represented by Spk of the coated area. Spk is a protrusion peak height parameter determined based on the area-to-material ratio curve. A surface roughness tester conforming to ISO 25178 is used to measure the three-dimensional surface morphology of the coated area to obtain Spk. Spk is then used as the characterization value of the particle protrusion height. Spk, as the protrusion peak height parameter defined by ISO 25178, characterizes the particle protrusion height of the organic anti-glare particles relative to the surrounding resin matrix surface within the coated area. Experiments have determined that when Spk is 0.6–1.2 μm, the particle protrusion height of the organic anti-glare particles within the coated area is within the target protrusion height range. At this point, the anti-glare performance and light transmittance of the resulting anti-glare coating are both achieved.

[0147] In this embodiment, the particle protrusion height is determined based on the following: the particle protrusion height can balance anti-glare performance and light transmittance. Anti-glare film samples with different organic anti-glare particle protrusion heights were prepared. Measurements showed that the corresponding Spk values ​​were 0.3μm, 0.6μm, 0.9μm, 1.2μm, and 1.5μm, respectively. Testing revealed that the haze values ​​for each anti-glare film sample were 32.4%, 41.7%, 48.6%, 54.8%, and 63.5%, respectively, with full light transmittance. The rates were 92.1%, 91.4%, 90.7%, 89.5% and 87.6%, respectively, and the 60° gloss was 86.2 GU, 72.5 GU, 58.7 GU, 47.6 GU and 34.1 GU, respectively. When the Spk was 0.6 μm to 1.2 μm, the haze increased with the increase of the Spk, and the total light transmittance remained above 89%. Therefore, the Spk range of 0.6 μm to 1.2 μm was determined as the target protrusion height characterization range for the particle protrusion height.

[0148] Understandably, the interface migration treatment adjusts the height of the organic anti-glare particles relative to the surrounding resin matrix surface. During the static setting process with the coated surface of the PC compensation film facing upwards, the ethanol in the anti-glare wet film gradually evaporates, reducing the solvent content in the wet film and causing the resin matrix to shrink, thereby changing the relative positional relationship between the organic anti-glare particles and the surrounding resin matrix surface.

[0149] Specifically, the embodiments of the present invention determine the particle protrusion height by correcting the Spk of the coating area, thereby reducing the insufficient or excessive migration of organic anti-glare particles caused by using the same resting time for areas with different wet film thicknesses. This allows the subsequent pre-curing treatment to correspond to the actual migration state of the organic anti-glare particles, enabling the organic anti-glare particles in coating areas with different wet film thicknesses to form similar particle protrusion heights, thus reducing the impact of wet film thickness variations on the optical performance of the anti-glare polarizing film.

[0150] In this embodiment, the pre-curing process involves maintaining a vertical height of 10cm and applying an irradiation at a wavelength of 365nm and an intensity of 10mW / cm. 2 Ultraviolet light is applied to the surface of the PC compensation film coating from top to bottom for 30 seconds to pre-cur the resin on the surface of the coating area, resulting in a pre-cured wet film.

[0151] It is understood that the pre-curing process causes the curable resin near the air-side interface to cross-link before the curable resin inside the wet film, forming a pre-cured resin network to fix the particle protrusion height of the organic anti-glare particles.

[0152] In this embodiment, the stepped heating and shaping process involves subjecting the pre-cured wet film to a stepped heating process.

[0153] In this embodiment, the step-heating process includes:

[0154] The pre-cured wet film is subjected to a first-stage heating treatment at 5°C / min, heated to 50°C and held for 10 min, and exhaust treatment is carried out during the holding process;

[0155] The pre-cured wet film is subjected to a second stage of heating treatment at 5°C / min, heated to 70°C and held for 5 min, and exhaust treatment is carried out during the holding process;

[0156] After the second stage of heat preservation is completed, the exhaust device is turned off and heating is stopped. The film is allowed to cool down naturally to obtain the anti-glare polarizing film.

[0157] The exhaust device is turned off during the first and second stages of heating, and is only turned on during the heat preservation process, so that heating and exhaust alternate.

[0158] In this embodiment, the exhaust process involves turning on the oven's exhaust device during the temperature maintenance stages of 50°C and 70°C, with a 2m exhaust flow rate. 3 The exhaust volume is 1 / min, which forces the hot air containing volatile solvents in the oven to be discharged and replenished with nitrogen; the nitrogen enters the oven from the side of the uncoated surface of the pre-cured wet film.

[0159] In this embodiment, the first-stage temperature and the second-stage temperature are determined based on the volatilization characteristics of residual ethanol in the anti-glare wet film and the shaping requirements of the pre-cured wet film. The anti-glare coating liquid uses ethanol as a solvent, and the evaporation rate of ethanol gradually increases as the temperature rises. In the first stage, the pre-cured wet film is heated to 50°C and held for 10 minutes, allowing the residual ethanol inside the film layer to gradually migrate to the film surface and the gas phase of the oven. During the holding stage, the residual ethanol is removed through exhaust treatment. Subsequently, the temperature is raised to 70°C and held for 5 minutes, allowing the residual ethanol to migrate further and be discharged, and further shaping the pre-cured film layer. The second-stage temperature is lower than the atmospheric pressure boiling point of ethanol to reduce the impact of the concentrated escape of residual solvent in a short time on the local shrinkage of the film layer and the protrusion of particles.

[0160] It is understandable that the exhaust device is turned off during the heating stage to prevent nitrogen from directly blowing on the surface of the pre-cured wet film, thereby reducing the interference of the supplementary airflow on the protrusion height of the organic anti-glare particles that have not yet been fully shaped. The exhaust device is turned on during the heat preservation stage to remove the volatile solvents in the gas phase entering the oven and to supplement nitrogen at the same time. By separating the heating process from the forced exhaust process, the influence of the airflow generated by continuous gas replacement on the protrusion state of the organic anti-glare particles that have not yet been fully shaped is reduced.

[0161] Specifically, in this embodiment of the invention, a pre-cured resin network is formed through a pre-curing process to fix the protrusion height of the organic anti-glare particles formed by interfacial migration. The pre-cured film is then subjected to a stepped heating process, with exhaust gas being vented at constant temperatures of 50°C and 70°C, respectively. This allows residual solvent to migrate and be discharged from the interior of the film in stages as the temperature rises, reducing local shrinkage and surface morphology changes caused by the concentrated escape of volatile components. This reduces the impact of the subsequent solvent removal process on the particle protrusion height and improves the consistency of the microstructure and optical properties of the anti-glare coating surface.

[0162] Example 1

[0163] A PC compensation film with a thickness of 50 μm was selected, and the PC compensation film was subjected to alkaline pretreatment and ultraviolet surface activation treatment. 100 parts by weight of polyurethane acrylate, 1.0 part by weight of UV-326, 3 parts by weight of photoinitiator 184 and 120 parts by weight of ethanol were mixed, and 10 parts by weight of cross-linked polymethyl methacrylate microspheres with a median particle size D50 of 5 μm were added to obtain an anti-glare coating solution.

[0164] The anti-glare coating liquid was applied to the surface of the PC compensation film using a micro-gravure coating method at a coating speed of 8 m / min. A second transmission image was acquired using 365 nm ultraviolet light. Image processing determined the average transmission intensity of the coated area to be 168.2; the average transmission intensity of the first detection unit was 137.9, corresponding to a relative deviation of -18.0%; the average transmission intensity of the second detection unit was 197.3, corresponding to a relative deviation of +17.3%, which were respectively identified as the first and second coating abnormality areas.

[0165] A point-contact ultrasonic probe was used to perform local vibration leveling on the first coating abnormality area. The vibration frequency was 30 kHz, the amplitude was 3 μm, and the vibration time was 2 min. The anti-glare coating liquid was used to compensate for the thickness of the second coating abnormality area at a speed of 5 m / min. After the thickness correction was completed, the average transmission intensity of the first corrected coating area was 161.6, with a relative deviation of -3.9%; the average transmission intensity of the second corrected coating area was 175.4, with a relative deviation of +4.3%, both within the range of [-10%, +10%], thus confirming that the thickness correction was successful.

[0166] The thickness-corrected PC compensation film was placed horizontally with the coated surface facing upwards, and interface migration treatment was performed. Interface migration was stopped when the measured Spk value was between 0.6 μm and 1.2 μm, with an actual settling time of 6 minutes. Measurements were taken at five locations within the coated area, with Spk values ​​of 0.86 μm, 0.90 μm, 0.92 μm, 0.88 μm, and 0.91 μm, respectively. The average value was 0.894 μm, and the range was 0.06 μm.

[0167] Subsequently, an irradiation intensity of 10 mW / cm² was applied at a wavelength of 365 nm. 2 The film is pre-cured by irradiating it with ultraviolet light at a distance of 10cm for 30 seconds; then the temperature is increased to 50℃ at 5℃ / min and held for 10 minutes. During the heat preservation stage, the first venting is performed. Then the temperature is increased to 70℃ at 5℃ / min and held for 5 minutes. During the heat preservation stage, the second venting is performed. After completion, the film is allowed to cool naturally to obtain the anti-glare polarizing film.

[0168] The test results showed that the Spk of the anti-glare polarizing film at five test locations was 0.86–0.92 μm, the haze was 47.7%–49.0%, and the average haze was 48.4%; the total light transmittance was 90.6%–90.8%, and the average total light transmittance was 90.7%; the 60° gloss was 58.0 GU–60.5 GU, and the average was 59.0 GU.

[0169] Example 2

[0170] The same raw material composition and preparation method as in Example 1 were used, except that the average transmission intensity of the coated area in the second transmission image was 171.0, the average transmission intensity of the first detection unit and the second detection unit were 131.6 and 213.8, respectively, and the corresponding relative deviations of transmission intensity were -23.0% and +25.0%, respectively.

[0171] The first coating abnormality area was locally vibrated and leveled for 2 minutes using point-contact ultrasonic vibration at 40 kHz and 5 μm amplitude, and thickness compensation was performed on the second coating abnormality area. After thickness correction, the average transmission intensities of the first and second corrected coating areas were 159.4 and 181.1, respectively, with corresponding relative deviations of -6.8% and +5.9%, confirming that the thickness correction was successful.

[0172] Interface migration was performed, with Spk as the endpoint. In this embodiment, the actual settling time corresponding to the target protrusion height was 8 minutes. The Spk values ​​at the five test locations were 1.02 μm, 1.07 μm, 1.10 μm, 1.04 μm, and 1.08 μm, with an average value of 1.062 μm and a range of 0.08 μm.

[0173] The same pre-curing and stepped heating exhaust treatment as in Example 1 was used. The resulting anti-glare polarizing film had a haze of 51.1%–52.7%, with an average of 51.9%; a total light transmittance of 89.9%–90.2%, with an average of 90.1%; and a 60° gloss of 51.3 GU–54.3 GU, with an average of 52.7 GU.

[0174] Example 3

[0175] The same raw material composition and preparation method as in Example 1 were used, except that the average transmission intensity of the coated area in the second transmission image was 165.5, and the average transmission intensities of the first detection unit and the second detection unit were 143.4 and 187.8, respectively, with corresponding relative deviations of -13.4% and +13.5%, respectively.

[0176] Local vibration leveling was performed using point-contact ultrasonic vibration at 20 kHz and an amplitude of 1 μm, with thickness compensation applied. After thickness correction, the average transmission intensities of the first and second corrected coating areas were 160.2 and 170.7, respectively, with corresponding relative deviations of -3.2% and +3.1%.

[0177] Interface migration processing was performed, with Spk as the endpoint of the interface migration. In this embodiment, the actual resting time corresponding to the target protrusion height was 5 minutes. The Spk values ​​at the five test locations were 0.70 μm, 0.73 μm, 0.76 μm, 0.71 μm, and 0.74 μm, respectively, with an average value of 0.728 μm and a range of 0.06 μm.

[0178] After undergoing the same pre-curing and stepped heating and exhaust treatment as in Example 1, the haze of the obtained anti-glare polarizing film was 44.0%–45.4%, with an average of 44.6%; the total light transmittance was 91.0%–91.2%, with an average of 91.1%; and the 60° gloss was 65.1 GU–67.9 GU, with an average of 66.6 GU.

[0179] Comparative Example 1

[0180] Using the same raw material composition and coating method as in Example 1, the relative deviations of the transmission intensity of the first detection unit and the second detection unit in the second transmission image were -18.0% and +17.3%, respectively. However, no thickness correction was performed on the first and second coating abnormal areas. Instead, interface migration was performed directly, and a fixed standing time of 6 minutes was adopted. The remaining pre-curing and stepped temperature rise shaping conditions were the same as in Example 1.

[0181] The Spk values ​​of the obtained anti-glare polarizing film at five test locations were 0.48 μm, 0.63 μm, 0.91 μm, 1.27 μm and 1.38 μm, respectively, with a Spk range of 0.90 μm; the corresponding haze was 38.0% to 60.0%, the total light transmittance was 88.4% to 91.7%, and the 60° gloss was 39.5 GU to 78.0 GU.

[0182] Comparative Example 2

[0183] The identification of coating abnormal areas and thickness correction were completed using the same method as in Example 2. However, the interface migration process was not terminated when Spk reached 0.6 to 1.2 μm. Instead, a fixed standing time of 6 minutes was used. All other conditions were the same as in Example 2.

[0184] The Spk values ​​of the obtained anti-glare polarizing film at five test locations were 0.54 μm, 0.61 μm, 0.68 μm, 0.74 μm and 0.79 μm, respectively, with an average value of 0.672 μm and a range of 0.25 μm; the corresponding haze was 39.8% to 46.1%, the total light transmittance was 91.0% to 91.5%, and the 60° gloss was 63.8 GU to 75.2 GU.

[0185] Comparative Example 3

[0186] The same method as in Example 1 was used to complete the identification of coating abnormal areas, thickness correction, interface migration and pre-curing treatment. The difference is that after pre-curing, the stepped heating and venting method of turning off the venting device during the heating stage and turning on the venting device during the heat preservation stage was not used. Instead, the temperature was continuously increased from room temperature to 70°C at 5°C / min, and the venting device was continuously turned on throughout the heating stage. The other conditions were the same as in Example 1.

[0187] After the heating treatment, the Spk values ​​at the five test locations were 0.69 μm, 0.74 μm, 0.79 μm, 0.82 μm, and 0.86 μm, respectively, with an average value of 0.78 μm and a range of 0.17 μm. The corresponding haze was 43.8%–47.7%, the total light transmittance was 90.8%–91.2%, and the 60° gloss was 60.5 GU–68.4 GU.

[0188] Example and Comparative Test Results

[0189]

[0190] In this embodiment of the invention, a comparison between Example 1 and Comparative Example 1 shows that after local thickness correction of the coating abnormal area, the Spk range of the five test locations decreased from 0.90 μm in Comparative Example 1 to 0.06 μm in Example 1, indicating that correcting the coating abnormal area can reduce the transmission of local coating differences to subsequent particle protrusion structures.

[0191] As can be seen from the comparison between Example 2 and Comparative Example 2, after the thickness correction is completed, the particle protrusion height reaches 0.6μm to 1.2μm as the endpoint of interface migration. Compared with the use of a uniform fixed resting time, the protrusion height of organic anti-glare particles in different areas can be concentrated in the target range, reducing the surface structure differences caused by insufficient or excessive migration of organic anti-glare particles.

[0192] As can be seen from the comparison between Example 1 and Comparative Example 3, after pre-curing, a stepped heating method is used, and venting is performed in each constant temperature stage. This allows the solvent removal and film temperature change to occur in stages. Compared with continuous heating and continuous venting, the change in particle protrusion height after the stepped heating and shaping treatment is smaller, which is beneficial to maintaining the protruding state of the particles formed by pre-curing.

[0193] In summary, under the condition of different initial relative deviations in transmission intensity, after correcting the thickness of the coating abnormal area, determining the interface migration endpoint by the particle protrusion height, and performing pre-curing and stepped heating and degassing treatments, the Spk of the obtained anti-glare polarizing film was maintained within the range of 0.6μm to 1.2μm. Furthermore, the haze, total light transmittance, and 60° gloss at different test locations were kept to have small regional differences, thus demonstrating the adaptability of the preparation method to local coating fluctuations.

[0194] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an anti-glare polarizing film based on adaptive coating thickness control, characterized in that, include: The surface of the PC compensation film is cleaned and chemically activated, and an anti-glare coating liquid containing organic anti-glare particles is prepared. The coating area on the surface of the PC compensation film is determined, and the coating area is divided into several detection units arranged radially along the PC compensation film. The boundary between adjacent detection units is the detection unit boundary position. The anti-glare coating liquid is applied to the coating area to form an anti-glare wet film. Acquire a transmission image of the coating area of ​​the anti-glare wet film, and determine the average transmission intensity of the coating area and the average transmission intensity of the detection unit; Based on the average transmission intensity of the coating area and the average transmission intensity of the detection unit, the relative deviation of the detection unit relative to the average transmission intensity of the coating area is obtained, and the coating abnormal area is determined. The thickness of the coating abnormal area is corrected, and based on the relative deviation of the average transmission intensity of the coating abnormal area after thickness correction, the thickness correction is completed, and a corrected wet film is obtained. The organic anti-glare particles in the corrected wet film are subjected to interface migration treatment to determine the particle protrusion height, and a coating to be cured is obtained. The coating to be cured is pre-cured to limit the continued migration of the organic anti-glare particles, resulting in a pre-cured wet film. The pre-cured wet film is then subjected to a stepped temperature setting process to obtain an anti-glare polarizing film.

2. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 1, characterized in that, The process of determining whether the PC compensation film surface has undergone chemical surface activation treatment includes: Based on the activation state of the PC compensation film surface, determine whether the PC compensation film surface has completed chemical surface activation treatment; Before applying the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the first wetting angle formed between the deionized water and the surface of the PC compensation film is collected. Based on the fact that the first wetting angle is greater than the reference wetting angle, the surface of the PC compensation film is determined to be in the first activated state, and the surface of the PC compensation film is subjected to chemical surface activation treatment. After removing the activation solution, deionized water is dropped onto the surface of the PC compensation film, and the second wetting angle formed between the deionized water and the surface of the PC compensation film is collected. Based on the fact that the second wetting angle is greater than the reference wetting angle, it is determined that the surface of the PC compensation film remains in the first activated state, and chemical surface activation treatment continues. Based on the second wetting angle being less than or equal to the reference wetting angle, the surface of the PC compensation film is determined to be in a second activated state, and the chemical surface activation treatment of the PC compensation film surface is determined to be completed.

3. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 1, characterized in that, The process of determining the coating area on the surface of the PC compensation film includes: A 365nm ultraviolet light was perpendicularly irradiated onto the surface of the PC compensation film at a distance of 20cm to acquire a first transmission image of the PC compensation film surface. Based on the radial transmission intensity distribution gradient of the first transmission image, the boundary positions of several detection units on the surface of the PC compensation film are determined sequentially. A detection unit is defined as the area between the boundary positions of adjacent detection units, and several detection units are arranged radially along the PC compensation film.

4. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 3, characterized in that, The determination of the boundary position of the detection unit includes: Based on the transmission intensity distribution along the radial direction of the PC compensation film in the first transmission image, the gradient change value of the transmission intensity is obtained; The detection unit boundary position is determined based on the gradient change value of the transmission intensity being greater than or equal to 5% of the average transmission intensity of the PC compensation film. Based on the fact that the gradient change value of the transmission intensity is less than 5% of the average transmission intensity of the PC compensation film, the coating area is divided into equal widths with a radial interval of 10-20 mm, and the position between adjacent equal width areas is determined as the boundary position of the detection unit. The average transmission intensity is the quotient obtained by summing the gray values ​​of all pixels in the region after the image is acquired using an industrial camera and dividing it by the total number of pixels in the region.

5. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 1, characterized in that, The process of identifying areas of coating abnormality includes: Ultraviolet light with a wavelength of 365nm was placed on the uncoated side of the PC compensation film and vertically irradiated for 10s at a distance of 20cm from the uncoated side of the PC compensation film, and a second transmission image was obtained. Based on the second transmission image, the average transmission intensity of the coating area is determined, and the average transmission intensity of each detection unit within the coating area is determined respectively. Based on the relative deviation between the average transmission intensity of the coating area and the average transmission intensity of each detection unit, the coating abnormal area is determined. The coating abnormality area includes a first coating abnormality area and a second coating abnormality area. The first coating abnormality area is defined as the area where the average transmission intensity of the detection unit is less than the average transmission intensity of the coating area, and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%. The second coating abnormality area is defined as the area where the average transmission intensity of the detection unit is greater than the average transmission intensity of the coating area, and the absolute value of the relative deviation is greater than 10% and less than or equal to 30%. The detection units with an absolute value of relative deviation greater than 30% are identified as coating defect areas, and the coating defect areas are recoated. The average transmission intensity and relative deviation of the coating defect areas are then re-determined.

6. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 5, characterized in that, The process of correcting the thickness of the coating abnormal area includes: The first coating abnormal area is subjected to local vibration leveling treatment to obtain the first corrected coating area and determine the average transmission intensity of the first corrected coating area. The second coating abnormal area is compensated for in thickness to obtain a second corrected coating area and the average transmission intensity of the second corrected coating area is determined. Based on the average transmission intensity of the first and second corrected coating regions, the relative deviations of the two regions relative to the average transmission intensity of the coating region in the second transmission image are determined respectively. When the absolute value of the relative deviation corresponding to the first correction coating area and the second correction coating area is less than or equal to 10%, the thickness correction is determined to be complete.

7. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 6, characterized in that, The local vibration leveling process involves using a point-contact ultrasonic probe to contact the uncoated surface of the PC compensation film, while keeping the central axis of the probe perpendicular to the surface of the PC compensation film. The probe is then moved within the orthographic projection range of the first coating abnormality area onto the uncoated surface of the PC compensation film to vibrate the first coating abnormality area. The thickness compensation process involves applying a compensation coating liquid to the second coating abnormality area, allowing the compensation coating liquid to combine with the original anti-glare wet film within the second coating abnormality area. The compensation coating liquid is the anti-glare coating liquid.

8. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 1, characterized in that, The interface migration process of the organic anti-glare particles includes: Place the PC compensation film on a horizontal workbench with the coated surface of the PC compensation film facing upwards and let it stand for 5 to 10 minutes. Determine the Spk of the coating area, and stop interface migration when the Spk is between 0.6 μm and 1.2 μm; Spk represents the particle protrusion height of the organic anti-glare particles.

9. The method for preparing an anti-glare polarizing film based on adaptive coating thickness control according to claim 1, characterized in that, The stepped heating and shaping process includes: The pre-cured wet film is subjected to a first-stage heating treatment at 5°C / min, heated to 50°C and held for 10 min, and exhaust treatment is carried out during the holding process; The pre-cured wet film is subjected to a second stage of heating treatment at 5°C / min, heated to 70°C and held for 5 min, and exhaust treatment is carried out during the holding process; After the second stage of heat preservation is completed, the exhaust device is turned off and heating is stopped. The film is allowed to cool down naturally to obtain the anti-glare polarizing film. The exhaust device is turned off during the first and second stages of heating, and is only turned on during the heat preservation process, so that heating and exhaust alternate.

10. An anti-glare polarizing film prepared by the method for preparing an anti-glare polarizing film based on adaptive coating thickness control as described in any one of claims 1-9, characterized in that, The anti-glare polarizing film includes a PC compensation film and an anti-glare coating formed on the surface of the PC compensation film. The anti-glare coating comprises a curable resin, an anti-UV agent, a photoinitiator, and organic anti-glare particles. The curable resin comprises 100 parts by weight, the anti-UV agent comprises 1 part by weight, the photoinitiator comprises 3 parts by weight, and the organic anti-glare particles comprise 10 parts by weight. The curable resin is polyurethane acrylate, the anti-UV agent is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, the photoinitiator is 1-hydroxycyclohexylphenyl ketone, and the organic anti-glare particles are cross-linked polymethyl methacrylate microspheres with a median particle size D50 of 5 μm.

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