Preparation method of anti-dazzle film with anti-dazzle and high transmission definition

Abstract

The invention belongs to the technical field of anti-dazzle film manufacturing, and discloses a preparation method of an anti-dazzle film with anti-dazzle and high transmission definition, and the method comprises the following steps: step 1, firstly preparing a coating liquid for forming a hard coating with a fine irregular shape on a transparent carrier; a transparent carrier is coated with a solution containing an active energy ray curing compound and a coating solution containing filler particles, a transparent support body is made of polyethylene glycol terephthalate, polybutylene terephthalate, polyethylene naphthalate glycol ester, a polyethylene film and a polypropylene film from plastic films, the thickness of the transparent support body ranges from 30 micrometers to 200 micrometers, and the thickness of the transparent support body ranges from 30 micrometers to 200 micrometers. And carrying out surface treatment on one or two surfaces of the transparent support body through an oxidation method and a roughening method. The anti-glare film of the present invention has an excellent anti-glare function, has high transmission definition, and has good visibility when used in various displays, including a liquid crystal display, a plasma display, a cathode ray tube, and a touch panel.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-glare film manufacturing, and particularly relates to a method for effectively manufacturing an anti-glare film. The anti-glare film has excellent anti-glare function, high transmission clarity, good visibility when used in various displays, including liquid crystal displays (LCDs), plasma displays (PDPs), cathode ray tubes (CRTs), and touch panels, and high surface hardness, and can also be used as a surface protection film, as well as an anti-glare film having the above properties. Background Art

[0002] In displays such as CRTs and liquid crystal displays, light enters the screen from the outside, and this light may be reflected (referred to as glare or dazzle), making it difficult to see the displayed image. In particular, in recent years, as the size of displays has increased, solving the above problems has become increasingly important. To solve such problems, various anti-glare measures have been taken for various displays so far. These include anti-glare treatments that roughen the surface of the hard coating film for the polarizing plate used in liquid crystal displays, the hard coating film for protecting various displays, etc. The anti-glare treatment method of this hard coating film can generally be divided into (1) a method of roughening the surface by a physical method during curing to form a hard coating film and (2) a method of mixing fillers in a hard coating agent to form a hard coating film. Among these two methods, the latter method of incorporating fillers into the hard coating agent is the mainstream, and silica particles are mainly used as the fillers. The reasons for using silica particles include that the whiteness of the obtained hard coating film can be reduced, the hardness will not be reduced, and it has good dispersibility when the silica particles are mixed into the coating agent. At the same time, in order for the anti-glare hard coating film to have excellent visibility when used in various displays, it is required that the anti-glare hard coating film has excellent anti-glare function and transmission clarity.

[0003] In a conventional anti-glare hard coating film, in order to satisfy the above-described required characteristics, measures for preventing sedimentation of filler particles in the coating film are usually taken. For example, a method has been tried in which silica particles having an average particle diameter of 0.5 to 5 μm and fine particles having an average particle diameter of 1 to 60 nm are combined and included in the hard coat. On the other hand, an anti-scratch anti-glare film has been proposed in which an anti-glare layer composed of resin beads having a refractive index of 1.40 to 1.60 and an ionizing radiation curable resin composition is formed on a transparent substrate. In this anti-glare film, it is preferable to use polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylate styrene beads, and polyvinyl chloride beads having a particle diameter in the range of 3 to 8 μm as the resin beads, and less than 0.1 part by weight of silica beads having a particle diameter of 0.5 μm or less is added to 100 parts by weight of the ionizing radiation curable resin to prevent precipitation of these resin beads in the coating agent. However, in order to obtain a high anti-glare effect, it is necessary to add a large amount of filler to the coating solution. As a result, the anti-glare function and the transmission clarity have opposite properties, resulting in a decrease in transmission clarity. In a conventional anti-glare film, it is difficult to simultaneously achieve an excellent anti-glare function and high transmission clarity. SUMMARY OF THE INVENTION

[0004] An object of the present invention is to provide a method for effectively manufacturing an anti-glare film that has an excellent anti-glare function, high transmission clarity, good visibility when used in various displays, high surface hardness, and serves as a surface protection film, and to provide an anti-glare film having the above-described properties.

[0005] To achieve the above object, the present invention provides the following technical solution: A method for preparing an anti-glare film having anti-glare and high transmission clarity, the method comprising the following steps:

[0006] Step 1, first prepare a coating solution for forming a hard coat having a fine irregular shape on a transparent carrier; apply a solution containing a radiation-curable compound and a coating solution containing filler particles on the transparent carrier, the transparent support is selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, and polypropylene film in plastic films, and the thickness is selected in the range of 30 to 200 μm, and one or both surfaces of the transparent support are surface-treated by an oxidation method or a roughening method;

[0007] Step 2, drying treatment to form a coating film

[0008] Apply the coating liquid of Step 1 onto a transparent carrier to form an undried coating film. Then, after setting the undried coating film on the transparent support in this way, install the transparent support with the surface of the undried coating film facing downwards, and perform a hot air drying treatment from the coating film surface side or the transparent support surface side. Thus, during the process of drying the undried coating film, the filler particles gradually settle towards the coating film surface side under the action of gravity, and when the coating film dries, the content density of the filler particles gradually becomes denser from the transparent support side towards the hard coating surface; due to the content density of the filler particles having an inclined structure,

[0009] Step 3: Then irradiate the coating film with active energy rays and cure it to form a hard coating having a fine uneven shape, with a large number of filler particles unevenly distributed near its surface, exhibiting a high anti-glare function; examples of the active energy rays are ultraviolet rays, which are obtained from a high-pressure mercury lamp, a fusion H lamp, or a xenon lamp, and the irradiation dose is usually 100 - 500 mJ / cm 2 , and the thickness of the hard coating formed in this way is 4 - 6 μm;

[0010] Step 4: The hard coating has an inclined structure in which the content density of the included filler particles gradually becomes denser from the transparent support side towards the hard coating surface, and many filler particles are unevenly distributed near the hard coating surface. This inclined structure is confirmed by the following method; photograph the cross-section of the hard coating with a scanning electron microscope (SEM) and divide it into a surface layer, an intermediate layer, and a bottom layer, such that each layer has almost the same area. In the cross-sectional area of each layer, calculate the area ratio of the included filler particles. If the value of (area ratio of the included filler particles in the surface layer) / (area ratio of the included filler particles in the bottom layer) is greater than 5, it is assumed to have an inclined structure.

[0011] Preferably, examples of the coating liquid include a solution containing an active energy ray-curable compound as a basic component and optionally containing a photoinitiator and various other additive components, as well as filler particles that impart an anti-glare function; examples of the active energy ray-curable compound include an active energy ray-polymerizable prepolymer and / or an active energy ray-polymerizable monomer; the active energy ray-polymerizable prepolymers include free radical polymerization type and cationic polymerization type, and examples of the free radical polymerization type active energy ray-polymerizable prepolymers include polyester acrylate, epoxy acrylate, polyurethane acrylate, and polyol acrylate.

[0012] Preferably, examples of solvents for preparing solutions containing photo-curable compounds as a basic component include one or more of aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane and vinyl chloride, alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, esters such as cyclohexanone, esters such as ethyl acetate and butyl acetate, and ethylene glycol ether solvents such as propylene glycol monomethyl ether used in combination.

[0013] Preferably, examples of various additive components used as needed include antioxidants, ultraviolet absorbers, light stabilizers, leveling agents and defoaming agents.

[0014] Preferably, in the coating liquid, the filler particles contained together with the solution containing the photo-curable compound as a basic component have a specific gravity greater than that of the solution and do not have too much adverse effect on the transmission clarity of the obtained antiglare film. The type of filler particles is any one of inorganic particles and organic particles, or a mixture thereof.

[0015] Preferably, examples of inorganic particles include silica, barium sulfate, calcium carbonate, talc, kaolin, titanium dioxide, zirconium oxide, mica and glass beads, and examples of organic particles include polymethyl methacrylate particles, polycarbonate particles, polystyrene particles, polypropylene styrene particles, polyvinyl chloride particles, benzoguanamine resin particles and benzoguanamine / melamine / formaldehyde condensate particles; these filler particles can be used alone or in combination of two or more. Among them, silica particles are selected according to the antiglare function, hard coating function, transmission clarity of the obtained antiglare film, and the specific gravity of the particles themselves. When silica particles are used as filler particles, the silica particles are obtained by treating their surfaces with an organic surface treatment agent. As the organic surface treatment agent, a silane coupling agent, silicone oil and silicone wax are used.

[0016] Preferably, the average particle size of the filler particles is 1.2 to 3.0 μm, and the shape of the filler particles is selected to be spherical because they are easier to settle.

[0017] Preferably, examples of the oxidation method include corona discharge treatment, and examples of the roughening method include sandblasting method and solvent treatment method.

[0018] Preferably, in step 2, examples of the drying method include infrared heating drying, electric heating drying, hot plate heating drying, and hot air convection drying. Among them, from the perspective of easily controlling the gradient structure of the filler particle content density, the hot air convection drying method is selected; this hot air convection drying system is a convective electrothermal drying system that blows hot air onto the surface of the undried coating film and / or the side of the transparent support. According to this hot air convection drying system, the drying rate of the undried coating film can be easily controlled in the following ways: (1) keeping the temperature of the hot air constant and changing the wind speed; (2) keeping the wind speed of the hot air constant and changing the temperature; (3) changing the temperature and wind speed of the hot air. By controlling the gradient structure of the content density of the filler particles in the dried coating film through the temperature of the hot air and the drying speed of the undried coating film, the anti-glare function can be easily controlled. In addition, when the undried coating film is dried at the same temperature, the anti-glare performance is improved when hot air is blown onto the surface side of the coating film.

[0019] Preferably, the hot air temperature in the hot air convection drying system is in the range of 35 - 70 °C because the content density of the filler particles in the dried coating film can form the required inclined structure; in addition, from the perspective of forming the inclined structure, the thickness of the undried coating film is 10 - 20 μm.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The anti-glare film has excellent anti-glare function, high transmission clarity, good visibility when used in various displays, including liquid crystal displays (LCDs), plasma displays (PDPs), cathode ray tubes (CRTs), and touch panels, and has high surface hardness, and can also be used as a surface protection film, as well as an anti-glare film with the above properties;

[0022] 2. In the anti-glare film prepared by this drying method, when the content of filler particles in the entire hard coating is the same as that in the hard coating of the traditional anti-glare film, the transmission clarity is basically the same as that of the traditional anti-glare film, but the anti-glare function is significantly improved. In addition, even when the content of filler particles in the entire hard coating is much lower than that in the hard coating of the traditional anti-glare film, it can still exhibit the same anti-glare function as the traditional anti-glare film. In this case, due to the smaller content of filler particles, the transmission clarity is higher than that of the traditional anti-glare film, and the strength of the hard coating and the adhesion to the transparent support are improved;

[0023] 3. This method also provides an anti-glare film with an inclined structure, in which the content density of the filler particles in the hard coating becomes denser from the transparent support side to the surface of the hard coating, and the transmission clarity / 60° gloss value is greater than 2.2. That is, although the 60° gloss value is low, the anti-glare film of this method has high transmission clarity. Description of the Drawings

[0024] Figure 1 is the technical roadmap of the present invention;

[0025] Figure 2 is the performance and tilt structure diagram of the anti-glare film. Specific embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] A preparation method of an anti-glare film with anti-glare and high transmission clarity, the method comprising the following steps:

[0028] Step 1, first prepare a coating solution for forming a hard coating with a fine irregular shape on a transparent carrier; apply a solution containing a photoactive radiation-curable compound and a coating solution containing filler particles on the transparent carrier. The transparent support is selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film and polypropylene film in plastic films, and the thickness is selected in the range of 30-200 μm, and one or both surfaces of the transparent support are surface-treated by an oxidation method or a roughening method;

[0029] Step 2, drying treatment to form a coating film

[0030] Apply the coating solution of Step 1 on the transparent carrier to form an undried coating film. Then, after the undried coating film is set on the transparent support in this way, install the transparent support with the surface of the undried coating film facing down, and perform hot air drying treatment from the coating film surface side or the transparent support surface side. Thus, during the drying of the undried coating film, the filler particles gradually settle to the coating film surface side under the action of gravity, and when the coating film is dried, the content density of the filler particles gradually becomes denser from the transparent support side to the hard coating surface; due to the content density of the filler particles having an inclined structure,

[0031] Step 3, then irradiate the coating film with photoactive radiation and cure it to form a hard coating with a fine concavo-convex shape, so that a large number of filler particles are unevenly distributed near its surface, showing a high anti-glare function; examples of the photoactive radiation include ultraviolet rays, and the ultraviolet rays are obtained from a high-pressure mercury lamp, a fusion H lamp, and a xenon lamp, and the irradiation dose is usually 100-500 mJ / cm 2 , and the thickness of the hard coating formed in this way is 4-6 μm;

[0032] Step 4. The hard coat has an inclined structure in which the content density of the included filler particles gradually becomes denser from the transparent support side toward the surface of the hard coat, and many filler particles are unevenly distributed near the surface of the hard coat. This inclined structure is confirmed by the following method: photograph the cross-section of the hard coat with a scanning electron microscope (SEM) and divide it into a surface layer, an intermediate layer, and a bottom layer such that each layer has almost the same area. In the cross-sectional area of each layer, calculate the area ratio of the included filler particles. If the value of (area ratio of the included filler particles in the surface layer) / (area ratio of the included filler particles in the bottom layer) is greater than 5, it is assumed to have an inclined structure. The arithmetic mean roughness Ra of the hard coat surface is 0.3 μm. In addition, the 10-point mean roughness Rz is 5 μm. The arithmetic mean roughness Ra and the 10-point mean roughness Rz are measured values. In the antiglare film obtained by this method, the general transmittance clarity is 150 or higher, the 60° gloss value is 80 or lower, and the haze value is 12% or higher. The transmittance clarity is an index of visibility. When this value is less than 150, sufficient display image quality (visibility) cannot be obtained. The transmittance clarity is the sum of four slits measured according to JIS K 7105. In addition, the 60° gloss value and the haze value are indexes of antiglare property. If the 60° gloss value exceeds 80, the surface glossiness is large (large light reflection), which has an adverse effect on the antiglare property. If the haze value is less than 12%, sufficient antiglare property cannot be exerted. The gloss value is a value measured according to JIS K7361, and the haze value is a value measured according to JISK 7136. Considering the balance among antiglare property, display image quality (visibility), and light transmittance, the transmittance clarity is 150 - 250, the 60° gloss value is 25 - 80, and the haze value is 12% - 30%. In addition, by reducing the content of the filler particles in the hard coat, the transmittance clarity can be increased to 200 or higher while maintaining the 60° gloss value at around 70. In this method, an antireflection layer including a siloxane-based film and a fluorine-based film can be provided on the surface of the hard coat to provide antireflection performance. In this case, the thickness of the antireflection layer is preferably about 0.05 - 0.2 μm. The reflectance at a wavelength of 550 nm is 3.5% or less. By providing the antireflection layer, the screen reflection caused by the reflection of sunlight and fluorescent lamps is eliminated, and by suppressing the reflectance of the surface, the total light transmittance is increased and the transparency is improved. Depending on the type of the antireflection layer, the antistatic property is improved. A pressure-sensitive adhesive layer for adhering to an adherend can be formed on the surface of the transparent support opposite to the hard coat. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, a pressure-sensitive adhesive for optical use is used, including an acrylic-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. The thickness of the pressure-sensitive adhesive layer is in the range of 10 - 60 μm. A release sheet can be provided on the PSA layer. Examples of the release sheet include release sheets obtained by coating a silicone resin release agent on glassine paper, coated paper, laminated paper, and various plastic films.The thickness of the release sheet is 20 to 150 μm. The method also provides an antiglare film having an inclined structure, in which the content density of the filler particles in the hard coat becomes denser from the transparent support side to the hard coat surface, and the transmittance clarity / 60° gloss value is greater than 2.2. That is, although the 60° gloss value is low, the antiglare film of the method has high transmittance clarity.

[0033] In this embodiment, examples of the coating liquid include a solution containing a radiation-curable compound as a basic component and optionally containing a photoinitiator and various other additive components, and filler particles that impart an antiglare function; examples of the radiation-curable compound include a radiation-polymerizable prepolymer and / or a radiation-polymerizable monomer; the radiation-polymerizable prepolymers include radical polymerization type and cationic polymerization type, and examples of the radical polymerization type radiation-polymerizable prepolymers include polyester acrylate, epoxy acrylate, polyurethane acrylate, and polyol acrylate.

[0034] In this embodiment, examples of the solvent for preparing a solution containing a radiation-curable compound as a basic component include one or more of aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane and vinyl chloride, alcohols such as methanol, ethanol, propanol, and butanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, esters such as cyclohexanone, esters such as ethyl acetate and butyl acetate, and ethylene glycol ether solvents such as propylene glycol monomethyl ether.

[0035] In this embodiment, examples of the various additive components used as needed include antioxidants, ultraviolet absorbers, light stabilizers, leveling agents, and defoaming agents.

[0036] In this embodiment, in the coating liquid, the filler particles contained together with the solution containing a radiation-curable compound as a basic component have a specific gravity greater than that of the solution and do not have too much adverse effect on the transmittance clarity of the obtained antiglare film. The type of the filler particles is any one of inorganic particles and organic particles, or a mixture thereof.

[0037] In this embodiment, examples of the inorganic particles include silica, barium sulfate, calcium carbonate, talc, kaolin, titanium dioxide, zirconium oxide, mica, and glass beads, and examples of the organic particles include polymethyl methacrylate particles, polycarbonate particles, polystyrene particles, polypropylene styrene particles, polyvinyl chloride particles, benzoguanamine resin particles, and benzoguanamine / melamine / formaldehyde condensate particles; these filler particles can be used alone or in combination of two or more. Among them, silica particles are selected according to the antiglare function, hard coat function, transmission clarity of the obtained antiglare film, and the specific gravity of the particles themselves. When the silica particles are used as the filler particles, the silica particles are obtained by treating their surfaces with an organic surface treatment agent. As the organic surface treatment agent, a silane coupling agent, silicone oil, and silicon wax are used.

[0038] In this embodiment, the average particle size of the filler particles is 1.2 - 3.0 μm, and the shape of the filler particles is selected as spherical because they are easier to settle.

[0039] In this embodiment, examples of the oxidation method use corona discharge treatment, and examples of the roughening method include sandblasting and solvent treatment.

[0040] In this embodiment, in step 2, examples of the drying method include infrared heating drying, electric heating drying, hot plate heating drying, and hot air convection drying. Among them, from the viewpoint of easily controlling the gradient structure of the filler particle content density, the hot air convection drying method is selected; this hot air convection drying system is a convective electrothermal drying system that blows hot air onto the surface of the undried coating film and / or the transparent support side. According to this hot air convection drying system, the drying rate of the undried coating film can be easily controlled in the following ways: (1) keeping the temperature of the hot air constant and changing the wind speed; (2) keeping the wind speed of the hot air constant and changing the temperature; (3) changing the temperature and wind speed of the hot air. By the temperature of the hot air and the drying speed of the undried coating film, the gradient structure of the filler particle content density in the dried coating film is controlled, so that the antiglare function can be easily controlled. In addition, when the undried coating film is dried at the same temperature, when hot air is blown onto the coating film surface side, the antiglare performance is improved.

[0041] In this embodiment, the hot air temperature in the hot air convection drying system is in the range of 35 - 70 °C because the content density of the filler particles in the dried coating film can form a desired inclined structure; in addition, from the viewpoint of forming the inclined structure, the thickness of the undried coating film is 10 - 20 μm.

[0042] Example 1

[0043] 90.0 parts by mass of trimethylolpropane triacrylate manufactured by Changxing Special Materials Co., Ltd., trade name "EM235C" (specific gravity 1.179), 10.0 parts by mass of silica fine particles with an average particle diameter of 1.5 μm [Suzhou Youhao Nano Materials Co., Ltd., trade name "UG-SP30" (specific gravity 2.150)], and 5.0 parts by mass of the photopolymerization initiator 1-hydroxycyclohexyl phenyl ketone [Changzhou Qiangli Electronic Materials Co., Ltd., trade name "Ilgacure 184"] were mixed with propylene glycol monomethyl ether to prepare a coating liquid with a solid content concentration of 30% by mass. On the surface of a polyethylene terephthalate film with a thickness of 75 μm [manufactured by Zhejiang Jiemei Electronic Technology Co., Ltd., trade name "JFG10-075NI"] as a transparent support, the coating liquid was applied with an RDS bar to a cured film thickness of 4.5 μm. The surface of the undried coating film with a thickness of about 15 μm was facing downwards, and hot air with a temperature of 60 °C and a wind speed of 7.0 m / s was blown towards the surface side of the coating film for drying. Then, ultraviolet rays of 230 mJ / cm 2 were irradiated with a high-pressure mercury lamp to prepare an antiglare film. The performance of the antiglare film and the presence or absence of an inclined structure are as shown in Figure 2 . In the SEM photograph of the cross-section of the hard coat, the content area ratio of silica particles in each layer was surface layer: intermediate layer: bottom layer = 6:3:1, and the content area ratio of filler particles in the surface layer / the content area ratio of filler particles in the bottom layer was equal to 6, having an inclined structure.

[0044] Comparative Example 1

[0045] In Example 1, except that the drying treatment of the undried coating film was carried out with the surface of the undried coating film facing upwards, an antiglare film was prepared in the same manner as in Example 1. The performance of the antiglare film and the presence or absence of an inclined structure are as shown in Figure 2 . In the SEM photograph of the cross-section of the hard coat, the content area ratio of silica particles in each layer was surface layer: intermediate layer: bottom layer = 3:3:4, and the content area ratio of filler particles in the surface layer / the content area ratio of filler particles in the bottom layer = 0.75, without an inclined structure.

[0046] Example 2

[0047] Except that in Example 1, the undried coating film was dried by blowing hot air with a temperature of 40 °C and a wind speed of 7.0 m / s towards the surface side of the coating film, an antiglare film was prepared in the same manner as in Example 1. The performance of the antiglare film and the presence or absence of an inclined structure are as shown in Figure 2 . Comparative Example 2 In Example 1, except that the undried coating film was dried by blowing hot air with a temperature of 80 °C and a wind speed of 7.0 m / s towards the surface side of the coating film, an antiglare film was prepared in the same manner as in Example 1. The performance of the antiglare film and the presence or absence of an inclined structure are as shown inFigure 2 as shown

[0048] Example 3

[0049] In Example 1, except that the hot air temperature was set to 70°C and the undried coating film was dried by blowing hot air onto the surface side of the transparent support, an antiglare film was prepared in the same manner as in Example 1. The performance of the antiglare film and the presence or absence of the inclined structure are as Figure 2 shown. In Example 4, an antiglare film was prepared in the same manner as in Example 1, except that the coating liquid in Example 1 was prepared using 92.5 parts by mass of pentaerythritol triacrylate and 7.5 parts by mass of silica fine particles. The performance of the antiglare film and the presence or absence of the inclined structure are as Figure 2 shown

[0050] In summary, the antiglare film obtained by this method has excellent antiglare function and high transmission clarity, and is applied to various displays, including liquid crystal displays, plasma displays, cathode ray tubes, and touch panels

[0051] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device

[0052] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents

Claims

1. A preparation method of an anti-glare film with anti-glare and high transmission clarity, characterized in that: The method includes the following steps: Step 1: First, prepare a coating solution for forming a hard coating with a fine irregular shape on a transparent carrier; apply a solution containing a radiation-curable compound and a coating solution containing filler particles on the transparent carrier. The transparent support is selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, and polypropylene film among plastic films, and the thickness is selected in the range of 30 - 200 μm. Surface treatment is performed on one or both surfaces of the transparent support by an oxidation method or a roughening method. Step 2: Perform a drying treatment to form a coating film. Apply the coating solution in Step 1 on the transparent carrier to form an undried coating film. Then, after setting the undried coating film on the transparent support in this way, install the transparent support with the surface of the undried coating film facing down, and perform a hot air drying treatment from the surface side of the coating film or the surface side of the transparent support. Thus, during the process of drying the undried coating film, the filler particles gradually settle to the surface side of the coating film under the action of gravity, and when the coating film is dried, the content density of the filler particles gradually becomes denser from the transparent support side to the hard coating surface; due to the content density of the filler particles having an inclined structure. Step 3, then irradiate the coating film with active energy rays and cure it to form a hard coat having a fine uneven shape, with a large number of filler particles unevenly distributed near its surface, exhibiting a high antiglare function; examples of the active energy rays are ultraviolet rays, which are obtained from high-pressure mercury lamps, fusion H lamps, and xenon lamps, and the irradiation dose is usually 100 to 500 mJ / cm 2 , and the thickness of the hard coat formed in this way is 4 to 6 μm; Step 4: The hard coating has an inclined structure in which the content density of the included filler particles gradually becomes denser from the transparent support side to the hard coating surface, and many filler particles are unevenly distributed near the surface of the hard coating. This inclined structure is confirmed by the following method: Take a cross-section of the hard coating with a scanning electron microscope (SEM) and divide it into a surface layer, an intermediate layer, and a bottom layer such that each layer has almost the same area. In the cross-sectional area of each layer, calculate the area ratio of the filler particles contained. If the value of (the area ratio of the filler particles in the surface layer) / (the area ratio of the filler particles in the bottom layer) is greater than 5, it is assumed to have an inclined structure.

2. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: Examples of the coating solution include a solution containing a radiation-curable compound as a basic component and optionally containing a photoinitiator and various other additive components, as well as filler particles that impart an antiglare function; examples of the radiation-curable compound include radiation-polymerizable prepolymers and / or radiation-polymerizable monomers; examples of the radiation-polymerizable prepolymers include free radical polymerization types and cationic polymerization types. Examples of the free radical polymerization type radiation-polymerizable prepolymers include polyester acrylate, epoxy acrylate, polyurethane acrylate, and polyol acrylate.

3. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: Examples of the solvent for preparing a solution containing a radiation-curable compound as a basic component include one or more of aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane and vinyl chloride, alcohols such as methanol, ethanol, propanol, and butanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, esters such as cyclohexanone, esters such as ethyl acetate and butyl acetate, and ethylene glycol ether solvents such as propylene glycol monomethyl ether used in combination.

4. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 2, characterized in that: Examples of various additive components used as needed include antioxidants, ultraviolet absorbers, light stabilizers, leveling agents, and defoaming agents.

5. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: In the coating solution, the filler particles included together with the solution containing a radiation-curable compound as a basic component have a specific gravity greater than that of the solution and do not have too much adverse effect on the transmission clarity of the obtained antiglare film. The type of the filler particles is any one of inorganic particles and organic particles, or a mixture thereof.

6. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 5, characterized in that: Examples of the inorganic particles include silica, barium sulfate, calcium carbonate, talc, kaolin, titanium dioxide, zirconium oxide, mica, and glass beads. Examples of the organic particles include polymethyl methacrylate particles, polycarbonate particles, polystyrene particles, polypropylene styrene particles, polyvinyl chloride particles, benzoguanamine resin particles, and benzoguanamine / melamine / formaldehyde condensate particles. These filler particles can be used alone or in combination of two or more. Among them, silica particles are selected according to the antiglare function, hard coat function, transmission clarity of the obtained antiglare film, and the specific gravity of the particles themselves. When the silica particles are used as the filler particles, the silica particles are obtained by treating their surfaces with an organic surface treatment agent. As the organic surface treatment agent, a silane coupling agent, silicone oil, and silicone wax are used.

7. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: The average particle size of the filler particles is 1.2 to 3.0 μm, and the shape of the filler particles is selected as spherical because they are easier to settle.

8. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: Examples of the oxidation method include corona discharge treatment, and examples of the roughening method include sandblasting method and solvent treatment method.

9. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 1, characterized in that: In Step 2, examples of the drying method include infrared heating drying, electric heating drying, hot plate heating drying, and hot air convection drying. Among them, from the viewpoint of easily controlling the gradient structure of the filler particle content density, the hot air convection drying method is selected. The hot air convection drying system is a convection electrothermal drying system that blows hot air onto the surface of the undried coating film and / or the transparent support side. According to this hot air convection drying system, the drying rate of the undried coating film can be easily controlled in the following ways: (1) keeping the temperature of the hot air constant and changing the wind speed; (2) keeping the wind speed of the hot air constant and changing the temperature; (3) changing the temperature and wind speed of the hot air. By the temperature of the hot air and the drying speed of the undried coating film, the gradient structure of the filler particle content density in the dried coating film is controlled, so that the antiglare function can be easily controlled. In addition, when the undried coating film is dried at the same temperature, the antiglare performance is improved when hot air is blown onto the coating film surface side.

10. The preparation method of an anti-glare film with anti-glare and high transmission clarity according to claim 9, characterized in that: The hot air temperature in the hot air convection drying system is in the range of 35 to 70 °C because the content density of the filler particles in the dried coating film can form a required inclined structure. In addition, from the viewpoint of forming the inclined structure, the thickness of the undried coating film is 10 to 20 μm.

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