CN113655554B

CN113655554B - Antiglare film and polarizing plate having the same

Info

Publication number: CN113655554B
Application number: CN202010587065.6A
Authority: CN
Inventors: 范纲伦; 陈威宪; 游国轩
Original assignee: BenQ Materials Corp
Current assignee: BenQ Materials Corp
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2024-03-26
Anticipated expiration: 2040-06-24
Also published as: CN113655554A

Abstract

The invention discloses an anti-dazzle film and a polarizing plate with the same, wherein the anti-dazzle film comprises a transparent base material and an anti-dazzle layer, the anti-dazzle layer comprises acrylic binder resin, polyether modified siloxane and a plurality of silica nanoparticles, and the average secondary particle diameter of micron-sized floccules formed by the nanoparticles is between 1,500nm and 3,100nm under an optical microscope. The antiglare film can provide reliable antiglare properties at low haze.

Description

Antiglare film and polarizing plate having the same

Technical Field

The present invention relates to an antiglare film useful for image display equipment, and more particularly, to an antiglare film that can provide reliable antiglare properties at low haze.

Background

With the increasing development of display technology, image display devices such as Liquid Crystal Displays (LCDs), organic light emitting diode displays (OLEDs), etc., demands for display performance such as high contrast ratio, wide viewing angle, high luminance, thin, large, high definition, and additional function diversification have been widely put forward.

In general, the display is used in an environment where an external light source is mostly present, which generates a reflection effect on the surface of the panel to cause glare and further reduce the visual and organoleptic viewing effects, so that an optical film with a surface treatment, such as an antiglare film or an antireflection film, is usually required to be added on the surface of the display to modulate light, reduce reflection and reduce the influence of the reflected light of external clutter on the displayed image.

In order to provide an antiglare film with excellent antiglare properties in a bright room environment and with high contrast in a dark room environment, a method is known in which a low-haze antiglare film can be developed using small-particle-diameter organic fine particles to achieve high contrast. In the related art, it has been suggested to apply an antiglare layer containing organic fine particles on a transparent substrate, and to form an uneven structure on a film surface when the organic fine particles are applied by aggregation of the organic fine particles and the nanoparticles, thereby providing antiglare properties and achieving a low glare effect. However, the aggregation of organic microparticles and nanoparticles is not easily controlled, which tends to cause a less-than-expected uneven structure on the film surface, resulting in a decrease in antiglare properties or an increase in optical rotation. Further, an antiglare layer containing organic fine particles having a large particle diameter and/or micron-sized silica particles is coated on a transparent substrate, and the haze is high due to a strong light diffusion effect by the fine particles, so that an antiglare film having a low haze but good antiglare property is not provided.

Accordingly, there is a need for an antiglare film that has low haze but provides satisfactory antiglare properties.

Disclosure of Invention

The purpose of the present invention is to provide an antiglare film that has low haze but can provide satisfactory antiglare properties, and a polarizing plate having the antiglare film.

In order to achieve the above object, the present invention provides an antiglare film comprising a transparent substrate and an antiglare film on the transparent substrate, wherein the antiglare layer has micron-sized flocs formed of silica nanoparticles, and can provide reliable antiglare properties at low haze and under a fine surface. The antiglare film of the invention comprises a transparent substrate and an antiglare layer on the transparent substrate, wherein the antiglare layer comprises an acrylic binder resin, polyether modified siloxane and a plurality of silica nanoparticles, wherein micron-sized floccules formed by the silica nanoparticles exhibit an average secondary particle size of between 1,500nm and 3,100 under an optical microscope.

The antiglare film of the present invention is low in haze, has a fine surface, and provides excellent antiglare properties. The antiglare film of the present invention has a haze of not more than 5%, preferably not more than 3%, an arithmetic mean height (Sa) of surface roughness of 0.03 μm to 0.18 μm, a maximum height (Sz) of 0.30 μm to 1.80 μm, a center line mean roughness (Ra) of 0.01 μm to 0.16 μm, a full roughness height (Ry) of 0.10 μm to 0.90 μm, a mean peak pitch (RSm) of 20 μm to 200 μm, and a root mean square slope (Rdq) of 0.36 DEG to 4.60 DEG by agglomerating silica nanoparticles.

In the antiglare layer of the antiglare film of the present invention, the average primary particle diameter of each silica nanoparticle by the specific surface area method (BET) is between 10nm and 160nm, and preferably between 20nm and 100 nm.

According to a preferred embodiment of the antiglare film of the present invention, the silica nanoparticles may be present in the antiglare layer in an amount of from 0.1 to 15 parts by weight, preferably from 0.5 to 12 parts by weight, more preferably from 0.8 to 10 parts by weight, per hundred parts by weight of the acrylic binder resin.

According to a preferred embodiment of the antiglare film of the present invention, the polyether-modified siloxane may be present in the antiglare layer in an amount of 0.01 to 8 parts by weight, preferably 0.05 to 5 parts by weight, per hundred parts by weight of the acrylic binder resin. Furthermore, in the antiglare layer of the antiglare film of the present invention, the relative weight ratio of the silica nanoparticles to the polyether-modified siloxane is from 0.5 to 100, preferably from 0.5 to 80.

In the antiglare layer of the antiglare film of the present invention, the polyether-modified siloxane is a compound having the formula (I):

wherein R1 to R4, R6 to R11 are each hydrogen or C1 to C10 hydrocarbyl, R5 is C1 to C10 hydrocarbyl, x, y and a are integers of 1 or greater than 1, z and b are integers of 0 or greater than 0, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) average molecular weight of the polyether-modified siloxane is between 200 and 6,000, and the average ethylene oxide number (EO) unit is between 1 and 40.

In the antiglare film of the present invention, the antiglare layer may have a thickness of from 2 μm to 10 μm, preferably from 2 μm to 8 μm.

In still another aspect of the present invention, there is provided an antiglare film, which may further include organic fine particles in an antiglare layer to adjust haze, wherein the antiglare film comprises a transparent substrate and an antiglare layer, wherein the antiglare layer comprises an acrylic binder resin, a polyether-modified siloxane, a plurality of silica nanoparticles, and a plurality of organic fine particles, wherein micron-sized floccules formed from the silica nanoparticles exhibit an average secondary particle diameter of between 1,500nm and 3,100nm under an optical microscope.

The antiglare film of the present invention containing organic fine particles in the antiglare layer may have a refractive index of each organic fine particle of between 1.4 and 1.6, and may have a particle diameter of each organic fine particle of between 0.5 μm and 6 μm, and preferably between 1 μm and 4 μm.

In the antiglare film of the present invention, the acrylic binder resin of the antiglare layer comprises a (meth) acrylate composition and an initiator, wherein the (meth) acrylate composition comprises 35 to 50 parts by weight of a urethane (meth) acrylate oligomer having a functionality of 6 to 15, 12 to 20 parts by weight of a (meth) acrylate monomer having a functionality of 3 to 6, and 1.5 to 12 parts by weight of a (meth) acrylate monomer having a functionality of less than 3, wherein the urethane (meth) acrylate oligomer having a functionality of 6 to 15 has a number average molecular weight (Mn) of 1,000 to 4,500.

Another object of the present invention is to provide a method for preparing an antiglare film, which comprises uniformly mixing an acrylic binder resin, polyether-modified siloxane, and nanoparticles to form an antiglare solution, coating the antiglare solution on a transparent substrate, drying the substrate coated with the antiglare solution, and then curing by radiation or electron beam to form the antiglare film.

Another object of the present invention is to provide a polarizing plate comprising a polarizing element and the antiglare film.

The antiglare film and the polarizing plate of the present invention have micron-sized floccules formed of silica nanoparticles in the antiglare layer, and thus can provide reliable antiglare properties at low haze.

The above summary is intended to provide a simplified summary of the disclosure so that the reader is a basic understanding of the disclosure. This summary is not an extensive overview of the disclosure and is intended to neither identify key/critical elements of the embodiments of the invention nor delineate the scope of the invention. Those skilled in the art to which the present invention pertains will readily appreciate the basic spirit and technical means and aspects of the present invention after reviewing the following description.

The invention will now be described in more detail with reference to the drawings and specific examples, which are not intended to limit the invention thereto.

Drawings

Fig. 1 is a light transmission image of the antiglare film of example 1 of the present invention at a magnification of 200 x in an optical microscope.

Fig. 2 is a graph showing the light transmission image of the antiglare film of example 2 according to the present invention at a magnification of 200 x in an optical microscope.

Fig. 3 is a graph showing the light transmission image of the antiglare film of example 8 according to the present invention at a magnification of 200 x in an optical microscope.

Fig. 4 is a graph of an image of the antiglare film of example 1 of the present invention analyzed for surface roughness at 50 x with an OLYMPUS 3D laser microscope.

Fig. 5 is a graph of an image of the antiglare film of example 2 of the present invention analyzed for surface roughness at 50 x with an OLYMPUS 3D laser microscope.

FIG. 6 is a graph of an image of the antiglare film of example 8 of the present invention at 50 Xmagnification in an OLYMPUS 3D laser microscope.

Detailed Description

For a more complete and thorough disclosure, the following illustrative descriptions of embodiments and specific examples of the present invention are presented; this is not the only form of practicing or implementing the invention as embodied. The embodiments disclosed below may be combined with or substituted for each other as advantageous, and other embodiments may be added to one embodiment without further description or illustration.

The advantages, features, and technical approaches to the present invention will be more fully understood by reference to the exemplary embodiments that now follow, and in fact may be practiced in different but not limited to the embodiments set forth herein, but rather, to the contrary, are provided to fully convey the scope of the invention to those skilled in the art, and are defined solely by the appended claims.

And unless otherwise defined, all terms (including technical and scientific terms) used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and terms such as commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an excessively idealized or overly formal sense unless expressly so defined hereinafter.

In the present specification, the term "meth" acrylate refers to methacrylate and acrylate.

An object of the present invention is to provide an antiglare film that provides reliable antiglare properties at low haze, comprising a transparent substrate and an antiglare layer on the transparent substrate, wherein in the antiglare layer, micron-sized floccules formed of silica nanoparticles are present. The antiglare film of the invention comprises a transparent substrate and an antiglare layer on the transparent substrate, wherein the antiglare layer comprises an acrylic binder resin, polyether-modified oxygen alkane and a plurality of silica nanoparticles, wherein micron-sized floccules formed by the plurality of silica nanoparticles show an average secondary particle diameter of between 1,500nm and 3,100nm under an optical microscope.

The antiglare film of the present invention is low in haze but has excellent antiglare properties. In an antiglare film embodiment of the present invention, the antiglare film has a haze of not greater than 5%, preferably not greater than 3%. The antiglare film of the present invention has an arithmetic mean height (Sa) of surface roughness of 0.03 μm to 0.18 μm, a maximum height (Sz) of 0.30 μm to 1.8 μm, a center line mean roughness (Ra) of 0.01 μm to 0.16 μm, a full roughness height (Ry) of 0.10 μm to 0.90 μm, an average peak pitch (RSm) of 20 μm to 200 μm, and a square root slope (Rdq) of 0.36 DEG to 4.60 deg. The antiglare film of the present invention achieves low haze by agglomeration of silica nanoparticles and provides excellent antiglare properties under fine surfaces of such roughness.

In a preferred embodiment of the antiglare film of the present invention, the antiglare film has an arithmetic mean height (Sa) of surface roughness of 0.04 μm to 0.13 μm, a maximum height (Sz) of 0.40 μm to 1.50 μm, a center line mean roughness (Ra) of 0.02 μm to 0.15 μm, a full roughness height (Ry) of 0.10 μm to 0.80 μm, a mean peak pitch (RSm) of 30 μm to 180 μm, and a square root slope (Rdq) of 0.50 ° to 3.00 °.

In an embodiment of the present invention, a suitable transparent substrate may be selected from a film material with good mechanical strength and light transmittance, which may be, but not limited to, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), triacetyl cellulose (TAC), polyimide (PI), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), or cyclic olefin Copolymer (COP), etc.

In the preferred embodiment of the present invention, the transparent substrate is preferably selected to have a light transmittance of 80% or more, more preferably 90% or more. And the thickness of the transparent substrate is about 10 μm to 500. Mu.m, preferably 15 μm to 250. Mu.m, more preferably 20 μm to 100. Mu.m.

In the antiglare film of the present invention, the antiglare layer may have a thickness of between 2 μm and 10 μm, and preferably between 2 μm and 8 μm.

In the antiglare film of the present invention, the average primary particle diameter of each silica nanoparticle used in the antiglare layer by the specific surface area method (BET) is between 10nm and 160nm, and preferably between 20nm and 100 nm. In the embodiment of the present invention, the silica nanoparticles may be surface-unmodified or surface-modified silica nanoparticles, the surface-modified silica nanoparticles may be silica nanoparticles modified with siloxane having alkyl, acryl or epoxy groups, and the silica nanoparticles are distributed inside the antiglare layer with polarity close to that of the resin.

According to an embodiment of the antiglare film of the present invention, the silica nanoparticles in the antiglare layer are preferably in the range of 0.1 to 15 parts by weight, more preferably 0.5 to 12 parts by weight, particularly preferably 0.8 to 10 parts by weight, per hundred parts by weight of the acrylic binder resin. When the amount of the silica nanoparticles used is less than the aforementioned range, the antiglare property of the antiglare film may be insufficient. When the amount of the silica nanoparticles used is higher than the above range, there is a possibility that the haze of the antiglare film may be increased.

In the antiglare film of the present invention, the antiglare layer contains polyether-modified siloxane having the formula (I):

wherein R1 to R4, R6 to R11 are each hydrogen or C1 to C10 hydrocarbyl, R5 is C1 to C10 hydrocarbyl, x, y and a are integers of 1 or greater than 1, z and b are integers of 0 or greater than 0, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) of the polyether-modified siloxane has an average molecular weight of between 200 and 6,000, and an average oxyethylene group (EO) unit of between 1 and 40.

In the polyether modified siloxane of the above formula (I), wherein x is an integer of 1 to 500, preferably an integer of 1 to 100, more preferably an integer of 1 to 10; y is an integer from 1 to 100, preferably from 1 to 50; the z is an integer of 0 to 500, preferably an integer of 0 to 100, more preferably an integer of 0 to 10; the a is an integer of 1 to 40, preferably an integer of 1 to 35, more preferably an integer of 1 to 30; and b is an integer of 0 to 500, preferably an integer of 0 to 100, more preferably an integer of 0 to 40. In the polyether modified siloxane of the aforementioned formula (I), when R1 to R11 are each a C1 to C10 hydrocarbon group, the hydrocarbon group may be a substituted C1 to C10 hydrocarbon group, and the substituent may be a hydrocarbon group, a hydroxyl group, or an alkoxy group. In the polyether-modified siloxanes of the above formula (I), the Ethylene Oxide (EO) units and the Propylene Oxide (PO) units are linked in a random, alternating or block-copolymerized manner.

In a preferred embodiment of the antiglare film of the present invention, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) of the polyether-modified siloxane of formula (I) preferably has an average molecular weight of between 200 and 4,500, more preferably between 200 and 3,000, and preferably has an average oxyethylene group (EO) unit of between 1 and 35, more preferably between 1 and 30.

Examples of the polyether-modified siloxane of the aforementioned formula (I) include, but are not limited to, BYK-347, BYK-348, BYK-349, BYK-331, BYK-307, and BYK-3455 (manufactured by BYK-Chemie, germany).

In a preferred embodiment of the antiglare film of the present invention, the polyether-modified siloxane may be used in an amount of between 0.01 and 8 parts by weight, preferably between 0.05 and 5 parts by weight, per hundred parts by weight of the acrylic binder resin. When the amount of the polyether-modified siloxane used is less than the above range, the antiglare property of the antiglare film may be insufficient. When the amount of the polyether-modified siloxane used is more than the above range, there is a possibility that the haze of the antiglare film increases.

In the antiglare film of the present invention, polyether-modified siloxane of the formula (I) contained in the antiglare layer can flocculate silica nanoparticles to form micron-sized flocks having an average secondary particle diameter of 1,500nm to 3,100 nm. Without being bound by theory, in the antiglare layer of the antiglare film of the present invention, when the relative weight ratio of the silica nanoparticles to the polyether-modified siloxane is between 0.5 and 100, the polyether-modified siloxane facilitates flocculation of the silica nanoparticles to the aforementioned average secondary particle size, which can provide the antiglare film with excellent antiglare properties without affecting the film surface fineness of the antiglare film. When the relative weight ratio of the silica nanoparticles to the polyether-modified siloxane is outside the above range, the silica nanoparticle flocs having the above secondary particle size cannot be formed, and the antiglare film has defects such as low antiglare property, excessive haze, and appearance of the film surface. Furthermore, in the preferred embodiment of the antiglare film of the present invention, the relative weight ratio of the silica nanoparticles to the polyether modified siloxane in the antiglare layer is preferably between 0.5 and 80.

In the antiglare film of the present invention, the micron-sized floccules of the silica nanoparticles in the antiglare layer may be reagglomerated, disaggregated, or aggregated into a co-continuous network structure, and reagglomeration may help to improve the antiglare property again without reagglomerating and affecting the antiglare property.

In still another embodiment of the antiglare film of the present invention, the antiglare layer may further incorporate other silica nanoparticles having a higher degree of hydrophobicity without affecting the physical properties of the antiglare film, and be distributed on the surface of the antiglare layer due to a large polarity difference with the resin, to adjust the physical properties of the antiglare film surface, for example, to incorporate silica nanoparticles resistant to surface scratches.

In the antiglare film of the present invention, the acrylic binder resin used for the antiglare layer comprises a (meth) acrylate composition and an initiator, wherein the (meth) acrylate composition in the acrylic binder resin comprises 35 to 50 parts by weight of a urethane (meth) acrylate oligomer having a functionality of between 6 and 15, 12 to 20 parts by weight of a (meth) acrylate monomer having a functionality of 3 to 6, and 1.5 to 12 parts by weight of a (meth) acrylate monomer having a functionality of less than 3.

In a preferred embodiment of the present invention, the polyurethane (meth) acrylate oligomer having a functionality of between 6 and 15 has a molecular weight of not less than 1,000, preferably between 1,500 and 4,500. In a further preferred embodiment of the invention, urethane (meth) acrylate oligomers having a functionality of between 6 and 15 are preferably used, aliphatic urethane (meth) acrylate oligomers having a functionality of between 6 and 15 being preferred.

In a preferred embodiment of the present invention, the (meth) acrylate monomers having a functionality of 3 to 6 have a molecular weight of less than 1,000, preferably a molecular weight of less than 800. Suitable (meth) acrylate monomers for use in the present invention having a functionality of 3 to 6 may be, for example, one of pentaerythritol tetra (meth) acrylate (pentaerythritol tetra (meth) acrylate), dipentaerythritol penta (meth) acrylate (dipentaerythritol penta (meth) acrylate, DPP (M) a), dipentaerythritol hexa (meth) acrylate (dipentaerythritol hexa (meth) acrylate, DPH (M) a), trimethylolpropane tri (meth) acrylate (trimethylolpropane tri (meth) acrylate, TMPT (M) a), ditrimethylolpropane tetra (ditrimethylolpropane tetra (meth) acrylate, DTMPT (M) a), pentaerythritol tri (meth) acrylate (pentaerythritol tri (meth) acrylate, PET (M) a), or a combination thereof, but are not limited thereto. The (meth) acrylate monomer having a functionality of 3 to 6 is preferably one of pentaerythritol triacrylate (pentaerythritol triacrylate, PETA), dipentaerythritol hexaacrylate (dipentaerythritol hexaacrylate, DPHA), dipentaerythritol pentaacrylate (dipentaerythritol pentaacrylate, DPPA), or a combination thereof, but is not limited thereto.

In a preferred embodiment of the present invention, the (meth) acrylate monomer having a functionality of less than 3 may be a (meth) acrylate monomer having a functionality of 1 or 2, and a molecular weight of less than 500. (meth) acrylate monomers having a functionality of less than 3 suitable for use in the present invention may be, for example, 2-ethylhexyl (meth) acrylate (2-ethylhexyl (meth) acrylate,2-EH (M) A), 2-hydroxyethyl (meth) acrylate (2-hydroxyethyl (meth) acrylate,2-HE (M) A), 3-hydroxypropyl (meth) acrylate (3-hydroxypropyl (meth) acrylate,3-HP (M) A), 4-hydroxybutyl (meth) acrylate (4-hydroxybutyl (meth) acrylate,4-HB (M) A), 2-butoxyethyl (meth) acrylate (2-butoxyethyl (meth) acrylate), 1,6-hexanediol di (meth) acrylate, HDD (M) A), ditrimethylolpropane methylal (meth) acrylate (cyclic trimethylolpropane formal (meth) acrylate, CTF (M) A), 2-phenoxyethyl (meth) acrylate (2-phenoxyethyl (meth) acrylate, E (M), tetrahydrofuran (meth) acrylate (35A), tetrahydrofuran (meth) acrylate (35 methacrylate) and methyl methacrylate (35A), l (M) a), diethylene glycol di (meth) acrylate (diethylene glycol di (meth) acrylate, DEGD (M) a), dipropylene glycol di (meth) acrylate (dipropylene glycol di (meth) acrylate, DPGD (M) a), tripropylene glycol di (meth) acrylate (tripropylene glycol di (meth) acrylate, TPGD (M) a), isobornyl (meth) acrylate (isobornyl (meth) acrylate, IBO (M) a), or combinations thereof, but are not limited thereto. The (meth) acrylate monomer having a functionality of less than 3 is preferably one of 1,6-hexanediol diacrylate (HDDA), cyclotrimethylene propane methylal acrylate (CTFA), 2-phenoxyethyl acrylate (PHEA) or isobornyl acrylate (IBOA), or a combination thereof, but is not limited thereto.

Suitable initiators for the acrylic binder resin of the present invention may be any of those known to the art and may be used, and are not particularly limited, and examples thereof include acetophenone type initiators, diphenyl ketone type initiators, propiophenone type initiators, dibenzoyl type initiators, bifunctional α -hydroxy ketone type initiators, and acylphosphine oxide type initiators. The aforementioned initiators may be used alone or in combination.

The anti-dazzle film can adjust the haze by adding organic particles according to the use environment and the visual angle requirement of a product, and particularly adjust the internal scattering effect of the haze in the anti-dazzle layer.

Accordingly, still another aspect of the present invention provides an antiglare film comprising a transparent substrate and an antiglare layer on the transparent substrate, wherein the antiglare layer has a micron-sized aggregate formed of a plurality of silica nanoparticles and a plurality of organic microparticles thereon. The antiglare film of the invention comprises a transparent substrate and an antiglare layer on the transparent substrate, wherein the antiglare layer comprises an acrylic binder resin, polyether modified siloxane, a plurality of silica nanoparticles and a plurality of organic microparticles, wherein micron-sized floccules formed by the silica nanoparticles show an average secondary particle diameter of between 1,500nm and 3,100nm under an optical microscope.

The organic microparticles suitable for the antiglare film of the present invention may be selected from organic microparticles having a proper refractive index and particle size, and the amount of the organic microparticles added may be controlled to adjust the haze of the antiglare film. Suitable organic microparticles may have a refractive index of between 1.4 and 1.6 and a particle size of between 0.5 μm and 6 μm, and preferably between 1 μm and 4 μm. In an embodiment of the antiglare film in which the organic fine particles adjust the haze, the haze may range from 1% to 50%, but is not limited thereto.

When the haze of the antiglare film of the present invention is adjusted by using the organic fine particles, the amount of the organic fine particles to be added may be adjusted according to the haze actually required, and it is preferable to add between 0.5 and 15 parts by weight, particularly between 1 and 12 parts by weight, of the organic fine particles per hundred parts by weight of the acrylic binder resin.

Organic microparticles suitable for the antiglare layer of the antiglare film of the present invention are polymethyl methacrylate resin microparticles, polystyrene resin microparticles, styrene-methyl methacrylate copolymer microparticles, polyethylene resin microparticles, epoxy resin microparticles, polysiloxane resin microparticles, polyvinylidene fluoride resin microparticles, or polyvinyl fluoride resin microparticles. In the preferred embodiment of the present invention, polymethyl methacrylate resin fine particles, polystyrene resin fine particles or styrene/methyl methacrylate copolymer fine particles are preferably used.

On the film surface of the antiglare film of the present invention, other optical functional layers may also be optionally coated, for example, a low refractive layer to provide antireflection.

Another object of the present invention is to provide a method for producing an antiglare film. The preparation method of the antiglare film comprises the steps of uniformly mixing polyurethane (methyl) acrylate oligomer with the functionality of 6-15, at least one (methyl) acrylate monomer with the functionality of not less than 3, at least one (methyl) acrylate monomer with the functionality of less than 3 and an initiator with a proper solvent to form an acrylic adhesive resin; adding silicon dioxide nano particles and/or organic microparticles, polyether modified siloxane and an organic solvent into acrylic binder resin, and uniformly mixing to form an anti-dazzle solution; the antiglare film is obtained by coating an antiglare solution on a transparent substrate, drying the substrate coated with the antiglare solution, and forming an antiglare layer on the transparent substrate after irradiation or electron beam curing.

The solvent used in the method for producing an antiglare film of the present invention may be an organic solvent generally used in this technical field, for example, ketones, aliphatic or cycloaliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters or alcohols, etc. One or more organic solvents may be used in both the acrylate composition and the antiglare solution, and suitable solvents include, but are not limited to, acetone, butanone, cyclohexanone, methyl isobutyl ketone, hexane, cyclohexane, methylene chloride, dichloroethane, toluene, xylene, propylene glycol methyl ether, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isopropyl alcohol, n-butanol, isobutyl alcohol, cyclohexanol, diacetone alcohol, propylene glycol methyl ether acetate, tetrahydrofuran, and the like, or the like.

In other embodiments of the present invention, additives such as antistatic agents, colorants, flame retardants, ultraviolet absorbers, antioxidants, surface modifiers, leveling agents without polyether modification, and defoamers may be added to the prepared antiglare solution as desired to provide different functional properties.

The method for applying the antiglare solution may be, for example, a roll coating method, a doctor blade coating method, a dip coating method, a roll coating method, a spin coating method, a spray coating method, a slit coating method, or any other coating method commonly used in the art.

Another object of the present invention is to provide a polarizing plate including a polarizing element, wherein the polarizing plate has the antiglare film on the surface of the polarizing element.

The following examples are provided to further illustrate the invention, but the invention is not limited thereto.

Examples

Preparation example 1: preparation of acrylic binder resin I

42 parts by weight of urethane acrylate (functionality 6, available from Miwon, korea), 4.5 parts by weight of pentaerythritol triacrylate (PETA), 12 parts by weight of dipentaerythritol hexaacrylate (DPHA), 3 parts by weight of isobornyl acrylate (IBOA), 4 parts by weight of a monomolecular polymerization initiator (Chemcure-481, available from Hengqiao industry, taiwan, china), 24.5 parts by weight of Ethyl Acetate (EAC), and 10 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to form the acrylic adhesive resin I.

Example 1: preparation of antiglare film

220 parts by weight of an acrylic binder resin I, 10 parts by weight of a silica nanoparticle dispersion sol (MEK-ST-L, solid content: 30% by weight, solvent methyl ethyl ketone, available from Nissan chemical, japan) having a specific surface area method (BET) average primary particle diameter of 40nm to 50nm, 7.5 parts by weight of a polyether-modified polydimethylsiloxane (BYK-307, solid content: 10% by weight, solvent ethyl acetate, available from BYK, germany), 60 parts by weight of Ethyl Acetate (EAC), and 120 parts by weight of n-butyl acetate (nBAC) were mixed and stirred for 1 hour to uniformly disperse them, thereby forming an antiglare solution. The antiglare solution was coated on a polyethylene terephthalate (PET) substrate of 80 μm, dried, and then photocured under nitrogen atmosphere with a UV lamp of 80mJ/cm2 radiation dose to form an antiglare layer of 3.6 μm in thickness on the PET substrate.

The results of measuring the transmittance, haze, gloss and clarity of the obtained antiglare film by the optical measuring method described later are shown in table 1, and the secondary particle diameter and the size of the aggregated area of the nanoparticles, the surface roughness and the antiglare property were measured and evaluated, and the results are shown in table 2.

The obtained antiglare film was observed under an optical microscope 200 magnification, the obtained light transmission image was as shown in fig. 1, and the obtained surface roughness analysis image was as shown in fig. 4 under an OLYMPUS 3D laser microscope 50 magnification.

Example 2: preparation of antiglare film

An antiglare solution was prepared as in example 1 except that a silica nanoparticle dispersion sol was used instead of the silica nanoparticle dispersion sol having a specific surface area method (BET) average primary particle diameter of 70nm to 100nm (MEK-ST-ZL, solid content of 30%, solvent was butanone, commercially available from daily chemical, japan), and a polyether-modified silicone was used instead of 7.5 parts by weight of polyether-modified polydimethylsiloxane (BYK-3455, solid content of 10%, solvent was ethyl acetate, commercially available from BYK, germany) to form an antiglare solution.

The antiglare solution was coated on an 80 μm PET substrate, and the resultant was photocured under a nitrogen atmosphere by a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.3. Mu.m.

The obtained antiglare film was observed under an optical microscope 200 magnification, the obtained light transmission image was as shown in fig. 2, and the obtained surface roughness analysis image was as shown in fig. 5 under an OLYMPUS 3D laser microscope 50 magnification.

Example 3: preparation of antiglare film

An antiglare solution was prepared as in example 1 except that a silica nanoparticle dispersion sol was used instead of the silica nanoparticle dispersion sol having a specific surface area method (BET) average primary particle diameter of 40nm to 50nm (MEK-AC-4130Y, solid content of 30%, solvent was butanone, commercially available from japanese chemical, japan), and a polyether-modified silicone was used instead of 7.5 parts by weight of polyether-modified polysiloxane (BYK-349, solid content of 10%, solvent was ethyl acetate, commercially available from BYK, germany) to form an antiglare solution.

The antiglare solution was applied to a 80 μm PET substrate, dried, and then photocured under a nitrogen atmosphere with a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.3 μm on the PET substrate.

Example 4: preparation of antiglare film

The procedure was as in example 3, except that 7.5 parts by weight of polyether-modified polydimethylsiloxane (BYK-3455) was used instead to form the antiglare solution.

The antiglare solution was applied to a 80 μm PET substrate, dried, and then photocured under a nitrogen atmosphere with a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.4. Mu.m.

Example 5: preparation of antiglare film

The procedure was as in example 3 except that 5 parts by weight of a silica nanoparticle dispersion sol (MEK-AC-4130Y) having a specific surface area method (BET) average primary particle diameter of 40nm to 50nm was used instead of the silica nanoparticle dispersion sol, and 7.5 parts by weight of a polyether-modified polydimethylsiloxane (BYK-3455) was used as the polyether-modified silicone to form the antiglare solution.

The antiglare solution was coated on an 80 μm PET substrate, dried, and then light-cured under a nitrogen atmosphere with a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.6 μm on the PET substrate.

Example 6: preparation of antiglare film

The procedure was as in example 5, except that 20 parts by weight of a silica nanoparticle dispersion sol (MEK-AC-4130Y) having a specific surface area method (BET) average primary particle diameter of 40nm to 50nm was used instead to form an antiglare solution.

Example 7: preparation of antiglare film

The procedure was as in example 6, except that 1.5 parts by weight of polyether-modified polydimethylsiloxane (BYK-3455) was used instead to form the antiglare solution.

The antiglare solution was applied to a 80 μm PET substrate, dried, and then photocured under a nitrogen atmosphere with a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.6 μm on the PET substrate.

Example 8: preparation of antiglare film

The procedure was as in example 5, except that 40 parts by weight of a silica nanoparticle dispersion sol (MEK-AC-4130Y) having a specific surface area method (BET) average primary particle diameter of 40nm to 50nm was used instead, and 3 parts by weight of a polyether-modified polydimethylsiloxane (BYK-3455) was used instead to form an antiglare solution.

The obtained antiglare film was subjected to the measurement of transmittance, haze, gloss and clarity by the optical measurement method described later, and the secondary particle diameter and aggregation area size measurement of silica nanoparticles, the surface roughness and the antiglare property were evaluated, and the results are shown in table 1.

The obtained antiglare film was observed under an optical microscope 200 magnification, the obtained light transmission image was as shown in fig. 3, and the obtained surface roughness analysis image was as shown in fig. 6 under an OLYMPUS 3D laser microscope 50 magnification.

Example 9: preparation of antiglare film

The procedure was as in example 3, except that instead of the polyether-modified silicone, 15 parts by weight of polyether-modified polydimethylsiloxane (BYK-3455) was used to form an antiglare solution.

Example 10: preparation of antiglare film

The procedure was as in example 9, except that the polyether-modified silicone was changed to 45 parts by weight of polyether-modified polydimethylsiloxane (BYK-3455) to form an antiglare solution.

Optical measuring method

The antiglare film prepared in the foregoing examples was optically measured as follows.

Measurement of light transmittance: light transmittance was evaluated in accordance with the description of JIS K7361 using an NDH-2000 haze meter (manufactured by Nippon electric color industry Co., ltd.).

Measurement of haze: haze was evaluated according to the description of JIS K7136 using an NDH-2000 haze meter (manufactured by Nippon electric color industry Co., ltd.).

Measurement of gloss: the antiglare film was glued on a black acrylic plate, and measured according to the description of JIS Z8741 using a BYK Micro-Gloss meter, and Gloss values of 20, 60 and 85 degrees were selected.

Measurement of definition: the hard coat optical film having antiglare properties was cut into a size of 5x 8cm2, and measured according to the description of JIS K7374 using a SUGA ICM-IT image clarity meter, and the measured values of the slits of 0.125mm, 0.25mm, 0.50mm, 1.00mm and 2.00mm were summed up.

Optical property measuring method

Measurement of secondary particle size and aggregate area size of silica nanoparticles: cutting the antiglare film into proper size, placing in a Mitutoyo SV-320 high-magnification optical microscope, taking the light transmission image of the antiglare film by CCD camera with the magnification of 10 times of eyepiece and 20 times of objective lens, and calculating the secondary particle diameter and aggregation area of the silica nano particles by image measuring software.

Measurement of surface roughness: an antiglare film was attached to a black acrylic plate via a transparent optical adhesive, and four 3D surface roughness images were taken using an OLYMPUS LEXT OLS5000-SAF 3D laser conjugate focus microscope for 256x 256 μm2 area, and arithmetic average height (Sa) and maximum height (Sz) were calculated from the surface roughness description of ISO 25178, or center line average roughness (Ra), full roughness height (Ry), average peak pitch (RSm), and square root slope (tilt angle) (Rdq) were calculated from the line roughness description of ISO 4287.

Measurement of antiglare properties: the antiglare film was glued to a black acrylic plate, 2 fluorescent tubes were projected onto the surface of the antiglare film, and the antiglare properties of the antiglare film were evaluated on the following 5 grades by visually comparing the degree of blooming of the fluorescent tubes. And judging that the antiglare property is more than Lv.2 to be qualified.

Lv.1: the separated 2 fluorescent tubes can be clearly seen, and the outline of the fluorescent tube can be clearly distinguished to be linear;

lv.2: the separated 2 fluorescent tubes can be clearly seen, but the outline is slightly blurred;

lv.3: 2 separated fluorescent tubes can be seen, the outline can be seen in a fuzzy manner, but the shape of the fluorescent tubes can be distinguished;

lv.4: 2 fluorescent tubes can be seen, but the shape cannot be distinguished;

lv.5: the separated 2 fluorescent tubes cannot be seen, and the shape of the fluorescent tubes cannot be distinguished.

The optical measurement results of the antiglare films of examples 1 to 10 of the present invention are shown in table 1.

Table 1: optical measurement results of antiglare films of examples 1 to 10

The measurement results of the optical properties such as the secondary particle diameter and the size of the aggregation area, the surface roughness, and the antiglare property evaluation of the silica nanoparticles of the antiglare films of examples 1 to 10 of the present invention are shown in table 2.

Table 2: optical property measurement results of antiglare films of examples 1 to 10

The antiglare films prepared in examples 1 to 10 of the present invention have the effect of forming the nanoparticles into micron-sized floccules by the interaction between the silica nanoparticles and the polyether-modified siloxane compound, the flocculated silica nanoparticles having an average secondary particle diameter of 1,500nm to 3,100nm and an average secondary particle aggregation area of 354 μm2 to 958 μm2, or an aggregation co-continuous network structure providing excellent antiglare property and haze of less than 5%. Furthermore, in the antiglare film of the embodiment of the present invention, the secondary particles flocculated by the silica nanoparticles in the antiglare layer can be re-aggregated, not aggregated or aggregated into a co-continuous network structure, the re-aggregation does not affect the generation of antiglare property, and meanwhile, the antiglare films prepared in the embodiments 1 to 10 of the present invention have fine surfaces, and the arithmetic mean height Sa is 0.039 to 0.116 μm, the maximum height Sz is 0.406 to 1.055 μm, the center line mean roughness Ra is 0.026 to 0.096 μm, the full roughness height Ry is 0.148 to 0.518 μm, the mean peak pitch RSm is 40.213 to 111.591 μm, and the square root slope (tilt angle) Rdq is 0.686 to 2.188 degrees. The antiglare films produced in examples 1 to 10 of the present invention exhibited satisfactory fineness in surface roughness and had excellent antiglare properties.

Example 11: preparation of antiglare film

The same procedure as in example 4 was carried out except that 10 parts by weight of a silica nanoparticle dispersed sol (MEK-AC-4130Y) was added to the antiglare solution, followed by 10 parts by weight of methyl methacrylate polymer particles (SSX-102, available from water-logging end product Co., ltd., japan) having an average particle diameter of 2 μm and a refractive index of 1.49.

The antiglare solution was applied to a 80 μm PET substrate, dried, and then photocured under a nitrogen atmosphere with a UV lamp having a radiation dose of 80mJ/cm2 to form an antiglare layer having a thickness of 3.7. Mu.m.

The results of measuring the transmittance, haze, gloss and clarity of the obtained antiglare film according to the optical measurement method described above are shown in table 3, and the secondary particle diameter and the size of the aggregated area of the nanoparticles, the surface roughness and the antiglare property were measured and evaluated, and the results are shown in table 4.

Example 12: preparation of antiglare film

The same procedure as in example 4 was carried out except that 10 parts by weight of a silica nanoparticle dispersion sol (MEK-AC-4130Y) was added to the antiglare solution, followed by 5 parts by weight of polystyrene particles (SSX-302 ABE, available from the water-logging end product company, japan) having an average particle diameter of 2 μm and a refractive index of 1.59.

Examples 11 and 12 illustrate that the antiglare film disclosed in the present invention further comprises organic fine particles to adjust haze. The antiglare films of examples 11 and 12 each had organic fine particles of different refractive index added thereto, and the antiglare films had haze varying with the choice of the organic fine particles, and satisfactory gloss and clarity were maintained in the antiglare films having haze adjusted by adding the organic fine particles, as shown in table 3.

Table 3: optical measurement results of antiglare films of examples 11 and 12

Further, the average secondary particle size of the silica nanoparticles in the antiglare films of examples 11 and 12 was 2387nm and 2657nm, respectively, and although the haze was adjusted by adding organic fine particles to the antiglare layer, the surface roughness of the antiglare films remained excellent and satisfactory antiglare properties were provided, as shown in table 4.

Table 4: optical property measurement results of antiglare films of examples 11 and 12

Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto, but may be modified and practiced by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. An antiglare film, characterized by comprising:

a transparent substrate; and

An antiglare layer comprising an acrylic binder resin, a polyether-modified siloxane between 0.05 and 5 parts by weight per hundred parts by weight of the acrylic binder resin, and a plurality of silica nanoparticles between 0.1 and 15 parts by weight per hundred parts by weight of the acrylic binder resin, the polyether-modified siloxane being a compound having the formula (I):

wherein R1 to R4, R6 to R11 are each hydrogen or a C1 to C10 hydrocarbon group, R5 is a C1 to C10 hydrocarbon group, x, y and a are integers of 1 or more than 1, and z and b are integers of 0 or more than 0;

wherein the micron-sized floccules formed by the plurality of silica nanoparticles have an average secondary particle size of between 1,500nm and 3,100nm under an optical microscope.

2. The antiglare film according to claim 1, wherein: the antiglare film has an arithmetic average height of 0.03 μm to 0.18 μm, a maximum height of 0.30 μm to 1.8 μm, a center line average roughness of 0.01 μm to 0.16 μm, a full roughness height of 0.10 μm to 0.90 μm, an average peak pitch of 20 μm to 200 μm, and a square root slope of 0.36 DEG to 4.60 deg.

3. The antiglare film according to claim 1, wherein: the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry of the polyether-modified siloxane has an average molecular weight of 200 to 4,500 and an average oxyethylene group number of 1 to 35.

4. The antiglare film according to claim 1, wherein: the weight ratio of the plurality of silica nanoparticles to the polyether modified siloxane is between 0.5 and 100.

5. The antiglare film according to claim 1, wherein: the average primary particle diameter of the specific surface area method (BET) of each silica nanoparticle is between 10nm and 160 nm.

6. The antiglare film according to claim 1, wherein: the average primary particle diameter of the specific surface area method (BET) of each silica nanoparticle is between 20nm and 100 nm.

7. The antiglare film according to claim 1, wherein: the acrylic binder resin comprises a (meth) acrylate composition and an initiator, wherein the (meth) acrylate composition comprises:

35 to 50 parts by weight of a polyurethane (meth) acrylate oligomer having a functionality of between 6 and 15,

12 to 20 parts by weight of a (meth) acrylate monomer having a functionality of 3 to 6; and

1.5 to 12 parts by weight of a (meth) acrylate monomer having a functionality of less than 3.

8. The antiglare film according to claim 7, wherein: the polyurethane (meth) acrylate oligomer having a functionality of between 6 and 15 is an aliphatic polyurethane (meth) acrylate oligomer.

9. The antiglare film according to claim 7, wherein: the (meth) acrylate monomer having a functionality of 3 to 6 is at least one selected from the group consisting of pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, or a combination thereof.

10. The antiglare film according to claim 7, wherein: the (meth) acrylate monomer having a functionality of less than 3 is at least one selected from the group consisting of 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, cyclotrimethylol propane methylal (meth) acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofuran (meth) acrylate, lauryl (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, isobornyl (meth) acrylate, or a combination thereof.

11. The antiglare film according to claim 7, wherein: the initiator is at least one or a combination of acetophenone initiator, diphenyl ketone initiator, propiophenone initiator, dibenzoyl initiator, difunctional alpha-hydroxy ketone initiator and acyl phosphine oxide initiator.

12. An antiglare film, characterized by comprising:

a transparent substrate; and

An antiglare layer comprising an acrylic binder resin, a polyether modified siloxane between 0.05 and 5 parts by weight per hundred parts by weight of the acrylic binder resin, a plurality of silica nanoparticles between 0.1 and 15 parts by weight per hundred parts by weight of the acrylic binder resin, and a plurality of organic microparticles, the polyether modified siloxane being a compound having the formula (I):

13. The antiglare film according to claim 12, wherein: the particle size of each organic microparticle is between 0.5 μm and 6 μm.

14. The antiglare film according to claim 12, wherein: the refractive index of each organic microparticle may be between 1.4 and 1.6.

15. The antiglare film according to claim 12, wherein: the plurality of organic microparticles is 0.5 to 15 parts by weight per hundred parts by weight of the acrylic binder resin.

16. The antiglare film according to claim 12, wherein: the plurality of organic microparticles are at least one selected from the group consisting of polymethyl methacrylate resin microparticles, polystyrene resin microparticles, styrene-methyl methacrylate copolymer microparticles, polyethylene resin microparticles, epoxy resin microparticles, polysiloxane resin microparticles, polyvinylidene fluoride resin and polyvinyl fluoride resin microparticles, or a combination thereof.

17. A polarizing plate, characterized by comprising:

a polarizing assembly; and

the antiglare film according to any one of claims 1 to 16, which is formed on a surface of the polarizing element.