JP6458408B2 - Evaluation method of glare generation of anti-glare film - Google Patents

Description

  The present invention relates to an antiglare film management method and a roll body.

  An image display surface in an image display device such as a liquid crystal display (LCD), a cathode ray tube display device (CRT), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED) or the like is usually an observer and In order to suppress reflection of an observer's background or the like, an antiglare film having irregularities on the surface and an antireflection film having an antireflection layer on the outermost surface are provided.

  The antiglare film suppresses reflection of the observer and the background of the observer by scattering external light on the uneven surface of the antiglare layer. The antiglare film mainly includes a light-transmitting substrate and an antiglare layer having an uneven surface provided on the light-transmitting substrate (see Patent Document 1).

  The uneven surface of the antiglare layer can be formed by including fine particles in the antiglare layer or by applying a shaping treatment to the antiglare layer. An antiglare film having a relatively high total haze value of 20% or more and 30% or less having an uneven surface formed by including silica fine particles in the antiglare layer is inexpensive, so a monitor, a notebook PC, etc. Widely used in applications.

  When the antiglare film is disposed on the surface of the image display device, image light may be scattered by the uneven surface of the antiglare layer, and so-called glare may occur. In the antiglare film having a relatively high total haze value as described above, the glare has not been generated so far. However, the glare has been generated with the recent high definition of the image display device.

  Conventionally, quality control of anti-glare films has been performed by measuring haze and gloss. However, since the correlation between these and glare is poor, an anti-glare film that does not easily cause glare with haze or gloss is used. I can't figure it out. Moreover, as a management at the time of manufacture of an anti-glare film, a simple management method is required.

Japanese Patent No. 3465085

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide an antiglare film management method and a roll body of the antiglare film thus managed, which can supply only an antiglare film that is simple and hardly causes glare.

  According to one aspect of the present invention, there is provided a method for managing an antiglare film, comprising: a light transmissive substrate; and an antiglare layer provided on the light transmissive substrate and having an uneven surface, wherein The antiglare film has a total haze value of 20% or more and 30% or less, and the transmitted image definition of the antiglare film measured using an optical comb having a width of 2.0 mm is 8% or more. An antiglare film management method for managing a glare film is provided.

  According to the other aspect of this invention, the roll body of the said anti-glare film managed by the management method of the anti-glare film of Claim 1 by the said method is provided.

  According to the antiglare film of one embodiment of the present invention, it is possible to supply only an antiglare film that hardly causes glare by a simple method.

It is a schematic block diagram of the anti-glare film which concerns on embodiment. It is the figure which expanded a part of FIG. It is the schematic diagram which showed a mode that the transmission image definition of the anti-glare film which concerns on embodiment was measured with the transmission image definition measuring apparatus. It is the figure which showed typically the roll body which concerns on embodiment.

  Hereinafter, the management method of the anti-glare film which concerns on embodiment is demonstrated, referring drawings. FIG. 1 is a schematic configuration diagram of an antiglare film according to the present embodiment, FIG. 2 is an enlarged view of a part of FIG. 1, and FIG. 3 shows the transmitted image definition of the antiglare film according to the present embodiment. It is the schematic diagram which showed a mode that it measured with the transmitted image definition measuring apparatus, and FIG. 4 is the figure which showed typically the roll body which concerns on embodiment. In the present specification, terms such as “film”, “sheet”, and “plate” are not distinguished from each other only based on the difference in names. Therefore, for example, “film” is a concept including a member that can also be called a sheet or a plate. As a specific example, “antiglare film” includes members called “antiglare sheet”, “antiglare plate” and the like. In the present specification, the “weight average molecular weight” is a value obtained by dissolving in a solvent such as tetrahydrofuran (THF) and converting to polystyrene by a conventionally known gel permeation chromatography (GPC) method.

<<< Management method of anti-glare film >>>
The management method of the anti-glare film which concerns on this embodiment is the method of managing an anti-glare film so that the transmitted image definition of an anti-glare film measured using a 2.0 mm width optical comb may be 8% or more. is there.

  As shown in FIG. 2, the antiglare film 10 to be managed includes a light transmissive substrate 11 and an antiglare layer 12 provided on the light transmissive substrate 11 and having an uneven surface 12A. ing.

  The surface 10A of the antiglare film 10 is an uneven surface 12A. In this embodiment, since the functional layer such as the low refractive index layer is not provided on the antiglare layer 12, the uneven surface 12A of the antiglare layer 12 is the surface 10A of the antiglare film 10. “Functional layer” is a layer intended to exhibit some function in an antiglare film, and specifically, for example, exhibits functions such as antireflection, antistatic, or antifouling properties. The layer for doing is mentioned. The functional layer is not limited to a single layer but may be a laminate of two or more layers.

  In the anti-glare film 10, the total haze value is 20% or more and 30% or less. In the anti-glare film 10, it is preferable that the ratio of the internal haze value to the total haze (internal haze value / total haze value) is 0 or more and 0.1 or less. The total haze value and the internal haze value are values when measured as the whole antiglare film. For example, in the present embodiment, since no functional layer such as a low refractive index layer is provided on the antiglare layer 12, the total haze value and the internal haze value of the antiglare film 10 are the light-transmitting substrate 11 and It is a value measured using the antiglare film 10 composed of the antiglare layer 12. Further, for example, when a functional layer such as a low refractive index layer is provided on the antiglare layer, the total haze value and the internal haze value of the antiglare film are the light transmissive substrate, the antiglare layer, and It is the value measured using the anti-glare film which consists of a functional layer.

The total haze value and the internal haze value can be measured by a method based on JIS K7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory). Specifically, the total haze value of the antiglare film is measured using a haze meter in accordance with JIS K7136. Moreover, an internal haze value is calculated | required as follows. On the surface of the antiglare layer of the antiglare film, a resin having a refractive index equal to that of the resin forming the uneven surface, or a resin having a refractive index difference of 0.02 or less with a wire bar is 8 μm in dry film thickness, That is, it was applied so that the uneven shape of the uneven surface disappeared completely and the surface could be flattened, dried at 70 ° C. for 1 minute, and then irradiated with 100 mJ / cm ² of ultraviolet light on the applied resin. Harden. Thereby, the unevenness existing on the surface of the antiglare film is crushed, and a film having a flat surface is obtained. However, if a leveling agent or the like is contained in the composition for forming the antiglare layer having the uneven shape, the resin applied to the surface of the antiglare layer is likely to be repelled and difficult to get wet. After saponifying the surface of the glare layer (2 mol / L NaOH (or KOH) solution at 55 ° C. for 3 minutes, washing with water, removing water drops with Kimwipe (registered trademark) etc. For 1 minute). And in this state, an internal haze value is calculated | required by measuring a haze value according to JISK7136 using a haze meter (HM-150, Murakami Color Research Laboratory make). This internal haze does not take into account the uneven shape of the surface of the antiglare film.

  The lower limit of the total haze value of the antiglare film is preferably 22% or more, and the upper limit is preferably 28% or less.

  The surface haze value of the antiglare film 10 is preferably 22% or more and 28% or less. The surface haze value is caused only by the uneven surface shape of the anti-glare film, and the surface haze value obtained only by the uneven surface shape of the anti-glare film is obtained by subtracting the internal haze value from the overall haze value. It is done.

  The “transparent image clarity of the antiglare film” means the transmitted image clarity measured for the entire antiglare film. In the present embodiment, since a functional layer such as a low refractive index layer is not provided on the antiglare layer 12, the transmitted image clarity of the antiglare film 10 is determined from the light transmissive substrate 11 and the antiglare layer 12. It is the transmitted image clarity measured using the anti-glare film 10 which becomes. For example, when a functional layer such as a low refractive index layer is provided on the antiglare layer, the transmitted image definition of the antiglare film is determined from the light-transmitting substrate, the antiglare layer, and the functional layer. It is the transmitted image clarity measured using the anti-glare film.

  The transmission image definition can be measured by a transmission image definition measuring device based on the image definition transmission method of JIS K7374. As such a measuring apparatus, Suga Test Instruments Co., Ltd. image clarity measuring device ICM-1T etc. are mentioned.

As shown in FIG. 3, the transmitted image definition measuring apparatus 100 includes a light source 101, a slit 102, a lens 103, a lens 104, an optical comb 105, and a light receiver 106. The transmission sharpness measuring device 100 converts light emitted from the light source 101 and passing through the slit 102 into parallel light by the lens 103, and irradiates the parallel light to the light transmissive substrate 11 side of the antiglare film 10 to prevent the light. The light transmitted from the irregular surface 12A of the antiglare layer 12 of the glare film 10 is collected by the lens 104, and the light that has passed through the optical comb 105 is received by the light receiver 106. The light received by the light receiver 106 Based on the amount of light, the transmitted image definition C is calculated by the following equation (1).
C (n) = {(M−m) / (M + m)} × 100 (%) (1)
In formula (1), C (n) is the transmitted image definition (%) when the width of the optical comb is n (mm), M is the maximum light intensity when the width of the optical comb is n (mm), and m is This is the minimum light amount when the width of the optical comb is n (mm). In this embodiment, the transmitted image clarity of the antiglare film 10 is measured using an optical comb 105 having a width of 2.0 mm. Therefore, C (n) in the above formula (1) is C (2.0). Become.

  The optical comb 105 is movable along the longitudinal direction of the optical comb 105 and has a light shielding portion and a transmission portion. The ratio of the width of the light shielding portion and the transmission portion of the optical comb 105 is 1: 1. Here, in JIS K7374, five types of optical combs having a width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are defined as optical combs. In the case of using an optical comb having a width of 2.0 mm, when an optical comb having a width other than 2.0 mm is used, an antiglare film that is likely to cause glare, and an antiglare film that is less likely to cause glare, and The difference in transmitted image sharpness does not appear so much between the two, but when an optical comb with a width of 2.0 mm is used, it is between an anti-glare film that is susceptible to glare and an anti-glare film that is less likely to cause glare. This is because there is a clear difference in transmitted image clarity.

  From the viewpoint of further suppressing glare, the antiglare film 10 is preferably managed so that the transmitted image sharpness measured using an optical comb having a width of 2.0 mm is 10% or more. From the viewpoint of obtaining sufficient antiglare properties, the upper limit of the antiglare film 10 transmission image sharpness measured using an optical comb having a width of 2.0 mm is preferably 30% or less, and 20% or less. Is more preferable.

  In this embodiment, since the anti-glare film 10 is managed so that the transmitted image clarity of the anti-glare film 10 measured using an optical comb having a width of 2.0 mm is 8% or more, a simple method, It is possible to provide the antiglare film 10 that is less likely to cause glare stably. That is, as a result of intensive studies conducted by the present inventors, it has been found that although the reason is not clear, glare is unlikely to occur when the transmitted image sharpness increases. As a result of further intensive studies by the present inventors, it has been found that glare is unlikely to occur if the transmitted image clarity measured with an optical comb having a width of 2.0 mm is 8% or more. Here, in the anti-glare film having a high total haze of 20% to 30%, the optical image having a narrow width has a low transmission image sharpness between the anti-glare film that easily causes glare and the anti-glare film that hardly causes glare. There is no difference, but when measuring the transmitted image clarity of an anti-glare film that tends to cause glare using an optical comb with a width of 2.0 mm and an anti-glare film that hardly causes glare, the anti-glare film that tends to cause glare There is a clear difference in transmitted image sharpness in an antiglare film that is less likely to cause glare. Specifically, if the transmitted image definition of the antiglare film measured using an optical comb having a width of 2.0 mm is 8% or more, glare hardly occurs, but an optical comb having a width of 2.0 mm is used. If the transmitted image clarity of the measured antiglare film is less than 8%, glare tends to occur. For this reason, it was decided to manage the antiglare film so that the transmission sharpness measured using an optical comb having a width of 2.0 mm was 8% or more. In addition, an antiglare film that hardly causes glare can be determined by a simple method of transmission clarity. Therefore, it is possible to provide only the antiglare film 10 which is less likely to cause glare stably by a simple method.

  The antiglare film 10 preferably has a total light transmittance of 85% or more. When the total light transmittance is 85% or more, color reproducibility and visibility can be further improved when the antiglare film 10 is mounted on the surface of the image display device. The total light transmittance is more preferably 90% or more. The total light transmittance can be measured by a method based on JIS K7361 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

  In the surface 10A of the antiglare film 10, the average interval Sm of the unevenness constituting the surface 10A is preferably 0.02 mm or more and 0.5 mm or less, and is 0.05 mm or more and 0.3 mm or less. It is more preferable. On the surface of the antiglare film, the average inclination angle θa of the unevenness constituting this surface is preferably 2 ° or more and 8 ° or less, and more preferably 3 ° or more and 6 ° or less.

  In the surface 10A of the antiglare film 10, the arithmetic average roughness Ra of the unevenness constituting this surface is preferably 0.1 μm or more and 1.0 μm or less, and is 0.3 μm or more and 0.6 μm or less. More preferably. In the surface 10A of the antiglare film 10, the maximum height roughness Ry of the unevenness constituting this surface is preferably 1 μm or more and 10 μm or less, and more preferably 3 μm or more and 6 μm or less. On the surface 10A of the antiglare film 10, the 10-point average roughness Rz of the unevenness constituting this surface is preferably 0.6 μm or more and 6.0 μm or less, and more preferably 1 μm or more and 4 μm or less. preferable.

The definitions of the above “Sm”, “Ra”, “Ry” and “Rz” shall conform to JIS B0601-1994. The definition of “θa” is in accordance with the surface roughness measuring instrument: SE-3400 / Kosaka Laboratory Co., Ltd. instruction manual (revised 1995.07.20). Specifically, θa is represented by the following formula (2).
θa = tan ⁻¹ Δa (2)
In the formula, Δa represents the slope as an aspect ratio, and is a value obtained by dividing the total sum of the differences between the minimum and maximum portions of each unevenness (corresponding to the height of each convex portion) by the reference length.

Sm, θa, Ra, Ry, and Rz can be measured under the following measurement conditions using, for example, a surface roughness measuring instrument (model number: SE-3400 / manufactured by Kosaka Laboratory).
1) Stylus of surface roughness detector (trade name SE2555N (2μ standard) manufactured by Kosaka Laboratory Ltd.)
・ Tip radius of curvature 2μm, apex angle 90 degrees, material diamond 2) Measurement conditions of surface roughness measuring instrument ・ Reference length (cutoff value λc of roughness curve): 0.8 mm
Evaluation length (reference length (cutoff value λc) × 5): 4.0 mm
・ Feeding speed of stylus: 0.5mm / s
・ Preliminary length: (cutoff value λc) × 2
・ Vertical magnification: 2000 times ・ Horizontal magnification: 10 times

  The antiglare film 10 is provided on the surface of the image display device, and is particularly preferably used on the surface of an image display device (for example, a liquid crystal display for a monitor) having a resolution of 90 ppi or more and 110 ppi.

<Light transmissive substrate>
The light-transmitting substrate 11 is not particularly limited as long as it has light-transmitting properties. For example, a cellulose acylate substrate, a cycloolefin polymer substrate, a polycarbonate substrate, an acrylate polymer substrate, a polyester substrate, or A glass substrate is mentioned.

  As a cellulose acylate base material, a cellulose triacetate base material and a cellulose diacetate base material are mentioned, for example. As a cycloolefin polymer base material, the base material which consists of polymers, such as a norbornene-type monomer and a monocyclic cycloolefin monomer, is mentioned, for example.

  Examples of the polycarbonate substrate include aromatic polycarbonate substrates based on bisphenols (bisphenol A and the like), aliphatic polycarbonate substrates such as diethylene glycol bisallyl carbonate, and the like.

  Examples of the acrylate polymer base material include a poly (meth) methyl acrylate base material, a poly (meth) ethyl acrylate base material, and a (meth) methyl acrylate- (meth) butyl acrylate copolymer base material. Can be mentioned.

  Examples of the polyester base material include base materials containing at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as constituent components.

  Examples of the glass substrate include glass substrates such as soda lime silica glass, borosilicate glass, and alkali-free glass.

  Among these, a cellulose acylate base material is preferable because of excellent retardation and easy adhesion with a polarizer, and among the cellulose acylate base materials, a triacetyl cellulose base material (TAC base material) is preferable. A triacetyl cellulose base material is a light-transmitting base material capable of setting an average light transmittance to 50% or more in a visible light region of 380 to 780 nm. The average light transmittance of the triacetyl cellulose base material is preferably 70% or more, and more preferably 85% or more.

  In addition, as a triacetyl cellulose base material, in addition to pure triacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like may be used in combination with components other than acetic acid as a fatty acid forming an ester with cellulose. Good. Further, these triacetylcelluloses may be added with other additives such as other cellulose lower fatty acid esters such as diacetylcellulose, or plasticizers, ultraviolet absorbers, and lubricants as necessary.

  A cycloolefin polymer substrate is preferred from the standpoint of retardation and heat resistance, and a polyester substrate is preferred from the standpoint of mechanical properties and heat resistance.

  The thickness of the light-transmitting substrate 11 is not particularly limited, but can be 5 μm or more and 1000 μm or less. The lower limit of the thickness of the light-transmitting substrate 11 is preferably 15 μm or more from the viewpoint of handling properties, etc., and 25 μm The above is more preferable. The upper limit of the thickness of the light transmissive substrate 11 is preferably 80 μm or less from the viewpoint of thinning.

<Anti-glare layer>
The antiglare layer 12 is a layer that exhibits antiglare properties. The antiglare layer 12 may exhibit antiglare properties and other functions. Specifically, the anti-glare layer 12 may be a layer that exhibits anti-glare properties and, for example, functions such as hard coat properties, antireflection properties, antistatic properties, and antifouling properties.

  When the antiglare layer 12 is a layer that exhibits hard coat properties in addition to the antiglare property, the antiglare layer 12 has a pencil hardness test (4.9 N) defined by JIS K5600-5-4 (1999). It has a hardness equal to or higher than “H” in terms of load.

  As described above, the surface of the antiglare layer 12 is an uneven surface 12A. The “surface of the antiglare layer” means a surface opposite to the surface on the light transmissive substrate side of the antiglare layer (the back surface of the antiglare layer).

  As a method of forming the uneven surface 12A, for example, (A) a method of forming an uneven surface using a composition for an antiglare layer containing a curable resin precursor and a fine particle that becomes a binder resin after curing, and (B) a mold (C) A method of forming an uneven surface by roughening the surface of the antiglare layer by sandblasting, or (D) An uneven surface is imparted to the surface of the antiglare layer by an embossing roll. And a method for forming an uneven surface by doing so. Among these, the method (A) is preferable because the production is easy.

  In the method (A), an antiglare layer having an uneven surface can be formed by appropriately selecting the type and size of fine particles and the type of curable resin precursor and adjusting the coating film forming conditions. it can.

  The antiglare layer 12 includes a binder resin 13 and fine particles 14 as shown in FIG. 2 and is formed by the method (A).

(Binder resin)
The binder resin 13 includes a cured product (polymer, cross-linked product) of a curable resin precursor. The “curable resin precursor” in the present specification means a resin precursor in which the resin precursor has photocurability or thermosetting and becomes a resin by photocuring or thermosetting. The resin may contain a solvent-drying resin in addition to the cured product of the curable resin precursor. The photocurable resin precursor having photocurability has at least one photopolymerizable functional group. In the present specification, the “photopolymerizable functional group” is a functional group capable of undergoing a polymerization reaction by light irradiation. Examples of the photopolymerizable functional group include ethylenic double bonds such as a (meth) acryloyl group, a vinyl group, and an allyl group. In the present specification, “(meth) acryloyl group” means both “acryloyl group” and “methacryloyl group”. Moreover, examples of the light irradiated when the photocurable resin precursor is cured include visible light and ionizing radiation such as ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays. The thermosetting resin precursor having thermosetting properties has at least one thermopolymerizable functional group.

  Examples of the photocurable resin precursor include photopolymerizable monomers, photopolymerizable oligomers, and photopolymerizable prepolymers, which can be appropriately adjusted and used. As a photocurable resin precursor, the combination of a photopolymerizable monomer and a photopolymerizable oligomer or a photopolymerizable prepolymer is preferable.

(Photopolymerizable monomer)
The photopolymerizable monomer has a weight average molecular weight of less than 1000. The photopolymerizable monomer is preferably a polyfunctional monomer having two or more photopolymerizable functional groups (that is, bifunctional).

  Examples of the bifunctional or higher monomer include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and pentaerythritol tri (meth). Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditri Methylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, Lapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra ( (Meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentane di (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and these are PO, EO And the like modified.

  Among these, from the viewpoint of obtaining a first functional layer having high hardness, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPPA), etc. Is preferred.

(Photopolymerizable oligomer)
The photopolymerizable oligomer has a weight average molecular weight of 1000 or more and less than 10,000. The photopolymerizable oligomer is preferably a bifunctional or higher polyfunctional oligomer. Polyfunctional oligomers include polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and isocyanurate (meth). Examples include acrylate and epoxy (meth) acrylate.

(Photopolymerizable prepolymer)
The photopolymerizable polymer has a weight average molecular weight of 10,000 or more, and the weight average molecular weight is preferably from 10,000 to 80,000, more preferably from 10,000 to 40,000. When the weight average molecular weight exceeds 80,000, the viscosity is high, so that the coating suitability is lowered, and the appearance of the obtained optical laminate may be deteriorated. Examples of the polyfunctional polymer include urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, and epoxy (meth) acrylate.

  The thermosetting resin precursor is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea Examples thereof include respective precursors such as co-condensation resins, silicon resins, and polysiloxane resins.

  The solvent-drying resin is a resin that forms a film only by drying a solvent added to adjust the solid content during coating, such as a thermoplastic resin. When the solvent-drying type resin is added, film defects on the coating surface of the coating liquid can be effectively prevented when the antiglare layer 12 is formed. It does not specifically limit as solvent dry type resin, Generally, a thermoplastic resin can be used.

  Examples of thermoplastic resins include styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins. , Cellulose derivatives, silicone resins and rubbers or elastomers.

  The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoint of transparency and weather resistance, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) and the like are preferable.

(Fine particles)
The fine particles 14 may be either inorganic fine particles or organic fine particles. Among these, for example, silica (SiO ₂ ) fine particles, alumina fine particles, titania fine particles, tin oxide fine particles, antimony-doped tin oxide (ATO) fine particles, Inorganic oxide fine particles such as zinc oxide fine particles are preferred. The inorganic oxide fine particles can form an aggregate in the antiglare layer, and an uneven surface can be formed by the degree of aggregation of the aggregate.

  Among inorganic oxide particles, silica fine particles are preferable because they are highly transparent and can be obtained at low cost. Examples of the method for producing silica fine particles include a dry method and a wet method, but a wet method is preferable because an aggregate capable of imparting high antiglare properties is easily formed. The wet method is classified into a precipitation method and a gel method, but any method may be used in the present invention.

  Examples of the organic fine particles include plastic beads. Specific examples of the plastic beads include polystyrene beads, melamine resin beads, acrylic beads, acrylic-styrene beads, silicone beads, benzoguanamine beads, benzoguanamine / formaldehyde condensation beads, polycarbonate beads, polyethylene beads, and the like.

  When inorganic oxide particles are used as the fine particles 14, the inorganic oxide particles are preferably subjected to surface treatment. By subjecting the inorganic oxide fine particles to a surface treatment, the distribution of the fine particles in the antiglare layer 12 can be suitably controlled, and the chemical resistance and saponification resistance of the fine particles themselves can be improved.

  As the surface treatment, a hydrophobizing treatment for making the surface of the fine particles 14 hydrophobic is preferable. Such a hydrophobic treatment can be obtained by chemically reacting the surface of the fine particles 14 with a surface treatment agent such as silanes or silazanes. Specific examples of the surface treatment agent include dimethyldichlorosilane, silicone oil, hexamethyldisilazane, octylsilane, hexadecylsilane, aminosilane, methacrylsilane, octamethylcyclotetrasiloxane, and polydimethylsiloxane.

  Although content of the microparticles | fine-particles 14 with respect to the glare-proof layer 12 is not specifically limited, It is preferable that they are 5 mass% or more and 30 mass% or less. Since the content of the fine particles is 5% by mass or more, the antiglare property can be reliably obtained, and since the content of the fine particles is 30% by mass or less, aggregates may be excessively generated. In addition, it is possible to suppress the occurrence of excessive unevenness on the surface of the internal diffusion and / or the antiglare layer, thereby suppressing the cloudiness. The lower limit of the content of fine particles is more preferably 10% by mass or more, and the upper limit of the content of fine particles is more preferably 20% by mass or less.

  When inorganic oxide fine particles are used as the aggregate 14, the average secondary particle diameter of the inorganic oxide fine particles is preferably 0.5 μm or more and 5 μm or less. If it is 0.5 μm or more, an antiglare layer having a surface haze of 20% or more and 30% or less can be formed, and if it is 5 μm or less, formation of excessively large unevenness can be suppressed and generation of glare can be suppressed. can do. The average secondary particle diameter of the aggregates of the fine particles 14 is preferably 1 μm or more at the lower limit, and preferably 3 μm or less at the upper limit. The average secondary particle diameter of the inorganic oxide fine particles can be measured as a volume average diameter by a Coulter counter method.

  The antiglare layer 12 can be formed by the following method, for example. First, the following antiglare layer composition is applied to the surface of the light transmissive substrate 11. Examples of the method for applying the antiglare layer composition include known coating methods such as spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, and die coating.

  The antiglare layer composition contains at least the curable resin precursor and the fine particles. In addition, you may add a solvent and a polymerization initiator to the composition for anti-glare layers as needed. Further, the antiglare layer composition includes conventionally known dispersants, surfactants and antistatic agents depending on purposes such as increasing the hardness of the antiglare layer, suppressing cure shrinkage, and controlling the refractive index. , Silane coupling agents, thickeners, anti-coloring agents, colorants (pigments, dyes), antifoaming agents, leveling agents, flame retardants, UV absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modification A quality agent, a lubricant, etc. may be added.

(solvent)
The solvent is used for adjusting the viscosity for easy application of the antiglare layer composition, adjusting the evaporation rate and dispersibility for fine particles, and adjusting the degree of aggregation of the fine particles when forming the antiglare layer. It can be used for the purpose of easily forming a predetermined uneven surface. Examples of the solvent include alcohols (eg, methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol), ketones (acetone, methyl ethyl ketone (MEK), cyclohexanone. , Methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone, etc.), ethers (1,4-dioxane, dioxolane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate) ), Cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., and mixtures thereof may be used. .

(Polymerization initiator)
The polymerization initiator is a component that is decomposed by light irradiation to generate radicals to initiate or advance polymerization (crosslinking) of the photopolymerizable compound.

  The polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by light irradiation. The polymerization initiator is not particularly limited, and known ones can be used. Specific examples include, for example, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, thioxanthones, propiophenone. , Benzyls, benzoins, acylphosphine oxides. In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

  As the polymerization initiator, when the binder resin is a resin system having a radically polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like alone or in combination. .

  The content of the polymerization initiator in the antiglare layer composition is preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound. By making the content of the polymerization initiator within this range, inhibition of curing can be suppressed.

  Although it does not specifically limit as a content rate (solid content) of the raw material in the composition for glare-proof layers, Usually, 5 to 70 mass% is preferable, and it is more preferable to set it as 25 to 60 mass%. .

(Leveling agent)
As the leveling agent, for example, silicone oil, fluorine-based surfactant and the like are preferable because it prevents the antiglare layer from having a Benard cell structure. When a resin composition containing a solvent is applied and dried, a surface tension difference or the like is generated between the coating film surface and the inner surface in the coating film, thereby causing many convections in the coating film. The structure generated by this convection is called a Benard cell structure, and causes problems such as the skin and coating defects in the antiglare layer to be formed.

  In the Benard cell structure, the unevenness on the surface of the antiglare layer may become too large. When the leveling agent as described above is used, this convection can be prevented, so that not only a glare-proof layer free from defects and unevenness can be obtained, but also the uneven shape of the surface of the glare-proof layer can be easily adjusted.

  The method for preparing the composition for the antiglare layer is not particularly limited as long as each component can be uniformly mixed. For example, the composition can be performed using a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer.

  After coating the antiglare layer composition on the surface of the light-transmitting substrate 11, it is transported to a heated zone for drying the coating-like antiglare layer composition, and various known methods are used. The antiglare layer composition is dried and the solvent is evaporated. Here, the distribution state of the fine particles can be adjusted by selecting the solvent relative evaporation rate, solid content concentration, coating solution temperature, drying temperature, drying air velocity, drying time, solvent atmosphere concentration in the drying zone, and the like.

  In particular, a method of adjusting the distribution state of the fine particles by selecting the drying conditions is simple and preferable. The specific drying temperature is preferably 30 to 120 ° C., and the drying wind speed is preferably 0.2 to 50 m / s. The drying treatment appropriately adjusted within this range is performed once or a plurality of times to thereby form fine particles. The distribution state can be adjusted to a desired state.

  Thereafter, the coating-like antiglare layer composition is irradiated with light such as ultraviolet rays, and the curable resin precursor is polymerized (crosslinked) to cure the antiglare layer composition. And the mixed region 11A is formed.

  When ultraviolet rays are used as the light for curing the composition for the antiglare layer, ultraviolet rays emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, or the like can be used. Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

  According to this embodiment, since the anti-glare film 10 includes the anti-glare layer 12 having the uneven surface 12A, the light reflected at the interface between the light transmissive substrate 11 and the anti-glare layer 12 and the anti-glare layer Interference with light reflected by the twelve irregular surfaces 12A can be suppressed. Thereby, generation | occurrence | production of an interference fringe can be suppressed. In addition, when the mixed region 11A is formed, reflection at the interface between the light transmissive substrate 11 and the antiglare layer 12 can be suppressed, so that the generation of interference fringes can be further suppressed.

<Roll body>
The antiglare film is usually managed in the state of a roll body, cut into a predetermined size at the time of use, and incorporated into a polarizing plate, an image display device or the like. Therefore, as shown in FIG. 5, the antiglare film 10 is also preferably managed in the state of the roll body 20.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited to these descriptions.

<Preparation of composition for antiglare layer>
First, each component was mix | blended so that it might become a composition shown below, and the composition for glare-proof layers was obtained.
(Composition for anti-glare layer)
Amorphous silica (gel method, average secondary particle size (volume average) 2.0 μm): 15 to 20 parts by mass Pentaerythritol triacrylate: 100 parts by mass Cellulose derivative (cellulose acetate propionate): 1 part by mass Parts / silicone leveling agent: 0.2 parts by mass / toluene (solvent): 200 parts by mass / methyl isobutyl ketone (solvent): 50 parts by mass The above-mentioned amorphous silica has an organic surface treated (hydrophobized). Met.

<Preparation of antiglare film>
An 80 μm thick triacetyl cellulose resin film (manufactured by Fuji Film Co., Ltd., TD80UL) as a light-transmitting substrate was prepared, and the antiglare layer composition 1 was applied to one side of the triacetyl cellulose resin film. Formed. Next, 50 ° C. dry air was passed through the formed coating film at a flow rate in the range of 0.2 to 1 m / s for 15 seconds, and then 70 ° C. dry air was further supplied at a flow rate of 10 m / s for 30 seconds. By allowing the solvent in the coating film to evaporate by circulating and drying, and curing the coating film by irradiating ultraviolet rays with a cumulative amount of light of 100 mJ / cm ² under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) An antiglare layer having a thickness of 1 to 3 μm (during curing) was formed, and the mass part, drying conditions, and thickness of the amorphous silica were appropriately adjusted to produce antiglare films according to Samples 1 to 10.

<Measurement of transmitted image clarity>
In each of the antiglare films of Samples 1 to 10, the transmitted image clarity was measured as follows. First, a image clarity measuring device (model number: ICM-1T, manufactured by Suga Test Instruments Co., Ltd.) was prepared. And each anti-glare film which concerns on samples 1-10 is installed so that the triacetyl cellulose resin film side may become the light source side of a image clarity measuring device, and it conforms to the measuring method of the image clarity by the transmission method of JIS K7374. The transmission image definition was measured. As optical combs, those having a width of 0.125 mm, a width of 0.25 mm, a width of 0.5 mm, a width of 1.0 mm, and a width of 2.0 mm were used. In Table 1, the transmission image definition of the antiglare film measured using an optical comb of 0.125 mm width, 0.25 mm width, 0.5 mm width, 1.0 mm width, 2.0 mm width, C (0.125), C (0.25), C (0.5), C (1.0), and C (2.0), respectively.

<Overall haze, internal haze, surface haze measurement>
About each anti-glare film of samples 1-10, the whole haze, the internal haze, and the surface haze were measured as follows. First, the overall haze value of the antiglare film was measured according to JIS K7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory). Thereafter, the internal haze value was determined by measuring the haze value according to the method described in the above embodiment. And the surface haze value was calculated | required by subtracting an internal haze value from the whole haze value.

<Measurement of gloss (60 degree specular gloss)>
About each anti-glare film of samples 1-10, the gloss (60 degree specular gloss) of the anti-glare film was measured according to JISZ8741 using the precision gloss meter (GM-26PRO, Murakami Color Research Laboratory make).

<Glare evaluation (1)>
In each of the antiglare films of Samples 1 to 10, a glass plate (thickness 3 mm) was bonded to the surface of the antiglare film on which the antiglare layer was not formed with a transparent adhesive. Furthermore, the glass surface in which the anti-glare film in this glass plate was not bonded, and the glass surface in which the matrix of 200 ppi black matrix (glass thickness 0.7mm) was not formed were bonded together with the adhesive. For the sample thus obtained, a white surface light source (LIGHTBOX manufactured by HAKUBA, average luminance of 1000 cd / m ² ) was installed on the black matrix side, thereby causing pseudo glare. This was photographed from the antiglare film side with a CCD camera (KP-M1, C mount adapter, close-up ring; PK-11A Nikon, camera lens; 50 mm, F1.4s NIKKOR). The distance between the CCD camera and the antiglare film was 250 mm, and the focus of the CCD camera was adjusted to match the antiglare film. Images taken with a CCD camera were taken into a personal computer and analyzed with image processing software (ImagePro Plus ver. 6.2; manufactured by Media Cybernetics) as follows. First, an evaluation location of 200 × 160 pixels was selected from the captured image, and converted to a 16-bit gray scale at the evaluation location. Next, the low-pass filter was selected from the enhancement tab of the filter command, and the filter was applied under the conditions of 3 × 3, number of times 3, and strength 10. As a result, components derived from the black matrix pattern were removed. Next, flattening was selected, and shading correction was performed under the condition of background: dark, object width 10. Next, contrast enhancement was performed with a contrast enhancement command with a contrast of 96 and a brightness of 48. The obtained image was converted to an 8-bit gray scale, and the variation in the value for each pixel was calculated as a standard deviation value for 150 × 110 pixels in the image, thereby glaring was digitized. It can be said that the smaller the numerical value of the glare value, the less the glare.

<Glare evaluation (2)>
In each of the antiglare films of Samples 1 to 10, glare was evaluated as follows. A 21.5 inch, full HD liquid crystal display monitor was prepared, the polarizing film on the outermost surface was peeled off, and a polarizing film on which no antiglare layer was laminated was pasted with a transparent adhesive film. The antiglare films of Samples 1 to 10 were placed thereon, and it was determined whether or not the glare was anxious from a distance of about 30 cm, and evaluated according to the following criteria.
○: I was not worried about glare.
X: I was worried about glare.

The results are shown in Table 1.

  As shown in Table 1, in Samples 4 to 7, glare occurred because C (2.0) of the antiglare film was less than 8%.

  On the other hand, in samples 1 to 3 and 8 to 10, since C (2.0) of the antiglare film was 8% or more, no glare occurred.

  On the other hand, it can be understood that haze and gloss have no correlation with glare and it is not possible to manage whether glare of the antiglare film is likely to occur.

  Moreover, since the result of the glare evaluation 1 corresponds to the result of the glare evaluation 2, the measurement method used in the glare evaluation 1 is determined to be reliable.

DESCRIPTION OF SYMBOLS 10 ... Anti-glare film 10A ... Surface 11 ... Light-transmitting base material 12 ... Anti-glare layer 12A ... Uneven surface 13 ... Binder resin 14 ... Fine particle

Claims (4)

A light-transmitting base material and an antiglare layer provided on the light-transmitting base material and having an uneven surface, the total haze value is 20% to 30%, and the internal haze value with respect to the total haze value The ratio of (internal haze value / total haze value) is 0 or more and 0.1 or less.
Evaluation that the occurrence of glare in the antiglare film is suppressed when the transmitted image clarity of the antiglare film measured using a 2.0 mm wide optical comb is 8% or more and 20% or less. Method.   The evaluation method according to claim 1, wherein the antiglare film contains fine particles.   The evaluation method according to claim 2, wherein the fine particles are silica fine particles.   After evaluating the glare generation | occurrence | production of an anti-glare film by the evaluation method as described in any one of Claims 1-3, the anti-glare film evaluated that the glare generation | occurrence | production is suppressed is made into the state of a roll body. A method for producing a roll of glare film.

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