JP2011248289A - Anti-glare film, anti-glare polarizing plate and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anti-glare film which shows an excellent anti-glare property and the like, and prevents generation of air bubbles.SOLUTION: An anti-glare film 1 comprises an anti-glare layer 101 which has a fine rugged surface and is formed on a transparent support 104. The fine rugged surface includes 95% or more of the surfaces which have inclination angles equal to or below 5°. The anti-glare layer is formed by applying coating liquid containing an active energy ray-curable resin, fine particles, and a diluent solvent on the transparent support, drying, and then applying a hardening treatment while pressing a stamper. And the settling degree of the coating liquid is limited within an appropriate range.

Description

  The present invention relates to an antiglare film in which an antiglare layer having a fine uneven surface is formed on a transparent support and a method for producing the same. Moreover, it is related with the anti-glare polarizing plate using these anti-glare films, and an image display apparatus.

  In an image display device such as a liquid crystal display, a plasma display panel, or an organic electroluminescence (EL) display, visibility is significantly impaired when external light is reflected on the display surface. In order to prevent such reflection of external light, TVs and personal computers that emphasize image quality, video cameras and digital cameras used outdoors with strong external light, mobile phones that display using reflected light, etc. In general, an antiglare film is disposed on the surface of an image display device.

  As such an antiglare film, a coating solution containing fine particles is applied on a transparent support without using a mold, and then dried and cured to form an antiglare layer (patent) Documents 1 and 2) and a coating liquid containing fine particles, dried and then cured while transferring an uneven shape with a shaping film to form an antiglare layer (Patent Document 3) ,Are known.

JP-A-6-18706 Japanese Patent Laid-Open No. 10-20103 JP 2007-256962 A

  The antiglare film is required to have antiglare properties, and when arranged on the surface of the image display device, the pixels of the image display device interfere with the uneven surface shape of the antiglare film, resulting in a luminance distribution. Therefore, there is a demand for suppressing the occurrence of so-called “glare” that is difficult to see. However, the above-mentioned known antiglare film is not necessarily sufficient in these respects. Moreover, like the anti-glare film described in patent document 3, after coating the coating liquid containing microparticles | fine-particles on a transparent support body, it dries and then transfers uneven | corrugated shape with a shaping film, When curing, depending on the coating solution used, bubbles may occur in the resulting antiglare film, or fine particles may accumulate on the die that supplies the coating solution, which may contaminate the product or manufacturing equipment. there were.

One aspect of the present invention has the following configuration.
The antiglare layer having a fine uneven surface is an antiglare film formed on a transparent support,
The fine uneven surface includes 95% or more of a surface having an inclination angle of 5 ° or less,
The anti-glare layer is formed by applying a coating liquid containing an active energy ray-curable resin, fine particles and a diluting solvent on the transparent support, then drying, and then curing while pressing a stamper. And
An anti-glare film, wherein a sedimentation degree S of fine particles in the coating liquid represented by the following formula (A) is 1 or more and 76 or less.
S = 100−x / 30 × 100 (A)
[In the formula, x represents 30 ml of the coating liquid in which fine particles are dispersed in a 100 ml graduated cylinder and then left to stand for 6 hours and observed between the transparent supernatant layer and the suspension layer of the coating liquid. It represents the scale (ml) of the interface, and S represents the sedimentation degree of the coating solution. ]

One of the present invention is a method for producing the antiglare film,
A coating process for coating the coating liquid on the transparent support;
A drying step of drying the coating liquid applied in the coating step to obtain a laminate;
A curing step of curing the active energy ray-curable resin by irradiating an active energy ray while pressing a stamper on the coated surface of the laminate obtained in the drying step, and
After the said hardening process, the manufacturing method of the anti-glare film including the peeling process which peels a casting_mold | template from a coating surface is provided.

  In addition, the present invention provides an antiglare polarizing plate in which a polarizing film is bonded to a surface opposite to the antiglare layer of the antiglare film, and further the antiglare polarizing plate. And an image display element, wherein the antiglare polarizing plate is disposed on the viewing side of the image display element with the antiglare layer outside.

  According to the present invention, an anti-glare film that exhibits excellent anti-glare properties, prevents deterioration in visibility due to the occurrence of “glare”, and further prevents the generation of bubbles, and provides it with stable quality. can do. Moreover, the anti-glare film of this invention can be used suitably as a member of an anti-glare polarizing plate or an image display apparatus.

It is sectional drawing which shows typically an example of the anti-glare film of this invention. It is a perspective view which shows typically the surface of the anti-glare film of this invention. It is a schematic diagram for demonstrating the measuring method of the inclination-angle of the fine uneven | corrugated surface. It is a graph which shows an example of the histogram of the inclination angle distribution of the fine uneven surface of the anti-glare layer with which an anti-glare film is provided. It is a schematic diagram which shows the state from which the function h (x, y) showing an altitude is obtained discretely. It is the figure which represented the altitude of the fine uneven surface of the anti-glare layer with which the anti-glare film of this invention is provided with the two-dimensional discrete function h (x, y). The altitude energy spectrum H ² (f _x , f _y ) obtained by discrete Fourier transform of the two-dimensional function h (x, y) shown in FIG. 6 is shown in white and black gradations. Energy spectrum _{^{H 2 (f x, f y}} ) shown in FIG. 7 is a view showing a cross section taken along f _x = 0 in. It is a figure which shows a part of image data which is a pattern which can be used in order to produce the anti-glare film of this invention. Is a graph showing white and black gradation gradation two-dimensional discrete function g (x, y) the energy spectrum obtained by discrete Fourier transform _{^{G 2 (f x, f y}} ) a shown in FIG. 9 . Energy spectrum _{^{G 2 (f x, f y}} ) shown in FIG. 10 is a view showing a cross section taken along f _x = 0 in. It is a figure which shows typically a preferable example of the first half part of the manufacturing method of the metal mold | die preferably used for manufacture of the anti-glare film of this invention. It is a figure which shows typically a preferable example of the second half part of the manufacturing method of the metal mold | die preferably used for manufacture of the anti-glare film of this invention. It is a figure which shows typically the state where the uneven surface formed by the 1st etching process dulls by the 2nd etching process.

<Anti-glare film>
FIG. 1 is a cross-sectional view schematically showing an example of the antiglare film of the present invention. The antiglare film of the present invention comprises a transparent support 104 and an antiglare layer 101 laminated on the transparent support 104 as in the example shown in FIG. The antiglare layer 101 contains a cured product 102 of active energy ray-curable resin and fine particles 103. The surface of the antiglare layer 101 opposite to the transparent support 104 is a fine uneven surface. Hereinafter, the antiglare film of the present invention will be described in more detail.

  The transparent support is not particularly limited as long as it is a substantially optically transparent film. For example, a triacetyl cellulose film, a polyethylene terephthalate film, a polymethyl methacrylate film, a polycarbonate film, and an amorphous material containing a norbornene compound as a monomer. Examples thereof include solvent cast films of thermoplastic resins such as cyclic polyolefins and resin films such as extruded films. Although the thickness in particular of a transparent support body is not restrict | limited, Usually, it is 10-250 micrometers, Preferably it is 20-125 micrometers.

  The antiglare layer is coated with a coating solution containing an active energy ray-curable resin, fine particles and a diluent solvent on the transparent support, then dried, and then pressed against the uneven surface of the mold having an uneven shape. It is formed by curing treatment. The active energy ray-curable resin herein is a resin that is polymerized and cured by irradiation with active energy rays, and can contain, for example, a polyfunctional (meth) acrylate compound. The polyfunctional (meth) acrylate compound is a compound having at least two (meth) acryloyloxy groups in the molecule. The active energy ray-curable resin may be a commercially available product, and in many cases includes an additive such as a polymerization initiator or other surfactant added to the active energy ray-curable resin as necessary. It is marketed as an active energy ray-curable resin composition.

  Specific examples of the polyfunctional (meth) acrylate compound include, for example, ester compounds of polyhydric alcohol and (meth) acrylic acid, urethane (meth) acrylate compounds, polyester (meth) acrylate compounds, epoxy (meth) acrylate compounds, and the like. And a polyfunctional polymerizable compound containing two or more (meth) acryloyl groups.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, propanediol, butanediol, pentanediol, Hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2′-thiodiethanol, divalent alcohols such as 1,4-cyclohexanedimethanol, trimethylolpropane, glycerol, pentaerythritol, Examples thereof include trihydric or higher alcohols such as diglycerol, dipentaerythritol, and ditrimethylolpropane.

  From these, as an esterified product of polyhydric alcohol and (meth) acrylic acid, specifically, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tetramethylol Methane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol tri (meth) acrylate Rate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate.

  Moreover, as a urethane (meth) acrylate compound, it can obtain by the urethanation reaction of the isocyanate which has several isocyanate groups in 1 molecule, and the (meth) acrylic acid derivative which has a hydroxyl group. Examples of organic isocyanates having a plurality of isocyanate groups in one molecule include two isocyanates in one molecule such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and dicyclohexylmethane diisocyanate. Organic isocyanate having a group, organic isocyanate having three isocyanate groups in one molecule obtained by subjecting these organic isocyanates to isocyanurate modification, adduct modification, biuret modification, and the like. As the (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy- Examples thereof include 3-phenoxypropyl (meth) acrylate and pentaerythritol triacrylate.

  Moreover, what is preferable as polyester (meth) acrylate is the polyester (meth) acrylate obtained by making hydroxyl-containing polyester and (meth) acrylic acid react. What is preferable as the hydroxyl group-containing polyester used here is a hydroxyl group-containing polyester obtained by an esterification reaction of a polyhydric alcohol and a compound having a carboxylic acid or a plurality of carboxyl groups and / or its anhydride, Can be exemplified by the same compounds as described above. Moreover, bisphenol A etc. are mentioned as phenols other than a polyhydric alcohol. Examples of the carboxylic acid include formic acid, acetic acid, butyl carboxylic acid, benzoic acid and the like. The compounds having a plurality of carboxyl groups and / or their anhydrides include maleic acid, phthalic acid, fumaric acid, itaconic acid, adipic acid, terephthalic acid, maleic anhydride, phthalic anhydride, trimellitic acid, cyclohexanedicarboxylic anhydride Thing etc. are mentioned.

  Among the polyfunctional (meth) acrylate compounds as described above, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and diethylene glycol from the viewpoint of improving the strength of the cured product (coating film) and availability. Ester compounds such as di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexamethylene diisocyanate, 2-hydroxyethyl (meth) acrylate adduct, isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate adduct, tolylene diisocyanate and 2-hydroxyethyl (meth) acrylate Adduct, adduct of adduct modified isophorone diisocyanate with 2-hydroxyethyl (meth) acrylate adduct and biuret modified isophorone diisocyanate with 2-hydroxyethyl (meth) acrylate is preferred. Furthermore, as the active energy ray curable resin, it is preferable to use a urethane acrylate compound from the viewpoint of good flexibility (flexibility: property showing flexibility) when the film is thickened. Moreover, these polyfunctional (meth) acrylate compounds are each used individually or in mixture of 2 or more types.

  The active energy ray curable resin may contain a monofunctional (meth) acrylate compound in addition to the polyfunctional (meth) acrylate compound. Examples of the monofunctional (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine N-vinylpyrrolidone, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, aceto (Meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxy (meth) acrylate, ethylene oxide modified phenoxy (meta ) Acrylate, propylene oxide (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide modified (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2 -Hydroxypropyl phthalate, dimethylaminoethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, etc. (Meth) acrylates, styrene, N-vinyl-2-pyrrolidone, di-t-butyl fumarate, di-n-butyl fumarate, diethyl fumarate, monomethyl itaconate, dimethyl itaconate, monoethyl itaconate, diethyl itaconate, N -Isopropyl acrylamide etc. can be mentioned. These compounds may be used alone or in combination of two or more.

  Moreover, the active energy ray-curable resin may contain a polymerizable oligomer. By including the polymerizable oligomer, the hardness of the antiglare layer can be adjusted. As the polymerizable oligomer, the polyfunctional (meth) acrylate compound, that is, an ester compound of a polyhydric alcohol and (meth) acrylic acid, a urethane (meth) acrylate compound, a polyester (meth) acrylate compound, and an epoxy (meth) ) Oligomers such as dimers and trimers such as acrylates.

  Further, as other polymerizable oligomers, urethane (meth) obtained by reaction of polyisocyanate having at least two isocyanate groups in the molecule and polyhydric alcohol having at least one (meth) acryloyloxy group. An acrylate oligomer is mentioned. Examples of the polyisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and a polymer of xylylene diisocyanate. The polyhydric alcohol having at least one (meth) acryloyloxy group includes And (meth) acrylic acid ester obtained by esterification reaction of (meth) acrylic acid, for example, 1,3-butanediol, 1,4-butanediol, 1,6-hexane as polyhydric alcohol Diol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, glycerin, pentaerythritol, dipe Data erythritol, and the like. In this polyhydric alcohol having at least one (meth) acryloyloxy group, a part of the alcoholic hydroxyl group of the polyhydric alcohol is esterified with (meth) acrylic acid, and the alcoholic hydroxyl group is present in the molecule. It remains.

  Furthermore, other examples of the polymerizable oligomer include polyesters obtained by reacting a compound having a plurality of carboxyl groups and / or anhydrides thereof with a polyhydric alcohol having at least one (meth) acryloyloxy group ( And (meth) acrylate oligomers. Examples of the compound having a plurality of carboxyl groups and / or anhydrides thereof include those described for polyester (meth) acrylate of the polyfunctional (meth) acrylate compound. Examples of the polyhydric alcohol having at least one (meth) acryloyloxy group include those described for the urethane (meth) acrylate oligomer.

  In addition to the polymerizable oligomers as described above, as examples of urethane (meth) acrylate oligomers, hydroxyl groups-containing polyesters, hydroxyl group-containing polyethers, and hydroxyl group-containing (meth) acrylic acid esters each react with isocyanates. The compound obtained by making it contain is mentioned. Preferred as the hydroxyl group-containing polyester is a hydroxyl group-containing polyester obtained by an esterification reaction of a polyhydric alcohol, a carboxylic acid, a compound having a plurality of carboxyl groups and / or an anhydride thereof, and includes a polyhydric alcohol and a plurality of carboxyls. Examples of the group-containing compound and / or anhydride thereof are those listed for the polyfunctional (meth) acrylate compound polyester (meth) acrylate compound. Preferred as the hydroxyl group-containing polyether is a hydroxyl group-containing polyether obtained by adding one or more alkylene oxides and / or ε-caprolactone to the polyhydric alcohol, It is the same as that which can be used for a hydroxyl-containing polyester. Preferable examples of the hydroxyl group-containing (meth) acrylic acid ester are those exemplified as the polymerizable oligomer urethane (meth) acrylate oligomer. As the isocyanates, compounds having one or more isocyanate groups in the molecule are preferable, and divalent isocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferable.

  These polymerizable oligomer compounds are used alone or in admixture of two or more. In addition, the said polyfunctional (meth) acrylate compound, the said monofunctional (meth) acrylate type compound, and the polymerizable oligomer are also used individually or in mixture of 2 or more types, respectively.

  The coating liquid preferably contains a polymerization initiator. Examples of the polymerization initiator herein include acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl-2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone, 4 , 4′-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone, 2,2-dimethoxy-2-phenylacetophenone, 1- (4-dodecylphenyl) -2 -Hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, Fe Rubis (2,4,6-trimethylbenzoyl) -phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzo Isopropyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra-tert-butylperoxycarbonylbenzophenone (BTTB), 2- (dimethylamino) -1- [4- (morpholinyl) phenyl ] -2-phenylmethyl) -1-butanone, 4-benzoyl-4′-methyldiphenyl sulfide, benzyl, and derivatives thereof. These polymerization initiators may be used alone or in combination of several kinds as necessary.

  The polymerization initiator may be used in combination with a dye sensitizer. Examples of the dye sensitizer include xanthene, thioxanthene, coumarin, and ketocoumarin. As a combination of a polymerization initiator and a dye sensitizer, for example, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl) benzophenone (BTTB / manufactured by NOF Corporation) and xanthene Combinations, combinations of BTTB and thioxanthene, combinations of BTTB and coumarin, combinations of BTTB and ketocoumarin, and the like can be mentioned.

  As the fine particles, either organic fine particles or inorganic fine particles can be used. Examples of the organic fine particles include polyolefin resins such as polystyrene, polyethylene, and polypropylene; fine particles made of a polymer compound such as an acrylic resin, and may be a crosslinked polymer. A copolymer obtained by copolymerizing two or more monomers selected from ethylene, propylene, styrene, methyl methacrylate, benzoguanamine, formaldehyde, melamine, butadiene, and the like can also be used. Examples of the inorganic fine particles include fine particles made of silica, silicone, titanium oxide, and the like, and glass beads. Moreover, these may be used independently and 2 or more types may be used. In the present invention, it is preferable that at least one kind of fine particles contained in the antiglare layer is an organic fine particle.

  The shape of the fine particles can be appropriately selected, but at least one kind of fine particles contained in the antiglare layer is preferably spherical. The average particle size of at least one kind of fine particles contained in the antiglare layer is preferably 6 μm or more and 15 μm or less, and more preferably 6 μm or more and 10 μm or less. When the average particle diameter is less than 6 μm, the scattered light intensity on the wide-angle side due to the fine particles increases, and this tends to decrease the transmission sharpness when applied to an image display device. On the other hand, when the average particle diameter exceeds 15 μm, the lens effect due to the fine particles becomes remarkable, which tends to increase glare when applied to an image display device, which is not preferable.

  The difference in refractive index between at least one kind of fine particles contained in the antiglare layer and the cured product of the active energy ray-curable resin is preferably 0.005 or more and 0.16 or less, and 0.02 or more. More preferably, it is 0.05 or less. When the refractive index difference exceeds 0.16, the reflectance at the interface between the cured product of the active energy ray-curable resin and the fine particles increases, and as a result, the backscattering increases and the total light transmittance tends to decrease. is there. A decrease in the total light transmittance is not preferable because it increases the haze of the antiglare film and causes a decrease in contrast when applied to an image display device. When the difference in refractive index is less than 0.005, the effect of light refraction at the interface between the cured product of active energy ray-curable resin and fine particles is hardly obtained, and as a result, the desired antiglare performance cannot be obtained. Therefore, it is not preferable.

The material constituting the fine particles preferably satisfies the above-described refractive index difference. Since the refractive index of the cured product of the active energy ray-curable resin forming the antiglare layer is usually about 1.50, the refractive index of the fine particles is from about 1.40 to 1.65. Can be appropriately selected according to the design of the conductive film. Examples of such suitable fine particles are listed below.
Melamine beads (refractive index 1.60),
Polymethyl methacrylate beads (refractive index 1.49),
Methyl methacrylate / styrene copolymer resin beads (refractive index of 1.50 to 1.59),
Polycarbonate beads (refractive index 1.55),
Polyethylene beads (refractive index 1.53),
Polystyrene beads (refractive index 1.60),
Polyvinyl chloride beads (refractive index 1.46),
Silicone resin beads (refractive index 1.43).

  The content of the fine particles in the coating liquid is preferably 10 parts by weight or more and 100 parts by weight or less, more preferably 15 parts by weight or more and 70 parts by weight or less with respect to 100 parts by weight of the active energy ray-curable resin. . When the amount is less than 10 parts by weight, the antiglare performance due to the fine particles is insufficient, which is not preferable. On the other hand, when the amount exceeds 100 parts by weight, it is not preferable because the sharpness of transmission clarity due to the fine particles is remarkable.

  Diluent solvents include aliphatic hydrocarbons such as hexane, cyclohexane and octane, aromatic hydrocarbons such as toluene and xylene, alcohols such as ethanol, 1-propanol, isopropanol, 1-butanol and cyclohexanol, methyl ethyl ketone and methyl isobutyl. Ketones, ketones such as cyclohexanone, esters such as ethyl acetate, butyl acetate, isobutyl acetate, glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Ethers, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, etc. Stealted glycol ethers, cellsolves such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol, 2- (2- It can be appropriately selected from carbitols such as butoxyethoxy) ethanol. These solvents may be used alone or as a mixture of several kinds as required. After coating, it is necessary to evaporate the solvent. Therefore, the boiling point is desirably in the range of 60 ° C to 160 ° C. The saturated vapor pressure at 20 ° C. is preferably in the range of 0.1 kPa to 20 kPa.

  The coating liquid for forming the antiglare layer in the present invention contains an active energy ray-curable resin, fine particles and a diluting solvent, and sedimentation of the coating liquid represented by the following formula (A) The degree S is 1 or more and 76 or less.

  S = 100−x / 30 × 100 (A)

[In the formula, x represents 30 ml of the coating liquid in which fine particles are dispersed in a 100 ml graduated cylinder and then left to stand for 6 hours and observed between the transparent supernatant layer and the suspension layer of the coating liquid. It represents the scale (ml) of the interface, and S represents the sedimentation degree of the coating solution. ]

  Here, as described above, the sedimentation degree S is an index for evaluating the degree of sedimentation of the fine particles by leaving a predetermined amount of the coating liquid in which the fine particles are dispersed for a predetermined time. This means that the fine particles settle faster, and the higher the sedimentation degree S, the slower the fine particles settle. In the present invention, the sedimentation degree S is preferably 10 or more and 40 or less. If the sedimentation degree S is less than 1, fine particles accumulate on a die or the like that supplies the coating liquid, and this causes contamination of the product or the manufacturing apparatus. On the other hand, when the sedimentation degree S exceeds 76, bubbles are generated in the formed antiglare layer.

  In order to control the sedimentation degree S, it is only necessary to adjust the viscosity of the coating liquid, the average particle diameter of the fine particles, and the density of the fine particles. Since the average particle diameter of fine particles and the density of fine particles are often determined from the point of imparting desired optical characteristics to the antiglare film, the viscosity of the coating liquid is adjusted as a means for controlling the sedimentation degree S. It is preferable to do. In order to adjust the viscosity of the coating solution, it is preferable to adjust the amount and type of the diluent solvent. In order to reduce the viscosity of the coating liquid, it is sufficient to use a large amount of the dilution solvent and use a dilution solvent having a low viscosity. To increase the viscosity of the coating liquid, the amount of the dilution solvent is small and the viscosity is low. A high dilution solvent may be used.

    The coating liquid preferably contains a fluorine-based or silicone-based leveling agent. When a coating solution containing a leveling agent is used, it is possible to impart stain resistance and scratch resistance. The leveling agent is preferably used for a film-like light-transmitting substrate (for example, triacetyl cellulose) that requires heat resistance.

  In addition to the components described above, a thermoplastic resin, a thermosetting resin, an antistatic agent, an antifouling agent, and the like may be added to the coating liquid as necessary.

  As shown in FIG. 1, the antiglare layer 101 of the antiglare film of the present invention has a fine uneven surface, and the fine uneven surface contains 95% or more of a surface having an inclination angle of 5 ° or less. It is a waste. By having such a predetermined inclination angle distribution, it becomes more effective in effectively preventing whitening while exhibiting excellent antiglare performance. If the ratio of the surface with an inclination angle of 5 ° or less is less than 95%, the inclination angle of the uneven surface becomes steep, condensing light from the surroundings, and the display surface is whitened as a whole. It becomes easy to do. In order to suppress such a light collecting effect and prevent whitishness, the higher the proportion of the surface where the inclination angle of the fine uneven surface is 5 ° or less, the better, preferably 97% or more. 99% or more is more preferable.

  Further, the antiglare layer of the present invention is formed by applying a predetermined coating solution on a transparent support, then drying, and then performing a curing treatment while pressing a stamper. Since the curing process is performed while pressing with the stamper as described above, the fine particles 103 are dispersed in the antiglare layer 101 and do not protrude from the surface of the antiglare layer 101 as shown in FIG. Yes. Further, since the fine particles 103 do not protrude from the surface of the antiglare layer 101, it is possible to eliminate the influence on the surface shape, for example, the fine uneven surface shape shake accompanying the shake of the fine particle shape. The shape can be controlled with high accuracy.

  FIG. 2 is a perspective view schematically showing the surface of the antiglare film of the present invention. As shown in FIG. 2, the antiglare film 1 of the present invention includes an antiglare layer having a fine uneven surface composed of fine unevenness 2. Here, “the inclination angle of the surface of the fine unevenness” as used in the present invention refers to the main normal direction 5 of the antiglare film at an arbitrary point P on the surface of the antiglare film 1 with reference to FIG. This means the angle (surface inclination angle) ψ formed by the local normal 6 taking into account the unevenness. The inclination angle of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM).

Here, FIG. 3 is a schematic diagram for explaining a method of measuring the inclination angle of the surface of the fine irregularities.
A specific method for determining the tilt angle will be described. As shown in FIG. 3, a point of interest A on a virtual plane FGHI indicated by a dotted line is determined, and the point of interest on the x-axis passing there passes in the vicinity. The points B and D are approximately symmetrical with respect to the point A, and the points C and E are approximately symmetrical with respect to the point A in the vicinity of the point of interest A on the y-axis passing through the point A. , C, D, and E, the points Q, R, S, and T on the antiglare film surface are determined. In addition, in FIG. 3, the orthogonal coordinate in the anti-glare film surface is displayed by (x, y), and the coordinate of the anti-glare film thickness direction is displayed by z. The plane FGHI is parallel to the x axis passing through the point C on the y axis and parallel to the x axis passing through the point E on the y axis and to the y axis passing through the point B on the x axis. It is a plane formed by the respective intersections F, G, H, and I with a straight line and a straight line passing through the point D on the x-axis and parallel to the y-axis. Further, in FIG. 3, the actual position of the antiglare film surface is drawn with respect to the plane FGHI, but naturally, depending on the position taken by the point of interest A, the actual antiglare film surface is drawn. The position may be above the plane FGHI or may be below.

  The inclination angle is on the actual anti-glare film surface corresponding to the point P on the actual anti-glare film surface corresponding to the point of interest A and the four points B, C, D, E taken in the vicinity thereof. A polygon obtained by averaging four normal planes 6a, 6b, 6c, 6d of four polygons PQR, PRS, PST, PTQ, which are stretched by a total of five points Q, R, S, T. Obtaining the polar angle of the normal vector (the average normal vector is synonymous with the local normal 6 with the irregularities shown in FIG. 2) from the three-dimensional information of the measured surface shape Can do. After obtaining the tilt angle for each measurement point, a histogram is calculated.

  FIG. 4 is a graph showing an example of a histogram of the inclination angle distribution of the fine uneven surface of the antiglare layer provided in the antiglare film. In the graph shown in FIG. 4, the horizontal axis is the inclination angle, and is divided in increments of 0.5 °. For example, the leftmost vertical bar shows the distribution of a set having an inclination angle in the range of 0 to 0.5 °, and the angle increases by 0.5 ° as going to the right. In FIG. 4, the lower limit value is displayed for every two scales on the horizontal axis. For example, a portion with “1” on the horizontal axis is a distribution of a set whose inclination angle is in the range of 1 to 1.5 °. Indicates. In addition, the vertical axis represents the distribution of the tilt angle, which is a value that becomes 1 (100%) when summed up. In this example, the ratio of the surface having an inclination angle of 5 ° or less is approximately 100%.

Moreover, it is preferable that the fine uneven surface of the anti-glare layer has a specific spatial frequency distribution defined using “the energy spectrum of the altitude of the fine uneven surface”. That is, the energy spectrum H ₁ ² in a spatial frequency 0.01 [mu] m ^-1 elevation of the fine uneven surface of the antiglare layer, the energy spectrum H ₂ ² ratio H _{1 ²} / H ^{2 2} in a spatial frequency 0.04 .mu.m ^-1 3-15 is in the range of an energy spectrum H ₃ ² in the spatial frequency 0.1 [mu] m ^-1, the ratio H _{3 ²} / H ^{2 2} energy spectrum H ₂ ² in the spatial frequency 0.04 .mu.m ^-1 0.1 It is preferable that: When the antiglare film having such a numerical range exhibits excellent antiglare performance and can prevent a decrease in visibility due to whitishness, and when applied to a high-definition image display device However, high contrast is exhibited without causing glare.

  In addition, as described above, since the fine particles do not protrude from the surface of the antiglare layer, the influence of the fine particles on the fine uneven surface of the antiglare layer can be eliminated, so the predetermined spatial frequency distribution is accurately controlled. As a result, the antiglare film of the present invention having excellent optical properties can be obtained with good reproducibility. Moreover, since the anti-glare film of the present invention contains fine particles in the anti-glare layer, it can exhibit anti-glare performance more effectively than an anti-glare film that does not contain fine particles. Conventionally, when an antiglare film in which fine particles having a refractive index different from a cured product of an active energy ray curable resin is dispersed in an antiglare layer is disposed on the surface of an image display device, the fine particles and the active energy ray curable resin Due to light scattering at the interface with the cured product, there was a problem of excessive decrease in transmission clarity, but according to the antiglare film of the present invention, without causing excessive decrease in transmission clarity, An antiglare effect due to the fine particles can be obtained.

  The altitude energy spectrum of the fine uneven surface of the antiglare layer will be described. As shown in FIG. 2, the antiglare film 1 of the present invention includes an antiglare layer having a fine uneven surface composed of fine unevenness 2. Here, the “elevation of the fine uneven surface” as used in the present invention is an imaginary plane having the height at the lowest point of the fine uneven surface at an arbitrary point P on the surface of the antiglare film 1 ( The altitude means a linear distance in the main normal direction 5 (normal direction in the virtual plane) of the antiglare film from 0 μm as a reference. As shown in FIG. 2, when the orthogonal coordinates in the antiglare film plane are displayed as (x, y), the elevation of the surface of the fine irregularities is a two-dimensional function h (x, y) of the coordinates (x, y). Can be expressed as In FIG. 2, the entire surface of the antiglare film is displayed on the projection surface 3.

The elevation of the surface of the fine irregularities can be obtained from three-dimensional information of the surface shape measured by an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM). The horizontal resolution required for the measuring instrument is at least 5 μm or less, preferably 2 μm or less, and the vertical resolution is at least 0.1 μm or less, preferably 0.01 μm or less. Non-contact three-dimensional surface shape / roughness measuring instruments suitable for this measurement include New View 5000 series (manufactured by Zygo Corporation, available from Zygo Corporation in Japan), three-dimensional microscope PLμ2300 (manufactured by Sensofar), etc. Can be mentioned. Since the resolution of the energy spectrum of the altitude needs to be 0.01 μm ⁻¹ or less, the measurement area is preferably at least 200 μm × 200 μm, more preferably 500 μm × 500 μm.

Next, a method for obtaining the energy spectrum of the altitude from the two-dimensional function h (x, y) will be described. First, from the two-dimensional function h (x, y), a two-dimensional function H (f _x, f _y) by a two-dimensional Fourier transform defined by the following formula (1) is obtained.

Here, f _x and f _y are the spatial frequencies of the x and y directions, with the dimensions of the reciprocal of length. Further, in Expression (1), π is a pi and i is an imaginary unit. The resulting two-dimensional function H (f _x, f _y) by squaring the energy spectrum ^{_{H 2 (f x, f y}} ) of altitude can be obtained. The energy spectrum ^{_{H 2 (f x, f y}} ) represents the spatial frequency distribution of the fine uneven surface of the antiglare layer.

  Hereinafter, the method for obtaining the energy spectrum of the fine uneven surface of the antiglare layer will be described more specifically. The three-dimensional information of the surface shape actually measured by the above confocal microscope, interference microscope, atomic force microscope or the like is generally obtained as discrete values, that is, elevations corresponding to a large number of measurement points. FIG. 5 is a schematic diagram showing a state in which the function h (x, y) representing the altitude is obtained discretely. As shown in FIG. 5, the orthogonal coordinates in the antiglare film plane are represented by (x, y), and the line divided by Δx in the x axis direction on the projection plane 3 of the antiglare film and the y axis direction When the line divided by Δy is indicated by a broken line, the elevation of the fine uneven surface is obtained as a discrete elevation value at each intersection of the broken lines on the projection surface 3 of the antiglare film in actual measurement.

  The number of altitude values obtained is determined by the measurement range and Δx and Δy, and is obtained when the measurement range in the x-axis direction is X = MΔx and the measurement range in the y-axis direction is Y = NΔy as shown in FIG. The number of elevation values is (M + 1) × (N + 1).

  As shown in FIG. 5, the coordinates of the point of interest A on the projection surface 3 of the antiglare film are (jΔx, kΔy) (where j is 0 or more and M or less, and k is 0 or more and N or less. ), The elevation of the point P on the antiglare film surface corresponding to the point of interest A can be expressed as h (jΔx, kΔy).

  Here, the measurement intervals Δx and Δy depend on the horizontal resolution of the measuring device, and in order to accurately evaluate the fine uneven surface, both Δx and Δy are preferably 5 μm or less as described above, and are 2 μm or less. It is more preferable. Further, as described above, the measurement ranges X and Y are both preferably 200 μm or more, and more preferably 500 μm or more.

In this way, in actual measurement, a function representing the altitude of the fine uneven surface is obtained as a discrete function h (x, y) having (M + 1) × (N + 1) values. Thus, a discrete function H (f _x, f _y) by a discrete Fourier transform defined by obtained by measuring discrete function h (x, y) and the following formula (2) is Motomari, discrete function H (f _x, f discrete function H ² (f _x of energy spectrum by squaring _y), f _y) is determined. In the formula (2), l is an integer from − (M + 1) / 2 to (M + 1) / 2, and m is an integer from − (N + 1) / 2 to (N + 1) / 2. Also, Delta] f _x and Delta] f _y are the spatial frequency intervals of the x and y directions, is defined by equation (3) and (4). Delta] f _x and Delta] f _y correspond to the horizontal resolution of the energy spectrum of the altitude.

  FIG. 6 is an example of a diagram representing the elevation of the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention by a two-dimensional discrete function h (x, y). In FIG. 6, the altitude is indicated by a gradation of white and black. The discrete function h (x, y) shown in FIG. 6 has 512 × 512 values, and the horizontal resolutions Δx and Δy are 1.66 μm.

As in the example shown in FIG. 6, the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention consists of randomly formed unevenness, so that the energy spectrum of altitude is as shown in FIG. In addition, it is symmetric about the origin. Therefore, energy spectrum H ₁ ² elevation in the spatial frequency 0.01 [mu] m ^-1, the energy spectrum H ₃ ² elevation in the energy spectrum H ₂ ² and the spatial frequency 0.1 [mu] m ^-1 elevation in the spatial frequency 0.04 .mu.m ^-1 is The energy spectrum H ² (f _x , f _y ), which is a two-dimensional function, can be obtained from a cross section passing through the origin. 8, showing a cross section of an f _x = 0 of the energy spectrum ^{_{H 2 (f x, f y}} ) shown in FIG. From FIG. 8, the altitude energy spectrum H ₁ ² at a spatial frequency of 0.01 μm ⁻¹ is 4.4, the altitude energy spectrum H ₂ ² at a spatial frequency of 0.04 μm ⁻¹ is 0.35, and the spatial frequency is 0.1 μm ^−. The energy spectrum H ₃ ² of the altitude at ¹ is found to be 0.00076, the ratio H ₁ ² / H ₂ ² is calculated to be 14, and the ratio H ₃ ² / H ₂ ² is calculated to be 0.0022.

As described above, in the antiglare layer of the present invention, the energy spectrum H ₁ ² elevation of the fine uneven surface in the spatial frequency 0.01 [mu] m ^-1, the energy spectrum of the altitude in the spatial frequency 0.04μm ^-1 H _{² 2} The ratio H ₁ ² / H ₂ ² is in the range of 3-15. When the ratio H ₁ ² / H ₂ ² of the energy spectrum of the altitude is less than 3, there are few irregular shapes with a long period of 100 μm or more contained in the fine irregular surface of the antiglare layer, and irregular shapes with a short period of less than 25 μm. It shows that there are many. In such a case, reflection of external light cannot be effectively prevented, and sufficient antiglare performance cannot be obtained. On the other hand, the fact that the ratio H ₁ ² / H ₂ ² of the energy spectrum of the altitude exceeds 15 indicates that there are many irregular shapes having a long period of 100 μm or more contained in the fine irregular surface, and a short period of less than 25 μm. It shows that there are few uneven | corrugated shapes. In such a case, the glare tends to occur when the antiglare film is placed in a high-definition image display device. In order to suppress glare more effectively while exhibiting better anti-glare performance, the altitude energy spectrum ratio H ₁ ² / H ₂ ² should be in the range of 3.5 to 14.5. Is preferable, and it is more preferable that it is in the range of 4-14.

The ratio of the antiglare layer of the present invention, the energy spectrum H ₃ ² elevation of the fine uneven surface in the spatial frequency 0.1 [mu] m ^-1, the energy spectrum H ₂ ² elevation in a spatial frequency 0.04 .mu.m ^-1 H ₃ ² / H ₂ ² is 0.1 or less, preferably 0.01 or less. When the ratio H ₃ ² / H ₂ ² is 0.1 or less, it indicates that the short period component of less than 10 μm contained in the fine irregular surface is sufficiently reduced. Can be effectively suppressed. Short-period components of less than 10 μm contained in the fine uneven surface do not contribute effectively to the antiglare property, but cause the light incident on the fine uneven surface to scatter and cause whitening.

  The antiglare film of the present invention preferably has a surface haze of 0.1% to 5% and a total haze of 5% to 30%. When the surface haze is less than 0.1%, the antiglare performance is insufficient. When the surface haze exceeds 5%, light scattering due to the surface unevenness is increased, so that the transmission sharpness is lowered and the whitishness is generated. Further, when the total haze is less than 5%, the antiglare performance is insufficient, and when it exceeds 30%, the transmission sharpness decreases, which is not preferable.

The total haze of the antiglare film can be measured according to the method shown in JIS K 7136. The surface haze and the internal haze can be separated by measuring the overall haze, pasting a transparent film with a haze of approximately O on the uneven surface, measuring the internal haze, and obtaining the surface haze by the following formula.
Surface haze (%) = Overall haze (%)-Internal haze (%)

  The haze value measured in a state in which a transparent film having a haze of approximately 0% is attached to the uneven surface of the antiglare film effectively represents the internal haze because the surface haze caused by the original unevenness is almost canceled out. You can see it. The transparent film having a haze of almost 0% is not particularly limited as long as the haze is small, and for example, a triacetyl cellulose film may be used.

  The antiglare film of the present invention preferably has a high transmission clarity. At this time, it is preferable that the transmission sharpness is as high as possible within a range in which the antiglare performance is sufficiently satisfied. By increasing the transmission definition, a display image with a high definition can be obtained. The transmission sharpness is measured using an image clarity measuring device ICM-IDP (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K 7105. More specifically, in order to prevent the sample from warping, it is bonded to a glass substrate using an optically transparent adhesive so that the uneven surface becomes the surface, and measurement light is incident from the glass side. I did it. The measured value here is a total value of values measured using four types of optical combs in which the widths of the dark part and the bright part are 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. . In this case, the maximum value of the transmission clarity is 400%.

<Method for producing antiglare film>
In the method for producing an antiglare film of the present invention, a coating process for coating the coating liquid on a transparent support [coating process], and the coating liquid coated in the coating process is dried. Drying step to obtain a laminate (drying step), a curing step of curing the active energy ray-curable resin by irradiating the active surface with a stamper on the coated surface of the laminate obtained in the drying step [ Curing step] and a peeling step [peeling step] for peeling the stamper from the coated surface after the curing step.

[Coating process]
As a method for coating the coating liquid on the transparent support, a known method can be appropriately selected. Specific examples include wire bar coating, roll coating, gravure coating, knife coating, slot die coating, spin coating, spray coating, slide coating, curtain coating, and ink jet. Of these, the slot die coating method is desirable from the viewpoint of preventing contamination of the resin solution during coating as much as possible.

[Drying process]
The coating liquid applied in the coating step can be dried to obtain a laminate in which a coating film (coating surface) is formed on the transparent support. As this drying method, a known method can be employed. The drying temperature is appropriately selected depending on the solvent used and the transparent support, but is usually in the range of 20 ° C to 120 ° C. When there are a plurality of drying furnaces, the temperature may be changed for each drying furnace.

[Curing process]
In the present invention, the active energy ray-curable resin is cured by irradiating active energy rays while pressing a stamper on the coated surface of the laminate obtained in the drying step. Examples of the stamper include a mold plate, a glass plate, a rubber plate, and a mold roll. In addition, examples include a mirror-like one and an emboss-like one having a concavo-convex shape. Examples of the mold plate include an embossed plate and a mirror-like plate. Examples of the mold roll include an embossed roll and a mirror-like roll. Is mentioned. From the viewpoint of accurately controlling the shape of the fine uneven surface of the antiglare layer, a mold having an uneven shape is preferable, and an embossing roll is particularly preferable.

  When the stamper is pressed, it is preferable to use a crimping device such as a nip roll in order to prevent bubbles from entering between the coating film and the stamper and causing defects. At that time, the nip pressure is not particularly limited, but is preferably 0.05 MPa or more and 0.5 MPa or less. When it is 0.05 MPa or less, bubbles are likely to be mixed. On the other hand, if it is 0.5 MPa or more, the transparent support may be broken by a slight shift during the conveyance of the transparent support, or the coated resin may protrude from the end part and cause process contamination, which is not preferable. .

  Irradiate active energy rays while pressing the stamper against the coated surface. The active energy ray may be irradiated from the coated surface side or may be irradiated from the side opposite to the coated surface. Among these, it is preferable to irradiate from the side opposite to the coated surface. The active energy ray can be appropriately selected from γ ray, X ray, ultraviolet ray, near ultraviolet ray, visible light, near infrared ray, infrared ray, electron beam, etc., depending on the type of the active energy ray curable resin and the polymerization initiator. Of these, ultraviolet rays and electron beams are preferred, and ultraviolet rays are preferred from the viewpoint of excellent curability and productivity because they are particularly easy to handle and high energy can be obtained.

  As an ultraviolet light source, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon arc lamp, or the like can be used. However, there is no particular limitation as long as the light source generates ultraviolet rays. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. Among these, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon arc lamp, and a metal halide lamp can be preferably used. Moreover, there is no restriction | limiting in the number of light sources, 1 lamp | ramp may be sufficient and it may be 2 or more lamps.

Range of the illuminance of the UVA region of the ultraviolet rays is preferably ^{200mW / cm 2 ~700mW / cm 2} , more preferably from ^{300mW / cm 2 ~700mW / cm 2} . If it is 200 mW / cm ² or less, the resin may not be cured sufficiently. On the other hand, when it exceeds 700 mW / cm ² , there is a possibility of inhibiting the sufficient curing of the resin, and there is a risk of damaging the transparent support. Moreover, the range of the integrated light quantity in the UVA region of the ultraviolet ray in the curing step is preferably 40 mJ / cm ² or more, and more preferably 70 mJ / cm ² or more. If it is 40 mJ / cm ² or less, the antiglare layer may not be cured sufficiently. On the other hand, there is no particular limitation on the upper limit of the integrated light quantity.

  In order to prevent the transparent support, the antiglare film, and the stamper from being excessively heated by being irradiated with ultraviolet rays, the stamper is preferably provided with a cooling mechanism. When using an embossing roll as a stamper, as a cooling mechanism, for example, a cooling pipe is provided inside the embossing roll, the cooling pipe inside the embossing roll is connected to a chiller unit installed outside, and the refrigerant is circulated. Structure. The cooling temperature is set so that the surface temperature of the embossing roll is 10 ° C to 70 ° C, preferably 20 ° C to 60 ° C. If it is 10 ° C. or lower, the viscosity of the resin increases, and it may not be possible to transfer a specific surface uneven shape. If it exceeds 70 ° C., the metal of the embossing roll or the transparent support may be deteriorated due to thermal damage, which is not preferable. .

[Peeling process]
As a method of peeling the stamper from the coating surface, a known method can be adopted, but in order to prevent the film from peeling off from the stamper during irradiation of active energy rays, a pressure bonding device such as a nip roll is also installed at the peeling point and cured. In order to accurately transfer the specific shape, it is preferable to maintain the close contact with the stamper until the process is completed.

  As the stamper used in the curing step described above, an embossing roll created using a predetermined pattern is more preferable from the viewpoint of accurately controlling the shape of the fine uneven surface of the antiglare layer. The embossing roll will be described below.

[Embossing roll created using a predetermined pattern]
The embossing roll is intended to be manufactured by using a pattern showing an energy spectrum that does not have a maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1. By using such a pattern, it is possible to form a fine uneven shape having a predetermined spatial frequency distribution on the surface of the embossing roll. The “pattern” here is a source of the surface unevenness shape of the antiglare layer in the antiglare film, and is typically used by the computer to create the surface unevenness 2 Means image data consisting of gradation (for example, image data binarized into white and black) or gradation of three or more gradations, but data that can be uniquely converted to the image data (matrix data, etc.) May also be included. Examples of data that can be uniquely converted to image data include data in which only the coordinates and gradations of each pixel are stored.

If the energy spectrum of the pattern used when creating the emboss roll is, for example, image data, the image data is converted to a gray scale of 256 gradations, and then the gradation of the image data is converted into a two-dimensional function g (x, y It expressed in), resulting two-dimensional function g (x, two-dimensional function G (f _x by Fourier transform y), calculate the f _y), two resulting dimensional function G (f _x, f _y) Is obtained by squaring. Here, x and y represent orthogonal coordinates of the image data plane, respectively f _x and f _y, it represents the spatial frequency of the spatial frequency and the y direction of the x-direction.

As in the case of obtaining the energy spectrum of the elevation of the fine surface irregularities, the two-dimensional function g (x, y) of the gradation is generally obtained as a discrete function when obtaining the energy spectrum of the pattern. In that case, the energy spectrum is calculated by discrete Fourier transform, as in the case of obtaining the energy spectrum of the elevation of the fine surface irregularities. Specifically, computes the discrete function G (f _x, f _y) by a discrete Fourier transform defined by equation (5), discrete function G (f _x, f _y) is the energy spectrum by squaring the determined It is done. Here, π in the equation (5) is a pi, and i is an imaginary unit. M is the number of pixels in the x direction, N is the number of pixels in the y direction, l is an integer from −M / 2 to M / 2, and m is from −N / 2 to N / 2. It is an integer. Furthermore, Delta] f _x and Delta] f _y is the spatial frequency intervals of the x and y directions, is defined by equation (6) and (7). Δx and Δy in the equations (5) and (6) are horizontal resolutions in the x-axis direction and the y-axis direction, respectively. If the pattern is image data, Δx and Δy are equal to the length of one pixel in the x-axis direction and the length in the y-axis direction, respectively. That is, when a pattern is created as 6400 dpi image data, Δx = Δy = 4 μm, and when a pattern is created as 12800 dpi image data, Δx = Δy = 2 μm.

  FIG. 9 is a diagram showing a part of image data, which is a pattern that can be used for producing the antiglare film of the present invention, and is represented by a two-dimensional discrete function g (x, y) of gradation. Is. The image data which is the pattern shown in FIG. 9 has a size of 2 mm × 2 mm and was created at 12800 dpi.

Figure 10 is a two-dimensional discrete function g (x, y) of the gradation shown in Fig energy spectrum obtained by discrete Fourier transform ^{_{G 2 (f x, f y}} ) are shown in white and black gradation It is a figure. Since the pattern shown in FIG. 9 is obtained by randomly arranging dots, the energy spectrum is symmetric about the origin as shown in FIG. Therefore, the spatial frequency indicating the maximum value of the energy spectrum of the pattern can be obtained from a cross section passing through the origin of the energy spectrum. Figure 11 is a view showing a cross section taken along f _x = 0 of the energy spectrum ^{_{G 2 (f x, f y}} ) shown in FIG. 10. Pattern shown now to Figure 9, but has a maximum value in the spatial frequency 0.045 .mu.m ^-1, is in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It can be seen that no maximum value.

Specific energy spectrum pattern for making an antiglare film when having the maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, fine uneven surface of the obtained antiglare film was the Therefore, it is impossible to combine the elimination of glare and the sufficient antiglare property.

  Next, the manufacturing method of the said embossing roll is demonstrated. The embossing roll is not particularly limited as long as it is a method capable of obtaining a predetermined surface shape using the above-described pattern. In order to manufacture a fine uneven surface with high accuracy and reproducibility, [1] First Plating step, [2] polishing step, [3] photosensitive resin film forming step, [4] exposure step, [5] development step, [6] first etching step, [7] photosensitivity It is preferable to basically include a resin film peeling step and [8] a second plating step. FIG. 12 is a diagram schematically showing a preferred example of the first half of the mold manufacturing method. In FIG. 12, the cross section of the metal mold | die in each process is shown typically. Hereinafter, the above steps will be described in detail with reference to FIG.

[1] First plating step In this step, copper plating or nickel plating is applied to the surface of the substrate used for the mold. Thus, by performing copper plating or nickel plating on the surface of the mold base, it is possible to improve the adhesion and gloss of chromium plating in the subsequent second plating step. This is because copper plating or nickel plating has a high covering property and a strong smoothing action, so that a flat and glossy surface is formed by filling minute irregularities and voids of the mold base. is there. Due to these copper plating or nickel plating characteristics, even if chrome plating is applied in the second plating step, which will be described later, the rough surface of the chrome plating that appears to be caused by minute irregularities and voids that existed on the substrate is eliminated. In addition, the occurrence of fine cracks is reduced due to the high coverage of copper plating or nickel plating.

  The copper or nickel used in the first plating step may be a pure metal, or may be an alloy mainly composed of copper or an alloy mainly composed of nickel. “Copper” means to include copper and copper alloy, and “nickel” means to include nickel and nickel alloy. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electrolytic plating is usually employed.

  When copper plating or nickel plating is performed, if the plating layer is too thin, the influence of the underlying surface cannot be completely eliminated. Therefore, the thickness is preferably 50 μm or more. Although the upper limit of the plating layer thickness is not critical, it is preferable that the upper limit is about 500 μm in view of cost and the like.

  Examples of the metal material constituting the mold base include aluminum and iron from the viewpoint of cost. Furthermore, considering the convenience of handling, it is preferable to use lightweight aluminum. The aluminum and iron here may be pure metals, respectively, or may be an alloy mainly composed of aluminum or iron.

  The shape of the mold base is preferably a columnar or cylindrical roll. If a mold is produced using a roll-shaped substrate, there is an advantage that the antiglare film can be produced in a continuous roll shape.

[2] Polishing Step In the subsequent polishing step, the surface of the substrate that has been subjected to copper plating or nickel plating in the first plating step described above is polished. It is preferable that the base material surface is grind | polished in the state close | similar to a mirror surface through the said process. This is because the metal roll as the base material is often subjected to machining such as cutting and grinding in order to achieve the desired accuracy, and as a result, the processing marks remain on the surface of the base material. Alternatively, even if nickel plating is applied, those processed marks may remain, and the surface may not be completely smooth in the plated state. That is, even if a process described later is performed on the surface where such deep processed marks remain, unevenness such as processed marks may be deeper than the unevenness formed after each process is performed. Such effects may remain, and when an antiglare film is produced using such a mold, the optical characteristics may be unexpectedly affected. In FIG. 12 (a), a plate-shaped mold substrate 7 is subjected to copper plating or nickel plating on its surface in the first plating step (for the copper plating or nickel plating layer formed in this step). Further, a state in which the surface 8 is mirror-polished by a polishing process is schematically shown.

  There is no particular limitation on the method for polishing the surface of the substrate on which copper plating or nickel plating has been applied, and any of mechanical polishing, electrolytic polishing, and chemical polishing can be used. Examples of the mechanical polishing method include super finishing, lapping, fluid polishing, and buff polishing. Moreover, it is good also considering the base material surface 7 for metal mold | die as a mirror surface by carrying out mirror surface cutting using a cutting tool. The material and shape of the cutting tool at that time are not particularly limited, and carbide tools, CBN tools, ceramic tools, diamond tools, etc. can be used, but diamond tools should be used from the viewpoint of processing accuracy. Is preferred.

  As for the surface roughness after polishing, the center line average roughness Ra in accordance with the provisions of JIS B 0601 is preferably 0.1 μm or less, and more preferably 0.05 μm or less. If the centerline average roughness Ra after polishing is greater than 0.1 μm, the final unevenness of the mold surface may remain affected by the surface roughness after polishing. Further, the lower limit of the center line average roughness Ra is not particularly limited, and is appropriately determined in consideration of processing time, processing cost, and the like.

[3] Photosensitive resin film forming step In the subsequent photosensitive resin film forming step, the photosensitive resin was dissolved in the solvent on the polished surface 8 of the mold substrate 7 that was mirror-polished by the polishing step described above. A photosensitive resin film is formed by applying as a solution, heating and drying. FIG. 12B schematically shows a state where the photosensitive resin film 9 is formed on the polished surface 8 of the mold base 7.

  A conventionally known photosensitive resin can be used as the photosensitive resin. Examples of the negative photosensitive resin having a property of curing the photosensitive part include, for example, a monomer or prepolymer of an acrylate ester having an acrylic group or a methacrylic group in the molecule, a mixture of bisazide and a diene rubber, polyvinyl Cinnamate compounds and the like can be used. Further, as a positive photosensitive resin having such a property that a photosensitive part is eluted by development and only an unexposed part remains, for example, a phenol resin type or a novolac resin type can be used. Moreover, you may mix | blend various additives, such as a sensitizer, a development accelerator, an adhesiveness modifier, and a coating property improving agent, with a photosensitive resin as needed.

  When these photosensitive resins are applied to the polished surface 8 of the mold base 7, it is preferable to dilute and apply in an appropriate solvent in order to form a good coating film. As the solvent, cellosolve solvents, propylene glycol solvents, ester solvents, alcohol solvents, ketone solvents, highly polar solvents, and the like can be used.

  As a method for applying the photosensitive resin solution, known methods such as meniscus coating, fountain coating, dip coating, spin coating, roll coating, wire bar coating, air knife coating, blade coating, and curtain coating may be used. it can. The thickness of the coating film is preferably in the range of 1 to 6 μm after drying.

[4] Exposure Step In the subsequent exposure step, exposure is performed on the photosensitive resin film 9 formed in the above-described photosensitive resin film forming step. The light source used in the exposure process may be appropriately selected according to the photosensitive wavelength and sensitivity of the coated photosensitive resin. For example, the g-line (wavelength: 436 nm) of the high-pressure mercury lamp, the h-line (wavelength: 405 nm) of the high-pressure mercury lamp. ), I line (wavelength: 365 nm) of high pressure mercury lamp, semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF excimer laser (wavelength) 193 nm), F2 excimer laser (wavelength: 157 nm), or the like.

  In order to accurately form the surface unevenness of the mold, and thus the surface unevenness of the antiglare layer, in the exposure step, it is preferable to expose the pattern on the photosensitive resin film in a precisely controlled state, Specifically, it is preferable that a pattern is created as image data on a computer, and a pattern based on the image data is drawn by laser light emitted from a computer-controlled laser head. When performing laser drawing, a laser drawing apparatus for making a printing plate can be used. An example of such a laser drawing apparatus is Laser Stream FX (manufactured by Sink Laboratories).

  FIG. 12C schematically shows a state in which the pattern is exposed to the photosensitive resin film 9. In the case where the photosensitive resin film is formed of a positive photosensitive resin, the exposed region 11 is cut by the bond of the resin by the exposure, and the solubility in the developer described later increases. Therefore, the area 11 exposed in the development process is dissolved by the developer, and only the unexposed area 10 remains on the substrate surface, resulting in a mask as shown in FIG. On the other hand, when the photosensitive resin film is formed of a negative photosensitive resin, a cross-linking reaction of the resin proceeds in the exposed region 11 by exposure, and the solubility in a developing solution described later decreases. Accordingly, the unexposed area 10 in the developing process is dissolved by the developer, and only the exposed area 11 remains on the substrate surface, resulting in a mask as shown in FIG.

[5] Development Step In the subsequent development step, when a negative photosensitive resin is used for the photosensitive resin film 9, the unexposed area 10 is dissolved by the developer, and only the exposed area 11 is gold. It remains on the mold substrate and acts as a mask in the subsequent first etching step. On the other hand, when a positive photosensitive resin is used for the photosensitive resin film 9, only the exposed region 11 is dissolved by the developer, and the unexposed region 10 remains on the mold substrate. It acts as a mask in the subsequent first etching step.

  A conventionally well-known thing can be used about the developing solution used for a image development process. For example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di-n-butylamine and the like Secondary amines, tertiary amines such as triethylamine, methyldiethylamine, alcohol amines such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, etc. Examples include alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and piperidine; and organic solvents such as xylene and toluene.

  The development method in the development step is not particularly limited, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 12E schematically shows a state in which a development process is performed using a negative photosensitive resin for the photosensitive resin film 9. In FIG. 12C, the unexposed area 10 is dissolved by the developer, and only the exposed area 11 remains as a mask 12 on the substrate surface. FIG. 12D schematically shows a state in which a development process is performed using a positive photosensitive resin for the photosensitive resin film 9. In FIG. 12C, the exposed region 11 is dissolved by the developer, and only the unexposed region 10 becomes the remaining mask 12 on the substrate surface.

[6] First Etching Step In the subsequent first etching step, the mold base is mainly used in a portion where there is no mask, using the photosensitive resin film remaining on the mold base surface after the development step as a mask. The material is etched to form irregularities on the polished plated surface. FIG. 13 is a diagram schematically illustrating a preferred example of the latter half of the mold manufacturing method. FIG. 13A schematically shows a state in which the mold base 7 in the portion 13 where no mask is mainly etched by the first etching step. The mold base 7 below the mask 12 is not etched from the mold base surface, but etching from the portion 13 without the mask proceeds with the progress of etching. Therefore, in the vicinity of the boundary between the mask 12 and the portion 13 without the mask, the mold base 7 under the mask 12 is also etched. In the vicinity of the boundary between the mask 12 and the portion 13 without the mask, the die base material 7 under the mask 12 is also etched, which is called side etching.

The etching process in the first etching step is usually performed using a ferric chloride (FeCl ₃ ) solution, a cupric chloride (CuCl ₂ ) solution, an alkali etching solution (Cu (NH ₃ ) ₄ Cl ₂ ), etc. Although it is performed by corroding the surface, a strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can also be used. The concave shape formed on the mold base material when the etching process is performed differs depending on the type of the base metal, the type of the photosensitive resin film, the etching technique, and the like. In the following cases, the etching is performed isotropically from the metal surface in contact with the etching solution. The etching amount here is the thickness of the base material to be cut by etching.

  The etching amount in the first etching step is preferably 1 to 50 μm, more preferably 2 to 10 μm. When the etching amount is less than 1 μm, the unevenness shape is hardly formed on the metal surface, and the die is almost flat, so that the antiglare property is not exhibited. In addition, when the etching amount exceeds 50 μm, the height difference of the concavo-convex shape formed on the metal surface becomes large, and in the image display device to which the antiglare film produced using the obtained mold is applied, it is white. There is a risk of injury. In order to obtain an antiglare film having a fine uneven surface including 95% or more of a surface having an inclination angle of 5 ° or less, the etching amount in the first etching step is more preferably 2 to 8 μm. The etching process in the first etching step may be performed by one etching process, or the etching process may be performed twice or more. In the case where the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is within the above range.

[7] Photosensitive resin film peeling step In the subsequent photosensitive resin film peeling step, the remaining photosensitive resin film used as a mask in the first etching step is completely dissolved and removed. In the photosensitive resin film peeling step, the photosensitive resin film is dissolved using a peeling solution. As the stripper, the same developer as that described above can be used. By changing the pH, temperature, concentration, immersion time, etc. of the stripping solution, the exposure part is exposed when a negative photosensitive resin film is used, and the non-exposure is performed when a positive photosensitive resin film is used. Part of the photosensitive resin film is completely dissolved and removed. There is no particular limitation on the peeling method in the photosensitive resin film peeling step, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 13B schematically shows a state where the photosensitive resin film used as the mask 12 in the first etching process is completely dissolved and removed by the photosensitive resin film peeling process. The first surface irregularities 15 are formed on the surface of the mold substrate by etching using the mask 12 made of a photosensitive resin film.

[8] Second plating step Subsequently, the formed uneven surface is subjected to chromium plating to further dull the surface uneven shape. In FIG. 13 (c), by forming the chromium plating layer 16 on the first surface uneven shape 15 formed by the etching process of the first etching step, the unevenness is duller than the first surface uneven shape 15. The state where the surface (the surface 17 of chrome plating) is formed is shown.

As the chrome plating, it is preferable to employ a chrome plating that is glossy on the surface of the roll, has a high hardness, has a low friction coefficient, and can provide good releasability. The chrome plating is not particularly limited, but it is preferable to use a chrome plating that expresses good gloss, so-called gloss chrome plating or decorative chrome plating. Chromium plating is usually performed by electrolysis, and an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid is used as the plating bath. By adjusting the current density and electrolysis time, the thickness of the chromium plating can be controlled.

  In the second plating step, it is not preferable to perform plating other than chromium plating. This is because plating other than chromium has low hardness and wear resistance, so that the durability as a mold is lowered, and unevenness is worn away during use or the mold is damaged. In an antiglare film obtained from such a mold, there is a high possibility that a sufficient antiglare function cannot be obtained, and there is a high possibility that defects will occur on the antiglare film.

  Also, surface polishing after plating is not preferable. That is, without providing a step of polishing the surface after the second plating step, the concavo-convex surface subjected to chrome plating can be used as the concavo-convex surface of the mold transferred to the resin layer surface on the base film as it is. preferable. By polishing, a flat part is generated on the outermost surface, which may lead to deterioration of optical characteristics, and since shape control factors increase, shape control with good reproducibility becomes difficult. Depending on the reason.

  Thus, by performing chromium plating on the surface on which the fine surface irregularities are formed, a mold having an irregular shape that is dulled and whose surface hardness is increased can be obtained. The bluntness of the irregularities at this time varies depending on the type of the base metal, the size and depth of the irregularities obtained from the first etching process, and the type and thickness of the plating. The greatest factor in controlling is the plating thickness. If the thickness of the chrome plating is thin, the effect of dulling the surface shape of the unevenness obtained before the chrome plating process is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape are not so good. On the other hand, when the plating thickness is too thick, productivity is deteriorated and a projection-like plating defect called a nodule is generated, which is not preferable. Therefore, the thickness of the chrome plating is preferably in the range of 1 to 10 μm, and more preferably in the range of 3 to 6 μm.

  The chromium plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, and more preferably 1000 or more. When the Vickers hardness of the chrome plating layer is less than 800, the durability when using the mold is reduced, and the decrease in hardness due to the chrome plating is that there is an abnormality in the plating bath composition, electrolysis conditions, etc. during the plating process. This is because the possibility of occurrence is high, and the possibility of undesirably affecting the occurrence of defects is also high.

Moreover, in the manufacturing method of the metal mold | die for producing the anti-glare film of this invention, after the [7] photosensitive resin film peeling process, the uneven surface formed by the 1st etching process is further blunted by an etching process. A second etching step can be performed. That is, in the second etching step, the first surface irregularity shape 15 formed by the first etching step using the photosensitive resin film as a mask is further blunted by an etching process.
By this second etching process, there is no portion with a steep surface inclination in the first surface irregularity shape 15 formed by the first etching process, and the optical characteristics of the antiglare film manufactured using the obtained mold are reduced. It changes in the preferred direction. In FIG. 14, the first surface unevenness shape 15 of the mold base 7 is blunted by the second etching process, the portion having a steep surface inclination is blunted, and the second surface unevenness having a gentle surface inclination is obtained. The state where the shape 18 is formed is shown.

Similarly to the first etching step, the etching process in the second etching step is usually ferric chloride (FeCl ₃ ) solution, cupric chloride (CuCl ₂ ) solution, alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ) or the like, and by corroding the surface, strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can also be used. The bluntness of the unevenness after the etching process varies depending on the type of the underlying metal, the etching technique, and the size and depth of the unevenness obtained by the first etching process. The largest factor in controlling the amount is the etching amount. The etching amount here is also the thickness of the base material to be cut by etching, as in the first etching step. If the etching amount is small, the effect of dulling the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape are not so good. On the other hand, when the etching amount is too large, the uneven shape is almost lost and the die is almost flat, so that the antiglare property is not exhibited. Therefore, the etching amount is preferably in the range of 1 to 50 μm, and in order to obtain an antiglare film having a fine uneven surface including 95% or more of the surface having an inclination angle of 5 ° or less, it is 4 to 20 μm. More preferably, it is within the range. Similarly to the first etching process, the etching process in the second etching process may be performed by one etching process, or the etching process may be performed twice or more. In the case where the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is within the above range.

<Anti-glare polarizing plate, image display device>
The anti-glare film of the present invention exhibits excellent anti-glare properties, and can effectively prevent a decrease in visibility due to the occurrence of “blink” and “glare” while exhibiting good contrast. It becomes excellent in visibility when mounted on a display device. Moreover, although the anti-glare film of the present invention contains fine particles in the anti-glare layer, it prevents the generation of bubbles in the anti-glare layer and has a stable quality.

  In addition, the antiglare film of the present invention can be suitably used as a member for an antiglare polarizing plate or an image display device. When the image display device is a liquid crystal display, this antiglare film can be applied to a polarizing plate. That is, the polarizing plate generally has a form in which a protective film is bonded to at least one surface of a polarizing film made of a polyvinyl alcohol-based resin film in which iodine or a dichroic dye is adsorbed and oriented. Is composed of the antiglare film of the present invention. By attaching the polarizing film and the antiglare film of the present invention on the base film side of the antiglare film, an antiglare polarizing plate can be obtained. In this case, the other surface of the polarizing film may be in a state where nothing is laminated, a protective film or other optical film may be laminated, or an adhesive layer for bonding to a liquid crystal cell. May be laminated. In addition, the antiglare film of the present invention is bonded on the substrate film side of the polarizing film having a protective film bonded to at least one surface of the polarizing film to form an antiglare polarizing plate. You can also. Furthermore, in the polarizing plate in which the protective film is bonded to at least one surface of the polarizing film, after the base film is bonded to the polarizing film as the protective film, an antiglare layer is formed on the base film. Moreover, it can also be set as an anti-glare polarizing plate.

  The antiglare polarizing plate can be further used as a member of an image display device. In this case, the image display device includes the antiglare polarizing plate and the image display element, and the antiglare polarizing plate is disposed on the viewing side of the image display element with the antiglare layer outside. The

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

[1] Measurement of surface shape of antiglare film The surface shape of the antiglare film was measured using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar). In order to prevent the sample from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface became the surface. At the time of measurement, the magnification of the objective lens was 10 times. The horizontal resolutions Δx and Δy were both 1.66 μm and the measurement area was 850 μm × 850 μm.

(Ratio of energy spectrum of altitude H ₁ ² / H ₂ ² and H ₃ ² / H ₂ ² )
From the measurement data obtained using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar), the elevation of the fine uneven surface of the antiglare film is obtained as a two-dimensional function h (x, y), and the obtained two-dimensional function h (x, y) of the discrete Fourier transform to two-dimensional function H (f _x, f _y) was determined. Two-dimensional function H (f _x, f _y) a two-dimensional function ^{_{H 2 (f x, f y}} ) of energy spectrum was calculated by squaring, H ² (0 is a cross-sectional curve of f _x = 0, f _y ) than, determine the energy spectrum H ₂ ² in the energy spectrum H ₁ ² and the spatial frequency 0.04 .mu.m ^-1 in the spatial frequency 0.01 [mu] m ^-1, the ratio H _{1 ²} / H ^{2 2} energy spectrum was calculated. Further, an energy spectrum H ₃ ² at a spatial frequency of 0.1 μm ⁻¹ was obtained, and the energy spectrum ratio H ₃ ² / H ₂ ² was also calculated.

(Inclination angle of fine uneven surface)
Based on the measurement data obtained by using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar) based on the algorithm described above in the content of the embodiment for carrying out the invention, the histogram of the inclination angle of the uneven surface Was created, and the distribution for each inclination angle was obtained therefrom, and the ratio of the surfaces having an inclination angle of 5 ° or less was calculated.

(Evaluation of protruding degree of fine particles in the antiglare layer (buried state))
When the anti-glare film produced in the same manner except that the anti-glare layer does not contain fine particles is a comparison object, and the spatial frequency distribution of the fine uneven surface and the histogram of the inclination angle of the uneven surface are the same as the comparison object , i.e., two-dimensional function H (f _x, f _y) of the energy spectrum of the altitude H ² is a cross-sectional curve of f _x = 0 of (0, f _y) and if the histogram of the tilt angle is substantially overlaps with the comparison Since the uneven surface shape of the antiglare film containing fine particles is not affected by the fine particles, the fine particles do not protrude from the surface of the antiglare layer (being buried in the antiglare layer), The surface was judged to consist only of a surface formed by a cured product of an active energy ray curable resin. In the following Table 1, the case where it consists only of the surface formed with the hardened | cured material of active energy ray curable resin was shown as (circle), and the case where it was not so was shown as x.

(Observation of bubbles in the antiglare layer)
The antiglare films obtained in the examples and comparative examples are observed at three measurement points while enlarging the range of 1 mm × 1 mm with an optical microscope. When 5 or more bubbles of 10 μm or more were observed, it was indicated as “x”, and when less than 5 bubbles were indicated as “◯”.

[2] Measurement of optical properties of antiglare film (haze)
The haze of the antiglare film was measured by a method defined in JIS K 7136. Specifically, the haze was measured using a haze meter “HM-150 type” (manufactured by Murakami Color Research Laboratory) based on this standard. In order to prevent the anti-glare film from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface becomes the surface.

[3] Evaluation of anti-glare performance of anti-glare film (visual evaluation of reflection)
In order to prevent reflection from the back surface of the antiglare film, an antiglare film is bonded to the black acrylic resin plate so that the uneven surface becomes the surface, and visually observed from the uneven surface side in a bright room with a fluorescent lamp. Observation was performed and the presence or absence of reflection of a fluorescent lamp was visually evaluated. Reflection, whitishness and texture were evaluated according to the following criteria in three stages of 1 to 3, respectively.

Reflection 1: Reflection is not observed,
2: Reflection is slightly observed,
3: Reflection is clearly observed.

(Evaluation of glare)
The glare was evaluated by the following method. First, a unit cell was prepared in which a key-shaped chrome light-shielding pattern with a line width of 10 μm was formed on a transparent substrate, and the portion where the chrome light-shielding pattern was not formed was an opening. Since the unit cell has a size of 254 μm × 84 μm (vertical × horizontal), the size of the opening is 244 μm × 74 μm (vertical × horizontal). Next, a large number of the unit cells were arranged vertically and horizontally to form a photomask.
Next, the photomask was placed on a surface light source so that the chrome shading pattern was on the surface side. Further, a sample in which an antiglare film was attached to a glass plate with an adhesive so that the antiglare layer was on the surface side was placed on the photomask so that the antiglare layer was on the surface side.
From the bottom, the surface light source, the photomask, the glass plate, and the antiglare film are placed in this order.

  In this state, by visually observing at a position about 30 cm away from the sample, the degree of glare was sensory evaluated in seven stages. Level 1 corresponds to a state where no glare is recognized, level 7 corresponds to a state where severe glare is observed, and level 3 refers to a state where only slight glare is observed.

[4] Evaluation of pattern for production of anti-glare film The created pattern data was 256 gray scale image data, and the gray scale was expressed by a two-dimensional discrete function g (x, y). The horizontal resolutions Δx and Δy of the discrete function g (x, y) are both 2 μm. The resulting two-dimensional function g (x, y) and by discrete Fourier transform, two-dimensional function G (f _x, f _y) was determined. Two-dimensional function G (f _x, f _y) a two-dimensional function ^{_{G 2 (f x, f y}} ) of energy spectrum was calculated by squaring, G ² (0 is a cross-sectional curve of f _x = 0, f _y ), A local maximum value was obtained at a spatial frequency having a spatial frequency greater than 0 μm ⁻¹ and the smallest absolute value.

[5] Settling degree measurement of coating liquid 30 ml of coating liquid in which fine particles are dispersed is placed in a 100 ml graduated cylinder, and then left for 6 hours, and the interface between the transparent supernatant layer and the suspension layer of the coating liquid. The scale (ml) was observed. The value was set as x, and the sedimentation degree S was calculated from the following formula (A).
S = 100−x / 30 × 100 (A)

[6] Evaluation of contamination of the coating device by the coating liquid When fine particles settle inside the coating device (slot die coater), the slot that is the discharge part of the slot die coater is clogged with the accumulated fine particles. Unevenness such as continuous stripes occurs on the dazzling film. Therefore, the presence or absence of uneven stripes and the appearance of particles in the manifold part of the slot die coater are observed. If there is no stripe unevenness and there is no particle precipitation in the manifold part, ○, if there is stripe unevenness or particles in the manifold part. The case where precipitation of was confirmed was crossed.

<Example 1>
An aluminum roll having a diameter of 200 mm (A5056 according to JIS) was prepared by applying copper ballad plating to the surface. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the entire plating layer was set to be about 200 μm. The copper plating surface was mirror-polished, and a photosensitive resin was applied to the polished copper plating surface and dried to form a photosensitive resin film. Next, a pattern in which a plurality of patterns composed of image data shown in FIG. 9 were continuously arranged repeatedly was exposed on a photosensitive resin film with a laser beam and developed. Exposure by laser light and development were performed using “Laser Stream FX” (manufactured by Sink Laboratories). A positive photosensitive resin was used for the photosensitive resin film. Energy spectrum ^{_{G 2 (f x, f y}} ) calculated from the pattern shown in Figure 9 cross at f _x = 0 of is as shown in Figure 11. The pattern shown in FIG. 9 shows the maximum value of the energy spectrum at a spatial frequency of 0.045 μm ⁻¹ .

  Then, the 1st etching process was performed with the cupric chloride liquid. The etching amount at that time was set to 7 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with cupric chloride solution. The etching amount at that time was set to be 18 μm. Then, the chrome plating process was performed and the metal mold | die A was produced. At this time, the chromium plating thickness was set to 4 μm.

The following components were dissolved in ethyl acetate at a solid content concentration of 60% by weight, and an ultraviolet curable resin composition having a refractive index of 1.53 after curing was obtained.
60 parts by weight of pentaerythritol triacrylate,
40 parts by weight of polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate)
Leveling agent (Megafac F-477 (manufactured by DIC, fluorine leveling agent)) 0.5 part by weight Polymerization initiator (Lucirin TPO "(manufactured by BASF, chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) )) 5 parts by weight

  To this ultraviolet curable resin composition, methyl methacrylate polymer resin beads (fine particles) having an average particle size of 6.5 μm and a refractive index of 1.49 were added 100 parts by weight of ultraviolet curable resin (of the ultraviolet curable resin). After adding 20 parts by weight per binder resin formed by curing (substantially 100 parts by weight), ethyl acetate and propylene glycol monomethyl ether so that the concentration of solids (including resin beads) is 40% by weight. A 5/5 solvent was added to prepare a coating solution.

This coating solution was applied to a transparent support triacetylcellulose (TAC) film having a thickness of 80 μm so that the coating thickness after drying was 10 μm, and dried for 1 minute in a dryer set at 80 ° C. . The dried film was brought into close contact with the concavo-convex surface of the previously obtained mold A with a rubber roll so that the ultraviolet curable resin composition layer was on the mold side. In this state, ultraviolet rays were irradiated from the TAC film side with an integrated light amount of 550 mJ / cm ^{2 using} a Fusion “V bulb” lamp (maximum emission wavelength: 420 nm) as a light source (first irradiation). Thereafter, the cured coating film is peeled off from the nickel flat plate, and from the cured coating film side, UV light is continuously emitted twice at a cumulative light amount of 850 mJ / cm ^{2 using} a Fusion “D bulb” lamp (maximum emission wavelength: 380 nm) as a light source. (Second irradiation). Thus, a transparent antiglare film A consisting of a laminate of a hard coat layer and a TAC film was produced on the surface.

<Example 2>
An antiglare film B was produced in the same manner as in Example 1 except that propylene glycol monomethyl ether was used as the 5/5 solvent for ethyl acetate and propylene glycol monomethyl ether.

<Example 3>
An antiglare film C was produced in the same manner as in Example 1 except that propylene glycol monomethyl ether acetate was used as the 5/5 solvent for ethyl acetate and propylene glycol monomethyl ether.

<Comparative Example 1>
5/5 solvent of ethyl acetate and propylene glycol monomethyl ether is ethyl acetate, and the average particle diameter of methyl methacrylate polymer resin beads (fine particles) having a refractive index of 1.49 is 6.5 μm to 7.3 μm. An antiglare film D was produced in the same manner as in Example 1 except that.

<Comparative example 2>
A 5/5 solvent of ethyl acetate and propylene glycol monomethyl ether was used as propylene glycol monomethyl ether, and methyl methacrylate polymer resin beads having an average particle diameter of 6.5 μm and a refractive index of 1.49 were obtained. An anti-glare film E was produced in the same manner as in Example 1 except that it was made of methyl methacrylate / styrene copolymer resin beads having a refractive index of 1.59 μm and a refractive index of 1.59.

  Tables 1 and 2 show the evaluation results of the surface shape and optical properties of the obtained antiglare film.

DESCRIPTION OF SYMBOLS 1 Anti-glare film 101 Anti-glare layer 102 Cured product of active energy ray-curable resin 103 Fine particles 104 Transparent support

Claims (13)

The antiglare layer having a fine uneven surface is an antiglare film formed on a transparent support,
The fine uneven surface includes 95% or more of a surface having an inclination angle of 5 ° or less,
The anti-glare layer is formed by applying a coating liquid containing an active energy ray-curable resin, fine particles and a diluting solvent on the transparent support, then drying, and then curing while pressing a stamper. And
An antiglare film, wherein the coating solution represented by the following formula (A) has a sedimentation degree S of 1 or more and 76 or less.
S = 100−x / 30 × 100 (A)
[In the formula, x represents 30 ml of the coating liquid in which fine particles are dispersed in a 100 ml graduated cylinder and then left to stand for 6 hours and observed between the transparent supernatant layer and the suspension layer of the coating liquid. It represents the scale (ml) of the interface, and S represents the sedimentation degree of the coating solution. ]   The antiglare film according to claim 1, wherein at least one kind of fine particles is organic fine particles.   The antiglare film according to claim 1 or 2, wherein an average particle diameter of at least one kind of fine particles is 6 µm or more and 15 µm or less.   The anti-glare property according to any one of claims 1 to 3, wherein a difference in refractive index between at least one of the fine particles and a cured product of the active energy ray-curable resin is 0.005 or more and 0.16 or less. the film.   The antiglare film according to any one of claims 1 to 4, wherein the content of fine particles in the coating liquid is 10 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the active energy ray-curable resin.   6. The antiglare film according to claim 1, wherein the surface haze is 0.1% or more and 5% or less, and the total haze is 5% or more and 30% or less. The energy spectrum H ₁ ² in a spatial frequency 0.01 [mu] m ^-1 elevation of the fine uneven surface of the antiglare layer, the energy spectrum H ₂ ² ratio H _{1 ²} / H ^{2 2} in the spatial frequency 0.04 .mu.m ^-1 3 in the range of 15, the energy spectrum H ₃ ² in the spatial frequency 0.1 [mu] m ^-1, the energy spectrum H ₂ ² ratio H _{3 ²} / H ^{2 2} in the spatial frequency 0.04 .mu.m ^-1 is 0.1 or less The antiglare film according to any one of claims 1 to 6. A method for producing the antiglare film according to any one of claims 1 to 7,
A coating process for coating the coating liquid on the transparent support;
A drying step of drying the coating liquid applied in the coating step to obtain a laminate;
A curing step of curing the active energy ray-curable resin by irradiating an active energy ray while pressing a stamper on the coated surface of the laminate obtained in the drying step, and
A method for producing an antiglare film comprising a peeling step of peeling a stamper from a coated surface after the curing step.   The method for producing an antiglare film according to claim 8, wherein the stamper is a mold having an uneven shape, and is cured while pressing the uneven surface of the mold having an uneven shape against the coating surface of the laminate in the curing step. .   The method for producing an antiglare film according to claim 9, wherein the mold having an uneven shape is an embossing roll.   The anti-glare polarizing plate which the polarizing film has bonded to the surface on the opposite side to the anti-glare layer of the anti-glare film in any one of Claims 1-7.   The anti-glare polarizing plate which the polarizing film has bonded to the surface on the opposite side to the anti-glare layer of the anti-glare film manufactured by the method in any one of Claims 8-10. An antiglare polarizing plate according to claim 11 or 12, and an image display element,
An image display device in which the antiglare polarizing plate is disposed on the viewing side of the image display element with an antiglare layer on the outside.

Images