WO2012035849A1

WO2012035849A1 - Antiglare film, antiglare film manufacturing method, polarizing plate and liquid crystal display device

Info

Publication number: WO2012035849A1
Application number: PCT/JP2011/065157
Authority: WO
Inventors: 岡野　賢
Original assignee: コニカミノルタオプト株式会社
Priority date: 2010-09-14
Filing date: 2011-07-01
Publication date: 2012-03-22
Also published as: KR20130049202A; JP5799954B2; JPWO2012035849A1

Abstract

Disclosed is an antiglare film having improved coated film strength of the anti-glare layer, having film strength (such as excellent scratch resistance and chemical resistance even after weathering tests intended to simulate outdoor use), and having optical characteristics allowing achievement of contrast-rich image quality and reflection prevention of outside light or reflection images. Also disclosed are a manufacturing method of said antiglare film, an excellent polarizing and liquid crystal display device using said antiglare film. The disclosed antiglare film has an antiglare layer on a substrate film. The antiglare layer is aperiodic in the length direction and is arranged irregularly on the substrate film as irregularly shaped protrusions. The arithmetic average roughness Ra of the antiglare layer (JIS B0601: 1994) is 25-300nm, and the haze due to internal scattering of the antiglare layer is 0-1.0%.

Description

Antiglare film, method for producing antiglare film, polarizing plate and liquid crystal display device

The present invention relates to a novel antiglare film, a method for producing an antiglare film, a polarizing plate using the antiglare film, and a liquid crystal display device using the polarizing plate.

In recent years, in displays such as cathode ray tube display (CRT) displays, liquid crystal displays, plasma displays, touch panel input devices, organic or inorganic EL (electroluminescence) displays, FEDs (field emission displays), etc. When an external light source is reflected on the display surface, the reflected light becomes obstructive and the screen becomes difficult to see, and the visibility is significantly deteriorated. For various displays, the outline of the reflected image is blurred on the surface. A film (antiglare film) having an antiglare layer for reducing reflection is provided on the display surface.

Anti-glare treatment includes surface roughening by chemical etching or the like, surface unevenness by a transfer method using a mold, etc., and surface unevenness by dispersing fine particles in the resin layer. Some have been granted.

Among these anti-glare treatments, a method in which fine particles are dispersed and contained in the resin layer is generally used because surface irregularities can be easily imparted.

However, in the anti-glare film in which fine particles are dispersed and formed to form surface irregularities, the fine particles are likely to aggregate and it is difficult to control the surface irregularities on the surface, and the degree of freedom in designing the surface irregularities is restricted. In addition, there is a problem that unevenness occurs due to aggregation of fine particles, resulting in poor appearance. In addition, since the refractive index of the fine particles and the resin forming the anti-glare layer are different, haze (internal haze) due to internal scattering due to the difference in refractive index between the two occurs, increasing the overall haze as a film, and the entire display However, there is a problem in that it becomes white and causes a decrease in contrast. Therefore, in recent years, anti-glare films having a low internal haze have been studied (for example, Patent Documents 1 and 2).

In Patent Document 1, the total haze is 1 to 30%, the internal haze is 0 to 1%, and the average reflectance at 5 ° incidence in the wavelength range of 450 to 650 nm is 0.001 to 2.5%. An antiglare film is disclosed. The invention described in Patent Document 1 is a technique in which a polymer component (cellulose acetate propionate) is contained in a cured resin, and surface irregularities are formed by spinodal decomposition when the coating film is dried.

On the other hand, Patent Document 2 has one or more antiglare hard coat layers on a transparent film, the internal haze of the antiglare hard coat layer is 0.5% or less, and the surface haze / internal haze is 2.0 or more. An anti-glare hard coat film is disclosed. The invention described in Patent Document 2 uses surface separation by spinodal decomposition of two types of resins (resin A; for example, dipentaerythritol hexaacrylate, and resin B; for example, a methacrylate copolymer) to provide surface unevenness. It is a technology to form.

Further, a low-haze antiglare film in a transfer method using a mold is disclosed in Patent Document 3. In Patent Document 3, irregularities are formed by hitting fine particles against a polished metal surface, a mold is produced by electroless nickel plating on the irregular surface, and the irregular surface of the mold is transferred to a transparent resin film. And it is a manufacturing method of the glare-proof film which forms an unevenness | corrugation in a transparent resin film.

Both of these technologies are described as being able to prevent reflection of external light and reflected images and obtain an image with excellent contrast.

In addition to the above, examples of the method for forming the protrusion shape include a method in which resins having different SP values (solubility parameters) are mixed to form surface irregularities (for example, see Patent Document 4 and Patent Document 5). .

JP 2006-106290 A JP 2007-58204 A JP 2006-53371 A JP 2007-182519 A JP 2009-13384 A

However, in the method of forming surface irregularities by mold transfer in Patent Document 3, a transfer process is necessary in the manufacturing process, and the number of processes is increased and production equipment is required, leading to a problem that leads to high cost and mass productivity. It was low. In addition, when the regular arrangement is artificially performed as described above, there is a problem in that reflected light inevitably causes interference and causes iridescence.

Moreover, in the anti-glare film which forms surface unevenness using regular phase separation by spinodal decomposition as described in

Patent Documents

1 and 2, it is difficult to control phase separation, A slight change in the polymer composition or the like greatly changes the size of the phase separation structure, making it difficult to form stable surface irregularities.

In addition, film strength can be obtained sufficiently by simply forming a regular protrusion shape on the antiglare layer, such as a method of forming protrusions on the surface by pressing a mold, a method of spinodal decomposition or adding fine particles. However, the scratch resistance and chemical resistance performance after the weather resistance test was insufficient.

Furthermore, although the above-described conventional techniques can provide a certain level of image quality that prevents external light and reflected images from being reflected and is excellent in contrast, after the weather resistance test assuming outdoor use such as digital signage, scratch resistance Degradation of film strength such as deterioration of chemical resistance was remarkable.

The present invention has been made in view of the above problems, and the coating strength of the antiglare layer is improved, and it has excellent film strength such as scratch resistance and chemical resistance even after a weather resistance test assuming outdoor use. In addition, the antiglare film having optical properties such as prevention of reflection of external light and reflected images and image quality excellent in contrast, a method for producing the antiglare film, and an excellent polarizing plate and liquid crystal using the same An object is to provide a display device.

As a result of intensive studies, the present inventor has found that the above-mentioned problem can be solved by an antiglare film having the following constitution, and has further completed the present invention based on such findings.

An antiglare film according to one embodiment of the present invention is an antiglare film having an antiglare layer on a base film, and the antiglare layer has a protrusion shape having no period in the longitudinal direction, The protrusion shape is irregularly arranged on the base film, and the arithmetic average roughness Ra (JIS B0601: 1994) of the antiglare layer is 25 to 300 nm. An anti-glare film characterized by having a haze due to internal scattering of 0 to 1.0%.

With such a configuration, the coating strength of the antiglare layer is improved, it has excellent film strength such as scratch resistance and chemical resistance even after a weather resistance test assuming outdoor use, and it reflects external light and reflected images. It is possible to obtain an antiglare film having optical properties such as prevention of blurring and image quality excellent in contrast.

In the antiglare film according to the present embodiment, the arithmetic average roughness Ra (JIS B0601: 1994) of the antiglare layer is preferably 25 to 130 nm from the viewpoint of obtaining the above effect more reliably.

Furthermore, it is more desirable that the arithmetic average roughness Ra (JIS B0601: 1994) of the antiglare layer is 65 to 130 nm.

In addition, if the haze due to internal scattering of the antiglare layer is 0.60 to 1.0%, it is preferable in that the above effect can be exhibited more satisfactorily.

Furthermore, since the antiglare film according to the present embodiment is difficult to obtain the objective effect of the present invention and causes a decrease in contrast due to an increase in internal haze, inorganic fine particles and organic fine particles, and actinic radiation curable resin It is preferable that substantially no resin that is incompatible with the actinic radiation curable resin is contained.

Moreover, in the antiglare film according to the present embodiment, the tan δ in the film width direction of the base film has the following relationship:
0.5 ≧ tan δ ₋₄₀ / tan δ _peak ≧ 0.24
(Where tan δ _peak represents the maximum value of tan δ measured from 25 ° C. to 210 ° C., and tan δ ₋₄₀ represents the value of tan δ at a temperature of −40 ° C. when tan δ _peak was exhibited.)
It is preferable to have. With such a configuration, an antiglare film having film strength such as particularly excellent scratch resistance and chemical resistance can be obtained.

Further, in the method for producing an antiglare film according to the present embodiment, an antiglare layer containing an actinic radiation curable resin having a viscosity at 25 ° C. in the range of 30 to 2500 mPa · s is at least applied. Production of an antiglare film, characterized by being formed through a drying step and a curing step, and being processed under the condition that the temperature of the decreasing rate drying section in the drying step is maintained within a range of 90 to 140 ° C. A method is preferred.

The polarizing plate according to another embodiment of the present invention is a polarizing plate characterized by using the antiglare film on one surface. According to such a configuration, the coating strength of the antiglare layer is improved, the film has excellent film strength such as scratch resistance and chemical resistance even after a weather resistance test assuming outdoor use, and external light or a reflected image. Anti-glare film with optical properties such as anti-reflection and high contrast image quality can be used. For example, when applied to a liquid crystal display device, the liquid crystal display device has high image quality and high durability. A polarizing plate that can be obtained is obtained.

The liquid crystal display device according to another embodiment of the present invention is a liquid crystal display device including the polarizing plate in at least one of the liquid crystal cells. According to such a configuration, since the above-described excellent polarizing plate is used, it is possible to realize high image quality and high durability of the liquid crystal display device. Furthermore, by using the polarizing plate on the rear side of the liquid crystal cell, it is possible to suppress the occurrence of moire fringes.

According to the present invention, the antiglare layer is produced under the condition that the projection shape forming the surface unevenness of the antiglare layer has a period in the longitudinal direction and is formed in an irregular state, and further the arithmetic average roughness By controlling the Ra and internal haze to a specific range, the coating strength of the antiglare layer is improved, and film strength such as excellent scratch resistance and chemical resistance can be obtained even after a weather resistance test assuming outdoor use. In addition, an antiglare film having optical characteristics such as prevention of reflection of external light and reflected images and image quality excellent in contrast, a method for producing the antiglare film, and a polarizing plate and a liquid crystal display device using the same be able to.

Therefore, according to the present invention, it is possible to obtain an excellent antiglare film having high film strength without unevenness even under a high temperature and high humidity environment. Furthermore, by using the antiglare film, it is possible to provide a very excellent polarizing plate and liquid crystal display device that is excellent in unevenness and visibility, and does not cause eye fatigue even when viewed for a long time.

It is the schematic which shows the irregular protrusion of the glare-proof layer which concerns on one embodiment of this invention. It is explanatory drawing of protrusion. It is an observation figure of the optical interference type surface roughness meter of the anti-glare layer surface of an anti-glare film. It is the schematic of the apparatus which measures the high-definition definition used in the Example. It is an example of the photograph of the sample observed with the high-definition definition apparatus. It is sectional drawing of the polarizing plate created in the Example. It is sectional drawing of the liquid crystal panel created in the Example. It is the schematic of the liquid crystal cell of a liquid crystal display device.

<Anti-glare film>
The antiglare film referred to in the present invention is a layer that blurs the outline of reflected images and external light on the surface of the base film, and is used when an image display device such as a liquid crystal display, an organic EL display, or a plasma display is used. It is a film that prevents the reflection of external light and reflected images.

Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these.

(Surface shape)
The antiglare film of the present invention is composed of at least an antiglare layer and a base film, and the antiglare layer has a protrusion shape that forms surface irregularities, and the protrusion shape does not have a period in the longitudinal direction, and is irregular. It is characterized by the irregular shape of the protrusions having irregular shapes.

The anti-glare layer of the anti-glare film of the present invention has “irregularly shaped protrusions that do not have a period in the longitudinal direction”. It refers to protrusions of various shapes whose sizes are not fixed. For this reason, for example, when a concavo-convex structure is formed in the longitudinal direction with a roll shape having a diameter of about 5 cm, a protrusion shape having a period in the longitudinal direction formed by a surface transfer roll having a period of about 15 cm is included. Absent.

Specifically, although not limited thereto, for example, protrusions having different widths and heights shown in FIG. 1 are exemplified as irregularly shaped protrusions. The “irregular arrangement” means that the irregularly-protruding protrusions are not regularly arranged (for example, at regular intervals), but are irregularly arranged at random intervals, It may be isotropic or anisotropic.

The antiglare film of the present invention is characterized in that the haze caused by internal scattering of the antiglare layer (hereinafter also referred to as internal haze) is 0 to 1.0%. When forming the projection shape described above, by controlling the internal haze within the above range and controlling the arithmetic average roughness Ra of the projection shape within the range described later, the object and effects of the present invention can be exhibited well. Preferably, the internal haze is 0.60 to 1.0%. The internal haze can be measured by the following procedure. A few drops of silicone oil are dropped on the front and back surfaces of the antiglare film and sandwiched between two glass plates (micro slide glass product number S 9111, manufactured by MATSUNAMI) having a thickness of 1 mm from the front and back. An anti-glare film sandwiched between front and back glass is optically brought into close contact with two glass plates, and in this state, haze (Ha) is measured according to JIS-K7105 and JIS-K7136. Next, several drops of silicone oil are dropped between two glass plates and sandwiched to measure glass haze (Hb). And internal haze (Hi) is computable by drawing glass haze (Hb) from the haze (Ha) which pinched | interposed the glare-proof film with glass. Further, the surface haze (the haze due to the surface scattering of the film) is preferably 0.50 to 20%. The surface haze is obtained by subtracting the internal haze from the total haze. The total haze is preferably 0.50% to 20%.

The anti-glare film of the present invention has another feature that the arithmetic average roughness Ra (JIS B0601: 1994) of the anti-glare layer is 25 to 300 nm. The arithmetic average roughness Ra is more preferably 25 to 130 nm, and particularly preferably 65 to 130 nm. In order to obtain the arithmetic average roughness Ra within the above range, the height of the protrusion shape is preferably 20 nm to 4 μm. The width of the protrusion shape is 50 nm to 300 μm, preferably 50 nm to 100 μm. The height and width of the protrusion shape can be obtained from cross-sectional observation. In order to make it easier to understand, FIG. 2 shows an explanatory view of the protrusion. As shown in FIG. 2, the center line a is drawn on the cross-sectional observation image, and the distance between the two intersections of the lines b and c and the center line a forming the mountain ridge is defined as the protrusion size width t and did. Further, the distance from the summit to the center line a is obtained as the height h of the protrusion size.

The 10-point average roughness Rz of the antiglare layer of the antiglare film of the present invention is preferably 10 times or less the centerline average roughness Ra, and the average mountain valley distance Sm is preferably 5 to 150 μm, more preferably 20 to 100 μm. The standard deviation of the height of the convex part from the deepest part is preferably 0.5 μm or less, the standard deviation of the mean mountain-valley distance Sm with respect to the center line is 20 μm or less, and the surface with an inclination angle of 0 to 5 degrees is preferably 10% or more. By designing in this way, an effect of suppressing white sensation can be obtained. The arithmetic average roughness Ra, Sm, Rz is a value measured by an optical interference surface roughness meter (for example, RST / PLUS, manufactured by WYKO, New View 5030 manufactured by Zygo) according to JIS B0601: 1994. is there.

The kurtosis (Rku) of the antiglare layer is preferably 3 or less. The kurtosis (Rku) is a parameter that defines the shape of the concavo-convex convex portion. The larger the kurtosis (Rku) value, the more the concavo-convex convex portion becomes more sharp like a needle. It will be a different shape. If the kurtosis (Rku) exceeds 3, white blurring tends to occur. The kurtosis (Rku) of the antiglare layer is more preferably 1.5 to 2.8. Further, the absolute value of the degree of distortion (Rsk) of the surface is preferably 1 or less. The skewness (Rsk) is a parameter indicating the ratio of the convex portion and the concave portion to the average surface of the concavo-convex shape, and the concavo-convex shape becomes a positively large value when there are many convex portions with respect to the average surface, If there are many concave portions with respect to the average surface, the value becomes negatively large. When the absolute value of the skewness (Rsk) exceeds 1, white blur tends to occur. The absolute value of the skewness (Rsk) is preferably 0.01 to 0.5. The kurtosis (Rku) and the skewness (Rsk) can be measured using the optical interference type surface roughness meter.

In addition, although the antiglare layer having the characteristics as described above will be described in detail later, the surface shape is, for example, controlled at a high temperature for the treatment temperature of the rate-decreasing drying section in the drying process of the antiglare layer coating composition, It can be obtained by a method in which a convection of the resin is generated, a non-uniform state is formed on the surface of the antiglare layer, and the coating is formed by curing in this non-uniform surface state. By forming the coating film by such a method, the film strength of the antiglare layer is improved. In addition to the objective effect of the present invention, the method of controlling the treatment temperature in the decreasing rate drying section in the drying process of the antiglare layer coating composition is preferable in terms of excellent productivity.

(Anti-glare layer)
The antiglare layer according to the present invention contains an actinic radiation curable resin, that is, a resin that is cured through a crosslinking reaction when irradiated with an actinic ray (also referred to as an actinic energy ray) such as an ultraviolet ray or an electron beam. A layer is preferred.

As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and an actinic radiation curable resin layer is formed by curing by irradiation with actinic radiation such as ultraviolet rays or electron beams. The

Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, but the resin that is cured by ultraviolet irradiation is excellent in mechanical film strength (abrasion resistance, pencil hardness). preferable.

Examples of the ultraviolet curable resin include an ultraviolet curable acrylate resin, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet ray. A curable epoxy resin or the like is preferably used. Of these, ultraviolet curable acrylate resins are preferred.

As the ultraviolet curable acrylate resin, polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups or methacryloyloxy groups in the molecule. Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tri / tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, glycerol triacrylate relay , Dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, etc. isocyanurate derivatives of the active energy ray-curable are preferably exemplified.

The active energy ray-curable isocyanurate derivative is not particularly limited as long as it is a compound having a structure in which one or more ethylenically unsaturated groups are bonded to the isocyanuric acid skeleton, but three or more in the same molecule. A compound having an ethylenically unsaturated group and one or more isocyanurate rings is preferred. Specific examples include tris (acryloyloxyethyl) isocyanurate.

As these commercial products, Adekaoptomer N series (manufactured by ADEKA Corporation); Sun Rad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (Sanyo) Aronix M-6100, M-8030, M-8060, Aronix M-215, Aronix M-315, Aronix M-313, Aronix M-327 (manufactured by Toagosei Co., Ltd.); NK -Ester A-TMM-3L, NK-ester AD-TMP, NK-ester ATM-35E, NK ester A-DOG, NK ester A-IBD-2E, A-9300, A-9300-1CL (Shin Nakamura Chemical Co., Ltd.) Co., Ltd.); light acrylate TMP-A, PE-3A (Kyoeisha Chemical) and the like.

Further, the viscosity at 25 ° C. of the actinic radiation curable resin composition (consisting of the actinic radiation curable resin and an additive other than the solvent) in which the actinic radiation curable resin is used alone or in combination of two or more is preferably 30 mPa · s or more, It is 2500 mPa · s or less. By using such a low-viscosity resin composition, the above-described protrusion shape and arithmetic average roughness Ra are easily obtained. Moreover, if the viscosity of the resin composition is 30 mPa · s or more, a monomer having a high functionality can be used, and sufficiently high curability is obtained. If the viscosity is 2500 mPa · s or less, in the drying step. Sufficient fluidity of the resin composition is easily obtained.

In addition, the said viscosity is the value measured on 25 degreeC conditions using the B-type viscosity meter.

In addition, monofunctional acrylate may be used. Monofunctional acrylates include isobornyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, isostearyl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, lauryl acrylate, isooctyl acrylate, tetrahydrofurfuryl acrylate, behenyl Examples include acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, cyclohexyl acrylate, maleimide acrylate, N-acryloyloxyethyl hexahydrophthalimide, and the like. Such monofunctional acrylates can be obtained from Nippon Kasei Kogyo Co., Ltd., Shin-Nakamura Chemical Co., Ltd., Osaka Organic Chemical Co., Ltd., Toagosei Co., Ltd., etc.

In the case of using a monofunctional acrylate, it is preferable to contain polyfunctional acrylate: monofunctional acrylate = 80: 20 to 99: 2 in terms of mass ratio of polyfunctional acrylate and monofunctional acrylate.

Further, the antiglare layer of the present invention does not substantially contain a resin that is incompatible with the actinic radiation curable resin, it is difficult to obtain the object effect of the present invention, and internal haze This is preferable because the increase causes a decrease in contrast.

In the present invention, “incompatible” means that each of the resins constituting the molten mixture has a single peak when the melting temperature Tm or the glass transition point Tg of the molten mixture of two or more resins is measured and observed. Means what is observed. Further, it means that each phase is substantially observed in transmission electron microscope observation. On the other hand, “compatible” means that one or less peaks of the molten mixture are observed when the melting temperature Tm or the glass transition point Tg of the molten mixture of the same or two or more resins is measured and observed. Say.

In the present invention, examples of the resin that is incompatible with the actinic ray curable tree include resins and polyester resins obtained by polymerizing or copolymerizing (meth) acrylic or acrylic monomers, and will be described later. The thermoplastic acrylic resin used in a base film, a cellulose ester resin, etc. are mentioned.

“Substantially free of incompatible resin” means that the content in the antiglare layer is 0.01% by mass or less excluding the extract component from the base film.

In addition, the antiglare layer preferably contains a photopolymerization initiator in order to accelerate the curing of the actinic radiation curable resin. The amount of the photopolymerization initiator is preferably contained in a mass ratio of photopolymerization initiator: active ray curable resin = 20: 100 to 0.01: 100. Specific examples of the photopolymerization initiator include alkylphenone series, acetophenone, benzophenone, hydroxybenzophenone, Michler ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. In particular, it is not limited to these.

Commercially available products may be used as such photopolymerization initiators, and preferred examples include Irgacure 184, Irgacure 907, Irgacure 651, etc., manufactured by BASF Japan.

Further, the antiglare layer preferably does not substantially contain fine particles such as inorganic fine particles and organic fine particles because the object effect of the present invention is difficult to obtain and the contrast is lowered due to an increase in internal haze. In the present invention, “substantially not containing fine particles” means that the content of fine particles contained in the antiglare layer is 0.01% by mass or less. Further, the antiglare layer may contain a conductive agent in order to impart antistatic properties. A preferable conductive agent is a π-conjugated conductive polymer. An ionic liquid is also preferably used as the conductive compound.

From the viewpoint of coating properties, the antiglare layer contains a silicone-based surfactant, a fluorine-based surfactant, or a nonionic surfactant such as polyoxyether, an anionic surfactant, and a fluorine-siloxane graft compound. May be.

The fluorine-siloxane graft compound is a copolymer compound obtained by grafting polysiloxane containing siloxane and / or organosiloxane alone and / or organopolysiloxane to at least a fluorine resin. Such a fluorine-siloxane graft compound can be prepared by a method as described in Examples described later. Alternatively, examples of commercially available products include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Chemical Industry Co., Ltd. These components are preferably added in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

The anti-glare layer is prepared by diluting the above-described components forming the anti-glare layer with a solvent as an anti-glare layer composition (also referred to as an anti-glare layer coating composition). It is preferable to provide an antiglare layer by coating, drying and curing on the base film.

Solvents include ketones (such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone), esters (such as methyl acetate, ethyl acetate, butyl acetate, propyl acetate, propylene glycol monomethyl ether acetate), alcohols (ethanol, methanol, butanoic acid) -Nyl, n-propyl alcohol, isopropyl alcohol, diacetone alcohol), hydrocarbons (toluene, xylene, benzene, cyclohexane), glycol ethers (propylene glycol monomethyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, etc.) Etc.) can be preferably used. Of these solvents, esters, ketones, glycol ethers or alcohols are preferred. By using these preferred solvents in the range of 20 to 200 parts by mass with respect to 100 parts by mass of the actinic radiation curable resin, after applying the antiglare layer coating composition to the base film, the solvent of the antiglare layer coating composition In the process of forming the antiglare layer while evaporating, convection of the resin is likely to occur, and as a result, irregular surface roughness is likely to appear in the antiglare layer, and the arithmetic average roughness Ra is controlled. It is preferable because it is easy to do.

The coating amount of the antiglare layer is suitably 0.1 to 40 μm as a wet film thickness, and preferably 0.5 to 30 μm. The dry film thickness is from 0.1 to 30 μm, preferably from 1 to 20 μm, particularly preferably from 6 to 15 μm.

As a method for applying the antiglare layer, known methods such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, and an ink jet method can be used. Using these coating methods, an antiglare layer composition for forming an antiglare layer is applied, dried after application, irradiated with actinic radiation (also referred to as UV curing treatment), and further heated after UV curing as necessary. It can be formed by processing. The heat treatment temperature after UV curing is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. By performing the heat treatment after UV curing at such a high temperature, an antiglare layer having excellent pencil hardness can be obtained.

Drying is preferably performed by high-temperature treatment at a temperature of 90 ° C. or higher in the rate of drying section. More preferably, the temperature of the decreasing rate drying section is 90 ° C or higher and 140 ° C or lower. By setting the temperature of the rate-decreasing drying section to a high temperature treatment, convection occurs in the coating resin during formation of the antiglare layer, and as a result, irregular surface roughness is likely to appear on the antiglare layer surface, The arithmetic average roughness Ra is preferable because it is easy to control.

In general, it is known that the drying process changes from a constant state to a gradually decreasing state when drying starts. The decreasing section is called the decreasing rate drying section. In the constant rate drying section, the amount of heat flowing in is all consumed for solvent evaporation on the coating film surface, and when the solvent on the coating film surface decreases, the evaporation surface moves from the surface to the inside and enters the decreasing rate drying section. Thereafter, the temperature of the coating film surface rises and approaches the hot air temperature, so that the temperature of the actinic radiation curable resin composition rises, the resin viscosity decreases, and the fluidity increases.

As a light source for UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. 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 lamp, or the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 50 to 1000 mJ / cm ² , preferably 50 to 300 mJ / cm ² .

When irradiating actinic rays, it is preferably performed while applying tension in the transport direction of the film, more preferably while applying tension in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained.

Further, the antiglare layer may further contain an ultraviolet absorber described in the base film described later. As a structure of the film in the case of containing an ultraviolet absorber, the antiglare layer is preferably composed of two or more layers, and the antiglare layer in contact with the base film preferably contains the ultraviolet absorber.

As the content of the ultraviolet absorber, it is preferable that it is contained in a mass ratio of ultraviolet absorber: antiglare layer constituting resin = 0.01: 100 to 10: 100. When two or more layers are provided, the film thickness of the antiglare layer in contact with the base film is preferably in the range of 0.05 to 2 μm. Two or more layers may be formed as a simultaneous multilayer. The simultaneous multi-layering means that two or more anti-glare layers are applied on a wet substrate on a substrate without passing through a drying step to form the anti-glare layer. In order to laminate the second anti-glare layer on the first anti-glare layer without using a drying process, the layers are stacked one after another with an extrusion coater or simultaneously with a slot die having a plurality of slits. Can be done.

The antiglare film of the present invention has a pencil hardness, which is an index of hardness, of H or higher, more preferably 3H or higher. If it is 3H or more, it is not only difficult to be scratched in the polarizing plate forming step of the liquid crystal display device, but also used for outdoor applications, and is a surface protective film for large liquid crystal display devices and liquid crystal display devices for digital signage. Excellent mechanical properties when used. The pencil hardness is determined by JIS K5400 using a test pencil specified by JIS S 6006 under the condition of a weight of 500 g after conditioning the prepared antiglare film at a temperature of 23 ° C. and a relative humidity of 55% for 2 hours or more. It is a value measured according to the pencil hardness evaluation method specified. Next, the base film will be described.

<Base film>
The base film is preferably easy to manufacture, easily adheres to the antiglare layer, and is optically isotropic. Moreover, in this invention, a base film is used as a polarizing plate protective film.

Any base film having the above properties may be used. For example, cellulose ester-based films such as triacetyl cellulose film, cellulose acetate propionate film, cellulose diacetate film, and cellulose acetate butyrate film, polyethylene terephthalate, polyethylene Polyester film such as naphthalate, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, Syndiotactic polystyrene film, norbornene resin film, polymethylpente Films, polyether ketone films, polyether ketone imide film, a polyamide film, a fluorine resin film, nylon film, can be used cycloolefin polymer film, a polymethyl methacrylate film or an acrylic film or the like.

Among these, cellulose ester films (for example, Konica Minoltak KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UE, KC4UE, and KC12UR (above, Konica Minolta Opto Co., Ltd., Polycarbonate Film) An olefin polymer film and a polyester film are preferable, and in the present invention, the cellulose ester film is preferable from the viewpoint of easy production of the above-described protruding shape by the antiglare layer, productivity, and cost.

The refractive index of the base film is preferably 1.30 to 1.70, and more preferably 1.40 to 1.65. The refractive index is measured by the method of JIS K7142 using an upe refractometer 2T manufactured by Atago Co., Ltd.

Further, the tan δ measured by changing the temperature from 25 ° C. to 210 ° C. at a humidity of 55% RH in the width direction of the film has the following relationship. Is preferable from the standpoint of exhibiting good.

0.5 ≧ tan δ ₋₄₀ / tan δ _peak ≧ 0.24
Here, tan δ _peak is the maximum value obtained by measuring the tan δ value by changing the temperature from 25 ° C. to 210 ° C., and tan δ ₋₄₀ is the value of tan δ at a temperature of −40 ° C. when tan δ _peak is indicated.

The object effect of the present invention is more effectively exhibited by setting tan δ in the film width direction of the base film, that is, the balance between the storage elastic modulus and the loss elastic modulus with respect to the temperature within the above range. The tan δ can be measured, for example, by using a sample that has been conditioned for 24 hours in an atmosphere of 23 ° C. and 55% RH and increasing the humidity at 55% RH under the following conditions or setting the temperature. it can.

Measuring device: RSA III manufactured by TI Instruments
Sample: width 5 mm, length 50 mm (gap set to 20 mm)
Measurement conditions: Tensile mode Measurement temperature: 25-210 ° C
Temperature rising condition: 5 ° C / min
Frequency: 1Hz
(Cellulose ester film)
Next, it demonstrates in detail about a cellulose-ester film preferable as a base film.

The cellulose ester film is not particularly limited as long as it has the above characteristics, but the cellulose ester resin (hereinafter also referred to as cellulose ester) is preferably a lower fatty acid ester of cellulose. The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, etc. Further, mixed fatty acid esters such as cellulose acetate butyrate can be used.

Among the above descriptions, the lower fatty acid esters of cellulose particularly preferably used are cellulose diacetate, cellulose triacetate, and cellulose acetate propionate. These cellulose esters can be used alone or in combination.

Cellulose diacetate preferably has an average degree of acetylation (amount of bound acetic acid) of 51.0% to 56.0%. Commercially available products include Daicel L20, L30, L40, and L50, and Eastman Chemical's Ca398-3, Ca398-6, Ca398-10, Ca398-30, and Ca394-60S.

The cellulose triacetate preferably has an average degree of acetylation (bound acetic acid amount) of 54.0 to 62.5%, and more preferably cellulose triacetate having an average degree of acetylation of 58.0 to 62.5%. is there.

If the average degree of acetylation is small, the dimensional change is large, and the polarization degree of the polarizing plate decreases. When the average degree of acetylation is large, the solubility in a solvent is lowered and the productivity is lowered.

The cellulose triacetate has an acetyl group substitution degree of 2.80 to 2.95, a number average molecular weight (Mn) of 125,000 or more and less than 155000, a weight average molecular weight (Mw) of 265,000 or more and less than 310,000, Mw / Mn Triacetate A having a acetyl group substitution degree of 2.75 to 2.90, a number average molecular weight (Mn) of 155,000 or more and less than 180,000, Mw of 290000 or more and less than 360,000, Mw / Mn preferably contains cellulose triacetate B which is 1.8 to 2.0.

Furthermore, when cellulose triacetate A and cellulose triacetate B are used in combination, the mass ratio is preferably in the range of cellulose triacetate A: cellulose triacetate B = 100: 0 to 20:80. A preferred cellulose ester other than cellulose triacetate has an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree of acetyl group is X, and the substitution degree of propionyl group or butyryl group is Y, It is a cellulose ester containing the cellulose ester which satisfy | fills (I) and (II) simultaneously.

Formula (I) 2.6 ≦ X + Y ≦ 3.0
Formula (II) 0 ≦ X ≦ 2.5
In particular, cellulose acetate propionate is preferably used, and among them, 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9 are preferable.

The number average molecular weight (Mn) and molecular weight distribution (Mw) of cellulose ester can be measured using high performance liquid chromatography. The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G
(Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (GL Science Co., Ltd.)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation)
A calibration curve with 13 samples from Mw = 1000000 to 500 was used. The 13 samples are preferably used at approximately equal intervals.

(Cellulose ester resin / thermoplastic acrylic resin-containing film)
The base film contains a thermoplastic acrylic resin and a cellulose ester resin, and the mass ratio of the thermoplastic acrylic resin and the cellulose ester resin is thermoplastic acrylic resin: cellulose ester resin = 95: 5 to 50:50. You may use the film which is.

Acrylic resin includes methacrylic resin. The acrylic resin is not particularly limited, but is preferably composed of 50 to 99% by mass of methyl methacrylate units and 1 to 50% by mass of other monomer units copolymerizable therewith. Examples of other copolymerizable monomers include alkyl methacrylates having 2 to 18 alkyl carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, alkyl acrylates such as acrylic acid and methacrylic acid. Unsaturated group-containing divalent carboxylic acids such as saturated acid, maleic acid, fumaric acid and itaconic acid, aromatic vinyl compounds such as styrene and α-methylstyrene, α, β-unsaturated nitriles such as acrylonitrile and methacrylonitrile, Examples thereof include maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride and the like, and these can be used alone or in combination of two or more monomers.

Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoint of thermal decomposition resistance and fluidity of the copolymer. n-Butyl acrylate is particularly preferably used. Further, the weight average molecular weight (Mw) is preferably 80,000 to 500,000, and more preferably 110,000 to 500,000.

The weight average molecular weight of the acrylic resin can be measured by gel permeation chromatography including the measurement conditions. There is no restriction | limiting in particular as a manufacturing method of an acrylic resin, You may use any well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization. Here, as a polymerization initiator, a normal peroxide type and an azo type can be used, and a redox type can also be used. The polymerization temperature may be 30 to 100 ° C. for suspension or emulsion polymerization, and 80 to 160 ° C. for bulk or solution polymerization. In order to control the reduced viscosity of the obtained copolymer, polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent. Commercial products can also be used. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dianal BR52, BR80, BR83, BR85, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Electrochemical Industry Co., Ltd.) and the like can be mentioned. . Two or more acrylic resins can be used in combination. The acrylic resin may be a graft copolymer obtained by grafting a (meth) acrylic resin to a copolymer of (meth) acrylic rubber and an aromatic vinyl compound. In the graft copolymer, a copolymer of (meth) acrylic rubber and an aromatic vinyl compound forms a core, and the (meth) acrylic resin forms a shell around the copolymer. -A shell-type graft copolymer is preferred.

The total mass of the acrylic resin and the cellulose ester resin in the base film is preferably 55% by mass or more of the base film, more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The base film may be configured to contain resins and additives other than thermoplastic acrylic resins and cellulose ester resins.

(Acrylic particles)
The base film may contain acrylic particles because it is excellent in improving brittleness. An acrylic particle represents the acrylic component which exists in the state of particle | grains (it is also called an incompatible state) in the base film containing the said thermoplastic acrylic resin and cellulose-ester resin in a compatible state.

The acrylic particles are not particularly limited, but are preferably multi-layered acrylic granular composites. Examples of commercially available acrylic granular composites that are multi-layer structured polymers include, for example, “Metablene” manufactured by Mitsubishi Rayon Co., “Kaneace” manufactured by Kaneka Chemical Co., Ltd., “Paralloid” manufactured by Kureha Chemical Co., Ltd., Rohm and “Acryloid” manufactured by Haas, “Staffyroid” manufactured by Ganz Kasei Kogyo Co., Ltd., “Parapet SA” manufactured by Kuraray Co., Ltd., and the like can be used alone or in combination of two or more. When adding acrylic particles to the base film, it is preferable that the refractive index of the mixture of the acrylic resin and the cellulose ester resin is close to the refractive index of the acrylic particles in order to obtain a highly transparent film. Specifically, the refractive index difference between the acrylic particles and the acrylic resin is preferably 0.05 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less.

Acrylic fine particles are in a range of 0.5: 100 to 30: 100 in terms of the content of acrylic fine particles: acrylic resin and cellulose ester resin with respect to the total mass of acrylic resin and cellulose ester resin constituting the film. The content is preferably from the viewpoint that the intended effect is better exhibited, and more preferably, the total mass of acrylic fine particles: acrylic resin and cellulose ester resin = 1.0: 100 to 15: 100.

[Fine particles]
In order to improve the handleability, the base film according to the present embodiment includes, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, silica It is preferable to contain matting agents such as inorganic fine particles such as aluminum oxide, magnesium silicate, and calcium phosphate, and a crosslinked polymer. Among these, silicon dioxide is preferably used because it can reduce the haze of the film.

The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.

(Other additives)
A plasticizer can also be used in combination with the base film in order to improve the fluidity and flexibility of the composition. Examples of the plasticizer include phthalate ester, fatty acid ester, trimellitic ester, phosphate ester, polyester, and epoxy. Of these, polyester and phthalate plasticizers are preferably used. Polyester plasticizers are superior in non-migration and extraction resistance compared to phthalate ester plasticizers such as dioctyl phthalate. It can be applied to a wide range of uses by selecting or using these plasticizers according to the use.

The polyester plasticizer is a reaction product of a monovalent or tetravalent carboxylic acid and a monovalent or hexavalent alcohol, and is mainly obtained by reacting a divalent carboxylic acid with a glycol. . Representative divalent carboxylic acids include glutaric acid, itaconic acid, adipic acid, phthalic acid, azelaic acid, sebacic acid and the like. The polyester plasticizer is preferably an aromatic terminal ester plasticizer. The aromatic terminal ester plasticizer is preferably an ester compound having a structure obtained by reacting phthalic acid, adipic acid, at least one benzene monocarboxylic acid and at least one alkylene glycol having 2 to 12 carbon atoms. As long as it has an adipic acid residue and a phthalic acid residue as the structure of such a compound, when an ester compound is produced, it may be reacted as an acid anhydride or esterified product of dicarboxylic acid.

Examples of the benzene monocarboxylic acid component include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal propylbenzoic acid, aminobenzoic acid, acetoxybenzoic acid and the like. Most preferred is benzoic acid. Moreover, these can be used as a 1 type, or 2 or more types of mixture, respectively.

Examples of the alkylene glycol component having 2 to 12 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1, 3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol 1 , 6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1,3-hexanediol 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecane diol. Of these, 1,2-propylene glycol is particularly preferred. These glycols may be used as one kind or a mixture of two or more kinds.

The aromatic terminal ester plasticizer may be either an oligoester type or a polyester type, and the molecular weight is preferably in the range of 100 to 10,000, but is preferably in the range of 350 to 3000. The acid value is 1.5 mgKOH / g or less, the hydroxyl value is 25 mgKOH / g or less, more preferably the acid value is 0.5 mgKOH / g or less, and the hydroxyl value is 15 mgKOH / g or less.

The plasticizer is preferably added in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the base film. Specific examples include the following compounds (2-1 to 2-6, and 2-20 to 2-23), but are not limited thereto.

Furthermore, the base film may contain a sugar ester compound. The sugar ester compound is a compound obtained by esterifying all or part of the OH group of a sugar such as the following monosaccharide, disaccharide, trisaccharide or oligosaccharide. As a more specific example, a general formula (1) The compound etc. which are represented by these can be mention | raise | lifted.

(Wherein R ₁ to R ₈ represent a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms, or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, and R ₁ to R ₈ May be the same or different.)
The compounds represented by the general formula (1) are shown below in more detail (compound 1-1 to compound 1-23), but are not limited thereto.

The base film preferably contains an ultraviolet absorber, and examples of the ultraviolet absorber used include benzotriazole, 2-hydroxybenzophenone, and salicylic acid phenyl ester. For example, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3 Triazoles such as 5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone And benzophenones.

Among UV absorbers, UV absorbers with a molecular weight of 400 or more are difficult to volatilize at high boiling points and are difficult to disperse even during high temperature molding, so that the weather resistance can be effectively improved with a relatively small amount of addition. Can do.

Examples of the ultraviolet absorber having a molecular weight of 400 or more include 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole, 2,2-methylenebis [4- (1, 1,3,3-tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol], bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis ( Hindered amines such as 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid Bis (1,2,2,6,6-pentamethyl-4-piperidyl), 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] Such as til] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine A hybrid system having both structures can be mentioned, and these can be used alone or in combination of two or more. Among these, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole and 2,2-methylenebis [4- (1,1,3,3- Tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred.

These may be commercially available products, and for example, TINUVIN such as TINUVIN 109, TINUVIN 171, TINUVIN 234, TINUVIN 326, TINUVIN 327, TINUVIN 328, and TINUVIN 928 manufactured by BASF Japan Ltd. can be preferably used.

Furthermore, various antioxidants can be added to the base film in order to improve the thermal decomposability and thermal colorability during the molding process. It is also possible to add an antistatic agent to give the base film antistatic performance.

For the base film, a flame retardant acrylic resin composition containing a phosphorus flame retardant may be used. Phosphorus flame retardants used here include red phosphorus, triaryl phosphate ester, diaryl phosphate ester, monoaryl phosphate ester, aryl phosphonate compound, aryl phosphine oxide compound, condensed aryl phosphate ester, halogenated alkyl phosphorus. Examples thereof include one or a mixture of two or more selected from acid esters, halogen-containing condensed phosphates, halogen-containing condensed phosphonates, halogen-containing phosphites, and the like.

Specific examples include triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenylphosphonic acid, tris (β-chloroethyl) phosphate, tris (dichloropropyl) Examples thereof include phosphate and tris (tribromoneopentyl) phosphate. The base film is preferably a “film that does not cause ductile fracture”. Here, the ductile fracture is a fracture caused by applying a stress larger than the strength of a certain material, and is defined as a fracture accompanied by significant elongation or drawing of the material until the final fracture. The fracture surface is characterized by numerous indentations called dimples.

The base film is required to withstand use in a higher temperature environment, and the base film can be judged to exhibit sufficient heat resistance when the tension softening point is 105 ° C. to 145 ° C. 110 ° C. to 130 ° C. is particularly preferable.

As a specific method for measuring the tension softening point, for example, a Tensilon tester (ORIENTEC Co., RTC-1225A) is used to cut out the optical film at 120 mm (length) × 10 mm (width) and pull it with a tension of 10 N. However, the temperature can be continuously increased at a temperature increase rate of 30 ° C./min, and the temperature at 9 N can be measured three times, and the average value can be obtained.

The glass transition temperature referred to here is an intermediate value determined according to JIS K7121 (1987) using a differential scanning calorimeter (DSC-7 model manufactured by Perkin Elmer) at a heating rate of 20 ° C./min. Point glass transition temperature (Tmg).

When a substrate film is used as a protective film for a polarizing plate of a liquid crystal display device, unevenness or a change in retardation value occurs due to a dimensional change due to moisture absorption, causing problems such as a decrease in contrast and uneven color. In particular, the above problem becomes significant when the polarizing plate protective film is used in a liquid crystal display device used outdoors. For this reason, the dimensional change rate (%) is preferably less than 0.5%, and more preferably less than 0.3%. The base film preferably has a defect of 5 μm or more in diameter in the film plane of 1 piece / 10 cm square or less. More preferably, it is 0.5 piece / 10 cm square or less, more preferably 0.1 piece / 10 cm square or less. Here, the diameter of the defect indicates the diameter when the defect is circular, and when the defect is not circular, the range of the defect is determined by observing with a microscope by the following method, and the maximum diameter (diameter of circumscribed circle) is determined.

The range of the defect is the size of the shadow when the defect is observed with the transmitted light of the differential interference microscope when the defect is a bubble or a foreign object. When the defect is a change in the surface shape, such as transfer of a roll flaw or an abrasion, the size is confirmed by observing the defect with the reflected light of a differential interference microscope.

In addition, when observing with reflected light, if the size of the defect is not clear, aluminum or platinum is vapor-deposited on the surface for observation. In order to obtain a film having excellent quality expressed by such a defect frequency with high productivity, it is necessary to filter the polymer solution with high precision immediately before casting, to increase the cleanliness around the casting machine, It is effective to set drying conditions after rolling stepwise and to dry efficiently while suppressing foaming.

When the number of defects is more than 1/10 cm square, for example, when a tension is applied to the film during processing in a later process, the film may be broken with the defect as a starting point and productivity may be reduced. Moreover, when the diameter of a defect becomes 5 micrometers or more, it can confirm visually by polarizing plate observation etc., and when used as an optical member, a bright spot may arise.

Also, even when visual confirmation is not possible, when a hard coat layer or the like is formed on the film, the coating agent may not be formed uniformly, resulting in defects (coating defects). Here, the defect is a void in the film (foaming defect) generated due to the rapid evaporation of the solvent in the drying process of the solution casting, a foreign substance in the film forming stock solution, or a foreign substance mixed in the film forming process. This refers to the foreign matter (foreign matter defect) in the film.

Further, the base film preferably has a breaking elongation in at least one direction of 10% or more, more preferably 20% or more in the measurement based on JIS-K7127-1999.

The upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming.

The thickness of the base film is preferably 20 μm or more. More preferably, it is 30 μm or more.

The upper limit of the thickness is not particularly limited, but in the case of forming a film by a solution casting method, the upper limit is about 250 μm from the viewpoint of applicability, foaming, solvent drying, and the like. The thickness of the film can be appropriately selected depending on the application.

The base film preferably has a total light transmittance of 90% or more, more preferably 93% or more. Moreover, as a realistic upper limit, it is about 99%. In order to achieve excellent transparency expressed by such total light transmittance, it is necessary not to introduce additives and copolymerization components that absorb visible light, or to remove foreign substances in the polymer by high-precision filtration. It is effective to reduce the diffusion and absorption of light inside the film. Also, reduce the surface roughness of the film surface by reducing the surface roughness of the film contact part (cooling roll, calender roll, drum, belt, coating substrate in solution casting, transport roll, etc.) during film formation. It is also effective to reduce the diffusion and reflection of light on the film surface by reducing the refractive index of the acrylic resin.

(Formation of base film)
Next, although the example of the film forming method of a base film is demonstrated, it is not limited to this. As a method for forming the base film, a production method such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, a hot press method, or the like can be used.

From the viewpoint of suppressing the residual solvent using a cellulose ester resin or an acrylic resin for dissolution, a method of producing by a melt casting film forming method is preferable. Methods formed by melt casting can be classified into melt extrusion molding methods, press molding methods, inflation methods, injection molding methods, blow molding methods, stretch molding methods, and the like. Among these, the melt extrusion method is preferable, in which a film having excellent mechanical strength and surface accuracy can be obtained. From the viewpoints of suppressing coloring, suppressing defects of foreign matters, and suppressing optical defects such as die lines, solution casting by casting is preferred. Further, a method of extruding and forming a film forming material on a drum or an endless belt after the film forming material is heated to express its fluidity is also included as a melt casting film forming method.

[Organic solvent]
The organic solvent useful for forming the dope when the base film is produced by the solution casting method can be used without limitation as long as it dissolves acrylic resin, cellulose ester resin, and other additives at the same time. .

For example, as a chlorinated organic solvent, methylene chloride, as a non-chlorinated organic solvent, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro- 2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane, etc. Methylene chloride, methyl acetate, ethyl acetate and acetone can be preferably used.

In addition to the organic solvent, the dope preferably contains 1 to 40% by mass of a linear or branched aliphatic alcohol having 1 to 4 carbon atoms. When the proportion of alcohol in the dope increases, the web gels and peeling from the metal support becomes easy, and when the proportion of alcohol is small, the acrylic resin and cellulose ester resin dissolve in a non-chlorine organic solvent system. There is also a role to promote.

In particular, in a solvent containing methylene chloride and a linear or branched aliphatic alcohol having 1 to 4 carbon atoms, at least 15 to 45 mass in total of at least three kinds of acrylic resin, cellulose ester resin, and acrylic particles are used. It is preferable that the dope composition is dissolved in%.

Examples of the linear or branched aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Ethanol is preferred because of the stability of these dopes, the relatively low boiling point, and good drying properties.

[Solution casting method]
The base film can be produced by a solution casting method. In the solution casting method, a step of preparing a dope by dissolving a resin and an additive in a solvent, a step of casting the dope on a belt-like or drum-like metal support, and a step of drying the cast dope as a web , A step of peeling from the metal support, a step of stretching or maintaining the width, a step of further drying, and a step of winding up the finished film.

The concentration of cellulose ester in the dope, and the concentration of cellulose ester resin / acrylic resin is preferably higher because the drying load after casting on the metal support can be reduced. The load increases, and the filtration accuracy deteriorates. The concentration that achieves both of these is preferably 10 to 35% by mass, and more preferably 15 to 25% by mass. The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support.

The cast width can be 1 ~ 4m. The surface temperature of the metal support in the casting step is set to −50 ° C. to below the temperature at which the solvent boils and does not foam. A higher temperature is preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate.

A preferable support temperature is appropriately determined at 0 to 100 ° C., and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short.

When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. .

Particularly, it is preferable to efficiently dry by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

In order for the cellulose ester film to exhibit good flatness, the amount of residual solvent when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Particularly preferred is 20 to 30% by mass or 70 to 120% by mass.

The amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

Further, in the drying step of the cellulose ester film or the cellulose ester resin / acrylic resin film, it is preferable that the web is peeled off from the metal support and further dried to make the residual solvent amount 1% by mass or less, more preferably 0. 0.1 mass% or less, particularly preferably 0 to 0.01 mass% or less.

In the film drying process, generally, a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.

[Stretching process]
In the stretching step, the film can be sequentially or simultaneously stretched in the longitudinal direction (MD direction) and the width direction (TD direction) of the film. The draw ratios in the biaxial directions perpendicular to each other are preferably in the range of 1.0 to 2.0 times in the MD direction and 1.07 to 2.0 times in the TD direction, respectively. It is preferably performed in the range of 1.0 to 1.5 times and 1.07 to 2.0 times in the TD direction. For example, a method in which peripheral speed differences are applied to a plurality of rolls and a roll peripheral speed difference is used to stretch in the MD direction, both ends of the web are fixed with clips and pins, and the distance between the clips and pins is increased in the traveling direction. And a method of stretching in the MD direction, a method of stretching in the transverse direction and stretching in the TD direction, a method of stretching in the MD / TD direction simultaneously and stretching in both the MD / TD directions, and the like.

It is preferable to perform the width maintenance or the stretching in the width direction in the film forming process by a tenter, and it may be a pin tenter or a clip tenter.

The film transport tension in the film forming process such as in the tenter depends on the temperature, but is preferably 120 N / m to 200 N / m, and more preferably 140 N / m to 200 N / m. 140 N / m to 160 N / m is most preferable.

When stretching, assuming that the glass transition temperature of the substrate film is Tg, (Tg-30) to (Tg + 100) ° C., more preferably (Tg-20) to (Tg + 80) ° C., and more preferably (Tg-5) to (T Tg + 20) ° C.

The Tg of the base film can be controlled by the type of material constituting the film and the ratio of the constituting materials. In the application of the present invention, the Tg when the film is dried is preferably 110 ° C. or higher, more preferably 120 ° C. or higher. Especially preferably, it is 150 degreeC or more.

Therefore, the glass transition temperature is preferably 190 ° C. or lower, more preferably 170 ° C. or lower. At this time, the Tg of the film can be determined by the method described in JIS K7121.

When the stretching temperature is 150 ° C. or more and the stretching ratio is 1.15 times or more, the surface is preferably roughened. Roughening the film surface is preferable because it improves not only the slipperiness but also the surface processability, particularly the adhesion of the antiglare layer.

[Melting method]
The base film may be formed by a melt film forming method. The melt film-forming method refers to heating and melting a composition containing an additive such as a resin and a plasticizer to a temperature exhibiting fluidity, and then casting a melt containing a fluid cellulose ester.

The molding method for heating and melting can be further classified into a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, a stretch molding method, and the like. Among these molding methods, the melt extrusion method is preferable from the viewpoint of mechanical strength and surface accuracy. It is preferable that a plurality of raw materials used for melt extrusion are usually kneaded in advance and pelletized.

Pelletization may be performed by a known method. For example, dry cellulose ester, plasticizer, and other additives are fed to an extruder with a feeder and kneaded using a single-screw or twin-screw extruder, and formed into a strand from a die. It can be done by extrusion, water cooling or air cooling and cutting.

Additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.

A small amount of additives such as particles and antioxidants are preferably mixed in advance in order to mix uniformly.

The extruder is preferably processed at as low a temperature as possible so that it can be pelletized so as to suppress the shearing force and prevent the resin from deteriorating (molecular weight reduction, coloring, gel formation, etc.). For example, in the case of a twin screw extruder, it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.

Film formation is performed using the pellets obtained as described above. Of course, the raw material powder can be directly fed to the extruder by a feeder without being pelletized to form a film as it is.

Using a single-screw or twin-screw type extruder, the melting temperature at the time of extrusion is about 200 to 300 ° C, filtered through a leaf disk type filter, etc. to remove foreign matter, and then formed into a film from the T die. The film is nipped by a cooling roll and an elastic touch roll, and solidified on the cooling roll.

When introducing from the supply hopper to the extruder, it is preferable to prevent oxidative decomposition or the like under vacuum or reduced pressure or in an inert gas atmosphere.

The extrusion flow rate is preferably carried out stably by introducing a gear pump. Further, a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances. The stainless steel fiber sintered filter is a united stainless steel fiber body that is intricately intertwined and compressed, and the contact points are sintered and integrated. The density of the fiber is changed depending on the thickness of the fiber and the amount of compression, and the filtration accuracy is improved. Can be adjusted.

Additives such as plasticizers and particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.

The film temperature on the touch roll side when the film is nipped by the cooling roll and the elastic touch roll is preferably Tg or more and Tg + 110 ° C. or less of the film. A well-known roll can be used for the roll which has the elastic body surface used for such a purpose.

The elastic touch roll is also called a pinching rotator. As the elastic touch roll, a commercially available one can be used.

When peeling the film from the cooling roll, it is preferable to control the tension to prevent deformation of the film.

Moreover, it is preferable that the film obtained as described above is stretched by the stretching operation after passing through the step of contacting the cooling roll.

As the stretching method, a known roll stretching machine or tenter can be preferably used. The stretching temperature is usually preferably in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.

Before winding, the end may be slit and cut to the product width, and knurled (embossed) may be applied to both ends to prevent sticking or scratching during winding. The knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing. In addition, since the film has deform | transformed and cannot use as a product normally, the holding | grip part of the clip of both ends of a film is cut out and reused.

(Physical properties of base film)
The film thickness of the substrate film in the present embodiment is not particularly limited, but 10 to 200 μm is used. In particular, the film thickness is particularly preferably 10 to 100 μm. More preferably, it is 20 to 60 μm.

The base film according to the present invention has a width of 1 to 4 m. Particularly, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.6 to 3 m. If it exceeds 4 m, conveyance becomes difficult.

In addition, the arithmetic average roughness Ra of the base film is preferably 2.0 nm to 4.0 nm, more preferably 2.5 nm to 3.5 nm.

<Functional layer>
The antiglare film according to the present invention can be provided with functional layers such as a backcoat layer and an antireflection layer.

(Back coat layer)
The antiglare film according to the present invention is a back coat for preventing sticking when a curl or antiglare film is stored in a roll on the surface opposite to the side on which the antiglare layer of the base film is provided. A layer may be provided.

The back coat layer preferably contains fine particles for the above purpose, and the fine particles include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined silicic acid. Mention may be made of calcium, tin oxide, indium oxide, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Moreover, it is preferable to contain a solvent in order to disperse the fine particles and to dissolve a binder described later to form a coating composition. As the solvent, the solvent described in the functional layer is preferable. The particles contained in the back coat layer are preferably 0.1 to 50% by mass with respect to the binder. When the back coat layer is provided, the increase in haze is preferably 1.5% or less, and 0.5% or less. In addition, it is preferable to use a cellulose ester resin such as diacetyl cellulose as the binder.

(Antireflection layer)
The antiglare film according to the present invention can be used as an antireflection film having an external light antireflection function by coating an antireflection layer on the antiglare layer.

The antireflection layer is preferably laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced by optical interference. The antireflection layer is preferably composed of a low refractive index layer having a refractive index lower than that of the support, or a combination of a high refractive index layer having a refractive index higher than that of the support and a low refractive index layer. Particularly preferably, it is an antireflection layer composed of three or more refractive index layers, and three layers having different refractive indexes from the support side are divided into medium refractive index layers (high refractive index layers having a higher refractive index than the support). Are preferably laminated in the order of a layer having a lower refractive index) / a high refractive index layer / a low refractive index layer. Alternatively, an antireflection layer having a layer structure of four or more layers in which two or more high refractive index layers and two or more low refractive index layers are alternately laminated is also preferably used. As the layer structure of the antireflection film, the following structure is conceivable, but is not limited thereto.

Base film / Anti-glare layer / Low refractive index layer Base film / Anti-glare layer / Medium refractive index layer / Low refractive index layer Base film / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index Layer Base film / Anti-glare layer / High refractive index layer (conductive layer) / Low refractive index layer (Low refractive index layer)
The low refractive index layer essential for the antireflection film preferably contains silica-based fine particles, and the refractive index is lower than the refractive index of the substrate film as a support, measured at 23 ° C. and a wavelength of 550 nm. The range of 1.30 to 1.45 is preferable.

The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and most preferably 30 nm to 0.2 μm.

The composition for forming a low refractive index layer preferably contains at least one kind of particles having an outer shell layer and porous or hollow inside as silica-based fine particles. In particular, the particles having the outer shell layer and having a porous or hollow interior are preferably hollow silica-based fine particles.

Note that the composition for forming a low refractive index layer may contain an organosilicon compound represented by the following general formula (OSi-1), a hydrolyzate thereof, or a polycondensate thereof.

General formula (OSi-1): Si (OR) ₄
In the organosilicon compound represented by the above general formula, R represents an alkyl group having 1 to 4 carbon atoms. Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

In addition, a solvent, and if necessary, a silane coupling agent, a curing agent, a surfactant and the like may be added.

(High refractive index layer)
The refractive index of the high refractive index layer is preferably adjusted to a range of 1.4 to 2.2 by measuring at 23 ° C. and a wavelength of 550 nm. The thickness of the high refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm. The means for adjusting the refractive index can be achieved by adding metal oxide fine particles and the like. Metal oxide The metal oxide fine particles used preferably have a refractive index of 1.80 to 2.60, more preferably 1.85 to 2.50.

The kind of metal oxide fine particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one element selected from the group consisting of Al, In, Sn, Sb, Nb, a halogen element, Ta and the like is doped with a minute amount of atoms. May be. A mixture of these may also be used. In the present invention, at least one metal oxide fine particle selected from among zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium tin oxide (ITO), antimony doped tin oxide (ATO), and zinc antimonate is used. It is particularly preferable to use it as the main component. In particular, it is preferable to contain zinc antimonate particles.

The average particle diameter of the primary particles of these metal oxide fine particles is in the range of 10 nm to 200 nm, and is particularly preferably 10 to 150 nm. The average particle diameter of the metal oxide fine particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc. If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased. The shape of the metal oxide fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

The metal oxide fine particles may be surface-treated with an organic compound. By modifying the surface of the metal oxide fine particles with an organic compound, the dispersion stability in an organic solvent is improved, the dispersion particle size can be easily controlled, and aggregation and sedimentation over time can be suppressed. . Therefore, the amount of surface modification with a preferable organic compound is 0.1% by mass to 5% by mass, more preferably 0.5% by mass to 3% by mass with respect to the metal oxide particles. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Of these, silane coupling agents are preferred. Two or more kinds of surface treatments may be combined. The high refractive index layer may contain a π-conjugated conductive polymer. The π-conjugated conductive polymer can be used as long as it is an organic polymer having a main chain composed of a π-conjugated system. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylenes, polyacetylenes, polyphenylene vinylenes, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of ease of polymerization and stability, polythiophenes, polyanilines, and polyacetylenes are preferable.

The π-conjugated conductive polymer can provide sufficient conductivity and solubility in a binder resin even if it is not substituted, but in order to further improve conductivity and solubility, an alkyl group, a carboxy group, a sulfo group, an alkoxy group. A functional group such as a group, a hydroxy group, or a cyano group may be introduced.

Moreover, you may contain an ionic compound. Examples of the ionic compound include imidazolium-based, pyridium-based, alicyclic amine-based, aliphatic amine-based, aliphatic phosphonium-based cations and inorganic ion-based compounds such as BF ₄ ⁻ and PF ₆ ⁻ , CF ₃ SO ₂ ^{−, and the like.} , (CF ₃ SO ₂ ) ₂ N ⁻ , CF ₃ CO ₂ ^—, etc. The ratio of the polymer to the binder is preferably 10 to 400 parts by mass with respect to 100 parts by mass of the polymer, and particularly preferably 100 to 200 parts by mass of the binder with respect to 100 parts by mass of the polymer.

<Polarizing plate>
The polarizing plate of the present invention using the antiglare film according to the present invention will be described. The polarizing plate can be produced by a general method. The back surface side of the antiglare film according to the present invention is subjected to alkali saponification treatment, and a fully saponified polyvinyl alcohol aqueous solution is formed on at least one surface of a polarizing film prepared by immersing and stretching the treated antiglare film in an iodine solution. It is preferable to stick together.

The antiglare film may be used on the other surface, or another polarizing plate protective film may be used. The polarizing plate protective film used on the other surface of the antiglare film according to the present invention contains the cellulose triacetate film or thermoplastic acrylic resin and cellulose ester resin as the base film described above, and the heat It is preferable to use a protective film in which the mass ratio of the plastic acrylic resin to the cellulose ester resin is thermoplastic acrylic resin: cellulose ester resin = 95: 5 to 50:50. Details of the configuration are as described above, and specific examples include a non-oriented film having a retardation Ro of 590 nm and 0 to 5 nm and an Rt of −20 to +20 nm.

In addition, an optical compensation film (retardation film) having a retardation of in-plane retardation Ro of 590 nm, 20 to 70 nm, and Rt of 70 to 400 nm may be used to obtain a polarizing plate capable of widening the viewing angle. it can. Alternatively, it is preferable to use an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal. Also, commercially available polarizing plate protective films preferably used include KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-2, KC4FR-2, KC4FR-2, KC8FR-2 KC4UE (Konica Minolta Opto Co., Ltd.) etc. are mentioned.

The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are ones in which iodine is dyed on a system film and ones in which a dichroic dye is dyed, but it is not limited to this. As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. A polarizing film having a thickness of 5 to 30 μm, preferably 8 to 15 μm is preferably used.

On the surface of the polarizing film, one side of the antiglare film according to the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

(Adhesive layer)
The pressure-sensitive adhesive layer used on one side of the protective film to be bonded to the substrate of the liquid crystal cell is preferably optically transparent and exhibits moderate viscoelasticity and adhesive properties.

Specific examples of the adhesive layer include adhesives or adhesives such as acrylic copolymers, epoxy resins, polyurethane, silicone polymers, polyethers, butyral resins, polyamide resins, polyvinyl alcohol resins, and synthetic rubbers. A film such as a drying method, a chemical curing method, a thermal curing method, a thermal melting method, a photocuring method, or the like can be formed and cured using a polymer such as the above. Among them, the acrylic copolymer can be preferably used because it is most easy to control the physical properties of the adhesive and is excellent in transparency, weather resistance, durability and the like.

<Liquid crystal display device>
By incorporating the polarizing plate of the present invention produced using the antiglare film according to the present invention into a display device, various liquid crystal display devices having excellent visibility can be produced.

The antiglare film according to the present invention is incorporated in a polarizing plate, and is a reflective type, transmissive type, transflective liquid crystal display device or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), It is preferably used in liquid crystal display devices of various driving systems such as IPS type and OCB type. FIG. 8 shows a liquid crystal cell of a liquid crystal display device according to an embodiment of the present invention. By having the polarizing plate of the present invention in at least one of the liquid crystal cells, a liquid crystal display device excellent in visibility can be provided. Furthermore, as shown in FIG. 7, it is excellent in preventing the occurrence of moire fringes when used on the rear side (backlight side) of the liquid crystal cell of the liquid crystal display device.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
<Preparation of base film 1>
(Preparation of ester compound 1)
251 g of 1,2-propylene glycol, 278 g of phthalic anhydride, 91 g of adipic acid, 610 g of benzoic acid, 0.191 g of tetraisopropyl titanate as an esterification catalyst, 2 L four-neck equipped with thermometer, stirrer, and slow cooling tube The flask is charged and gradually heated with stirring until it reaches 230 ° C. in a nitrogen stream. The ester compound 1 was obtained by carrying out a dehydration condensation reaction for 15 hours, and distilling off unreacted 1,2-propylene glycol under reduced pressure at 200 ° C. after completion of the reaction. The acid value was 0.10 mg KOH / g, and the number average molecular weight was 450.

(Preparation of silicon dioxide dispersion)
Aerosil R812 (manufactured by Nippon Aerosil Co., Ltd., average particle size of primary particles: 7 nm) 10 parts by mass / ethanol 90 parts by mass The above was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred and mixed for 30 minutes with a dissolver to prepare a silicon dioxide dispersion dilution. The mixture was filtered with a fine particle dispersion dilution filter (Advantech Toyo Co., Ltd .: polypropylene wind cartridge filter TCW-PPS-1N).

<Preparation of base film 1>
(Dope composition)
・ 90 parts by mass of cellulose triacetate A1 (cellulose triacetate synthesized from linter cotton, acetyl group substitution degree 2.88, Mn = 14000)
-Ester compound 1 10 parts by mass-Tinuvin 928 (manufactured by BASF Japan Ltd.) 2.5 parts by mass-Silicon dioxide dispersion diluent 4 parts by mass-Methylene chloride 432 parts by mass-Ethanol 38 parts by mass The solution was completely dissolved while being heated and stirred, and Azumi Filter Paper No. No. 24 was used for filtration to prepare a dope solution.

Next, the belt was cast evenly on a stainless steel band support using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the residual solvent amount reached 100%, and the stainless steel band support was peeled off. The cellulose ester film web was evaporated at 35 ° C., slit to 1.65 m width, and stretched 1.3 times in the TD direction (film width direction) with a tenter, and the MD direction draw ratio was 1.01 times. While stretching, the film was dried at a drying temperature of 160 ° C. The residual solvent amount at the start of drying was 20%. Then, after drying for 15 minutes while transporting the inside of a drying device at 120 ° C. with a number of rolls, slitting to a width of 1.49 m, applying a knurling process with a width of 15 mm and a height of 10 μm at both ends of the film, and winding it around a winding core The base film 1 was obtained. The residual solvent amount of the base film was 0.2%, the film thickness was 40 μm, and the number of turns was 3900 m.

<Preparation of antiglare film 1>
The following anti-glare layer composition 1 filtered through a polypropylene filter having a pore diameter of 0.4 μm is applied on the base film 1 produced above using an extrusion coater, and a constant rate drying zone temperature of 95 ° C., a reduced rate drying zone temperature. After drying at 95 ° C., while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less, using an ultraviolet lamp, the illuminance of the irradiated part is 100 mW / cm ² and the irradiation amount is 0.25 J / cm ^2. The coating layer was cured to form an antiglare layer having a dry film thickness of 6 μm. After forming the antiglare layer, it was wound up to produce an antiglare film 1. As a result of observing the surface of the antiglare layer of the antiglare film 1 with an optical interference surface roughness meter (New View 5030, manufactured by Zygo Corporation), irregular projection shapes irregularly in the longitudinal direction and the width direction as shown in FIG. It was found that they are arranged in

[Anti-glare layer composition 1]
The following antiglare layer composition 1 was stirred and mixed with a disper to obtain an antiglare layer composition 1.

<Preparation of fluorine-siloxane graft compound>
The commercial name of the material used for the preparation of the fluorine-siloxane graft compound is shown.
Radical polymerizable fluororesin (A): Cephalal coated CF-803 (hydroxyl value 60, average molecular weight 15,000; manufactured by Central Glass Co., Ltd.)
Single-end radical polymerizable polysiloxane (B): Silaplane FM-0721
(Number average molecular weight 5,000; manufactured by Chisso Corporation)
・ Radical polymerization initiator: Perbutyl O (t-butylperoxy-2-ethylhexanoate; manufactured by NOF Corporation)
Curing agent: Sumidur N3200 (hexuremethylene diisocyanate biuret type prepolymer; manufactured by Sumika Bayer Urethane Co., Ltd.)
(Synthesis of radical polymerizable fluororesin)
A glass reactor equipped with a mechanical stirrer, a thermometer, a condenser and a dry nitrogen gas inlet was added to cefal coat CF-803 (1554 parts by mass), xylene (233 parts by mass), and 2-isocyanatoethyl methacrylate (6 3 parts by mass) and heated to 80 ° C. in a dry nitrogen atmosphere. After reacting at 80 ° C. for 2 hours and confirming that the absorption of isocyanate disappeared by the infrared absorption spectrum of the sampled material, the reaction mixture was taken out to obtain 50% by mass of a radically polymerizable fluororesin via a urethane bond. .

(Preparation of fluorine-siloxane graft compound)
In a glass reactor equipped with a mechanical stirrer, thermometer, condenser and dry nitrogen gas inlet, the above synthesized radical polymerizable fluororesin (26.1 parts by mass), xylene (19.5 parts by mass), acetic acid n-butyl (16.3 parts by mass), methyl methacrylate (2.4 parts by mass), n-butyl methacrylate (1.8 parts by mass), lauryl methacrylate (1.8 parts by mass), 2-hydroxyethyl methacrylate (1 8 parts by mass), FM-0721 (5.2 parts by mass), and perbutyl O (0.1 parts by mass) were heated to 90 ° C. in a nitrogen atmosphere, and held at 90 ° C. for 2 hours. Perbutyl O (0.1 part) was added, and the mixture was further maintained at 90 ° C. for 5 hours to obtain a 35 mass% fluorine-siloxane graft compound solution having a weight average molecular weight of 171,000. The weight average molecular weight was determined by GPC. The mass% of the fluorine-siloxane graft compound was determined by HPLC (liquid chromatography).
(Actinic radiation curable resin)
・ Pentaerythritol tri / tetraacrylate 90 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ 10 parts by mass of 4-hydroxybutyl acrylate (manufactured by Nippon Kasei Kogyo Co., Ltd.)
(Photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 5 parts by mass (leveling agent)
・ Fluoro-siloxane graft compound (35% by mass) 2 parts by mass (solvent)
-Propylene glycol monomethyl ether 10 parts by mass-Methyl acetate 55 parts by mass-Methyl ethyl ketone 55 parts by mass Only the actinic radiation curable resin of the above antiglare layer composition 1 is stirred and mixed with a disper, and B-type at 25 ° C. When measured using a viscometer, the resin viscosity was 440 mPa · s.

<Preparation of antiglare films 2 to 8>
Antiglare films 2 to 8 were produced in the same manner as the antiglare film 1 except that the conditions for changing the temperature of the decreasing rate drying section were changed as shown in Table 1 in the production of the antiglare film 1.

<Preparation of antiglare film 9>
In the production of the antiglare film 1, the antiglare layer composition 1 was changed to the following antiglare layer composition 2 and the temperature of the decreasing rate drying section in the drying step was changed to 100 ° C. in the same manner. Film 9 was produced.

[Anti-glare layer composition 2]
The following antiglare layer composition 2 was stirred and mixed with a disper to obtain an antiglare layer composition 2.
(Actinic radiation curable resin)
・ 70 parts by mass of ditrimethylolpropane tetraacrylate (NK ester AD-TMP, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-30 parts by mass of ethoxylated pentaerythritol tetraacrylate (NK ester ATM-35E, manufactured by Shin-Nakamura Chemical Co., Ltd.)
(Photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 5 parts by mass (leveling agent)
・ Fluoro-siloxane graft compound (35% by mass) 2 parts by mass (solvent)
-Propylene glycol monomethyl ether 10 parts by mass-Methyl acetate 55 parts by mass-Methyl ethyl ketone 55 parts by mass Only the actinic radiation curable resin of the above antiglare layer composition 2 is stirred and mixed with a disper, and the type B is obtained at 25 ° C. When measured using a viscometer, the resin viscosity was 800 mPa · s.

<Preparation of antiglare films 10 to 15>
Antiglare films 10 to 15 were produced in the same manner as in the antiglare film 7 except that the conditions for changing the temperature of the decreasing rate drying section in the production of the antiglare film 7 were changed as shown in Table 1.

<Preparation of antiglare film 16>
In the production of the antiglare film 7, the antiglare layer composition 2 was changed to the antiglare layer composition 3 prepared with reference to Example 1 of JP-A-2006-106290, and the drying temperature was further changed to JP-A-2006. An antiglare layer was produced in the same manner except that the temperature was set at 70 ° C. as in Example 1 of JP-106290A. Next, using an extrusion coater on the antiglare layer, a thermosetting fluorine-containing compound coating solution (manufactured by Nissan Chemical Co., Ltd., LR-202B, solid content 1 mass%) is dried to a film thickness of 100 nm. Then, it was cured by drying at 90 ° C. for 5 minutes to produce an antiglare film 16.

[Anti-glare layer composition 3]
The following antiglare layer composition 3 was stirred and mixed with a disper to obtain an antiglare layer composition 3.
(Actinic radiation curable resin)
Cyclomer P (ACA) 320 (unsaturated group-containing acrylic resin mixture,
Daicel Chemical Industries, Ltd.) 5.04 parts by mass Dipentaerythritol hexaacrylate (DPHA, manufactured by Daicel Cytec Co., Ltd.) 6.4 parts by mass (incompatible resin)
Cellulose acetate propionate (CAP-482-20,
0.9 parts by mass (photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 0.2 parts by mass (solvent)
-Methyl ethyl ketone 20 parts by mass-Cyclohexanone 5 parts by mass Only the actinic radiation curable resin of the antiglare layer composition 3 was stirred and mixed with a disper and measured using a B-type viscometer at 25 ° C. The resin viscosity was 10600 mPa · s. In Table 1, cellulose acetate propionate is indicated as CAP.

<Preparation of antiglare film 17>
In the production of the antiglare film 7, the antiglare layer composition 2 was changed to the antiglare layer composition 4 prepared with reference to Example 1 of JP2008-225195A, and the drying temperature was changed to JP2008. An antiglare film 17 was produced in the same manner as the antiglare film 1 except that the temperature was set to 70 ° C., which was the same as that in Example 1 of the -225195 publication.

[Anti-Glare Layer Composition 4]
The following antiglare layer composition 4 was stirred and mixed with a disper to obtain an antiglare layer composition 4.
(Actinic radiation curable resin)
Cyclomer P (ACA) 320 (unsaturated group-containing acrylic resin mixture,
Daicel Chemical Industries, Ltd.) 5.65 parts by mass / dipentaerythritol hexaacrylate (DPHA,
6.3 parts by mass (incompatible resin)
Polymethyl methacrylate (weight average molecular weight 480000; manufactured by Mitsubishi Rayon Co., Ltd., BR88) 0.9 part by mass (photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 0.5 parts by mass (solvent)
・ Methyl ethyl ketone 0.1 mass part ・ 1-butanol 5.4 mass parts ・ 1-methoxy-2-propanol 1.89 mass parts Only the actinic radiation curable resin of the antiglare layer composition 4 is stirred and mixed with a disper. The resin viscosity was 10500 mPa · s when measured using a B-type viscometer at 25 ° C. In Table 1, polymethyl methacrylate was shown as PMMA.

<Preparation of antiglare film 18>
In the production of the antiglare film 7, the antiglare layer composition 2 was changed to the antiglare layer composition 5 prepared with reference to Example 3 of JP-A-2007-58204, and the drying temperature was further changed to JP-A-2007. An antiglare film 18 was produced in the same manner as the antiglare film 1 except that the temperature was changed to 80 ° C., which was the same as that in Example 3 of the -58204 publication.

[Anti-Glare Layer Composition 5]
The following antiglare layer composition 5 was stirred and mixed with a disper to obtain an antiglare layer composition 5.
(Actinic radiation curable resin)
・ Dipentaerythritol hexaacrylate (DPHA, Daicel)
Cytec Co., Ltd.) 92 parts by mass (incompatible resin)
-Methacrylate copolymer (Saftmer ST3600, Mitsubishi Chemical Corporation 15 parts by mass (photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 4 parts by mass (solvent)
-Ethanol 45 parts by mass-Toluene 15 parts by mass Only the actinic radiation curable resin of the antiglare layer composition 5 was stirred and mixed with a disper and measured using a B-type viscometer at 25 ° C. The resin viscosity was 6000 mPa · s. In Table 1, the methacrylate copolymer was indicated as MACP.

<Preparation of antiglare film 19>
An uneven roll was produced with reference to Example 1 of JP-A-2006-53371. Next, referring to Example 1 of Japanese Patent Application Laid-Open No. 2006-53371, the antiglare layer composition 1 is applied on the base film 1 and then dried at 60 ° C. Further, the surface of the antiglare layer is uneven. Was pressed to bring the antiglare layer and the roll into close contact. In this close contact state, while purging with nitrogen so that the oxygen concentration is 1.0 volume% or less, the illuminance of the irradiated part is 100 mW / cm ² and the irradiation amount is 0.25 J / cm ² using an ultraviolet lamp. The coating layer was cured to form an antiglare layer having a dry film thickness of 6 μm. After forming the antiglare layer, it was wound up to produce an antiglare film 19.

<Preparation of antiglare film 20>
In the production of the anti-glare film 1, the anti-glare film 20 was changed in the same manner except that the anti-glare layer composition 1 was changed to the following anti-glare layer composition 6 and the temperature at which the drying rate was decreased to 110 ° C. Was made.

[Anti-Glare Layer Composition 6]
The following antiglare layer composition 6 was stirred and mixed with a disper to obtain an antiglare layer composition 6.
(Actinic radiation curable resin)
・ 80 parts by mass of pentaerythritol tri / tetraacrylate (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-Isocyanuric acid EO-modified diacrylate 20 parts by mass (Aronix M-215, manufactured by Toagosei Co., Ltd.)
(Photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 5 parts by mass (leveling agent)
・ Fluoro-siloxane graft compound (35% by mass) 2 parts by mass (solvent)
-Propylene glycol monomethyl ether 10 parts by mass-Methyl acetate 55 parts by mass-Methyl ethyl ketone 55 parts by mass <Preparation of antiglare film 21>
In the production of the antiglare film 1, the antiglare film 21 was changed in the same manner except that the antiglare layer composition 1 was changed to the following antiglare layer layer composition 7 and the temperature at which the rate of decrease drying zone was changed to 110 ° C. Was made.

[Anti-Glare Layer Composition 7]
The following antiglare layer composition 7 was stirred and mixed with a disper to obtain an antiglare layer composition 7.
(Actinic radiation curable resin)
・ 80 parts by mass of trimethylolpropane triacrylate (Light acrylate TMP-A, manufactured by Kyoeisha Chemical Co., Ltd.)
・ 20 parts by mass of 4-hydroxybutyl acrylate (4-HBA, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
(Photopolymerization initiator)
・ Irgacure 184 (manufactured by BASF Japan) 5 parts by mass (leveling agent)
・ Fluoro-siloxane graft compound (35% by mass) 2 parts by mass (solvent)
・ Propylene glycol monomethyl ether 10 mass parts ・ Methyl acetate 55 mass parts ・ Methyl ethyl ketone 55 mass parts (Evaluation of antiglare film)
For the obtained antiglare films 1 to 21, the following items were evaluated. The results are shown in Table 1.
a. Internal haze measurement The internal haze (Hi) of the antiglare films 1 to 21 produced above was measured by the following measurement. The obtained results are shown in Table 1.
(Internal haze measurement method)
A few drops of silicone oil were dropped on the front and back surfaces of the antiglare film. Next, the antiglare film to which silicone oil was dropped was sandwiched between two glass plates (micro slide glass product number S 9111, manufactured by MATSUNAMI) having a thickness of 1 mm from the front and back, and the resulting antiglare property was obtained with two glass plates. The film was optically adhered. The haze (Ha) of this optically adhered sample from which surface haze was removed was measured. Next, glass haze (Hb) was measured by sandwiching only silicone oil between two glass plates. Hb was subtracted from Ha, and the internal haze (Hi) of the antiglare film was calculated.
b. Arithmetic Average Roughness Ra Measurement The arithmetic average roughness Ra of the antiglare layers of the antiglare films 1 to 21 produced above was measured 10 times using an optical interference surface roughness meter (RST / PLUS, manufactured by WYKO). The arithmetic average roughness Ra of each antiglare film was determined from the average of the measurement results.

<Weather resistance test>
The antiglare films 1 to 21 produced above were cut out in a size of 10 cm × 10 cm, stored for 100 hours in an environment of ozone 10 ppm, 30 ° C., 60% RH, assuming outdoor use, and cycle thermo (− 500 cycles were carried out at 40 ° C. for 45 minutes and then 110 ° C. for 45 minutes alternately, and further irradiated with light for 165 hours with a light resistance tester (I Super UV Tester, manufactured by Iwasaki Electric Co., Ltd.). The antiglare film after the weather resistance test was evaluated for scratch resistance, chemical resistance, antiglare property and contrast. The obtained results are shown in Table 1.

b. Scratch resistance The steel anti-glare layer surface of the anti-glare film after the durability test was applied 10 times on a steel wool (SW) of No. 0000 manufactured by Nippon Steel Wool Co., Ltd. under a load of 1000 g / cm ^2. did. The number of scratches generated per 1 cm width after 10 reciprocations was measured, and the scratch resistance was evaluated according to the following criteria. The number of scratches is preferably 10 / cm width or less from the practical viewpoint, and particularly preferably 5 / cm width or less. The obtained results are shown in Table 1 below. In addition, the apparatus which reciprocated steel wool used the Shinto Kagaku Co., Ltd. friction abrasion tester (Tribo station TYPE: 32, moving speed 1000mm / min.).

Number of scratches ◎: 5 / cm width or less ○: 6-10 / cm width △: 10-20 / cm width ×: 21 / cm width or more c. Chemical resistance The surface of the antiglare layer of the antiglare film after the durability test was subjected to a load of 1000 g / kg using Bencot (product name M-3, manufactured by Asahi Kasei Co., Ltd.) impregnated with 0.1N potassium hydroxide aqueous solution. over cm ^2, it was rubbed back and forth 20 times the same place. Further, with a Bencot soaked with a 10% by mass sulfuric acid aqueous solution, a load of 1000 g / cm ² was applied and the same portion was rubbed 20 times. The state after rubbing with these alkalis and acids was observed and evaluated according to the following criteria. The following apparatus was used for surface rubbing.
Surface rubbing apparatus; Shinto Kagaku Co., Ltd. friction and wear tester (Tribo Station TYPE: 32, moving speed 4000 mm / min.)
(Evaluation criteria)
◎: No peeling ○: Level where slight peeling is seen (no problem in practical use)
Δ: Peeling is observed ×: All rubbed parts are peeled off.

d. Antiglare property The antiglare property of the antiglare film after the durability test was evaluated by visual sensory evaluation. Judgment criteria are as follows.

◎: The outline of the fluorescent lamp is slightly recognized but is not bothering ○: The outline of the fluorescent lamp is recognized but acceptable △: The outline of the fluorescent lamp is known and the reflection is recognized ×: The outline of the fluorescent lamp is clear I understand and am concerned about the reflection e. Contrast (high definition)
A sample was placed on the color filter, and observed with an optical microscope by transmitted light from the back surface (color filter side), and the clearness of the contour of the image was visually evaluated. FIG. 4 shows an outline of the apparatus, and FIG. 5 shows an actual observation example. Judgment criteria are as follows.

○: The outline of the color filter looks clear Δ: The outline of the color filter is blurred ×: The outline of the color filter is clearly blurred Level that sharpness deteriorates in high-definition real images

As can be seen from the results in Table 1, the antiglare film of the present invention in which the arithmetic average roughness Ra of the antiglare layer is 25 to 300 nm and the internal haze of the antiglare layer is 0 to 1.0% is weather resistant. Even after testing, the film has excellent film strength such as scratch resistance and chemical resistance, and excellent optical properties such as antiglare and contrast. Among them, the antiglare film of the present invention having an arithmetic average roughness Ra of 25 to 130 nm has good film strength, and the antiglare film of the present invention having an arithmetic average roughness Ra of 65 to 130 nm is It can be seen that the film has particularly excellent film strength. Further, an antiglare layer containing an actinic radiation curable resin having a viscosity at 25 ° C. in the range of 30 to 2500 mPa · s is formed through at least a coating step, a drying step and a curing step, and the drying step By processing under the condition of maintaining the temperature of the decreasing rate drying section in the range of 90 to 140 ° C., the arithmetic average roughness Ra and the internal haze of the antiglare layer can be easily controlled within the range of the present invention, And since the objective effect of this invention is acquired favorably, it turns out that it is preferable. In addition, the antiglare layer of the antiglare film of the present invention does not substantially contain an incompatible resin with respect to fine particles or actinic radiation curable resin, and the above characteristics are obtained. It is preferable that the anti-glare layer of the dazzling film does not substantially contain an incompatible resin with respect to the fine particles and the actinic radiation curable resin.

Example 2
In preparation of the anti-glare film 1, the cellulose triacetate A1 and the ester compound 1 of the base film 1 were changed as described in Table 2 to prepare base films 2 and 3. Next, anti-glare films 22 and 23 were produced in the same manner except that an anti-glare layer was provided on these substrates. The cellulose triacetate B1 shown in Table 2 has an acetyl substitution degree of 2.85 and a number average molecular weight of 120,000. The ester compound B is a compound synthesized by the following method. Further, tan δ in the width direction of the base films 1 to 3 was measured by the following method.

<Synthesis of ester compound B>
251 g of 1,2-propylene glycol, 370 g of adipic acid, 122 g of benzoic acid, and 0.09 g of tetraisopropyl titanate as an esterification catalyst were charged into a 2 L four-necked flask equipped with a thermometer, a stirrer, and a quick cooling tube. The temperature is gradually raised with stirring until it reaches 230 ° C. in an air stream. Ester compound B was obtained by carrying out dehydration condensation reaction for 15 hours, and distilling off unreacted 1,2-propylene glycol under reduced pressure at 200 ° C. after completion of the reaction. The acid value was 0.55 and the number average molecular weight was 500.

(Tan δ measurement)
After adjusting the humidity of the base film in an atmosphere of 23 ° C. and 55% RH for 24 hours, under the condition of humidity 55% RH, while raising the temperature as described below or setting the temperature, the dynamic viscosity of the base film is increased. Elasticity was measured and tan δ ₋₄₀ / tan δ _peak was determined.

Measuring device: RSA III manufactured by TI Instruments
Sample: width 5 mm, length 50 mm (gap set to 20 mm)
Measurement conditions: Tensile mode Measurement temperature: 25-210 ° C
Temperature rising condition: 5 ° C / min
Frequency: 1Hz
(Evaluation of anti-glare film)
The internal haze of the produced antiglare films 22 and 23 was measured in the same manner as in Example 1. The obtained results are shown in Table 2.
<Weather resistance test and evaluation>
The antiglare films 22 and 23 produced above and the antiglare film 1 produced in Example 1 were cut out in a size of 10 cm × 10 cm, and stored for 200 hours in an environment of ozone 10 ppm, 30 ° C., 60% RH, 750 cycles of cycle thermostat (-40 ° C for 45 minutes, then 110 ° C for 45 minutes alternately), and light irradiation for 200 hours with a light resistance tester (I Super UV Tester, Iwasaki Electric Co., Ltd.) did. The antiglare film after the weather resistance test was evaluated in the same manner as in Example 1. The obtained results are shown in Table 2.

As can be seen from the results in Table 2, in a severe weather resistance test, the base film in which the tan δ in the width direction is 0.5 ≧ tan δ ₋₄₀ / tan δ _peak ≧ 0.24 is used as the antiglare film according to the present invention. It can be seen that the film has particularly excellent film strength such as scratch resistance and chemical resistance.

Example 3
<Preparation of Polarizing Plate 101>
(Alkaline saponification treatment)
Anti-glare film 1 is attached to one surface of polarizing film 3, and protective film 4 made of Konica Minolta Tack KC4FR-2 (manufactured by Konica Minolta Opto Co., Ltd.) is attached to the other surface of polarizing film 3, A polarizing plate 101 was produced (see FIG. 6 for the configuration).

(A) Production of Polarizing Film What was impregnated with 10 parts by mass of glycerin and 170 parts by mass of water in 100 parts by mass of polyvinyl alcohol (hereinafter abbreviated as PVA) having a saponification degree of 99.95 mol% and a polymerization degree of 2400. After melt-kneading and defoaming, it was melt-extruded from a T-die onto a metal roll to form a film. Then, it dried and heat-processed and obtained the PVA film. The obtained PVA film had an average thickness of 25 μm, a moisture content of 4.4%, and a film width of 3 m.

Next, the obtained PVA film was continuously processed in the order of pre-swelling, dyeing, uniaxial stretching by a wet method, fixing treatment, drying, and heat treatment to produce a polarizing film. That is, the PVA film was preliminarily swollen in water at a temperature of 30 ° C. for 30 seconds, and immersed in an aqueous solution having an iodine concentration of 0.4 g / liter and a potassium iodide concentration of 40 g / liter at a temperature of 35 ° C. for 3 minutes. Subsequently, the film was uniaxially stretched 6 times in a 50% aqueous solution with a boric acid concentration of 4% under the condition that the tension applied to the film was 700 N / m, and the potassium iodide concentration was 40 g / liter and the boric acid concentration was 40 g / liter. Then, it was immersed in an aqueous solution having a zinc chloride concentration of 10 g / liter and a temperature of 30 ° C. for 5 minutes for fixing. Thereafter, the PVA film was taken out, dried with hot air at a temperature of 40 ° C., and further heat-treated at a temperature of 100 ° C. for 5 minutes. The obtained polarizing film had an average thickness of 13 μm, a polarizing performance of a transmittance of 43.0%, a polarization degree of 99.5%, and a dichroic ratio of 40.1.

(B) Production of Polarizing Plate A polarizing plate 101 was produced by bonding the polarizing film 13, the protective film 14, and the antiglare film 10 according to the following steps 1 to 4.

Step 1: The polarizing film 3 described above was immersed in a storage tank of a polyvinyl alcohol adhesive solution having a solid content of 2% by mass for 1 to 2 seconds.

Process 2: The alkali saponification process was implemented on the anti-glare film 10 and the protective film 14 which stuck the peelable protective film (product made from PET) on the anti-glare layer on the following conditions. Next, excess adhesive adhered to the polarizing film 13 immersed in the polyvinyl alcohol adhesive solution in Step 1 is gently removed, and the polarizing film 13 is sandwiched between the antiglare film 10 and the protective film 4 as shown in FIG. And laminated.

(Alkaline saponification treatment)
Saponification step 2.5M-KOH 50 ° C 120 seconds Water washing step Water 30 ° C 60 seconds Neutralization step 10 parts HCl 30 ° C 45 seconds Water washing step Water 30 ° C 60 seconds After saponification treatment, water washing, neutralization, water washing in this order And then dried at 100 ° C.

Step 3: The laminate was bonded at a speed of about 2 m / min at a pressure of 20 to 30 N / cm ² with two rotating rollers. At this time, it was carried out with care to prevent bubbles from entering.

Step 4: The sample prepared in Step 3 was dried in a dryer at a temperature of 100 ° C. for 5 minutes to prepare a polarizing plate. After producing the polarizing plate, a protective film for the antiglare layer was applied.

Step 5: A commercially available acrylic pressure-sensitive adhesive is applied to the protective film 14 of the polarizing plate prepared in Step 4 so that the thickness after drying is 25 μm, and dried in an oven at 110 ° C. for 5 minutes to form the pressure-sensitive adhesive layer 5. Then, a peelable protective film was attached to the adhesive layer 15. This polarized light was cut (punched) to produce a polarizing plate 101.

<Preparation of polarizing plates 102 to 119>
Polarizers 102 to 119 were produced in the same manner except that the antiglare film 1 was changed to the antiglare films 2 to 19 in the production of the polarizer 101.

<Production of Liquid Crystal Display Device 401>
Remove the polarizing plate of a commercially available liquid crystal display panel (manufactured by Sony: model name BRAVIA KDL-26J5), and apply the above-prepared polarizing plate 101 to the polarizing plate on the viewing side so that the antiglare layer is the front, and the adhesive layer 5 The peelable protective film was peeled off, and the liquid crystal cell glass and the polarizing plate 101 were bonded together to produce a liquid crystal panel 301. Next, the liquid crystal panel 301 was set on a liquid crystal television, and a liquid crystal display device 401 was manufactured.

<Production of liquid crystal display devices 402 to 419>
Liquid crystal display devices 402 to 419 were similarly manufactured except that the polarizing plate 101 was changed to the polarizing plates 102 to 119 in manufacturing the liquid crystal display device 401, respectively.

<Evaluation>
(Visibility evaluation)
The produced liquid crystal display devices 401 to 419 were placed on a desk 80 cm high from the floor. Next, on the ceiling 3m high from the floor, there are 10 sets of 40W x 2 daylight straight tube fluorescent lamps (FLR40S · D / MX Panasonic Corporation) at 1.5m intervals. Arranged. In this case, when the evaluator is in front of the display surface of the liquid crystal display panel, the fluorescent lamp is arranged so that the fluorescent lamp comes to the ceiling portion from the evaluator's overhead to the rear. Next, the visibility of the liquid crystal display devices 401 to 416 was evaluated according to the following criteria.

A: I don't care about the reflection of the nearest fluorescent lamp, and I can clearly read characters with a font size of 8 or less. B: The reflection of a nearby fluorescent lamp is a little anxious, but I don't care about the distance. Can manage to read characters with a font size of 8 or less. C: It is difficult to read characters with a font size of 8 or less due to the distraction of distant fluorescent lights.
About each produced said liquid crystal display device, after leaving for 100 hours on 60 degreeC and 90% RH conditions, it returned to 23 degreeC and 55% RH. Next, unevenness was evaluated according to the following criteria.

◎: Unevenness is not recognized at all ○: Slightly unevenness is recognized △: Fine unevenness is recognized (there is actual harm)
X: Unevenness is observed Table 3 shows the above evaluation results.

As can be seen from the results in Table 3, the polarizing plate and the liquid crystal display device using the antiglare film of the present invention are excellent in visibility and unevenness, and are very excellent without any fatigue of eyes even when viewed for a long time. It was.

Example 4
<Production of Liquid Crystal Display Device 420>
As shown in FIG. 7, the polarizing plate 101 produced in Example 3 was peeled off from the peelable protective film of the pressure-sensitive adhesive layer 15 and bonded to both the viewing side and the rear side through the glass of the liquid crystal cell. A liquid crystal panel 320 was produced. Next, the liquid crystal panel 320 was set on a liquid crystal television, and a liquid crystal display device 420 was manufactured.

<Production of liquid crystal display devices 421 to 438>
Liquid crystal display devices 421 to 438 were produced in the same manner except that the polarizing plate 101 was changed to the polarizing plates 102 to 119 in the production of the liquid crystal display device 420.

When the liquid crystal display devices 420 to 438 produced above were visually observed for moire fringes, no moire fringes were observed in the liquid crystal display device using the polarizing plate of the present invention, and the polarizing plate of the present invention was used. The liquid crystal display device was superior in preventing the occurrence of moire fringes.

a Center line a
b, c Lines forming the foot of the mountain h Projection size height h (distance between the summit and the center line a)
t Protrusion size width t (distance between two intersections of lines b and c forming a mountain ridge and center line a)
DESCRIPTION OF SYMBOLS 1 Hard coat layer 2 Protrusion 3 Transmission optical microscope 4 Sample 5 Color filter 6 Light source 10 Anti-glare film 11 Anti-glare layer 12 Base film 13 Polarizing film 14 Protective film 15 Adhesive layer 16 Liquid crystal cell 17 Liquid crystal 18 Alignment film 19 Color Filter 20 Spacer 101 Polarizing plate 320 LCD panel

Claims

An antiglare film having an antiglare layer on a base film, wherein the antiglare layer has a protrusion shape, and the protrusion shape has an irregular shape without a period in the longitudinal direction. It is irregularly arranged, and the arithmetic average roughness Ra of the antiglare layer is 25 to 300 nm, and the haze caused by internal scattering of the antiglare layer is 0 to 1.0%. Anti-glare film.
The antiglare film according to claim 1, wherein the antiglare layer has an arithmetic average roughness Ra of 25 to 130 nm.
The antiglare film according to claim 1 or 2, wherein the arithmetic average roughness Ra of the antiglare layer is 65 to 130 nm.
The antiglare film according to any one of claims 1 to 3, wherein the antiglare layer contains substantially no inorganic fine particles or organic fine particles.
The antiglare layer contains an actinic radiation curable resin and does not substantially contain a resin that is incompatible with the actinic radiation curable resin. The antiglare film according to item.
The antiglare film according to any one of claims 1 to 5, wherein the haze resulting from internal scattering of the antiglare layer is 0.60 to 1.0%.
7. The antiglare film according to claim 1, wherein tan δ in the film width direction of the base film has the following relationship.
0.5 ≧ tan δ −40 / tan δ peak ≧ 0.24
(Where tan δ peak represents the maximum value of tan δ measured from 25 ° C. to 210 ° C., and tan δ −40 represents the value of tan δ at a temperature of −40 ° C. when tan δ peak was exhibited.)
An anti-glare film production method for producing the anti-glare film according to any one of claims 1 to 7, wherein the viscosity at 25 ° C is in the range of 30 to 2500 mPa · s. Under the condition that the antiglare layer containing the resin is formed through at least the coating process, the drying process and the curing process, and the temperature of the decreasing rate drying section in the drying process is maintained within the range of 90 to 140 ° C. The manufacturing method of the anti-glare film characterized by processing.
A polarizing plate comprising the antiglare film according to any one of claims 1 to 7 on one surface.
A liquid crystal display device comprising the polarizing plate according to claim 9 in at least one of the liquid crystal cells.
The liquid crystal display device according to claim 10, wherein the polarizing plate according to claim 9 is used on the rear side of the liquid crystal cell.