JP2010186124A - Optical film, and polarizing plate and display device using the optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film which is free from the generation of curling, the occurrence of cracks and breakage, and the formation of wrinkles caused by surface shrinkage even when it is a thin film and which has a hard coat layer having extremely high hardness, and to provide a polarizing plate and a display device using the film. <P>SOLUTION: The optical film is obtained by laminating a hard coat layer containing cellulose nanofibers having an average fiber diameter of 4-200 nm on a support. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical film, a polarizing plate using the same, and a display device.

  An optical film is usually provided on the surface of the display device in order to impart antireflection properties, antiglare properties, and the like. Since such an optical film is usually a thin film and has a low hardness and is easily damaged, a hard coat layer is often applied to give the hardness. The optical characteristics of the optical film are required to be precise, and high hardness stability is required to stably exhibit the optical characteristics.

  As a technique of the hard coat layer, Patent Document 1 discloses that two kinds of specific acrylate compounds cause curling when the support is thinned in order to make an optical film having a hard coat layer on a transparent support thin. Although the technology which eliminates as a hard-coat layer which hardened | cured the composition containing this is disclosed, pencil hardness is about H, and still higher pencil hardness is requested | required.

  There is a means to increase the thickness of the hard coat layer to increase the hardness. However, curling occurs due to the difference in shrinkage between the hard coat layer and the support due to the increase in thickness, and cracks and cracks occur for the same reason. It has been found that there are practical problems such as generation and wrinkles due to surface shrinkage.

  In particular, when a hard coating layer with high hardness is applied to a polarizing plate protective film or retardation film used in a liquid crystal display device, the power supply of the display device is frequently turned on and off, and cracks and transparency deterioration due to temperature fluctuations occur. There was a problem that it was easy to appear.

JP 2005-109773 A

  Accordingly, an object of the present invention is to provide an optical film having a hard coat layer that does not cause curling, cracks, cracks, surface shrinkage, and has extremely high hardness even in a thin film, and polarization using the same. It is to provide a board and a display device. In particular, it is an object to provide a polarizing plate protective film and a retardation film having high hardness in which cracks due to temperature fluctuations and transparency deterioration hardly occur.

  The above object of the present invention is achieved by the following configurations.

  1. An optical film obtained by laminating a hard coat layer containing cellulose nanofibers having an average fiber diameter of 4 to 200 nm on a support.

  2. 2. The optical film as described in 1 above, wherein an amorphous region of the cellulose nanofiber is 3% to 60%.

  3. 3. The optical film as described in 1 or 2 above, wherein the hard coat layer contains fine particles.

  4). 4. The optical film as described in any one of 1 to 3 above, wherein the hard coat layer contains a dispersant.

  5. 5. The optical film as described in 4 above, wherein the dispersant has an HLB value of 5 to 15.

  6). 5. The optical film as described in 4 above, wherein the dispersant has both an acid value and an amine value.

  7). 7. The optical film as described in any one of 1 to 6, wherein the total light transmittance is 80% or more.

  8). A polarizing plate comprising a polarizer and two polarizing plate protective films sandwiching the polarizer, wherein one of the two polarizing plate protective films is the optical film described in any one of 1 to 7 above. There is a polarizing plate.

  9. 8. A display device using the optical film according to any one of 1 to 7 or the polarizing plate according to 8.

  10. 8. The optical film as described in any one of 1 to 7, wherein the support contains a cellulose ester as a composition.

  According to the present invention, an optical film having a hard coat layer that is extremely hard and does not cause curling, cracking, cracking, or surface shrinkage even in a thin film, and a polarizing plate using the same A display device can be provided. In particular, it is possible to provide a polarizing plate protective film and a retardation film having high hardness that hardly cause cracks due to temperature fluctuations and transparency deterioration.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The present invention has been made to solve the above problems, and the present inventors have focused on the fact that cellulose nanofibers have a small diameter and a large elastic modulus and a small linear expansion coefficient. Therefore, transparency is not impaired, curling is suppressed by elasticity, and the low expansion coefficient will contribute to dimensional stability, and when it is used for the hard coat layer, curling, cracks, cracks and wrinkles are generated. It has been found that it can be suppressed and has led to the present invention.

  Hereinafter, the present invention will be described in detail.

<Cellulose nanofiber>
The cellulose nanofiber according to the present invention refers to a cellulose-based fiber having an average fiber diameter of 4 to 200 nm as a fiber. This fiber may consist of what a single fiber exists apart without being arranged. In this case, the average fiber diameter is the average diameter of single fibers. Further, the fiber according to the present invention may be one in which a plurality of (may be many) single fibers are gathered into a bundle to form one yarn. The fiber diameter is defined as the average value of the diameter of one yarn.

  In the present invention, when the average fiber diameter of the fibers exceeds 200 nm, the wavelength approaches the wavelength of visible light, and refraction of visible light tends to occur at the interface with the hard coat layer, resulting in a decrease in transparency. The upper limit of the average fiber diameter of the fibers used in is preferably 200 nm. Since fibers having an average fiber diameter of less than 4 nm are difficult to produce, the lower limit of the average fiber diameter of the fibers used in the present invention is 4 nm. The average fiber diameter of the fiber used in the present invention is preferably 4 to 100 nm, more preferably 4 to 60 nm.

  In addition, as long as the fiber used by this invention has an average fiber diameter in the range of 4-200 nm, the thing of the fiber diameter outside the range of 4-200 nm may be contained in the fiber, but the ratio is the whole. It is preferable that the fiber diameter of all the fibers is 200 nm or less, particularly 100 nm or less, particularly 60 nm or less.

  The length of the fiber is not particularly limited, but the average length is preferably 100 nm or more. If the average length of the fibers is shorter than 100 nm, the reinforcing effect of the hard coat layer is low, and the hardness may be insufficient. In addition, although a fiber length less than 100 nm may be contained in the fiber, it is preferable that the ratio is 30 mass% or less.

  The measurement of the said fiber diameter and fiber length can be measured with a commercially available microscope and an electron microscope. For example, by taking a photograph of cellulose nanofibers magnified 2000 times with a scanning electron microscope, and then analyzing the photographic image using “SCANNING IMAGE ANALYZER” (manufactured by JEOL Ltd.) based on this photograph It was measured. Under the present circumstances, the average value of a fiber diameter and fiber length can be calculated | required using 100 cellulose nanofibers.

  The cellulose nanofiber according to the present invention refers to a microfibril of cellulose constituting a basic skeleton of a plant cell wall or the like or a constituent fiber thereof, and is an aggregate of unit fibers having a fiber diameter of 4 to 200 nm. In order to obtain high strength and a low linear expansion coefficient, it is preferable that this cellulose fiber contains a crystal region of 40% or more.

  It is said that it becomes an amorphous area | region except the said crystal | crystallization area | region, and exists about 40 to 50% in a wood pulp, and about 30% in a bacterial cellulose. In the present invention, the presence of the amorphous region imparts the property that the microfibril is softened and hardened but does not become brittle, and the use of cellulose nanofibers present as a proportion of the amorphous region of 3 to 60% is an effect of the present invention. It was found that it is more preferable in obtaining When the amorphous region is larger than 60%, the properties such as the high elastic modulus and low linear expansion coefficient of the cellulosic nanofiber cannot be maintained, and it becomes difficult to sufficiently exhibit the hardness. In addition, it is difficult to produce a non-crystalline region of less than 3% because it is difficult to produce both plant-derived and bacteria-derived materials.

  Here, the crystal region refers to a state in which the cellulosic fiber has a constant repeating structure, and the amorphous region refers to an amorphous state in which a specific periodic structure is not defined.

  The above state can be analyzed for cellulose nanofibers from X-ray diffraction, molecular chain structure analysis by high-resolution electron microscope observation, and three-dimensional structure analysis of glucose ring obtained from solid state NMR measurement. Specifically, the following methods are mentioned.

  The manufactured cellulose nanofiber was mounted on a sample holder, and the diffraction angle of X-ray diffraction was manipulated from 10 ° to 32 ° for measurement. After removing background scattering from the obtained X-ray diffraction pattern, the area obtained by connecting 10 °, 18.5 °, and 32 ° on the X-ray diffraction curve with a straight line becomes an amorphous region, and the others are crystal regions. Become. The ratio of the amorphous region was calculated by the following formula.

Ratio of amorphous region = (area of amorphous region) / (area of entire X-ray diffraction diagram) × 100 (%)
Cellulosic fibers used for the cellulose nanofibers of the present invention can be suitably used even if they are separated from plants or bacterial cellulose produced by bacterial cellulose.

  The pulp used as the raw material of the cellulose nanofiber of the present invention is a pulp obtained by a mechanical method (eg, groundwood pulp, refiner ground pulp, thermomechanical pulp, semichemical pulp, chemiground pulp), or a chemical method. Pulp (craft pulp, sulfite pulp, etc.) obtained in (1) can be used. As the pulp, wood pulp, linter pulp, waste paper pulp and the like are usually used. In addition, materials containing cellulose can be widely used, for example, refined pulp subjected to delignification treatment such as bamboo pulp and bagasse pulp, or cellulosic natural fibers such as cotton fiber, cotton linter and hemp fiber. Or refined natural fibers obtained by subjecting them to delignification, or regenerated cellulose moldings such as viscose, rayon, tencel, polynosic fibers, or dietary fibers derived from grains or fruits (for example, Wheat bran, oat bran, corn hull, rice bran, beer lees, soybean koji, pea fiber, okara, apple fiber, etc.), or lignocellulosic materials such as wood and rice straw To do.

  Further, non-wood fibers such as kenaf, shiogusa, esparto, cocoon, cocoon, cocoon, ramie, etc. may be used, and valonia cellulose, squirt cellulose, etc. can also be used.

  Among the above, it is preferable to use wood pulp as a main raw material, for example, chemical pulp such as sulfite pulp (SP), alkali pulp (AP), kraft pulp (KP) obtained from hardwood and softwood, semi-chemical Pulp, semi-mechanical pulp, mechanical pulp and the like can be mentioned. Further, the pulp can be used without distinction between unbleached pulp, bleached pulp and beating, and unbeaten. Hardwood bleached kraft pulp (hereinafter also referred to as LBKP) or softwood bleached kraft pulp is most suitable due to its quality and cost. As wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, and NUKP can be used, but it is preferable to use more LBKP, NBSP, LBSP, NDP, and LDP with a large amount of short fibers. However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

  In the present invention, a dispersion aid can be added to obtain cellulose fibers from the above raw materials. Dispersing aids include glucose, glucose, sucrose, fructose, lactose, maltose, cellobiose, cellotriose, cellotetraose, maltotriose, fructose, xylose, various oligosaccharides, sorbitol, dextrins, starches, sorbose, gum degradation products Water-soluble substances such as various gums, pullulan, curdlan, agar, pectin, dextran, gelatin, cellulose derivatives, alginic acid, farseleran, quince and the like, and water-swellable substances can be used.

  Moreover, the process by a phosphate etc. can be used, This weakens the bond strength between cellulose fibers by phosphoric esterifying the surface of a plant cell wall etc., Then, a refiner process is performed and fiber is made. This is a treatment method for obtaining cellulose fibers in pieces.

  Moreover, the fiber used as the raw material of the cellulose nanofiber may be one obtained by chemically and / or physically modifying the cellulose fiber to enhance functionality. Here, as chemical modification, functional groups are added by acetylation, cyanoethylation, acetalization, etherification, isocyanateation, etc., and inorganic substances such as silicates and titanates are combined or coated by chemical reaction or sol-gel method. For example.

  The cellulose nanofiber of the present invention can also be used without disaggregating a product obtained by alkaline treatment of a product from bacteria and dissolving and removing the bacteria.

  The cellulose nanofibers of the present invention are preferably refined using a plurality of pulverizing means. Although the pulverizing means is not limited, in order to finely pulverize to a particle size suitable for the purpose of the present invention, there is a method that can obtain a strong shearing force such as a high-pressure homogenizer, a media mill, a grindstone rotary grinder, and a stone mill grinder. Preferably used. For example, Japanese Patent Laid-Open No. 4-82907 proposes a method for producing fibrillated natural cellulose by pulverizing short fibers of natural cellulose fibers in a dry state. Furthermore, in Japanese Patent Application Laid-Open No. 06-10286, wet pulverization treatment is performed on a suspension of fibrous cellulose by a vibration mill pulverizer using beads or balls made of glass, alumina, zirconia, zircon, steel, titania or the like as a pulverization medium. The manufacturing method of the fine fibrous cellulose which gives is disclosed.

  A high-pressure homogenizer is a device that grinds by shear force due to accelerated high flow velocity, rapid pressure drop (cavitation), and impact force caused by high-velocity particles colliding face-to-face within a fine orifice, and is commercially available. As the device, a nanomizer (manufactured by Nanomizer Co., Ltd.), a microfluidizer (manufactured by Microfluidics) or the like can be used.

  The cellulose nanofibers thus obtained are added to the hard coat layer coating composition directly or as a dispersion, and the content in the composition is in the range of 0.1 to 50% by mass. Is preferred. More preferably, it is 5-50 mass%, and especially 10-40 mass% is preferable.

  When the content of the cellulose nanofiber in the composition is less than 0.1% by mass, the effect of sufficiently improving the pencil hardness of the hard coat layer tends to be insufficient, and when the content exceeds 50% by mass, the transparency decreases. The strength and surface flatness may be reduced.

<Hard coat layer>
The optical film of the present invention preferably has a hard coat layer on a support and is provided as a layer containing an actinic radiation curable resin or a thermosetting resin.

  In the present invention, the actinic radiation curable resin refers to a resin that cures through a crosslinking reaction or the like by irradiation with actinic radiation such as ultraviolet rays or electron beams, and preferably contains a monomer having an ethylenically unsaturated double bond. A resin that cures upon irradiation is preferred.

  Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to.

  As specific examples, for example, compounds described in JP-A-2006-146027, JP-A-2006-285217, JP-A-2006-293201, JP-A-301169, JP-A-2007-3767, and the like are used. Can be used.

  Moreover, it is also preferable to use a photoinitiator when using an ultraviolet curable resin, and the photoinitiator described in the said literature can be used.

As the ultraviolet light source for photopolymerizing the ultraviolet curable resin, any light source that generates ultraviolet light can be used. 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. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. Irradiation conditions vary depending on each lamp, but the amount of irradiation light is preferably 1 mJ / cm ² or more, more preferably 20 mJ / cm ^{2 to} 10000 mJ / cm ² , and particularly preferably 50 mJ / cm ^{2 to} 2000 mJ / cm ^2. It is.

  Moreover, when irradiating an ultraviolet-ray, it is preferable to carry out, applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also 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, an optical film having a hard coat layer with excellent flatness can be obtained.

  As a thermosetting resin used by this invention, the compound as described in Unexamined-Japanese-Patent No. 2005-164890, 2007-25040, Unexamined-Japanese-Patent No. 2007-298916 etc. can be used preferably, for example.

  The method for heating the thermosetting resin is not particularly limited, but it is preferable to use a method such as a heat plate, a heat roll, a thermal head, or hot air. Moreover, you may heat continuously as a heat roll the back roll used for film conveyance. The heating temperature cannot be generally defined by the type of thermosetting resin to be used, but is preferably in a temperature range that does not affect the heat deformation of the transparent substrate, preferably 30 to 200 ° C, Furthermore, 50-120 degreeC is preferable, Especially preferably, it is 70-100 degreeC.

  Further, the hard coat layer may contain fine particles of an inorganic compound or an organic compound in order to adjust scratch resistance and slipperiness.

  Examples of inorganic fine particles used in the hard coat layer include silicon oxide, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, and calcined kaolin. And calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  Organic particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder. Polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder can be added to the ultraviolet curable resin composition. Particularly preferred are cross-linked polystyrene particles (for example, SX-130H, SX-200H, SX-350H, manufactured by Soken Chemical) and polymethyl methacrylate-based particles (for example, MX150, MX300, manufactured by Soken Chemical).

  The average particle size of these fine particle powders is preferably 0.01 to 5 μm, more preferably 0.1 to 5.0 μm, and particularly preferably 0.1 to 4.0 μm. Moreover, it is preferable to contain 2 or more types of microparticles | fine-particles from which a particle size differs. The ratio of the hard coat layer coating composition and the fine particles is desirably blended so as to be 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin composition.

  These hard coat layers can be coated by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method. After application, it is dried by heating and subjected to a curing treatment.

  The coating amount of the hard coat layer coating solution is suitably from 0.1 to 40 μm, preferably from 0.5 to 30 μm, as the wet film thickness. Moreover, as a dry film thickness, it is an average film thickness of 0.1-30 micrometers, Preferably it is 1-20 micrometers.

  The hard coat layer coating solution may contain a solvent, or may be appropriately contained and diluted as necessary. Examples of the organic solvent contained in the coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), It can be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  In the present invention, the method for adding the cellulose nanofibers to the hard coat layer coating solution is not particularly limited, but it is preferable to add the cellulose nanofibers as a dispersion in which cellulose nanofibers are dispersed in advance.

  The method for preparing the dispersion containing cellulose nanofibers is not particularly limited, but the cellulose nanofibers are added in a solvent or binder having affinity for cellulose nanofibers, and dispersed by a known dispersing machine or method. Can do.

  Solvents include water, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, methyl acetoacetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-triate. Fluoroethanol, 2,2,3,3-tetrafluoro-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, 1,3-dimethyl-2-imidazolidinone Organic halogen compounds such as methylene chloride, dioxolane derivatives, methyl acetate, ethyl acetate, Ton, methyl acetoacetate and the like are preferable. These solvents may be used alone or as a mixed solvent of two or more.

  As the binder, the presence of a water-soluble polymer in the dispersion can improve the dispersibility and reduce the haze. The water-soluble polymers here include starches, mannans, seaweeds such as galactan and sodium alginate, plant mucilages such as tragacanth gum, gum arabic and dextran, proteins such as gelatin and casein, methylcellulose, hydroxycellulose and carboxymethylcellulose. Celluloses, polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, and other synthetic polymers.

  If the molecular weight of these water-soluble polymers is too small, an effect for improving dispersibility is not recognized. Therefore, the molecular weight is preferably 10,000 or more, more preferably 30,000 to 200,000. The molecular weight can be measured by a viscosity method, a diffusion method, a light scattering method, a gel filtration method, a high performance liquid chromatography method or the like, and particularly a gel filtration method or a high performance liquid chromatography method is preferably applied.

  The water-soluble polymer is preferably added in a mass ratio of 0.05 to 30 times with respect to the cellulose nanofibers to be dispersed, and the aqueous solution is preferably in the range of 1 to 20% by mass.

  It is also a useful method to use various surfactants for dispersion. As the surfactant, any of anionic, cationic, amphoteric, nonionic and the like can be used, but anionic and nonionic surfactants are preferable, and anionic surfactants are particularly preferable. In addition, when adjusting the pH, a general acid-alkali aqueous solution such as sodium hydroxide, potassium hydroxide, acetic acid, citric acid, phosphoric acid, sulfuric acid or the like, preferably a buffer solution is used.

  The cellulose nanofibers of the present invention are preferably added to the hard coat layer coating solution using a dispersant. In that case, it is preferable to use a dispersant having an HLB value of 3 to 18, more preferably an HLB value of 5 to 15, more preferably 9 to 15.

  The HLB value is Hydrophile-Lipophile-Balance, hydrophilic-lipophilic-balance, and is a value indicating the hydrophilicity or lipophilicity of a compound. The smaller the HLB value, the higher the lipophilicity, and the higher the value, the higher the hydrophilicity.

  The HLB value can be obtained by the following calculation formula.

HLB = 7 + 11.7Log (Mw / Mo)
In the formula, Mw represents the molecular weight of the hydrophilic group, Mo represents the molecular weight of the lipophilic group, and Mw + Mo = M (molecular weight of the compound).

  Alternatively, according to the Griffin method, HLB value = 20 × total formula weight of hydrophilic part / molecular weight (J. Soc. Cosmetic Chem., 5 (1954), 294) and the like.

  Specific examples of the compound having an HLB value of 3 to 18 are listed below, but the present invention is not limited thereto. Figures in parentheses indicate HLB values.

Made by Kao Corporation: Emulgen 102KG (6.3), Emulgen 103 (8.1), Emulgen 104P (9.6), Emulgen 105 (9.7), Emulgen 106 (10.5), Emulgen 108 (12. 1), Emulgen 109P (13.6), Emulgen 120 (15.3), Emulgen 123P (16.9), Emulgen 147 (16.3), Emulgen 210P (10.7), Emulgen 220 (14.2) , Emulgen 306P (9.4), Emulgen 320P (13.9), Emulgen 404 (8.8), Emulgen 408 (10.0), Emulgen 409PV (12.0), Emulgen 420 (13.6), Emulgen 430 (16.2), Emulgen 705 (10.5), Emulgen 707 (12.1), Emulgen 7 9 (13.3), Emulgen 1108 (13.5), Emulgen 1118S-70 (16.4), Emulgen 1135S-70 (17.9), Emulgen 2020G-HA (13.0), Emulgen 2025G (15. 7), Emulgen LS-106 (12.5), Emulgen LS-110 (13.4), Emulgen LS-114 (14.0), Emulgen MS-110 (12.7), Emulgen A-60 (12. 8), Emulgen A-90 (14.5), Emulgen A-500 (18.0), Emulgen B-66 (13.2), Latemul PD-420 (12.6), Latemul PD-430 (14. 4), Latemul PD-430S (14.4), Latemuru PD-450 (16.2), Rhedol SP-L10 (8.6), Rhedol SP- 10 (6.7), Rhedol SP-S10V (4.7), Rhedol SP-S20 (4.4), Rhedol SP-O10V (4.3), Rheodor Super SP-L10 (8.6), Rheodor AS10V (4.7), Rhedol AO-10V (4.3), Rheodor AO-15V (3.7), Emazole L-10V (8.6), Emazole P-10V (6.7), Emazole S- 10V (4.7), Emazole O-10V (4.3), Rheodor TW-L120 (16.7), Rhedol TW-L106 (13.3), Rheodor TW-P120 (15.6), Rhedol TW- S120V (14.9), Rheodor TW-S106V (9.6), Rheodor TW-S320V (10.5), Rheodor TW-O120V (15.0), R Odol TW-O106V (10.0), Rheodor TW-O320V (11.0), Rheodor Super TW-L120 (16.7), Rheodor 430V (10.5), Rheodor 440V (11.8), Rheodor 460V (13.8), Rhedol MS-60 (3.5), Rhedol MS-165V (11.0), Excel T-95 (3.8), Excel VS-95 (3.8), Excel O-95R (3.5), Excel 200 (3.5), Excel 122V (3.5), Emanon 1112 (13.7), Emanon 4110 (11.6), Emanon CH-25 (10.7), Emanon CH -40 (12.5), Emanon CH-60 (K) (14.0), Emanon CH-80 (15.0), Amit 102 (6.3), A 105 (9.8), Amite 105A (10.8), Amite 302 (5.1), Amite 320 (15.4), Aminone PK-02S (5.5), Aminone L-02 (5. 8)
Nissin Chemical Industry Co., Ltd .: Surfinol 104E (4), Surfinol 104H (4), Surfinol 104A (4), Surfinol 104BC (4), Surfinol 104DPM (4), Surfinol 104PA (4), Surfinol 104PG-50 (4), Surfinol 104S (4), Surfinol 420 (4), Surfinol 440 (8), Surfinol 465 (13), Surfinol 485 (17), Surfinol SE (6) Surfinol SE-F (6), Surfinol 61 (6), Surfinol 604 (8), Surfinol 2502 (8), Surfinol 82 (4), Surfinol DF110D (3), Surfinol CT111 (8 To 11), Surfinol CT121 (11- 5), Surfynol CT136 (13), Surfynol TG (9), Surfynol GA (13), Olfin STG (9 to 10), Olfine E1004 (7 to 9), OLFINE E1010 (13 to 14)
Shin-Etsu Chemical Co., Ltd .: X-22-4272 (7), X-22-6266 (8), KF-351 (12), KF-352 (7), KF-353 (10), KF-354L ( 16), KF-355A (12), KF-615A (10), KF-945 (4), KF-618 (11), KF-6011 (12), KF-6015 (4), KF-6004 (5) )
The dispersant having an HLB value of 3 to 18 is preferably used in an amount of 0.01% by mass or more and less than 50% by mass in the solid content of the dispersion.

  Moreover, it is also preferable to use the dispersing agent which has an acid value and an amine value as a dispersing agent used for this invention. The acid value or amine value referred to in the present invention can be determined by a known method such as potentiometric titration. For example, it can be measured by the method described in Color Material Association Journal 61, [12] 692-698 (1988).

  As a dispersant having an acid value and an amine value, DA-234, DA-325, DA-703-50, DA-7300 manufactured by Enomoto Kasei Co., Ltd., PB822, PB821 manufactured by Ajinomoto Fine Techno Co., EFKA manufactured by Fuka Additives Co., Ltd. -4300, EFAK-7411, EFKA-7476, EFKA-5244, EFKA-6220, EFKA-6225, EFKA-7544, EFKA-7564, Disperbyk-109, Disperbyk-108, Disperbyk-byk, 106 Examples include Hinoact T-8000 and Hinoact T-6000 manufactured by Kawaken Fine Chemical Co., and a dispersant having an acid value larger than the amine value is preferred.

  The amine value and acid value of the dispersant were determined as follows.

<Measurement of amine value of dispersant>
The dispersant was dissolved in methyl isobutyl ketone, potentiometric titration was performed with a 0.01 N methyl isobutyl ketone perchlorate solution, and the value converted to KOH mg / g was used as the amine value. Potentiometric titration was measured using an automatic titrator COM-1500 manufactured by Hiranuma Sangyo Co., Ltd.

<Measurement of acid value of dispersant>
The dispersant was dissolved in methyl isobutyl ketone, and potentiometric titration was performed with a 0.01N potassium methoxide-methyl isobutyl ketone / methanol (4: 1) solution, and the acid value was calculated as KOH mg / g. Potentiometric titration was measured using an automatic titrator COM-1500 manufactured by Hiranuma Sangyo Co., Ltd.

  It is presumed that the use of a dispersant having an acid value and an amine value is advantageous because it can be effectively adsorbed on both acidic and basic sites on the surface of the cellulose nanofiber.

  Dispersers used for dispersing cellulose nanofibers include, for example, centrifugal dispersers (flow jet mixer, fine flow mill, etc.), media type dispersers (ball mill, sand mill, etc.), ultrasonic dispersers, homogenizers, A high-pressure homogenizer and the like can be mentioned, among which a centrifugal disperser and a media type disperser are preferable.

  Further, the hard coat layer preferably contains a silicone surfactant or a polyoxyether compound. These improve applicability | paintability and it is preferable to add these components in 0.01-3 mass% with respect to the solid content component in a coating liquid.

  The hard coat layer may have a multilayer structure of two or more layers. One of the layers may be, for example, a so-called antistatic layer containing conductive fine particles or an ionic polymer, or a color tone adjusting agent (dye having a color tone adjusting function as a color correction filter for various display elements. Or a pigment or the like) or an electromagnetic wave blocking agent or an infrared absorbing agent or the like to have the respective functions.

  The hard coat layer is a clear hard coat layer having a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, or fine particles are added to adjust Ra to 0.1 to 1 μm. The antiglare hard coat layer is preferably used. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  Moreover, it is preferable that the total light transmittance of the optical film which has a hard-coat layer is 80% or more. The total light transmittance is measured using a spectrophotometer U-3200 (manufactured by Hitachi, Ltd.), and the spectral transmittance in the visible light region of the optical film is measured and then averaged to obtain the total light transmittance (%).

<Support>
The support used in the present invention preferably has requirements for being easy to manufacture, having good adhesion to the curable resin layer, optically isotropic, and optically transparent. It is preferably a long film.

  The term “transparent” as used in the present invention means that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.

  Although it will not specifically limit if it has said property, For example, a cellulose-ester type film, a polyester-type film, a polycarbonate-type film, a polyarylate-type film, a polysulfone (a polyether sulfone is also included) type film, a polyethylene terephthalate, polyethylene Polyester film such as naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose triacetate film, cellulose acetate propionate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film , Syndiotactic polystyrene film, polycarbonate film, norvo Nene resin film, a polymethylpentene film, a polyether ketone film, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, acrylic film or a glass plate or the like. Among these, a polycarbonate film, a polyester film, a norbornene resin film, and a cellulose ester film are preferable.

  In particular, a cellulose ester film is preferably used, and may be a film manufactured by melt casting film formation or a film manufactured by solution casting film formation.

  Hereinafter, the cellulose ester film particularly preferably used in the present invention will be described in more detail.

(Cellulose ester film)
Examples of the cellulose ester used in the present invention include cellulose acetate, cellulose propionate, cellulose butyrate and the like, JP-A Nos. 10-45804, 08-231761, and US Pat. No. 2,319,052. Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate as described in the literature can be used. Particularly preferred are cellulose triacetate and cellulose acetate propionate. These cellulose esters can be used alone or in combination. The molecular weight is preferably 70000-200000 in terms of number average molecular weight (Mn), more preferably 100000-200000.

  In the case of cellulose triacetate, those having an average degree of acetylation (bound acetic acid amount) of 54.0 to 62.5% are preferably used, and more preferably an average degree of acetylation of 58.0 to 62.5%. Cellulose triacetate.

  Preferred cellulose esters other than cellulose triacetate have an acyl group having 2 to 4 carbon atoms as a substituent, and when the substitution degree of acetyl group is X and the substitution degree of propionyl group or butyryl group is Y, the following formula ( It is a cellulose ester containing the cellulose ester which satisfy | fills I) and (II) simultaneously.

Formula (I) 2.0 ≦ X + Y ≦ 2.6
Formula (II) 0.1 ≦ Y ≦ 1.2
Furthermore, a cellulose acetate propionate (total acyl group substitution degree = X + Y) resin of 2.4 ≦ X + Y ≦ 2.6 and 1.4 ≦ X ≦ 2.3 is preferable. Among them, 2.4 ≦ X + Y ≦ 2.6, 1.7 ≦ X ≦ 2.3, 0.1 ≦ Y ≦ 0.9, cellulose acetate propionate resin, cellulose acetate butyrate (total acyl group substitution degree = X + Y ) Resins are preferred. The portion not substituted with an acyl group usually exists as a hydroxyl group. These cellulose ester resins can be synthesized by a known method. The measuring method of the substitution degree of an acyl group can be measured according to the rule of ASTM-D817-96.

  As the cellulose ester, a cellulose ester synthesized using cotton linter, wood pulp, kenaf or the like as a raw material can be used alone or in combination. In particular, it is preferable to use a cellulose ester synthesized from cotton linter alone or in combination.

(Plasticizer)
When a cellulose ester film is used for the support used in the present invention, it is preferable to contain a plasticizer. Examples of the plasticizer include a phosphate ester plasticizer, a phthalate ester plasticizer, and a trimellitic ester ester. A plasticizer, a pyromellitic acid plasticizer, a glycolate plasticizer, a citrate plasticizer, a polyester plasticizer, a polyhydric alcohol ester plasticizer, or the like can be preferably used.

  The amount of these plasticizers used is preferably from 1 to 20% by mass, particularly preferably from 3 to 13% by mass, based on the cellulose ester, in terms of film performance, processability and the like.

(UV absorber)
It is preferable to add an ultraviolet absorber to the support used in the present invention.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having a small absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.

  Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, and the like. For example, but not limited to.

  As the ultraviolet absorber preferably used in the present invention, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber, which are highly transparent and excellent in preventing the deterioration of the polarizing plate and the liquid crystal, are preferable, and unnecessary coloring occurs. Less benzotriazole-based UV absorbers are particularly preferably used.

(Fine particles)
In the present invention, the cellulose ester film preferably contains fine particles. Examples of the fine particles include those similar to those used for the hard coat layer. Of these, silicon dioxide is preferable because it can reduce the haze of the film. The average particle size of the secondary particles of the fine particles is in the range of 0.01 to 1.0 μm, and the content is preferably 0.005 to 0.3% by mass with respect to the cellulose ester. In many cases, fine particles such as silicon dioxide are surface-treated with an organic substance, but such particles are preferable because they can reduce the haze of the film. Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes (particularly alkoxysilanes having a methyl group), silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the mat effect, and on the contrary, the smaller the average particle size, the better the transparency. Therefore, the average particle size of the preferred primary particles is 5 to 50 nm, more preferably 7 to 16 nm. It is. These fine particles are usually present as aggregates in the cellulose ester film, and it is preferable to form irregularities of 0.01 to 1.0 μm on the surface of the cellulose ester film. Examples of the fine particles of silicon dioxide include Aerosil (Aerosil) 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600 manufactured by Aerosil Co., preferably AEROSIL (Aerosil) 200V, R972, R972V, R974, R202, and R812. Two or more kinds of these fine particles may be used in combination.

(Acrylic polymer)
In addition, it is also preferable to include an acrylic polymer described in JP-A-2003-12859 in order to adjust retardation and haze.

  It is preferable to contain an acrylic polymer having a weight average molecular weight of 500 to 30,000, and the acrylic polymer is preferably an acrylic polymer having an aromatic ring in the side chain or an acrylic polymer having a cyclohexyl group in the side chain.

  By controlling the composition of the polymer so that the weight average molecular weight of the polymer is 500 or more and 30000 or less, the compatibility between the cellulose ester and the polymer can be improved.

  In particular, for an acrylic polymer, an acrylic polymer having an aromatic ring in the side chain, or an acrylic polymer having a cyclohexyl group in the side chain, if the weight average molecular weight is preferably 500 or more and 10,000 or less, in addition to the above, The transparency of the cellulose ester film is excellent, the moisture permeability is extremely low, and the cellulose ester film exhibits excellent performance.

  The polymerization method of such a polymer includes a method using a peroxide polymerization initiator such as cumene peroxide and t-butyl hydroperoxide, a method using a polymerization initiator in a larger amount than a normal polymerization, and a polymerization initiator. In addition, a method using a chain transfer agent such as a mercapto compound or carbon tetrachloride, a method using a polymerization terminator such as benzoquinone or dinitrobenzene in addition to the polymerization initiator, and further JP-A No. 2000-128911 or 2000- Examples thereof include a method of bulk polymerization using a compound having one thiol group and a secondary hydroxyl group as described in Japanese Patent No. 344823, or a polymerization catalyst in which the compound and an organometallic compound are used in combination.

  Further, the cellulose ester film comprises an ethylenically unsaturated monomer Xa having no aromatic ring and a hydrophilic group in the molecule and an ethylenically unsaturated monomer Xb having no aromatic ring and having a hydrophilic group in the molecule. Polymer Y having a weight average molecular weight of 5,000 to 30,000 obtained by polymerization, and more preferably a polymer Y having a weight average molecular weight of 500 to 3,000 obtained by polymerizing an ethylenically unsaturated monomer Ya having no aromatic ring And may be contained. Preferably, Xa is an acrylic or methacrylic monomer that does not have an aromatic ring and a hydrophilic group in the molecule, and Xb is an acrylic or methacrylic monomer that does not have an aromatic ring in the molecule and has a hydrophilic group.

The content of the polymer X and the polymer Y in the cellulose ester film is preferably in a range satisfying the following formulas (i) and (ii). When the content of the polymer X is Xg (mass% = the mass of the polymer X / the mass of the cellulose ester × 100) and the content of the polymer Y is Yg (mass%),
Formula (i) 5 ≦ Xg + Yg ≦ 35 (mass%)
Formula (ii) 0.05 ≦ Yg / (Xg + Yg) ≦ 0.4
A preferable range of the formula (i) is 10 to 25% by mass.

  If the total amount of the polymer X and the polymer Y is 5% by mass or more, the polymer X and the polymer Y sufficiently act to reduce the retardation value Rt. Moreover, if it is 35 mass% or less as a total amount, adhesiveness with polarizer PVA is favorable.

  The polymer X and the polymer Y can be directly added and dissolved as materials constituting the dope solution described later, or can be added to the dope solution after being dissolved in advance in an organic solvent for dissolving the cellulose ester.

  The total content of the plasticizer in the cellulose ester film is preferably 5 to 20% by mass, more preferably 6 to 16% by mass, and particularly preferably 8 to 13% by mass with respect to the total solid content. The contents of the two kinds of plasticizers are each at least 1% by mass, preferably 2% by mass or more.

  The production of the cellulose ester film which is a preferred support according to the present invention may be either a solution casting method or a melt casting method. In the case of the solution casting method, for example, JP 2005-134609 A, JP Examples thereof include methods described in JP-A Nos. 2005-156683 and 2008-268568.

  Although the film thickness of a cellulose-ester film is not specifically limited, 10-200 micrometers is used preferably. In particular, the film thickness is particularly preferably 10 to 70 μm. More preferably, it is 20-60 micrometers. Most preferably, it is 35-60 micrometers. Moreover, the cellulose ester film made into the multilayer structure by the co-casting method can also be used preferably.

  The cellulose ester film has a width of 1 m or more and preferably has a width of 1.4 to 4 m. Especially preferably, it is 1.4-3 m. If it exceeds 4 m, conveyance becomes difficult. Moreover, it is preferable that the centerline average roughness (Ra) of the cellulose-ester film surface is the range of 0.001-1 micrometer.

  The cellulose ester film has an in-plane retardation Ro represented by the following formula in an environment of 23 ° C. and 55% RH within a range of 0 ≦ Ro ≦ 50 nm and a thickness direction retardation Rt of −400 nm ≦ Rt ≦ 400 nm. It is preferable.

Ro = (nx−ny) × d
Rt = {(nx + ny) / 2−nz} × d
(In the formula, the refractive index in the slow axis direction in the film plane is nx, the refractive index in the direction perpendicular to the slow axis in the plane is ny, the refractive index in the thickness direction is nz, and d is the film thickness (nm). Represents.)
<Functional layer>
The following functional layers can be further provided on the optical film having the hard coat layer of the present invention. Examples thereof include an antireflection layer, an antifouling layer, a backcoat layer, an anti-curl layer, an antistatic layer, an undercoat layer, a light scattering layer, and an adhesive layer.

  Among these, a back coat layer particularly useful for curling will be described.

<Back coat layer>
In the optical film of the present invention, a back coat layer is preferably provided on the surface of the support opposite to the side on which the hard coat layer is provided. The back coat layer is provided in order to correct curling caused by providing a curable resin layer or other layers. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. The back coat layer is preferably applied also as an anti-blocking layer. In this case, it is preferable that fine particles are added to the back coat layer coating composition in order to provide an anti-blocking function.

  As fine particles added to the back coat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxidation. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Those containing silicon as fine particles are preferable in terms of low haze, and silicon dioxide is particularly preferable.

  Examples of the resin used as the binder of the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin Rubber resins such as polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile resin, Examples thereof include, but are not limited to, silicone resins and fluorine resins. Particularly preferred are cellulose resin layers such as diacetylcellulose and cellulose acetate propionate.

  Furthermore, it is also preferable to contain the cellulose nanofiber which concerns on this invention, and it can be made to contain by the method similar to a hard-coat layer.

<Polarizer>
A polarizing plate using the optical film of the present invention will be described.

  The polarizing plate can be produced by a general method. When the optical film of the present invention is a cellulose ester film, the back side of the film is subjected to alkali saponification treatment, and the treated optical film is immersed and stretched in an iodine solution. Bonding is performed using an aqueous polyvinyl alcohol solution. The optical film may be used on the other surface, or another polarizing plate protective film may be used. With respect to the optical film of the present invention, the polarizing plate protective film used on the other surface has an in-plane retardation Ro of 590 nm, an optical compensation film having a phase difference of 20 to 70 nm and Rt of 100 to 400 nm (phase difference). Film). These can be prepared, for example, by the methods described in JP-A No. 2002-71957 and Japanese Patent Application No. 2002-155395. Alternatively, a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal can be used. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348.

  Moreover, as another polarizing plate protective film used for the other surface, a non-oriented film having Ro of 590 nm to 0 to 5 nm and Rt of -20 to +20 nm is also preferably used.

  As the polarizing plate protective film used on the back side, a commercially available cellulose ester film can be used, and KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR -1, KC4FR-2 (manufactured by Konica Minolta Opto Co., Ltd.) and the like are preferably used.

  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 optical film of 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.

<Display device>
By incorporating a polarizing plate using the optical film of the present invention on at least one surface into a liquid crystal display, various liquid crystal displays of the present invention having excellent visibility can be produced. The optical film of the present invention is incorporated in the polarizing plate, and is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, OCB. It is preferably used in LCDs of various drive systems such as molds.

  When the polarizing plate of the present invention is used in place of the pre-bonded polarizing plate of Sharp's 32-inch TV AQ-32AD5, which is a VA liquid crystal display, it has excellent visibility and has scratches on the surface. High durability that is difficult.

  The cellulose nanofiber-containing optical film with a hard coat layer of the present invention is excellent in mechanical strength as a polarizing plate protective film, so that the film thickness can be reduced. A polarizing plate using the film, and a liquid crystal display using the polarizing plate Can also be thinned.

  The optical film of the present invention is excellent in flatness and is preferably used for various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
<Production of support>
<Preparation of TAC film 1>
Table 1 shows the cellulose ester, (meth) acrylic polymer, plasticizer, and ultraviolet absorber used in the examples.

  (Meth) acrylic polymer A: a glass flask equipped with a stirrer, two dropping funnels, a gas introduction tube and a thermometer, 40 g of a monomer mixture of the types and mass ratios shown in Table 1, and a chain transfer agent mercaptopropion The acid 3.0g and toluene 30g were prepared, and it heated up at 90 degreeC. Thereafter, from one dropping funnel, 60 g of a monomer mixture of the types and ratios shown in Table 1 was dropped over 3 hours, and at the same time, 0.6 g of azobisisobutyronitrile dissolved in 14 g of toluene was added from the other funnel. The solution was added dropwise over 3 hours. Thereafter, 0.6 g of azobisisobutyronitrile dissolved in 56 g of toluene was added dropwise over 2 hours, and the reaction was further continued for 2 hours to obtain (meth) acrylic polymer A.

  The weight average molecular weight of the (meth) acrylic polymer A is shown in Table 1 by the following measurement method.

(Molecular weight measurement)
The weight average molecular weight was 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 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples were used. Thirteen samples are used at approximately equal intervals.

(Fine particle dispersion 1)
Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

<In-line additive solution>
Cellulose ester A was added to a dissolution tank containing methylene chloride and heated to completely dissolve, and this was then added to Azumi filter paper No. 3 manufactured by Azumi Filter Paper Co., Ltd. Filtered using 244.

  The fine particle dispersion was slowly added thereto while sufficiently stirring the filtered cellulose ester solution. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare Inline Additive Solution 1.

Methylene chloride 99 parts by weight Cellulose ester A 4 parts by weight Fine particle dispersion 1 11 parts by weight A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose ester A was added to a pressurized dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope solution was prepared by filtration using 244.

(Main dope composition)
Methylene chloride 380 parts by weight Ethanol 70 parts by weight Cellulose ester A 100 parts by weight Plasticizer A 10 parts by weight UV absorber A 2 parts by weight The above is put into a closed container, heated and stirred, and completely dissolved. Azumi filter paper No. No. 24 was used for filtration to prepare a dope solution.

  The dope solution was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. in the film production line. In the inline additive solution line, the inline additive solution was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. Add 2 parts by weight of the filtered in-line additive to 100 parts by weight of the filtered dope solution, mix thoroughly with an in-line mixer (Toray static type in-pipe mixer Hi-Mixer, SWJ), and then use a belt casting apparatus. Used at a temperature of 35 ° C. and a width of 1.8 m and uniformly cast on a stainless steel band support. With the stainless steel band support, the solvent was evaporated until the residual solvent amount became 120%, and then peeled off from the stainless steel band support. The peeled cellulose ester web was evaporated at 50 ° C. and slit to a width of 1.65 m, and then in a TD direction (direction perpendicular to the film transport direction) with a tenter, a temperature of 130 ° C. and a draw ratio of 1.15. And stretched. Drying is completed while transporting the 120 ° C drying zone with many rolls, slitting to a width of 1.5m, knurling with a width of 15mm and an average height of 10μm at both ends of the film, and an TAC film with an average film thickness of 80μm 1 was produced. The winding length was 5000 m.

<Preparation of CAP film 1>
CAP film 1 having an average film thickness of 80 μm and a winding length of 5000 m was produced in the same manner except that cellulose ester B described in Table 1 was used instead of cellulose ester A of TAC film 1.

<Preparation of acrylic resin film 1>
An acrylic resin film 1 having an average film thickness of 80 μm and a winding length of 5000 m was produced in the same manner except that the (meth) acrylic polymer A was used instead of the plasticizer A of the TAC film 1.

(Main dope composition)
Methylene chloride 380 parts by mass Ethanol 70 parts by mass Cellulose ester A 100 parts by mass (Meth) acrylic polymer A 10 parts by mass Ultraviolet absorber A 2 parts by mass <Preparation of acrylic resin film 2>
(Preparation of acrylic fine particles (C1))
A reactor with a reflux condenser with an internal volume of 60 liters was charged with 38.2 liters of ion-exchanged water and 111.6 g of sodium dioctylsulfosuccinate, and the temperature was raised to 75 ° C. under a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. The effect of oxygen was virtually eliminated. 0.36 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of 1657 g of MMA, 21.6 g of BA, and 1.68 g of ALMA was added all at once, and after the exothermic peak was detected, the mixture was held for another 20 minutes to polymerize the innermost hard layer. Completed.

  Next, 3.48 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of BA 8105 g, PEGDA (200) 31.9 g, and ALMA 264.0 g was continuously added over 120 minutes. Hold for a minute to complete the soft layer polymerization. Next, 1.32 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of 2106 g of MMA and 201.6 g of BA was continuously added over 20 minutes. The polymerization of was completed. Next, 1.32 g of APS was added, and after 5 minutes, a monomer mixture consisting of 3148 g of MMA, 201.6 g of BA, and 10.1 g of n-OM was continuously added over 20 minutes, and the mixture was held for another 20 minutes after the addition was completed. Next, the temperature was raised to 95 ° C. and held for 60 minutes to complete the polymerization of the outermost hard layer 2.

  A small amount of the polymer latex thus obtained was collected, and the flat particle size was determined by the absorbance method, which was 0.10 μm. The remaining latex was put into a 3% by mass sodium sulfate warm aqueous solution, salted out and coagulated, and then dried after repeated dehydration and washing to obtain acrylic fine particles (C1) having a three-layer structure.

  The above abbreviations are the following materials.

MMA; methyl methacrylate BA; n-butyl acrylate ALMA; allyl methacrylate PEGDA; polyethylene glycol diacrylate (molecular weight 200)
n-OM; n-octyl mercaptan APS; ammonium persulfate (Preparation of dope solution)
Delpet 80N (MMA and MA (methyl acrylate) copolymer acrylic resin, manufactured by Asahi Kasei Chemicals) 70 parts by mass Cellulose ester B 30 parts by mass The above prepared acrylic fine particles (C1) 20 parts by mass Methylene chloride 300 parts by mass Ethanol 40 Mass part (film formation of acrylic resin film 2)
The produced dope solution was uniformly cast on a stainless steel band support at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the residual solvent amount reached 100%, and the film was peeled off from the stainless steel band support with a peeling tension of 162 N / m. The peeled acrylic resin web was evaporated at 35 ° C., slit to 1.6 m width, and then dried at a drying temperature of 135 ° C. while being stretched 1.15 times in the width direction with a tenter. At this time, the residual solvent amount when starting stretching with a tenter was 10%. After stretching with a tenter and relaxing at 130 ° C for 5 minutes, drying was completed while transporting the drying zone at 120 ° C and 130 ° C with a number of rolls, slitting to a width of 1.5 m, and 10 mm wide at both ends of the film. A knurling process having a thickness of 5 μm was applied, and the core was wound around a 6-inch inner diameter core with an initial tension of 220 N / m and a final tension of 110 N / m to obtain an acrylic resin film 2. The draw ratio in the MD direction calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times. The residual solvent amount of the acrylic resin film 2 was 0.1%, the film thickness was 60 μm, and the winding number was 5000 m.

<Preparation of cycloolefin resin film 1>
A cycloolefin-based resin film stretched in the width direction was produced as follows.

  In a nitrogen atmosphere, 500 parts of dehydrated cyclohexane, 1.2 parts of 1-hexene, 0.15 part of dibutyl ether, and 0.30 part of triisobutylaluminum were mixed in a reactor at room temperature, and then kept at 45 ° C. 20 parts of tricyclo [4.3.0.12,5] deca-3,7-diene (dicyclopentadiene, hereinafter abbreviated as DCP), 1,4-methano-1,4,4a, 9a-tetrahydrofluorene ( Hereinafter, a norbornene-based monomer comprising 140 parts of MTF) and 40 parts of 8-methyl-tetracyclo [4.4.0.12, 5.17,10] -dodec-3-ene (hereinafter abbreviated as MTD). The mixture and 40 parts of tungsten hexachloride (0.7% toluene solution) were continuously added over 2 hours for polymerization. To the polymerization solution, 1.06 part of butyl glycidyl ether and 0.52 part of isopropyl alcohol were added to deactivate the polymerization catalyst and stop the polymerization reaction.

  Next, 270 parts of cyclohexane is added to 100 parts of the reaction solution containing the obtained ring-opening polymer, and further 5 parts of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) is added as a hydrogenation catalyst. The mixture was heated to 200 ° C. while being pressurized and stirred, and then reacted for 4 hours to obtain a reaction solution containing 20% of a DCP / MTF / MTD ring-opening polymer hydrogenated polymer. After removing the hydrogenation catalyst by filtration, a soft polymer (manufactured by Kuraray; Septon 2002) and an antioxidant (manufactured by Ciba Japan; Irganox 1010) are added and dissolved in the obtained solutions. (Both 0.1 parts per 100 parts polymer). Next, cyclohexane and other volatile components, which are solvents, are removed from the solution using a cylindrical concentration dryer (manufactured by Hitachi, Ltd.), the hydrogenated polymer is extruded in a strand form from an extruder in a molten state, and pellets after cooling. And recovered. When the copolymerization ratio of each norbornene monomer in the polymer was calculated from the composition of the residual norbornenes in the solution after polymerization (by gas chromatography method), it was almost charged at DCP / MTF / MTD = 10/70/20. It was equal to the composition. This hydrogenated ring-opened polymer had a weight average molecular weight (Mw) of 31,000, a molecular weight distribution (Mw / Mn) of 2.5, a hydrogenation rate of 99.9%, and a Tg of 134 ° C.

  The obtained pellets of the ring-opened polymer hydrogenated product were dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated to remove moisture. Next, the pellets were subjected to a short shaft extruder having a coat hanger type T die having a lip width of 1400 mm (manufactured by Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip material is tungsten carbide, peel strength 44N from molten resin). It was used for melt extrusion molding to produce a cycloolefin resin film 1 having a thickness of 50 μm. Extrusion molding was performed in a clean room of class 10,000 or less under molding conditions of a molten resin temperature of 240 ° C. and a T die temperature of 240 ° C. The resulting film was stretched 1.50 times in the width direction at a stretching temperature of 155 ° C. using a tenter device in the middle of the drying process, and the obtained cycloolefin resin film 1 having a film thickness of 80 μm was slit at both ears. And processed to a width of 1.5 m. Moreover, when winding up, the polyester film was wound up together with the winding length of 5000 m as a protective film.

<Preparation of polycarbonate film 1>
In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 152400 parts of ion-exchanged water and 84320 parts of 25% aqueous sodium hydroxide solution were added, and 9,9-bis (4-hydroxy-3 having a purity of 99.8% by HPLC analysis. -Methylphenyl) fluorene (hereinafter sometimes abbreviated as “biscresol fluorene”) 34848 parts, 2,2-bis (4-hydroxyphenyl) propane 9008 parts (hereinafter sometimes abbreviated as “bisphenol A”) and After dissolving 88 parts of hydrosulfite, 178400 parts of methylene chloride was added, and 18248 parts of phosgene was blown in at 60 ° C. for 15 minutes at 15-25 ° C. with stirring. After completion of the phosgene blowing, a solution obtained by dissolving 177.8 parts of p-tert-butylphenol in 2640 parts of methylene chloride and 10560 parts of a 25% aqueous sodium hydroxide solution were added. The reaction was terminated by stirring for a period of time. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and when the conductivity of the aqueous phase is almost the same as that of ion-exchanged water, the methylene chloride phase is concentrated and dehydrated to remove polycarbonate. A solution with a concentration of 20% was obtained. The polycarbonate (copolymer A) obtained by removing the solvent from this solution had a molar ratio of biscresol fluorene to bisphenol A of 70:30 (polymer yield 97%). In addition, this polymer had an intrinsic viscosity of 0.674 and a Tg of 226 ° C.

  To 75 parts by mass of a mixed solvent of methylene chloride and ethanol containing 4 parts by mass of ethanol, 25 parts by mass of the polycarbonate was dissolved while stirring at 25 ° C. to obtain a transparent and viscous dope. The dope was cast on a 100 m stainless steel belt, which was blown with dry air and the dew point was controlled to 12 ° C. or less, and was peeled off. The residual solvent concentration at that time was 35%. From the fact that the peelability was good and the charge was small, no peeling step or peeling streaks were observed on the film surface by visual observation. Thereafter, when the residual solvent concentration was 2%, the width was maintained and dried. Then, it dried until the residual solvent density | concentration became 1% or less, and obtained the aromatic polycarbonate film 1 with a film thickness of 80 micrometers and winding length 5000m.

<Preparation of hard coat film>
<Preparation of cellulose nanofiber dispersion 1>
After pulverizing the softwood kraft pulp NDP-T of Nippon Paper Chemical Co., Ltd. with a high-pressure homogenizer until the average fiber diameter is 1 μm or less, this water suspension is used with a grinder (“KM1-10” manufactured by Kurita Machinery Co., Ltd.). The disk was rotated 30 times (30 pass) from the center to the outside through the disk rotating at 1200 rpm in a substantially contacted state. The obtained suspension was once dried, the cellulose on the bulk was put into Methylkuro, pulverized with a high-pressure homogenizer, and further dispersed with a bead disperser using zirconia beads having an average particle diameter of 2 μm. Zirconia beads were removed by centrifugation and filtration to obtain a methylo dispersion of cellulose nanofibers. A part of this dispersion was taken out and the methylochrome was evaporated, and then 100 cellulose nanofibers were observed with an electron microscope and measured to have an average fiber diameter of 60 nm and an average fiber length of 450 nm. The obtained dispersion was concentrated and adjusted so that the solid concentration was 50% by mass.

  Moreover, when the ratio of the amorphous region was measured by adjusting the X-ray diffraction angle of the cellulose nanofiber using an X-ray diffractometer LabX XRD-6100 (manufactured by Shimadzu Corporation), it was 10%.

(Measurement of ratio of amorphous region)
Cellulose nanofibers were mounted on a sample holder, and the diffraction angle of X-ray diffraction was manipulated from 10 ° to 32 ° for measurement. After removing background scattering from the obtained X-ray diffraction pattern, the area obtained by connecting 10 °, 18.5 °, and 32 ° with straight lines on the X-ray diffraction curve was defined as an amorphous region. The ratio of the amorphous region was calculated by the following formula.

Ratio of amorphous region = (area of amorphous region) / (area of entire X-ray diffraction diagram) × 100 (%)
<Preparation of cellulose nanofiber dispersions 2-6>
In cellulose nanofiber dispersion 1, the rotation conditions of the grinder, the crushing conditions of the high-pressure homogenizer, and the dispersion conditions in the bead disperser using zirconia beads were changed, and the average fiber diameter and amorphous region shown in Table 2 were changed. Cellulose nanofibers 2 to 6 were prepared.

<Preparation of hard coat film 1>
(Hardcoat layer coating composition 1)
Dipentaerythritol hexaacrylate monomer 60 parts by mass Dipentaerythritol hexaacrylate dimer 20 parts by mass Dipentaerythritol hexaacrylate trimer or higher component 20 parts by mass Diethoxybenzophenone photoinitiator 6 parts by mass Cellulose nanofiber dispersion Liquid 1 80 parts by mass (40 parts by mass as the solid content of cellulose nanofiber)
Silicone-based surfactant FZ2207 (Nihon Unicar 10% by weight propylene glycol monomethyl ether solution) 1 part by mass of solid component 75 parts by mass of propylene glycol monomethyl ether 75 parts by mass of methyl ethyl ketone (Backcoat layer coating composition 1)
Acetone 35 parts by weight Ethyl acetate 45 parts by weight Isopropyl alcohol 5 parts by weight Diacetylcellulose 0.5 part by weight Ultrafine silica 2% acetone dispersion (Aerosil: 200 V, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by weight The back coat layer coating composition 1 was gravure coated on one surface of the film 1 so as to have a wet film thickness of 13 μm, and dried at a drying temperature of 80 ± 5 ° C. Next, the hard coat layer coating composition 1 is applied to the other surface of the TAC film 1 so as to have a wet film thickness of 15 μm, dried at a drying temperature of 90 ° C., and then irradiated with ultraviolet rays at 150 mJ / m. ^The hard coat film 1 was prepared by providing a hard coat layer having a dry film thickness of 7 μm.

<Preparation of hard coat films 2-17>
Similar to the production of the hard coat film 1, the type of support (TAC film 1, CAP film 1, acrylic resin films 1, 2, cycloolefin resin film 1, polycarbonate film 1), the type of cellulose nanofiber dispersion, Addition amount, type of dispersant, presence / absence of addition of cellulose nanofiber to back coat layer, film thickness of hard coat layer (HC layer in Table 3), presence / absence of addition of fine particles were changed as shown in Table 3. Thus, hard coat films 2 to 17 were produced.

  In addition, the cycloolefin resin film 1 was described as COP film 1 in the table, and the polycarbonate film 1 was described as PC film 1.

  The dispersing agents in the table are the following compounds.

Emulgen 404: Kao Corporation HLB value 8.8
D108: Disperbyk-108 manufactured by Big Chemie
When adding cellulose nanofibers to the backcoat layer (BC layer), 1 part by mass of the cellulose nanofiber dispersion 2 was added to the backcoat layer coating composition 1.

  When fine particles were added to the hard coat layer, 20 parts by mass of a 2% methanol dispersion of silica particles (KE-P30, manufactured by Nippon Shokubai Co., Ltd.) was added to the composition of the hard coat layer coating composition 1.

<Evaluation>
The following evaluation was performed using the hard coat films 1 to 17 produced above.

(Transmittance)
Each sample was subjected to a storage cycle of 12 hours at a temperature of 40 ° C. and a relative humidity of 55% for 12 hours and at a temperature of 20 ° C. and a relative humidity of 55% for 7 days, after which a spectrophotometer U-3200 (Hitachi The spectral transmittance in the visible light region of the hard coat film was measured using a manufacturing method, and then averaged to evaluate the total light transmittance (%) according to the following criteria.

◎: 85% or more ○: 80% or more and less than 84% △: 70% or more and less than 80% ×: less than 70% (pencil hardness)
The prepared hard coat film was conditioned for 2 hours under conditions of a temperature of 25 ° C. and a relative humidity of 55%, and then each sample was subjected to conditions of a temperature of 40 ° C. and a relative humidity of 55% for 12 hours, a temperature of 20 ° C. and a relative humidity of 55%. After a 12-hour storage cycle was repeated for 7 days under the above conditions, measurement was performed according to the pencil hardness evaluation method specified by JIS K 5400 using a test pencil specified by JIS S 6006. Evaluation was made according to the following criteria.

◎: 4H or more ○: 3H to less than 4H △: 2H to less than 3H ×: 1H or less (curl)
Each sample was subjected to a storage cycle of 12 hours under a condition of a temperature of 40 ° C. and a relative humidity of 55% for 12 hours, and under a condition of a temperature of 20 ° C. and a relative humidity of 55% for 7 days. , Using a curl measurement template of Method A in “Measuring Method for Curling of Photographic Film” of JIS K7619-1988. Here, “curl plus” means a curl where the hard coat layer coating side of the film is inside the curve, and “minus” means a curl where the coating side is outside the curve. Further, the curl is expressed by the following formula A.

[Formula A] Curl = 1 / R R is the radius of curvature (m)
The ranking was as follows according to the curl amount of the measurement result.

◎ (Excellent): Minus 5 to Plus 5
○ (excellent): minus 10 to minus 5, plus 5 to plus 10
Δ (slightly inferior and has practical problems): minus 15 to minus 10, plus 10 to plus 15
X (Inferior): minus 15 or less, plus 15 or more (crack)
Each sample was subjected to a storage cycle of 12 hours at a temperature of 40 ° C. and a relative humidity of 55% for 12 hours and at a temperature of 20 ° C. and a relative humidity of 55% for 7 days. The hard coat film was conditioned at a temperature of 25 ° C. and a relative humidity of 55% for 2 hours, and then subjected to a method based on the MIT test described in JIS P 8115: 2001. It was confirmed and evaluated visually.

  ○: No crack is generated in a bending test of 100 times or more.

  X: A crack occurs in a bending test less than 100 times.

(Shrinkage)
The prepared hard coat film was conditioned at a temperature of 50 ° C. and a relative humidity of 80% for 24 hours, and then visually evaluated whether shrinkage wrinkles were generated on the surface of the hard coat film.

○: The occurrence of shrinkage wrinkles is not apparent ×: The occurrence of shrinkage wrinkles is visible (antiglare property)
Each sample was subjected to a storage cycle of 12 hours at a temperature of 40 ° C. and a relative humidity of 55% for 12 hours and at a temperature of 20 ° C. and a relative humidity of 55% for 7 days, and then the hard coat film was placed under a fluorescent lamp. Then, sensory evaluation was performed on the reflected image of the fluorescent lamp. Judgment criteria are as follows.

  The case where the outline of the fluorescent lamp is blurred and the reflection is not bothered at all, or the case where the outline of the fluorescent lamp is slightly noticeable but has an anti-glare property that does not bother much is given.

  Table 3 shows the configuration of the hard coat film and the evaluation results.

  The hard coat films 1 to 13, 16, and 17 of the present invention have high pencil hardness even after being stored under high temperature and low temperature fluctuations, and transmittance, curl, cracking, and shrinkage wrinkle are comparative examples. On the other hand, it can be seen that it has been improved.

Example 2
<Production of polarizing plate and liquid crystal display device>
(Alkaline saponification treatment)
The produced hard coat films 1 to 15 and Konica Minolta Tack KC8UCR-5 (manufactured by Konica Minolta Opto) were subjected to alkali saponification treatment as described below.

Saponification step 2.5M-NaOH 50 ° C. 90 seconds Water washing step Water 30 ° C. 45 seconds Neutralization step 10 parts HCl 30 ° C. 45 seconds Water washing step Water 30 ° C. 45 seconds Water treatment, neutralization, water washing in this order Followed by drying at 80 ° C. for 15 minutes.

<Production and bonding of polarizers>
A 120 μm-thick long roll polyvinyl alcohol film was immersed in 100 parts by mass of an aqueous solution containing 1 part by mass of iodine and 4 parts by mass of boric acid, and stretched in the film forming direction 6 times at 50 ° C. to produce a polarizer.

  Next, using a polyvinyl alcohol-based adhesive, the hard coat film is bonded to one side of the polarizer so that the transmission axis of the polarizer and the in-plane slow axis of the cellulose ester film are parallel, and the opposite side Konica Minolta Tac KC8UCR-5 (manufactured by Konica Minolta Opto Co., Ltd.) was laminated on the surface of the film to obtain polarizing plates 101 to 115.

  About the hard-coat films 16 and 17, it bonded to the single side | surface of the polarizing plate which bonded Konica Minolta Tack KC8UCR-5 on both surfaces using the acrylic adhesive, and was set as the polarizing plates 116 and 117.

  The polarizing plate using the hard coat film of the present invention was free from curling and scratches in the above operation, and the yield was clearly improved.

<Production of liquid crystal display device>
The obtained polarizing plate was carefully peeled off from the viewing side polarizing plate that had been bonded in advance to Sony's 32-inch LCD TV “BRAVIA” KDL-32J5000, and aligned with the transmission axis of the polarizing plate originally applied. A liquid crystal display device was produced by pasting on the cell side via an adhesive.

  The liquid crystal display device equipped with the polarizing plate using the hard coat film of the present invention was excellent in surface flatness and scratches, and the eyes did not get tired even when viewed for a long time.

Claims (10)

  An optical film obtained by laminating a hard coat layer containing cellulose nanofibers having an average fiber diameter of 4 to 200 nm on a support.   The optical film according to claim 1, wherein an amorphous region of the cellulose nanofiber is 3% to 60%.   The optical film according to claim 1, wherein the hard coat layer contains fine particles.   The optical film according to claim 1, wherein the hard coat layer contains a dispersant.   The optical film according to claim 4, wherein the dispersant has an HLB value of 5 to 15.   The optical film according to claim 4, wherein the dispersant has both an acid value and an amine value.   The optical film according to any one of claims 1 to 6, wherein the total light transmittance is 80% or more.   A polarizing plate comprising a polarizer and two polarizing plate protective films sandwiching the polarizer, wherein one of the two polarizing plate protective films is the optical film according to any one of claims 1 to 7. A polarizing plate characterized by the above.   A display device comprising the optical film according to claim 1 or the polarizing plate according to claim 8.   The optical film according to claim 1, wherein the support contains a cellulose ester as a composition.