TW201105480A - Method for producing optical film, optical film, and apparatus for producing optical film - Google Patents

Abstract

Disclosed are: a method for producing an optical film in which the release properties of a thermoplastic resin film from a touch roller is improved and transverse irregularities are not caused; an optical film produced by the production method; and an apparatus for producing an optical film. The method for producing an optical film comprises a casting step in which a molten material containing a thermoplastic resin is extruded into a film shape on the surface of a rotary support from a casting die; and a sandwiching and pressing step in which the film-shaped molten material extruded in the casting step is sandwiched and pressed between the rotary support and a sandwiching and pressing rotator. In the production method, in order to improve release properties between the sandwiching and pressing rotator and the film-shaped molten material, a release property adjusting agent is applied to the surface of the sandwiching and pressing rotator.

Description

[Technical Field] The present invention relates to a method for producing an optical film for producing an optical film containing a thermoplastic resin such as a cellulose resin by a melt casting film formation method, a manufacturing apparatus, and an optical film. . [Prior Art] Compared with the conventional CRT display device, the liquid crystal display device is widely used as a monitor because it is space-saving and energy-saving. Further popularization as used on television. In such a liquid crystal display device, various optical films such as a protective film for a polarizing plate or a retardation film are used. The protective film for a polarizing plate is attached to a polarizing film made of a stretched polyvinyl alcohol to protect a film for a polarizing film, and a film containing a thermoplastic resin such as a cellulose resin is used. The retardation film is used to extend a film or the like of a thermoplastic resin such as a cellulose resin to provide a retardation. Sometimes referred to as an optical compensation film. The method for producing such an optical film can be classified into a melt casting film forming method and a solution casting film forming method. The former is a method in which a molten stream obtained by heating and melting a thermoplastic resin is extended on a support, and after cooling and solidifying, a film can be formed by stretching or the like if necessary, and the latter is obtained by dissolving the polymer in a solvent and casting the solution to a support. After the solvent is evaporated, a method of forming a film such as stretching may be carried out if necessary. In the past, the reason for the uniformity of the film thickness is easy, etc.

E -5- 201105480 The manufacture of the liquid casting film forming method is the mainstream. However, since the solution casting film forming method requires a large production facility due to the solvent recovery, it has been attracting attention by the melt casting film forming method without such a problem. These optical films require optical properties, particularly delay uniformity. With the increase in size or weight of monitors or TVs, the uniformity of delay is becoming more stringent, and the widening, thinning, and smoothness of optical films are strongly demanded. The optical film produced by the melt-casting film formation method is generally obtained by extruding a melt of a thermoplastic resin containing a cellulose resin or the like into a film shape on a rotary support by a casting die (hereinafter also referred to as a cast roll). The surface of the film-like melt (hereinafter also referred to as a film) after extrusion is pressed by a rotary support and a rolling rotating body (hereinafter also referred to as a touch roll) to obtain a film. The surface of the contact roller is mirror-finished in order to improve the surface smoothness of the film. When this rolling is performed, the pressure applied to the film affects the alignment state of the resin, and the retardation of the obtained film changes. Therefore, in order to obtain an optical film having high retardation uniformity, it is important to press at a sufficiently uniform pressure. However, as the width of the optical film is widened, the width of the casting die is widened, and the melted film-like melt is difficult to be uniformly pressed by the casting roll and the contact roll. A method for solving such a problem, for example, a method in which a contact roller uses an elastic roller having a metal cylinder on the outer circumference (hereinafter also referred to as an elastic metal roller) to make the pressure at the time of rolling uniform, or Patent Document 1 proposes to flow from a casting die to casting. The temperature of the melt of the roll is set higher than the conventional one, and even if the pressure of the casting roll and the contact roll is not uniform, the method of suppressing the unevenness of the delay can be suppressed. [PRIOR ART DOCUMENT] [Patent Document 1] [Patent Document 1] Japanese Laid-Open Patent Publication No. 2005- 1 72940 [Summary of the Invention] [Problem to be Solved by the Invention] However, the thermoplasticity contained in the casting roll is contained. When the melt of the resin is pressed and brought into contact with the surface-finished contact roll, the film of the contact roll is liable to be peeled off, and unevenness (lateral unevenness) may occur in the film width direction. Further, when the contact roller is an elastic metal roller or when the temperature of the melt is raised as in Patent Document 1, the adhesion to the contact roller is increased, and peeling failure may occur, and lateral unevenness is more likely to occur, and unevenness is uneven. It also becomes a big problem. Therefore, the object of the present invention is to provide a method for producing an optical film which does not cause lateral unevenness or unevenness in retardation, and a method for producing an optical film, and an optical film produced by the method. [Means for Solving the Problem] In order to solve the above problems, the present invention has the following features. A method for producing an optical film, comprising: a casting step of extruding a melt containing a thermoplastic resin into a film form on a surface of a rotating support sheet 201105480; and extruding the casting step The method for producing an optical film in which the molten material is subjected to a rolling step of rolling the rotating support and the rolling rotating body, wherein the rolling rotating body is coated with the rolling rotating body and the film. A mold release property adjuster having a good mold release property. The method for producing an optical film according to the above aspect, wherein the release property adjuster contains at least one of the same as the additive contained in the melt. 3. The method for producing an optical film according to the above item 1 or 2, wherein the release property adjusting agent is an ultraviolet absorber for absorbing ultraviolet rays inside the optical film. The method for producing an optical film according to any one of the items 1 to 3, wherein the release property adjuster has a boiling point of from 150 to 250. The method for producing an optical film according to any one of the above items 1 to 4, wherein the thickness of the release mold adjusting agent is from 0.05 to 100 μm. A method for producing an optical film, wherein a contact angle S1 between a surface of the rotary support and water and a contact angle S 2 of the surface of the rotating body after applying the release modifier are 0.5° < 7. The method of producing an optical film according to any one of the above-mentioned items 1 to 6, wherein the film-like melting of the rolling rotating body in a state of being pressed against the rotating support The difference T1 - T2 between the transport tension T1 of the object and the transport of the film-like melt in the state in which the rolling rotor is not pressed against the rotary support is -1 to 250N. The method of producing an optical film according to any one of the items 1 to 7, wherein the thermoplastic resin is a cellulose ester resin. 9. An optical film characterized by the optical according to any one of items 1 to 8. Manufacturer of the manufacturing method of the film. 10. Manufacturing of optical film Further, the method further comprises: casting a melt containing a thermoplastic resin into a film-forming casting die on a surface of a rotating support; and extruding the film-shaped melt extruded from the casting die by the rotating support and rolling The apparatus for producing an optical film of a rolling apparatus for pressing a body has a mold release property of applying a mold release property to the surface of the rolling rotating body to improve the mold release property of the rolling rotating body and the film-shaped melt. According to the present invention, the release property adjuster is applied to the surface of the rolling rotating body, and then the film is formed by rotating the support and the rolling rotating body. The melt is thus improved in the release property of the film of the rolling rotating body. Therefore, it is possible to provide a method for producing an optical film which does not cause lateral unevenness or uneven retardation when the film is peeled off from the rolling rotating body, and the production of the optical film. The apparatus and the optical film manufactured by the manufacturing method. [Embodiment of the invention] Hereinafter, the embodiment of the invention will be described with reference to the drawings, but the invention is not limited to -9 - 201105480. The method for producing an optical film according to the invention includes a casting step of extruding a melt containing a thermoplastic resin into a film form on a surface of a rotary support (casting roll), and extruding the casting step. a method for producing an optical film in which a molten material is subjected to a rolling step of rolling a rotating body and a rolling rotating body (contact roll), characterized in that the surface of the rolling rotating body is coated with the rolling rotating body and the foregoing Method for producing an optical film of a release property adjusting agent having a good mold release property as a film-like melt. FIG. 1 is a view showing a casting step and rolling of a manufacturing apparatus using an embodiment of the method for producing an optical film of the present invention. A step of the step of casting the melt containing the thermoplastic resin to the position of the crucible 1 on the casting roll 5 by the casting die 4 as a casting means. At this time, the surface of the touch roll 6 is moved upward from the position of the pressing portion ,2, and the release property adjusting agent 104 is applied by the release-adjusting agent applying device 1 。. The melt enthalpy which is extruded from the casting die 4 to the nip 1 position on the casting roll 5 is pressed by the contact roll 6 and the casting roll 5 at the Ρ 2 position by the pressing means at the Ρ 2 position. The melted product is formed into a film shape, conveyed to the casting roll 5, peeled off at the Ρ3 position, and then moved to the next step. The release-adjusting agent coating device 100 is configured to suck the liquid release-reducing agent 104 in the storage tank 105 heated to a predetermined temperature by the suction roller 102, and is limited to a certain amount by the restriction blade 103. The release-adjusting agent 104 on the selected suction roll 1 〇2 is transferred to the coating roll 101 and applied to the contact roll 6-10-201105480. As described above, before the rolling step, after the release agent is applied to the surface of the touch roll 6, the film is pressed by the casting roll 5 and the contact roll 6 in the rolling step, so that the adhesion of the film to the casting roll 5 is greater than that of the film. The adhesion to the contact roller 6 can suppress the occurrence of peeling failure of the contact roller 6 and the film at the time of peeling. In particular, in order to improve the smoothness of the surface of the film, when the surface of the touch roll 6 is mirror-finished or when the elastic metal roll is used for the contact roll, in order to prevent the pressing step from being uneven, the residual phase difference is lowered, and the film temperature is made high. When the rolling or the like is performed, peeling failure of the contact roll and the film is liable to occur, but the peeling failure can be effectively removed by the present invention. The above-mentioned constitution applies the release-adjusting agent to the contact roller 6, but the release-adjusting agent can also be applied to both surfaces of the contact roller 6 and the casting roller 5, and the adhesion of the film to the casting roller 5 is adjusted to be larger than The adhesive force of the film and the contact roll 6 can suppress the peeling failure of the contact roll 6 and the film at the time of peeling. The release agent of the present invention is a material which improves the release property of the contact roll 6 from the film, that is, It is not particularly limited and may be liquid or solid, and the product is preferably one which does not affect the necessary optical film properties. More preferably, the same material as that used for the optical film is used as a mold release adjuster. When a release property adjusting agent of the same material as the additive is used, even if the release property adjusting agent applied to the touch roll 6 is attached to the surface of the optical film, the optical film characteristics are hardly affected, and the contact can be effectively eliminated. The peeling of the roller 6 from the film is poor. Specific examples of the mold release modifier include polyoxyxane oil or dimethyloxane, I S] -11 - 201105480 methylene chloride, a plasticizer used as an additive for an optical film, an ultraviolet absorber, and the like. Further, a liquid in which organic or inorganic fine particles are dispersed may also be used. The release point of the release modifier is preferably from 150 to 250 °C. When the boiling point is this range, the surface temperature of the contact roller on the surface of the contact roller 6 is lower than 150. Therefore, the release property adjuster becomes liquid or solid, and functions as a release property adjuster. 'The mold release agent adjusted to the surface of the film after being released from the contact roll 6 is subjected to a high temperature step. The step is set to be more than the boiling point to cause volatilization, and the release property adjuster does not remain on the surface of the film, and the performance of the optical film can be maintained, which is preferable. The release modifier is particularly preferably an ultraviolet absorber. Since the ultraviolet ray absorbing agent has a high peeling property and the release property is exhibited by a thin layer, the smoothness of the surface of the film after the release of the contact roll 6 is improved, which is preferable. Further, since the constituent material of the optical film originally used for the optical film is added, it is preferable since it is incorporated in the optical film without affecting the characteristics of the optical film in the production step. The coating film thickness of the release property adjusting agent applied to the surface of the contact roll is preferably from 0.05 to 1,000 / zm. When the coating film thickness is set to this range, coating is too small to cause coating failure or too large, so that the release property adjusting agent stays between the contact roller and the cooling roller, resulting in lateral unevenness or unevenness of the film. It is less dangerous and therefore better. The contact angle S1 between the surface of the casting roll 5 and the contact angle S2 between the surface of the contact roll 6 after application of the release agent is preferably 0.5° < S2_S1 < 100°. S 2-S 1 is set to this range, and it is possible to reduce the coating failure (〇.5° or less) in which the release property is adjusted to -12-201105480, and the coating unevenness of the release property adjuster becomes the film thickness. It is better to have a risk of (1 〇〇 or more). The contact angle between the light surface and the water is measured by using a fully automatic contact angle meter r CA-W type roll type (manufactured by Kyowa Interface Science Co., Ltd.) at 23 ° C, 50 % RH. . In order to take into consideration the change in the measurement enthalpy of pure water evaporation and the stability of the measurement, the measurement is completed within 5 seconds to 30 seconds after the dropping of the pure water droplets. The measurement is performed by the 0/2 method of obtaining the contact angle from the angle of the solid surface to the line connecting the left and right end points of the droplet to the apex. The axial direction of the roller was measured at a right angle, and the amount of dripping was set to 70^1. The measurement was performed at the center of the measuring roller and at the position of 5 cm at the left and right end portions, and each of the circumferential directions of each of 90 degrees was 12 places. , using this average 値 as the contact angle. When the conveying tension of the film-like melt in the state where the contact roller 6 is pressed against the casting roll 5 is T1, and the conveying tension T2 of the film-like melt in a state where the contact roller 6 is not pressed against the casting roller 5, The enthalpy of T1-T2 is preferably from 1 to 2 50 N. The measurement of the conveyance tension is performed by loading a load gauge for taking the load in the vertical direction at both ends of the shaft of the nearest roller on the flow side below the casting roller 5, and calculating the respective loads when the contact roller 6 is pressed or not pressed against the casting roller 5. The difference between the counts and the total is ΤΙ-Τ'2. When the 値1 to Τ2 of the difference in the conveyance tension is set in the above range, the film (the film-like melt after curing to some extent) when peeled off by the contact roll 6 is not uneven (uniform), and there is no excessive stretching, so The film thickness may be uneven due to the deviation or the stretching may cause breakage, etc., and may be sent to the contact roller 6 in a stable manner.

F -13- 201105480 Peeled film. In particular, when the film thickness is 40/zm, the peeling property by the contact roll 6 can be improved, and when the film is conveyed, a more stable film can be conveyed, and a smooth film having no unevenness is obtained. . As described above, the optical film of the present invention is used to eliminate the peeling failure of the contact roll and the film, the unevenness of the line on the surface of the film in the direction of the film, and the unevenness of the surface or unevenness of the optical film. In particular, when the surface of the contact roll is processed into a mirror surface, or when a metal roll is used, or the adhesion of the melt contact roll extruded from the casting die is increased, the peeling of the contact roll and the film can be improved by the present invention. Poor, an optical film with uneven thickness or uneven retardation can be obtained. Hereinafter, the production of the optical film of the present invention will be described in detail. In the method for producing an optical film of the present invention, the film forming method of heat can be formed by dissolving a film formed by casting a molten resin. The main material of the optical film of the present invention is preferably excellent in adhesion to a film, optically transparent, and the like. As long as it is a thermoplastic resin having the above properties, it is defined as, for example, a cellulose diacetate film, a fiber film, a cellulose acetate butyrate film, a cellulose acetate film such as cellulose acetate, or a polyester film. The polycarbonate film-based film, the polyfluorene-based film (including the polyether maple)-based film, and the lower optical film are fed in the above-mentioned unevenness or retardation method, and no lateral unevenness can be obtained (the use of the non-contact roller can be confirmed) When the temperature of the bomb is used, etc., there is no lateral method on the surface of the film. The plastic resin film is easy to melt and cast, and when it is polarized, there is no thin film of triacetate film. Polyterephthalic acid-14- 201105480 Polyester film of ethylene glycol, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film 'ethylene Vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film 'cycloolefin polymer film, ZEONEX (trade name, manufactured by Zeon Corporation, Japan), ZEONOR (trade name, Japan Zeon Corporation) System), polymethylpentene film, polyetherketone film, polyether ketoximine film, polyamide film, fluororesin film, nylon film, polymethyl methacrylate film, acrylic film or glass A plate or the like is preferably a cellulose ester film, a cycloolefin polymer film, a polycarbonate film, or a polyether (including a polyether boron) film. In the present invention, in terms of production, cost, transparency, Particularly, a cellulose ester-based film or a resin film containing a cyclic hydrocarbon-based addition polymer of 8% or more is particularly preferable. The material constituting the optical film of the present invention contains these resins and, if necessary, contains a resin film. The stabilizer and the plasticizer 'ultraviolet absorber' are used as a matting agent and a retardation controlling agent for the slipping agent. These materials are appropriately selected depending on the desired characteristics of the optical film of the object. When the material of the optical film of the present invention is a cellulose resin a cellulose resin having a structure of a cellulose ester, comprising a cellulose alone or a mixed acid ester of at least one of a fatty acid sulfhydryl group, a substituted or unsubstituted aromatic fluorenyl group (hereinafter only It is called "cellulose resin" and is amorphous. "Amorphous" refers to an irregular molecular arrangement, and is not a crystal, but a solid substance, which indicates the crystal state of the raw material. The cellulose resin for use in the invention is exemplified as disclosed in Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. The bright spot foreign matter means that two polarizing plates are arranged in a cross direction (Nico, Cross Nicols), and a cellulose ester film is disposed therebetween, and the retardation axis of the polarizing plate protective film and the light source side of one of the light sources are polarized. When the position of the plate passing through the axis is parallel, when it is observed at a position perpendicular to the outer side surface of the other polarizing plate, foreign matter causing light leakage is caused. In this case, the polarizing plate for evaluation is preferably formed of a protective film which is free from foreign matter, and it is preferable to use a glass plate to protect the polarizer. One of the causes of the esterification of the hydroxyl group contained in the cellulose resin is that it is a bright spot foreign matter, and the foreign matter can be reduced by using a cellulose resin having a small amount of foreign matter and a cellulose resin which is heated and melted to remove foreign matter. The thinner the film thickness, the less the number of bright foreign matter per unit area, and the less the content of the cellulose resin contained in the film, the less the tendency of bright foreign matter. The number of bright spots is 250 mm2, and the bright spot with a size of 5 to 50 /z m which can be confirmed by the polarized Nicols state is 300 or less, and the bright spot of 50 # m or more is preferably one. More preferably, the highlight of 5~5〇em is 200 or less. When there are many bright spots, it has a great influence on the image of the liquid crystal display. When the phase difference film functions as a polarizing plate protective film, the presence of this bright spot is an important cause of the disorder of birefringence, which has a great adverse effect on the image. When the bright foreign matter is removed by melt filtration, the step of removing the foreign matter including the bright spot is carried out, and the film forming step of the melt casting can be continuously performed. Melt-casting process containing a filtration step by hot-melting bright-spotted foreign matter -16-201105480 Membrane method, a plasticizer and a cellulose resin, which will be described later, are used as a composition in a system in which no plasticizer is added, and the hot melting temperature is lowered. The removal efficiency of foreign matter and the viewpoint of avoiding thermal decomposition. The other additives described later may be filtered in the same manner as the ultraviolet absorber and the demixer. The filter medium is preferably a conventional filter material such as a fluororesin such as glass fiber or cellulose fiber fluorinated vinyl resin, and ceramic or metal. The absolute filtration accuracy is 50, preferably 30 μm or less, and more preferably l〇#m or less 5 // m or less. These can be used in appropriate combinations. The constituent materials other than the cellulose resin of the film constituting material are uniformly mixed, and the polymer material other than the cellulose resin or the vegetal resin can be appropriately selected in terms of the meltability at the time of heating. Such a polymer material or oligomer preferably has a resin compatibility of at least 400 nm to 800 nm when formed into a film, and preferably has a transmittance of 80% or more, more preferably 92% or more. At least one of the other than the cellulose resin or the oligomer is included for the purpose of improving the viscosity of the film or the film properties after the film processing. The material or the oligomer system may also contain other additives. Next, the additives used for the optical film will be explained. These are used for mold release modifiers. Suitable plasticizers are preferably used, for example, a phosphate ester-based ester, a tricresol phosphate, a cresol diphenyl phosphate, or an octyl group. It is better to make the melting of the resin better than the one below #m. The oligomer and the fiber are in the area of the cellulose (I 90% or more of the polymer material is heated and melted. The additive of the tube molecule can be triphenylphosphoric acid diphenyl phosphate-17-201105480 vinegar, diphenylbiphenyl phosphate Ester, trioctyl phosphate, tributyl phosphate, etc., phthalate esters are diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate , dibutyl phthalate, di-2-ethylhexyl decanoate, etc., glycolic acid esters are triacetin 'glycerol tributyrate, butyl decyl butyl glycolate, ethyl酞醯 乙基 ethyl glycolate, methyl decyl ethyl glycolate, butyl decyl butyl glycolate, etc. The above plasticizers may be used in more than two types. At this time, the phosphate vinegar system When the use ratio of the plasticizer is 50% by mass or less, hydrolysis of the cellulose ester-based resin film is less likely to occur, and durability is excellent, and the ratio of the phosphate-based plasticizer is less preferable, and in particular, only the phthalate is used. A glycolic acid-based plasticizer is preferred. In order to set the water absorption rate and moisture content to a specific range Therefore, the amount of the plasticizer to be added is preferably from 3 to 30% by mass, more preferably from 1 to 25% by mass, even more preferably from 15 to 25% by mass, based on the mass% of the cellulose ester-based resin. When the amount is more than 30% by mass, the mechanical strength and dimensional stability of the cellulose ester resin film are deteriorated. Therefore, the oxidation inhibitor is preferably a hindered phenol compound, and specific examples are 2,6-di- Tributyl-p-cresol, pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol bis[3-(3-third butyl) 5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol·bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid Ester], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, 2,2 - thio-di-extension ethyl bis[3-(3,5-di-t-butyl-4-hydroxy-18 - 201105480 phenyl)propionate], octadecyl_3· (3,5 -di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxyl Benzyl)benzene and tris(3,5·di-t-butyl-4-hydroxyl Benzyl)isocyanurate, etc. Particularly preferred is 2,6-di-t-butyl-p-cresol, pentaerythritol tetra[3-(3,5-di-t-butyl-4-hydroxybenzene) Propionate] and triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate]. Also, for example, N, N, - A metal inert agent or tris(2,4-di-t-butylphenyl) of bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propanyl]anthracene A phosphorus-based processing stabilizer such as phosphite. In order to obtain an effect, the amount of such a compound is preferably from 1 ppm to 1% by weight, particularly preferably from 10 to 1,000 ppm, based on the mass ratio of the cellulose ester resin. Preferably, the cellulose ester resin is added with ultraviolet light absorption. Agent. From the viewpoint of preventing deterioration of the liquid crystal, the ultraviolet absorber is preferably excellent in ultraviolet absorption energy at a wavelength of 3 to 70 nm or less, and has a small absorption of visible light having a wavelength of 400 nm or more from the viewpoint of good liquid crystal display properties. Particularly preferably, the transmittance of ultraviolet rays having a wavelength of 3 to 70 nm is 10% or less, and more preferably the transmittance is 5% or less, more preferably 2% or less. The ultraviolet absorber to be used is, for example, an oxybenzophenone-based compound, a benzotriazole-based compound, a salicylate-based compound, a benzophenone-based compound, a cyanoacrylate-based compound, a nickel-salted salt-based compound, or the like. , but not limited to this. These ultraviolet absorbers are preferably used singly or in combination of two or more kinds, and may contain two or more kinds of ultraviolet absorbers.

-19- 201105480 A suitable UV absorber is a benzotriazole-based UV absorber or a ketone-based UV absorber. It is preferable to add a benzotriazole-based ultraviolet absorber having less unnecessary coloring to the cellulose ester-based resin film. The ultraviolet absorber is added by dissolving the ultraviolet absorber in an organic solvent such as an alcohol or methylene chloride or dioxolane, and then adding it to the dope or directly adding it to the dope composition. If the inorganic powder is not dissolved in an organic solvent, it can be dispersed in an organic solvent and a cellulose ester resin using a dispersing machine or a sand mixer, and then added to the dope. The amount of the ultraviolet absorber to be used is 0.1 to 2 - 5 mass% relative to the mass% of the cellulose ester resin, preferably 〇 5 to 2.0 mass%, more preferably 0.8 to 2 mass%. When the amount of the ultraviolet absorber used exceeds 25 mass%, the transparency of the cellulose vinegar-based resin film tends to be deteriorated. Therefore, the cellulose ester-based resin film is not easy to adhere to each other or to impart slipiness. When using the operation, microparticles can be added as a matting agent. The kind of the microparticles may be an inorganic compound or an organic compound. The fine particles of the inorganic compound are, for example, fine particles such as cerium oxide, titanium oxide, aluminum oxide, zirconium oxide or tin oxide. Among them, a compound containing a ruthenium atom is preferred, and ruthenium dioxide is particularly preferred. The cerium oxide microparticles are, for example, AEROSIL-200, 200V, 300, R972 'R972V, R974, R976, R976S, R202' R812, R805, 0X50, TT600, RY50, RX50, NY50, NAX 50, manufactured by AERO SIL Co., Ltd. NA 5 0 Η, NA 5 0 Y, NX90, RY200S, RY200, RX200, R8200, RA200H, -20- 201105480 RA200HS > NA200Y, R816, R104, RY300, RX300 'R l 06, etc. Among these, from the viewpoint of controlling dispersibility or particle size, AEROSIL-200V and R972V are preferred. The average particle diameter of the fine particles in the film is preferably from 50 nm to 2; / m from the viewpoint of imparting slipperiness and ensuring transparency. It is preferably from 100 nm to 1 OOO nm, more preferably from 100 nm to 500 nm. The average particle size in the film is a photograph of the cross-section of the photograph. In the case of microparticles, the primary particle diameter, the particle diameter after dispersion in a solvent, and the particle diameter after addition to a film often change, and it is important to control the particle size formed by the complex aggregation of the microparticles and the cellulose ester resin in the film. . The amount of the fine particles added is 〇·02 to 0.5% by mass, preferably 0.04 to 0.3% by mass based on the cellulose ester resin film. These additives added to the optical film are applied to the surface of the contact roll, so that the adhesion between the contact roll and the film is less than that of the cooling roll and the film, and the release property of the contact roll and the film can be improved. Fig. 2 is a schematic flow chart showing a first embodiment of an apparatus for carrying out the method for producing an optical film of the present invention by a melt casting film forming method. The embodiment in which the film (melt) initially contacts the surface of the casting roll 5 (Ρ 1 ) is different from the point at which the film contacts the surface of the contact roll (rolling rotating body) 6 (, 2), but sometimes the film is initially in contact with the casting roll. The point ( 51) of the surface of 5 is the same as the point (Ρ2) where the film is in contact with the surface of the contact roll (squeezing rotating body) 6. Further, sometimes the film comes into contact with the contact roller 6 and then comes into contact with the crucible 2. In the present embodiment, a film material containing a resin such as a cellulose resin is mixed - 21 - 201105480, and a resin mixture is obtained, which is then melt-extruded from the casting die 4 onto the casting roll 5 using an extruder 1. The surface of the touch roll 6 was coated with a predetermined amount of the ultraviolet absorber as a release property adjuster 104 by a release agent coating device 1 . The extruded film-like melt is circumscribing the casting roll 5 while the surface of the casting roll 5 is pressed by the contact roller 6 at a predetermined pressure. The rolls circulated to the cooling rolls 7 and 8 in this order were cooled and solidified, and peeled off by the peeling rolls 9. The peeled film 17 is stretched in the longitudinal direction (transport direction) and the lateral direction (width direction) of the film by the longitudinal stretching device 10 and the lateral stretching device 20, and then wound by the winding device 60. The details are as follows. The film-formed thermoplastic resin-containing melt extruded by the casting die 4 is extruded onto a casting roll 5 having a cooling function, and is pressed by the contact roll 6 while being cooled and surface-corrected. The casting roll 5 and the touch roll 6 are not limited to the roll, and may be a drum or a belt or the like. The temperature of the casting roll 5 is preferably set to be lower than the glass transition temperature (Tg) of the resin mixture and above the melting point of the additive. The contact roll 6 is for the film, and the film is pressed by the opposite side of the casting roll 5 in the direction of the casting roll 5. The rotating body of the purpose. The surface of the touch roll 6 is preferably metal and has a thickness of from 1 mm to 10 mm. It is preferably 2 mm to 6 mm. The surface of the rolling rotating body is biased by [] plating, and the surface roughness is preferably 〇·1; ζπι or less, more preferably 0.05/zm or less. The smoother the surface of the roll, the smoother the surface of the resulting film. In the rolling step, the contact roll 6 is preferably composed of an elastic roll (elastic metal roll) having a metal cylinder on its outer periphery. -22- 201105480 In other words, when the pressure of the light 6 is uneven, the film is unevenly distributed. This is orthogonal (Cross Nicols) and becomes uneven brightness. In order to face-correct the film with a uniform pressure, it is preferable to have a contact roller having elasticity of a metal cylinder as described above. The metal material of the surface of the touch roll 6 is required to be smooth and has moderate elasticity and durability. It is preferable to use nickel or the like which is made of carbon steel, stainless steel, titanium, or electroforming. It is preferable to apply a surface treatment such as hard chrome plating, nickel plating, amorphous chromium plating, or ceramic flame spraying, in order to increase the hardness of the surface or to improve the release property from the resin. It is preferable that the surface-processed surface is further honed to become the above-mentioned surface roughness. The contact roller 6 has a double structure of a metal outer cylinder and an inner cylinder, and has a structure in which a cooling fluid flows therebetween and has a space double cylinder. The inner cylinder is made of carbon steel, stainless steel, aluminum, titanium, etc., and the rigid metal inner cylinder is preferable. The inner cylinder is made rigid, and the rotation of the roller can be suppressed. When the inner tube has a tube thickness of 2 to 10 times the outer tube, sufficient rigidity can be obtained. The inner cylinder may be further covered with a resin elastic material such as polyoxane or fluororubber, and the space structure for allowing the cooling fluid to flow may be any one that can uniformly control the surface temperature of the roller, for example, can flow back and forth in the width direction to form a mutual flow. The spiral flow controls the small temperature of the temperature distribution on the surface of the roll. The cooling fluid is not particularly limited, and water or oil can be used in combination with the temperature range. The contact roller 6 is of a Taiko type in which the outer diameter of the center portion is larger than the outer diameter of both end portions. The contact roller generally presses the film at both ends thereof by pressurization means. At this time, since the contact roller is flexible, it has a stronger pressing force at the end portion, and the stronger the pressing, the image is -23-201105480. The roller is set to the Taiko type, and a highly uniform press can be obtained. The diameter of the contact roller 6 is preferably in the range of 200 mm to 500 mm. The effective width of the contact roller 6 must be greater than the film width of the rolling. By the difference between the radius of the central portion of the contact roller 6 and the radius of the end portion (hereinafter referred to as the maximum amount), unevenness in the line or the like occurring in the central portion of the film can be prevented. The highest amount is preferably in the range of 50 to 300 m. The casting rolls 5 and the contact rolls 6 are disposed at opposite sides with respect to the plane of the film to press the film. The casting roll 5 and the touch roll 6 may be in surface contact or in line contact with the film. The surface of the touch roll 6 is coated with a predetermined amount of the release property adjuster 1 〇4 by the release property adjusting agent coating device 100 before the film on the casting roll 5 is pressed. The application of the release modifier 〇4 has been previously described in detail and will be omitted here. In the method for producing an optical film of the present embodiment, the conditions of melt extrusion can be carried out in the same conditions as those used for other thermoplastic resins such as polyester. The material is preferably pre-dried. The water is dried to 100 ppm or less, preferably 200 ppm or less, in a vacuum or a vacuum dryer or a dehumidifying hot air dryer. For example, the cellulose ester-based resin which is dried by hot air or vacuum or under reduced pressure is melted by using the extruder 1 at an extrusion temperature of 200 to 30 CTC, and the foreign matter is removed by filtration using a leaf type filter 2 or the like. When the hopper (not shown) is introduced into the extruder 1, it is preferable to prevent oxidative decomposition or the like under the action of a vacuum or under a reduced pressure or an inert gas atmosphere. When the additive such as a plasticizer is not previously mixed, it can be kneaded on the way of the extruder 24-201105480. In order to allow uniform addition, it is preferred to use a mixing device such as a static mixer 3. The resin such as cellulose resin and other stabilizers which are added as needed are preferably mixed before melting. The mixing may be carried out by a mixer or the like, or may be mixed in a resin preparation process such as a cellulose resin as described above. When using a mixer, a general mixer such as a V-type mixer, a conical spiral type mixer, or a horizontal cylinder type mixer can be used. After the film constituting material is mixed as described above, the mixture is directly melted by using the extruder 1 to form a film. However, once the film constituting material is granulated, the granules may be melt-formed by the extruder 1. Further, when the film constituent material contains a plurality of materials having different melting points, the temperature at which only the material having a lower melting point is melted may be formed. Once the so-called rice porridge-like semi-melt is produced, the semi-melt is introduced into the extruder 1 to form a film. . In the case where the film constituent material contains a material which is easily thermally decomposed, in order to reduce the number of times of melting, it is preferred to form a film without directly forming a film, or a method of forming a film after the above-mentioned rice porridge-like semi-molten. The extruder 1 may use various extruders commercially available, but it is preferably a melt-kneading extruder, and may be a single-shaft extruder or a twin-screw extruder. The pellets are not made of a film-forming material, and when a film is directly formed, since a suitable kneading degree is required, it is preferable to use a twin-screw extruder, and even a single-axis extruder can change the spiral shape to Maddock type, Unimelt type, and Dulmage. The mixing type spiral can be used for moderate mixing. Film constituting material Once a granule or rice porridge semi-melt is used, a single screw extruder or a twin screw extruder can be used. -25- 201105480 The cooling step in the extruder 1 and after the extrusion may be replaced by an inert gas such as nitrogen gas or by reducing the oxygen concentration by pressure reduction. The melting temperature of the film constituent material in the extruder 1 depends on the viscosity or discharge amount of the film constituent material, the thickness of the sheet to be produced, and the like, and thus the preferable conditions are also different 'generally for the glass transition temperature Tg of the film (resin mixture) It is Tg or more and Tg+io〇°c or less, preferably Tg+urc or more and Tg+90°C or less. The melt viscosity at the time of extrusion is from 1 to 100 PaPas, preferably from 10 to 10 00 Pa's. Further, the film forming material in the extruder 1 preferably has a shorter residence time, and is usually within 5 minutes, preferably within 3 minutes, more preferably within 2 minutes. The residence time is affected by the type of the extruder 1 and the extrusion conditions, but the residence time can be shortened by adjusting the supply amount of the material, the L/D, the number of revolutions, the depth of the spiral groove, and the like. The spiral shape or the number of revolutions of the extruder 1 is appropriately selected by the viscosity or discharge amount of the film constituent material. In the present embodiment, the cutting speed of the extruder 1 is from 1/sec to 1 0000/sec, preferably from 5/sec to 1 000/sec, more preferably from 10/sec to 100/sec. The extruder 1 can use a commercially available extruder of a general plastic molding machine. The film constituent material extruded from the extruder 1 is sent to the casting die 4, and is extruded into a film shape by the casting die 4. The molten material discharged from the extruder 1 is supplied to the casting die 4. The casting die 4 is not particularly limited as long as it is used for producing a sheet or a film. The material of the casting die 4 is, for example, sprayed or plated with hard chrome, chromium carbide, chromium nitride, titanium carbide, titanium carbonitride, titanium nitride, ultra-steel, ceramics (tungsten carbide, alumina, chrome oxide). Apply 'and then apply surface finish to polish '1' grinding using the grindstone below #1000 -26- 201105480, using the plane grinding of the diamond grindstone above 000 (the cutting direction is perpendicular to the flow direction of the resin) The processor of electrolytic honing, electrolytic honing, etc., etc. The preferred material of the lip (1 ip) of the casting die 4 is the same as that of the casting die 4. Further, the surface accuracy of the lip sound is preferably 〇 · 5 s or less, more preferably 0.2 S or less. In the present embodiment, the molten resin mixture is extruded into a film-like resin from a casting die 4 installed in an extruder, and then the film-form resin to be extruded is adhered to the casting rolls 5 and the contact rolls 6, and pressurized. After the steps taken. The temperature at which the film-like melt initially contacts the surface of the casting roll 5 and reaches the surface of the contact roller 6 is lowered, preferably within 20 °C. When the temperature at which the film is initially brought into contact with the surface of the casting roll 5 to the surface of the contact roll 6 is too large, the film thickness unevenness is increased due to uneven shrinkage. Further, when the temperature at which the film contacts the touch roll 6 is too low, since the viscosity of the film is high, the correction of the planarity or film thickness unevenness of the film is not sufficient even if the contact roll 6 is narrow. Preferred materials of the casting roll 5 and the contact roll 6 are, for example, carbon steel or stainless steel. The higher the surface precision, the better, and the surface roughness at the maximum height Ry is preferably 0 · 1 / m or less, more preferably 〇. 〇 5 / zm or less. It is preferable that the contact roller 6 presses the film against the casting roll 5 by pressing means. At this time, the line pressure of the contact roller 6 to press the film can be adjusted by a hydraulic piston or the like, preferably from 0.1 to 100 N/mm', more preferably from 1 to 50 N/mm. The casting roll 5 or the contact roll 6 can reduce the diameter of both ends of the roll or have a flexible roll surface in order to improve the adhesion to the film. -27- 201105480 When the portion (the lip portion) of the casting die 4 is decompressed to a portion below the casting roll 5 to 7 OkPa or less, it is found that the above-mentioned mold line has a larger correction effect. Preferably, the pressure is 50 kPa or more and 7 kPa or less. The method of maintaining the pressure of the portion of the casting die 4 from the lip portion of the casting die 4 to 7 OkPa or less is not particularly limited. For example, there is a method in which the casting die 4 is covered with a pressure-resistant member around the roller and pressure-reduced. In this case, the suction device is preferably a measure for heating the heater or the like in order to prevent the device itself from becoming a place where the sublimate is attached. When the suction pressure is too small, there is no way to attract the sublimate, so it is necessary to have an appropriate suction pressure. In the casting die 4, the film-like cellulose ester-based resin in a molten state is adhered to the casting roll 5, the cooling roll 7, and the cooling roll 8 in order, and is cooled and solidified to obtain a cellulose ester-based resin film 17 . In the embodiment of the present invention shown in Fig. 2, the film 17 which has been cooled and solidified by the peeling roller 9 by the cooling roll 8 is introduced into the longitudinal stretching device 1 and is stretched by the roller in the conveying direction (MD direction). Then, the film which has been longitudinally stretched is introduced into a lateral stretching device (tenter) 20' to extend the film 17 in the lateral direction (width direction). By this stretching, the molecules in the film are aligned. After the horizontal extension, the end portion of the film 17 is cut by the width of the product cut by the cutter 19, and then the edge portions of the film are formed by the embossing ring 53 and the back roller 52. Embossing processing (embossing processing), and then winding by the winding device 60 to prevent adhesion or scratching of the optical film (original roll) F. The method of embossing can be performed by having a convex-concave pattern on the side surface. Gold-28- 201105480 is a ring heat or pressure to process. The grip portion of the jig at both ends of the film is usually deformed and cannot be used as a film product, so it is reused as a raw material after being cut. The winding machine to be used can be a general user, and can be wound by a winding method such as a tension method, a fixed torque method, a taper tension method, or a program tension control method in which internal stress is fixed. The step of performing the burring after the lateral stretching and the step of cutting the thick film portion at the end of the film can be performed before the winding step. As described above, the optical film produced in the present embodiment is used as a retardation film, and when the retardation film is used as a polarizing plate protective film, the thickness of the protective film is preferably from 10 to 500 // m. In particular, the lower limit is 20 # m or more, preferably 35 m or more. The upper limit is 150 m or less, preferably 120 m or less. The particularly good range is 35 to 90 // m. When the retardation film is thick, the polarizing plate after the polarizing plate is processed becomes too thick, and it is not suitable for the purpose of thinness and lightness when used for liquid crystal display of a notebook computer or a portable electronic device. Further, when the retardation film is thin, it is difficult to exhibit the retardation of the retardation film, and the moisture permeability of the film is increased, and the function of protecting the polarizer from moisture is lowered, which is not preferable. The optical film of the present invention is a liquid crystal display, a plasma display, an organic EL display, or the like, particularly a functional film for a liquid crystal display, including a polarizing plate protective film, a retardation film, an antireflection film, a brightness enhancement film, and a viewing angle. An optical compensation film or the like is expanded, in particular, a retardation film. ES:} -29-201105480 (Liquid crystal display device) A polarizing plate containing a retardation film composed of the optical film of the present invention has a high display quality as compared with a general polarizing plate, and is particularly suitable for use in a multi-region type. The liquid crystal display device is more preferably used in a multi-region type liquid crystal display device by a birefringence type. Multi-regionalization is also suitable for improving the symmetry of image display. There are various ways of "Maeda, Yamauchi: Liquid Crystal, 6 (3), 303 (2002)". The liquid crystal display unit cell is also described in "Yamada, Yamahara: Liquid Crystal, 7 (2), 184 (2003)", but is not limited thereto. The polarizing plate using the optical film of the present invention can be effectively used for a MVA (Multi-domein Vertical Alignment) type represented by a vertical alignment type, in particular, a MVA type of four divisions, and a known multi-region by electrode arrangement. The PVA (Patterned Vertical Alignment) type, the fusion electrode configuration and the chiral have a large CPA (Continuous Pinwheel Alignment) type. In addition, when it is applied to the OCB (Optical Compensated Bend) type, it is proposed to optically have a biaxial film "T. Miyashita, T. Uchida: J. SID, 3 (1), 29 (1 995 )", by using The polarizing plate of the optical film of the present invention can have a display quality effect. When the display quality effect is exhibited by the polarizing plate using the optical film of the present invention, the arrangement of the liquid crystal type and the polarizing plate is not limited. The display quality of the display unit cell is preferably bilaterally symmetrical when observed by a person. Therefore, when the display unit cell is a liquid crystal display cell, substantially the symmetry of the observation side is prioritized, and the region can be formed into a plurality of regions. The division of the region can be determined by the method known from -30 to 201105480, by considering the properties of the known liquid crystal form by the two-division method and more preferably the four-division method. The liquid crystal display device can also be used as a device for colorization and animation display. 'The optical film of the present invention improves the display quality, and the contrast is improved or the durability of the polarizing plate is improved, so that the eye is not easily fatigued and a faithful moving image can be obtained. display. In the liquid crystal display device, a polarizing plate containing a retardation film composed of the optical film of the present invention is disposed one on the liquid crystal cell, or two sheets are disposed on both sides of the liquid crystal cell. At this time, the retardation film included in the polarizing plate is used in the form of a liquid crystal cell of the liquid crystal display device, which contributes to an improvement in display quality. In the polarizing plate, a polarizing plate protective film of a cellulose derivative is used for the surface opposite to the retardation film from the viewpoint of a polarizer, and a general-purpose TAC film or the like can be used. The polarizing plate protective film located away from the liquid crystal cell side can be provided with other functional layers in order to improve the quality of the display device. The optical film of the present invention can impart antireflection, antiglare, scratch resistance, antifouling adhesion, and brightness enhancement, for example. It can be attached to the surface of the polarizing plate, but is not limited to this. When a retardation film is produced, a functional layer such as an antistatic layer, a hard coat layer, a slippery layer, an adhesive layer, an antiglare layer, and a barrier layer may be applied before and/or after stretching. At this time, various surface treatments such as corona discharge treatment, plasma treatment, and chemical liquid treatment can be performed as necessary. When the optical film of the present invention is used as a retardation film and is used for a protective film of a polarizing plate, the method for producing the polarizing plate is not particularly limited and can be produced by a general method. For example, the obtained retardation film is subjected to alkali treatment, -31 - 201105480, the polyvinyl alcohol film is immersed in an iodine solution, and both sides of the polarizer produced by stretching are completely saponified polyvinyl alcohol aqueous solution, and the polarizing plate is attached to both sides of the polarizer. The method of protecting the film, at least on one side, the retardation film of the polarizing plate protective film of the present invention directly adheres to the polarizer. The easy-adhesion process described in Japanese Laid-Open Patent Publication No. Hei-6-94915, No. Hei 6-118232, and the above-mentioned alkali treatment are carried out, and the polarizing plate processing is carried out. The polarizing plate is composed of a polarizing film and a protective film for protecting both sides thereof, and one surface of the polarizing plate is bonded to the protective film, and the other surface is laminated with the separating film. The protective film and the separator film are used to protect the polarizing plate when the polarizing plate is shipped, and when the product is inspected. At this time, the protective film is bonded to protect the surface of the polarizing plate, and the protective film is used to bond the polarizing plate to the opposite side of the surface of the liquid crystal panel. The separator film is used to protect the adhesive layer attached to the liquid crystal panel, and can be used to bond the polarizing plate to the surface side of the liquid crystal cell. [Embodiment] [Examples] Examples and comparative examples of a method for producing an optical film are shown below. (Examples 1 to 8) (Resin mixture) Cellulose acetate propionate 89% by mass (Ethylene thiol substitution degree: 1.4, propyl thiol substitution degree: 1.35, number average molecular weight: 6 0 0 0 0 -32- 201105480 Trimethylolpropane tribenzoate 9 mass% (plasticizer, melting point 8 51:) (oxidation inhibitor) (IRGANOX XP 420/FD) 0.25 mass% (Ciba Japan) UV absorption 1.6% by mass (TINUVIN 928, manufactured by Ciba Japan, melting point 115 °C) Matting agent (cerium oxide microparticles) 0.15 mass% (seahoster KEP-30: Japan Catalyst Co., Ltd., average particle size 0.3 μηι) Cellulose The thiol substitution degree of the acetate, propionate or the like is determined according to the method specified in ASTM-D8 17-96. After mixing the above materials in a V-type mixer for 30 minutes, a cylindrical pellet having a length of 4 mm and a diameter of 3 mm was melted at 23 CTC under a nitrogen atmosphere using a twin-screw extruder equipped with a strand mold. . The resulting pellet had a glass transition point (Tg) of 1 35 °C. (Production of Optical Film) The above pellets were dried at 100 ° C for 5 hours to have a water content of i 〇〇 ppm, and the pellets were supplied to a single-axis extruder equipped with a T-die 4 as shown in Fig. 2! Film formation is carried out. In the melt, the additive other than the resin contained 11% by mass. The uniaxial extruder 1 system had a spiral diameter of 90 mm and L/D = 30, and the number of revolutions of the spiral was adjusted so that the extrusion amount became 140 kg/h. A nitrogen gas was introduced from the vicinity of the material supply port to -33-201105480 to maintain a nitrogen atmosphere in the extruder 1. The extruder 1 and the T-die 4 were set to a temperature of 240 ° C " Τ 4 4 coat hanger type, width 1500 mm, hard chrome plated on the inner wall, and processed into a mirror surface having a surface roughness of 0. IS. The lip gap of the T die 4 is set to 2 m m. As shown in Fig. 2, the film-like melt extruded from the T-die 4 was dropped on a casting roller 5 having a chrome-plated mirror surface having a surface temperature of 120 ° C and a roll width of 1,600 mm, while being adjusted to a temperature of 120 ° C by the temperature. The contact roller (rolling rotating body) 6 having a roll width of 1600 mm presses the film. On the surface of the contact roller, the P2 position in contact with the melt Y on the casting roll 5 is on the upper side, as shown in Fig. 1, the release modifier is preliminarily coated by the release agent coating device 1 . The mold release modifier coating device 1 is heated to a temperature of 20 ° C at the same temperature as that of the touch roll 6 . The mold release modifier was a copolymer of a UV absorber TIN U V IN 9 2 8 (T - 9 2 8 ) with dimethyl oxa oxide or tetrafluoroethylene. T-928 and dimethyl siloxane are coated in a liquid form, and the tetrafluoroethylene copolymer is coated with 20 parts by mass of 1 part by mass of the solvent xylene. The tetrafluoroethylene copolymer is applied to the surface of the contact roll in a state of being dispersed in a liquid. The coating thickness applied to the contact _ 6 was as shown in Table 1 ' as the production conditions of Examples 1 to 8. The contact angle of the surface of the casting roll 5 with water was 75°. The contact angle of the surface of the contact roll 6 after application of the release agent to the water T-928 was 95. The tetrafluoroethylene copolymer was 109° and the dimethyloxane was 120. ^ The contact roller (squeezing rotary body) 6 presses the film with a linear pressure of 5 N/mm. The casting rolls 5 are made of stainless steel, and the maximum thickness of the surface roughness is -34 - 201105480 0.1 v m or less. The contact roll 6 is a double-tube structure having a metal outer cylinder, an inner cylinder, and a void portion. The material of the metal outer cylinder is stainless steel, and the surface roughness is the maximum height Ry of 0. 〇 5 / zm or less, and the tube thickness is 3 mm. The inner cylinder is made of aluminum and has a cylinder thickness of 30 mm. The gap between the metal outer cylinder and the inner cylinder is 5 mm. The gap portion 47 has oil flowing therein so that the surface temperature of the metal outer cylinder is 120 ° C. The film is pressed against the casting roll 5 and the contact roll (rolling rotating body) 6, and then sequentially connected to the cooling roll 7, and The roll of the cooling roll 8 is solidified by cooling and peeled off by the peeling roll 9. The film transport speed is 1 〇m/min. Then, longitudinal extension is performed in the longitudinal stretching device 10. In the extending step of the longitudinal stretching device 10, the unstretched film 17 after rolling is stretched by 2.0 times in the longitudinal direction. After the longitudinal stretching, the lateral stretching device 20 is transversely stretched using a tenter device, and the stretching magnification at the time of lateral stretching is 2.0 times. The stretched film was in a state of 13,000 in width, and was cut by a cutter, and then wound up by a winding device 60 to produce Examples 1 to 8 having a width of 1300 mm, a film thickness of l〇〇#m, and a length of l〇〇〇m. Optical film. (Evaluation of optical film) Next, the optical film of Examples 1 to 8 was observed by visually observing the surface of the entire region of the optical film. Wireless film-like unevenness (lateral unevenness) was observed in the film width direction. Those who have no horizontal unevenness are evaluated as level 4, those who have one or more than three are evaluated as level 3, those that have three or more are not evaluated as level 2, and those that have six or more are evaluated as level 1. Delayed homogeneity evaluation

[S-35-201105480 The film of the embodiment 8 is rubbed by two polarizers disposed under the orthogonality of the polarizing plate, that is, in the cross state (cross nicol state), and the light is irradiated from the outside of the polarizing plate. The level of uniformity of the delay is judged by visual observation from the outside of the other polarizing plate. The entire area of the optical film is light-transmissive, and the overall uniform dark field is evaluated as level A, and only part of the line-like light and dark is evaluated as level B, and some lines with light and dark are evaluated as level C, and some are clearly line-shaped. The darkness is evaluated as the grade D. The horizontal unevenness is observed by visual observation. There are 6 or more, and when the delay is not the grade D, there is a problem in the quality of the product. (Comparative Example 1) The method for producing an optical film of Example 1 was produced and evaluated in the same manner as in Example 1 except that the release property adjuster was not applied to the surface of the touch roll 6. The evaluation results are shown in Table 1. (Comparative Example 2) In the method for producing an optical film of Example 1, the surface of the casting roll 5 before the film-like melt was dropped without applying the release property adjusting agent to the surface of the touch roll 6 was applied. The release property adjuster (T-9 2 8 ) used in the above was formed and evaluated in the same manner as in Example 1 except that it was formed to have a thickness of 0.04 Am. 201105480 [Table 1]

Release factor lateral unevenness result unevenness type thickness (//m) Example 1 Τ-928 0.04 3 B Example 2 Τ-928 0.05 4 A Example 3 Τ-928 0.3 4 A Example 4 Τ -928 1 4 A Example 5 Τ-928 1000 4 A Example Τ 928-928 1100 3 B Example 7 Tetrafluoroethylene copolymer 1 2 C Example 8 Dimethyl oxime 1 3 B Comparative Example 1 Λτττ. Μ - 1 D Comparative Example 2 Coated casting roll coating release property adjuster coating) 1 D From the results of Table 1, it was found that the release modifier can be applied to the surface of the rotating support to produce ί An optical film having a high degree of flatness with uneven yellowness or less unevenness. Further, from the results of Examples 1 to 6, it is understood that the thickness of the release property adjusting agent applied to the surface of the rotary support is in the range of 0.5 to 5 Å/zm, and the lateral unevenness is more [pattern BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] is a schematic view showing a casting step and a rolling step of a method for producing an optical film of the present invention. Fig. 2 is a schematic view showing an embodiment of a method for producing an optical film of the present invention. [Explanation of main component symbols] 1 : Extruder 37 - 201105480 2 : Filter 3 : Static mixer 4 : Casting die 5 : Casting roll, rotating support 6 : Contact roll, rolling rotating body 7, 8 : Cooling Light P1: point P2 at which the film initially contacts the surface of the casting roll: point P3 at which the film contacts the surface of the contact roll: point 9 at which the film leaves the casting roll: peeling roll 1 〇: longitudinal stretching device 17: film 1 9 : cutting machine 2 〇 : Horizontal stretching device 5 2 : Back roller 5 3 : Embossing ring 60 : Winding device 1 : Release agent adjusting device 101 : Coating roller 102 : Suction roller 103 : Restricting blade 104 : Release property Conditioner 1 〇5 : Storage tank Y: melt -38- 201105480 F : Optical film (original roll) -39

Claims (1)

201105480 VII. Patent application scope: 1. A method for producing an optical film, which comprises a casting step of extruding a melt containing a thermoplastic resin into a film form on a surface of a rotating support by a casting die, a method for producing an optical film which is subjected to a rolling step of rolling a film-form melt to be subjected to rolling of the rotating support and the rolling rotating body, and is characterized in that the surface of the rolling rotating body is coated to cause the rolling A mold release property adjuster having a good mold release property between the rotating body and the film-like melt. 2. The method for producing an optical film according to claim 1, wherein the release property adjuster contains at least one of the same materials as the additives contained in the melt. 3. The method for producing an optical film according to claim 1 or 2, wherein the release modifier is an ultraviolet absorber for absorbing ultraviolet rays inside the optical film. 4. The method for producing an optical film according to any one of the above-mentioned claims, wherein the releasing agent has a boiling point of from 15 to 25 (rc. 5) as claimed in claims 1 to 4. The method for producing an optical film according to any one of the preceding claims, wherein the thickness of the release mold adjusting agent is 〇〇5 to 1 〇〇〇μm 〇6, as in any one of claims 1 to 5. A method for producing an optical film, wherein a contact angle S1 between the surface of the rotating support and water and a contact angle s 2 between the surface of the rotating rotating body and the water after coating the releasing agent are L5° < S2 - S1 < The method for producing an optical film according to any one of the first to sixth aspects of the present invention, wherein the rolling rotating body is pressed against the rotating support in the film state. The difference T1 - T2 between the transport tension T1 of the molten material and the transport tension T2 of the film-form melt in a state in which the rolling rotor is not pressed against the rotary support is 1 to 250 N. The method for producing an optical film according to any one of items 1 to 7, wherein The thermoplastic resin is a cellulose ester-based resin. The optical film is produced by the method for producing an optical film according to any one of the first to eighth aspects of the invention. A film manufacturing apparatus comprising: a casting die in which a melt containing a thermoplastic resin is extruded into a film form on a surface of a rotating support; and a film-like melt extruded from the casting die as the rotating support An apparatus for producing an optical film which is a pressing means for rolling a rolling rotating body, characterized in that the surface of the rolling rotating body is coated so that the mold release property of the rolling rotating body and the film-like melt is good. A mold release modifier coating device for a release modifier.