TW201213098A - Method for producing optical film, optical film, polarizing plate, and liquid crystal display device - Google Patents

Abstract

Disclosed is a method for producing an optical film by a solution casting film forming process wherein a resin solution that contains an acrylic resin and a cellulose ester resin at a mass ratio from 95:5 to 30:70 is used as a dope, said method comprising: a first stretching step wherein a film separated from a supporting body is MD stretched; a second stretching step wherein the film stretched in the first stretching step is TD stretched; a cutting step wherein both end portions of the film stretched in the second stretching step are cut off; and a third stretching step wherein the film, from which the cut end portions have been removed, is MD stretched. If the content of the acrylic resin is represented by A mass%, the total of the drawing ratio in the first stretching step and the drawing ratio in the third stretching step is from A/3 + 10 to A/5 + 40 in percentage. The drawing ratio in the first stretching step is 70-95% of the total drawing ratio in the machine direction of the film.

Description

[Technical Field] The present invention relates to a method for producing an optical film, an optical film obtained by the method for producing an optical film, a polarizing plate using the optical film as a transparent protective film, and And a liquid crystal display device including the polarizing plate described above. [Prior Art] Various optical films are disposed in the image display area of the liquid crystal display device, for example, a transparent protective film for protecting a polarizing element of the polarizing plate. As such an optical film, for example, a resin film excellent in transparency such as a cellulose ester film is used. Then, such an optical film is produced, for example, by a solution casting method or the like to produce a resin film of a large size. The solution casting film forming method is a film in which a resin solution (coating material) in which a transparent resin of a raw material resin is dissolved in a solvent is cast on a traveling support and dried to a peelable degree. A method of producing a long-sized resin film by peeling off the support and then transporting the peeled film by a conveyance roller while applying drying or stretching. Further, the liquid crystal display device is also widely used in the field of use, and the use of indoor use is not limited to the use of indoors. Specifically, s ' can be used as an advertisement medium by displaying a video or information on a liquid crystal display device, for example, instead of a poster, that is, a case where it is used as a digital signage device, or a street or a store setting. Used in the case of large display devices. In such a case, the liquid crystal display device, for example, is also used in a high-temperature and high-humidity environment, and the optical hysteresis of the optical-5-201213098 film causes deterioration to become an optical film to be solved, and is required to have moisture resistance. On the other hand, an acrylic resin such as polymethyl PMMA which is low in hygroscopicity is excellent in hygroscopicity and is often examined on an acrylic film of an olefinic resin on an optical film. It is fragile with cellulose esters. For this reason, it is described in Patent Document 1 and Patent Document 2 containing an acrylic resin, for example, when the end of the film is broken. Patent Document 1 describes a phase difference film in which acryl has a specific in-plane phase difference 全 or total ray. According to Patent Document 1, a property and a high phase difference performance are disclosed. Further, Patent Document 2 describes an optical film of an ester ester resin. According to Patent Document 2, an optical film-based resin which can significantly improve brittleness and which has a high heat resistance and which contains a cellulose ester-based resin can be used as a liquid crystal protective film. The problem. Here, methacrylate resin, which is widely known as a high-tech material for deterioration due to moisture absorption, has low properties, transparency, and dimensional stability. However, in the case of comparison with a propylene film or the like, it is difficult to have a capacity. In particular, it is difficult to use an optical film. In particular, a problem such as cracking occurs. The resin film is, for example, a retardation film having an acid-based polymer as a main component and a transmittance. Resin and fiber provide low hygroscopicity and transparency, that is, by the effect of improving the brittleness of acrylic acid, the obtained polarizing plate for display device -6-201213098, in addition, as a prior art for making the operation of the optical film easy, For example, Patent Document 3 discloses a solution casting method using an endless belt support to reduce the amount of residual solvent of the film which is peeled off from the endless belt support until the film is stretched. A method of producing an optical film higher in the central portion of the film than at the end of the film. According to Patent Document 3, it is disclosed that the endless belt can be used for support The solution casting method of the bulk is not limited to a specific raw material by adjusting the amount of residual solvent of the film at the time of stretching, and it is possible to manufacture a wide-width, thin-film optical film which is easy to handle by increasing the modulus of elasticity. [Patent Document 1] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-93-7 (Patent Document 2) International Publication No. 2009/47924 (Patent Document 3) Japanese Patent Laid-Open Publication No. 2008-200929 SUMMARY OF THE INVENTION An object of the present invention is to provide an optical film excellent in transparency, workability, and planarity even when an acrylic resin is contained in a cellulose ester-based resin in order to improve moisture resistance, heat resistance, and the like. Further, an object of the invention is to provide an optical film obtained by the method for producing an optical film, a polarizing plate using the optical film as a transparent protective film, and a liquid crystal display device including the polarizing plate. A method for producing an optical film according to an aspect of the invention is characterized in that: 201213098 is used to contain acrylic acid in a mass ratio of 95:5 to 30:70; a resin solution of a resin and a cellulose ester resin, a casting step of casting a casting film on a traveling support, and a peeling step of peeling the casting film from the support into a film, and conveying the peeled film. At the same time, in the first extending step of extending the film in the transport direction, the film extending in the first extending step is transported while extending in a second extending step in a direction perpendicular to the film transport direction, and the transport is performed by the (2) extending the film extending in the step, simultaneously cutting both end portions in a direction perpendicular to the conveying direction of the film, removing the cutting step of the cut end portion, conveying the film from which the cut end portion is removed, and extending the film to the film. a third extending step of the direction; a total of the elongation of the film in the first extending step and an elongation of the film in the third extending step, and a content ratio of the acrylic resin to the acrylic resin and the cellulose ester When the total amount of the resin is A mass percentage, it is expressed as a percentage in the range of A/3 + 10 to A/5 + 40; the elongation of the film of the first extension step, phase The total elongation of the film in the first stretching step and the elongation in the film in the third extending step are 70 to 95%. Further, another aspect of the present invention is an optical film obtained by the above-described method for producing an optical film. Further, another aspect of the present invention provides a polarizing plate comprising a polarizing element and a transparent protective film disposed on a surface of at least one of the polarizing elements, wherein the transparent protective film is a polarizing plate characterized by the optical film. Further, another aspect of the present invention provides a liquid crystal cell and a liquid crystal display device in which two polarizing plates are disposed to sandwich the liquid crystal cell, and 201213098 is characterized in that at least two of the two polarizing plates are included. The object, features, aspects and advantages of the present invention will be apparent from the following detailed description and drawings. [Embodiment] According to the review by the inventor of the present invention, the acrylic acid-containing propionate film 'as compared with the cellulose vine film or the like as described in Patent Document 1 has a property of being easily broken and brittle. Therefore, when a film is produced, there is a case where a workability-related problem such as a low cracking property at the end of the cut film occurs. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ situation. Specifically, depending on the production method, transparency such as haze may be lowered, or workability such as cutting property may not be sufficiently improved, or an optical film having reduced planarity may be insufficiently obtained. In addition, the cellulose ester film used as an optical film can be suitably produced by the method of producing an optical film described in Patent Document 3, but the production method is applied to a resin containing an acrylic resin. In the method for producing a film, there is a case where it is not possible to sufficiently suppress a problem such as cracking at the end of the film. In the case where the film of the cellulose ester resin is produced, the inventors of the present invention presumably produce a film containing acryl-9 - 201213098 acid resin or acrylic particles in addition to the cellulose ester resin. As described above, when the end portion of the film is cut, a problem such as cracking occurs, which affects the elongation at the time of manufacturing the optical film. Then, the inventors of the present invention reviewed the results of various extension conditions and found that the conditions suitable for extension differ depending on the content ratio of the cellulose ester resin to the acrylic resin. Here, the inventors of the present invention have thought of the prescribed extension conditions to complete the present invention as described below. Hereinafter, the embodiment of the method for producing an optical film according to the present invention will be described, but the present invention is not limited to these descriptions. The method for producing an optical film according to the present embodiment includes forming a resin solution containing an acrylic resin and a cellulose ester resin in a mass ratio of 95:5 to 30:70, and casting it on a traveling support. The casting step of the cast film, the peeling step of peeling the cast film from the support into a film, and transporting the peeled film while extending in the first extending step of the film transport direction (Machine Direction: MD direction) The film extending in the first extending step is transported while extending in a second extending step in a direction perpendicular to the film transport direction (Transverse Direction: TD direction), and the film extending by the second extending step is transported. At the same time, both end portions in the direction (wide direction) perpendicular to the conveying direction of the film are cut, and the cutting step of the cut end portion is removed, and the film from which the cut end portion is removed is conveyed while extending in the conveying direction of the film. The third stretching step (in the MD direction) is a manufacturing method according to a so-called solution casting film forming method. For example, it is carried out by the manufacturing apparatus of the optical film according to the solution casting film forming method shown in Fig. 1. Further, the apparatus for manufacturing an optical film is not limited to the one shown in Fig. 1 to -10-201213098, and may be of other types. Here, the film is dried by a cast film (web) support composed of a resin solution (coating material) cast on the body, and is an optical film to be peeled off from the support. The film finally obtained by the manufacture of the optical film relating to the present embodiment. When the ratio of the content of the acrylic resin to the total amount of the propylene resin and the cellulose ester resin is A mass%, the elongation (first elongation) of the film in the first stretching step is described. In the total of the elongation (third elongation) of the film in the third stretching step, the elongation rate of the film transport direction (MD direction) is expressed in the range of A/3+10 to A/5+40. Within the range, it is preferably within the range of A/3 to A/5+30. Specifically, when the content ratio (mass ratio) of the acrylate and the cellulose ester-based resin is 70: A is 70% by mass, and the total of the first elongation and the negative elongation is about 33 to 54. %, and about 38 to 44%, preferably, the total elongation of the film transport direction (MD direction) is too low, that is, when the MD direction extension (MD extension) is insufficient, the film strength does not become Fully inclined. This should be due to insufficient resin constituting the film. Further, in the case where the film is conveyed in a direction in which the total elongation of the MD is too high, that is, the extension in the MD direction is too excessive, the whitening of the film may not be suppressed. This should be the type of resin accompanying the film. Specifically, as the acrylic resin and the fiber-based resin differ in the degree of alignment of the resin, the difference is large. Therefore, the total elongation of the film in the transport direction is supported in the above range, and the method acid is supported. The ratio of the frontal and partial ratios + 15 phylogenetic tree 30 of the I 3 extended field, and some of the alignment of the field constitutively ester-induced -11 - 201213098 degree tree strong mesonic acid high olefinic When the film is the same, the structure of the film is guaranteed to be a good one. The film of the film is in the process of 'suppressing the film to the extent that it can be said before,' and then the alignment with the cellulose ester resin, while making the acrylic resin. The difference in the degree of alignment with the cellulose ester resin is not too large. The first elongation is preferably 70 to 95%, and preferably 80 to 95%, in terms of the total elongation in the film transport direction (MD direction). In the case where the first elongation is too low, the third elongation may be too high, and in the third extension step, an extension pattern (longitudinal wrinkles) may be formed in the film transport direction (longitudinal direction). The tendency is caused. In addition, when the first elongation is too high, the third elongation may be too low, which is formed in the second stretching step and extends in a direction perpendicular to the conveying direction of the film (in the short side direction). The crepe pattern (transverse wrinkles) tends to be insufficiently removed even when the third stretching step extends in the conveying direction. Therefore, when the first elongation is within the above range, the transparency and workability of the obtained film can be maintained in a high state, and the planarity can be improved. Further, the elongation (first elongation) of the film in the first stretching step and the elongation (third elongation) of the film in the third stretching step were determined as follows. First, the transport speed of the film in the above-described first step and the third step is measured. Then, the elongation in the MD direction (MD elongation) of the first elongation and the third elongation is calculated by the following formula (1) using the transport speed of the film obtained in each step. Coating MD elongation (%) = {(transport speed of film at each step - casting speed) / casting speed} ><100 (1) -12 - 201213098 Further, the casting speed is the aforementioned endless cylinder (drum) supports the running speed (week speed). Further, the first elongation and the third elongation may differ depending on the residual solvent ratio of the film or the film, but may be adjusted by the film tension, the ambient temperature of each step, and the roll temperature of each step. . 1 is a schematic view showing a manufacturing apparatus 11 of a schematic film according to a basic configuration of an apparatus for manufacturing an optical film according to an embodiment of the present invention, comprising an endless cylinder support 12 and a casting die roll. 1 . The first extension device 15 , the second extension device 16 , the cutting device 3 , the winding device 20 , and the like. In the casting die 13, a resin solution (coating material) 19 obtained by dissolving a cellulose ester resin and a propylene resin described later in a solvent is cast on the surface of the end cylinder support 12. The endless cylindrical support body 12 is rotatably supported, and a web composed of the aforementioned cast material 19 is formed on the surface thereof. Next, the web is conveyed while being dried by the rotation of the endless cylinder 12. The film which is peeled off from the endless cylindrical body support 12 by the above-mentioned net is formed, and the peeling roll 14 guides the peeled film from the endless cylindrical body support to the first extending device 15 . In the first aspect 15, the peeled film is conveyed while extending to the film (MD direction). The second extension device 16 conveys the film extending by the front stretcher 15 while extending in a direction perpendicular to the film (TD direction). The cutting device 17 cuts off the liquid transfer by the conveyance of the film group of the body 12. Optical 13, stripping 17 , olefinic acid The above-mentioned no, is a moldable 13 flow support line, so that. Next, 12 peeling extension conveyance direction t first extension direction The above-mentioned 201213098 2 both ends of the film extending from the extension device 16 in the direction perpendicular to the conveyance direction (wide direction), and the cut end portion is removed. The third extension device 18' conveys the film from which the cut end portion is removed, and extends in the conveyance direction (MD direction) of the film. Next, the winding device 20 winds up the film stretched by the third stretching device 18 to form a film roll. The film constituting the film roll is an optical film produced by the method for producing an optical film according to the present embodiment. Further, the endless cylindrical body support 12 and the casting die 13 correspond to those for performing the casting step. In the peeling step, the casting die is a step of peeling the film from the endless cylindrical body support 12, which is carried out by the peeling roller 14. In the first extending step, after the endless cylindrical body support 12 is peeled off, in the second extending step, the step of extending in the direction perpendicular to the conveying direction of the film extends in the conveying direction of the film. The step is carried out by the peeling roller 14 or the first stretching device 15 described above. The cutting device 17 is equivalent to the user who performs the cutting step. The third stretching device 18 corresponds to a user who performs the third extending step. Therefore, the optical film manufacturing device 11 is provided with a casting step, a peeling step, a first stretching step, and a second stretching. The steps, the cutting step, and the third extension step are not particularly limited. As shown in Fig. 1, the casting die 13 is supplied with a coating material 19 by a coating supply pipe which is connected to the upper end portion of the casting die 13. Then, the supplied paint is discharged from the casting die 13 to the endless tubular support 12, and a web is formed on the endless tubular support 12. -14- 201213098 The above-mentioned endless cylinder support 12 is a metal cylinder whose surface is mirror-rotated. As the cylindrical body, from the viewpoint of the peeling property of the film, for example, a cylindrical body made of stainless steel or the like is preferable. The wide width of the cast film cast by the casting die 13 is preferably a width of the endless cylindrical support 12 from the viewpoint of effectively utilizing the width of the endless cylindrical support 12. It is 80 to 99%. Further, in place of the above-described endless tubular body 12, a metal endless belt (endless belt supporting body) whose surface is infinitely traveling may be used. Further, as the endless belt support, specifically, for example, a supported belt that can be driven by a pair of driving rollers and driven rollers can be cited. Next, the endless cylindrical body support 12 is rotated to transport a cast film (web) formed on the surface thereof, and the solvent in the paint is dried. At this time, it is preferable to cool the endless cylindrical body support 1 2 . Specifically, for example, it is preferably 10 ° C or less, more preferably 0 ° C or less, and still more preferably -10 ° C or less. By doing so, there is a tendency to increase the strength of the obtained film. In this case, the cast film (web) formed on the surface of the endless cylindrical body support 1 2 is formed by cooling gelation to form a gel film having high strength. Further, the traveling speed (peripheral speed) of the endless cylindrical body support 12 is preferably, for example, about 50 to 300 m/min. Further, it is preferable that the ratio of the traveling speed of the endless cylindrical body support 12 to the flow velocity of the coating material discharged from the casting die 13 (draft ratio) is 0.5 to 2. When the aforementioned stretching ratio is within this range, the casting film can be stably formed. For example, if the stretching ratio is too large, there is a tendency for necking to occur, and thus -15-201213098 becomes unable to form a wide optical film. Further, when the endless belt support 12 is used instead of the endless tubular support 12, the temperature of the endless belt support varies depending on the solvent constituting the net, but is generally 〇. Above 〇, the boiling point of the solvent constituting the mesh is not filled. Further, in consideration of the transport speed, productivity, and the like accompanying the evaporation time of the solvent, for example, 5 t or more is lower than the boiling point of the solvent constituting the mesh. The temperature of the temperature is not particularly limited, and is generally controlled to be equal to or higher than the dew point of the peeling roller 14 as long as the film formed on the endless tubular body 12 can be formed as described above. The endless cylindrical body support 12 is peeled off, and the peeling film is guided to the first extension device 15 and is not particularly limited. Next, the peeling roller 14 is specifically disposed, for example, on the endless cylindrical body support. The coating of the body 12 is in the vicinity of the surface on the side of the casting, and the distance between the endless cylindrical support 1 2 and the peeling roller 14 is preferably 1 to 100 mm. The fulcrum pulls on the dried web (film) and pulls off the dried web (film). When the film is peeled off from the endless cylinder support 12, the film extends along with the peeling tension and the subsequent transport tension. In the film transport direction (MD direction), the peeling tension and the transport tension when the film is peeled off from the endless tubular body support body 12 are preferably 50 to 400 N/m. Further, the endless cylindrical body support is considered. 1 2 stripping Residual solvent ratio when 彔IJ is separated, transportability after peeling, physical properties of the resin film after transfer and drying, etc., and film residue when the film is peeled off from the endless cylindrical support 12-16-201213098 The solvent ratio, in the range of 3 〇 to 200 mass%, and the residual solvent ratio of the membrane, is defined by the following formula (2). Residual solvent ratio (% by mass) = UM 丨 M2: | / M2} X 丨〇〇 Μ] The mass of the film at any time point is displayed, and M2 is used to determine the mass of the film after drying at 115 ° C for 1 hour. The first stretching device 15 ′ can transport the film in the same direction as the film (MD) In particular, the first extension device 15' is not particularly limited, and for example, it has a plurality of layers. Then, the film is stretched in the MD direction by applying a tension to the film. The elongation of the first extension device, that is, the first elongation A may be within the above range. In this case, generally, the first extension device 15 extends the film to be dried. Specifically, for example, air is used alone. Infrared, etc. Further, as shown in Fig. 1, the first extension device 15 includes a case having an air take-out port, and the air is taken in from the inlet, and the inside of the case may be fed. In the case where the temperature of the extension device 15 is specifically provided with the above-mentioned case, when the temperature in the case is too low at 5 to 39 ° C, the drying of the film is not easy, and there is a tendency for the film to be dissolved. Further, in the case where the temperature is too large, there is a tendency that the film is low, and the film is broken in different cases. Therefore, the temperature in the above range can further increase the strength of the film, and the workability is further improved. Excellent optical film. This situation should be better. (2) Limit the extension of the measurement. The transfer roller and the transfer 15 are simultaneously made dry, and the inlet and the air are preferable. The strength of the front-end residual strength can be made by making the resin constituting the film more suitable for alignment according to the extension step of the first stretching device 15 described in the above -17-201213098. Further, when the first stretching device 15 is provided with a conveying roller, the surface temperature of the intermediate conveying roller is preferably -2 0 to 0 °c. When the temperature is too low, condensation may occur on the surface of the film, or condensation formed on the transfer roller may be transferred to the film, which may damage the planarity of the film, and may cause foreign matter, thereby improving the quality of the film. Reduce the tendency. Further, when the temperature is too high, the effect of improving the strength of the film may not be sufficiently exhibited. Therefore, by setting the temperature within the above range, the strength of the film can be further enhanced, and an optical film having more excellent workability can be produced. In this case, it is possible to make the resin constituting the film more suitable for alignment according to the step of extending the first stretching device 15. The second stretching device 16 is not particularly limited as long as it can transport the film while extending in a direction (TD direction) perpendicular to the conveying direction of the film. Specifically, for example, by holding the both ends of the direction perpendicular to the conveying direction of the film by the grip of the gripping means or the like, the distance between the opposing grips is increased to extend in the TD direction. In this case, the elongation (TD elongation) obtained by the following formula (3) is extended so as to be 20 to 50%. Further, the elongation is preferably from 22 to 48%, more preferably from 25 to 45%. If the elongation is too low, there is a tendency that the desired retardation is not obtained, or the width of the optical film tends to be difficult. Further, when the elongation is too high, the haze of the film becomes high and the transparency tends to decrease. Therefore, when the obtained optical film is used as a retardation film provided in a liquid crystal display device such as a liquid crystal panel, the contrast tends to decrease -18 to 201213098, which is not preferable. In addition, depending on the occasion, there is also a break from the film being cracked by the gripping portion (grip). TD elongation (%) = {(length in the width direction after stretching - length in the width direction before stretching) / length in the width direction before stretching} xl 〇〇 (3) Further, when the film is stretched, The film is usually heated. The heating of the film can be carried out, for example, by heating the air to blow the web, or by heating the heating device such as an infrared heater. More specifically, as shown in Fig. 1, the second extension device 16 is provided with a case having an air intake port and a discharge port, and the air is taken in from the inlet to feed the heating air into the case. Further, as the temperature (extension temperature) at which the stretching is performed, it is preferably 1 500 to 200 ° C, more preferably 155 to 190 ° C. When the stretching temperature is too low, excessive stress is applied to the film, and the haze of the film is increased, and the transparency tends to be lowered. Therefore, when the obtained resin film is used as a retardation film provided in a liquid crystal display device such as a liquid crystal panel, the contrast tends to decrease, which is not preferable. In addition, depending on the occasion, there is also a break from the film being cracked by the gripping means (grip). Further, if the stretching temperature is too high, the desired retardation may not be obtained, or the film may be melted, or the surface state or film thickness of the film may become uneven. The cutting device 7 is not particularly limited as long as it can cut both end portions in the direction (wide direction) perpendicular to the conveying direction of the film and remove the cut end portion. Specifically, for example, -19-201213098 includes a trimming blade or the like, and the trimming blade cuts out a direction in which the conveyed film is approximately perpendicular to the conveying direction (wide width) The end of the direction is cut so that the remaining portion of the cut film becomes an optical film of the product to be shipped. At this time, the end portion of the cut film, as shown in Fig. 1, leaves the transport path of the film The trimming blade is not particularly limited as long as it can cut the end of the film to be transported, and it is preferable to adjust the film to the end of the film in order to appropriately cut the end of the film. For the cutting depth, for example, a rotary disk type or a knife having a cutting blade formed by an upper round blade and a lower round blade may be used. The third extending device 18 is capable of transporting the end portion from which the cutting is removed. The film is not particularly limited as long as it extends in the transport direction (MD direction) of the film. Specifically, the first aspect is the same as the first one. The stretching device 15 is the same as the winding device 20, and the film may be wound around the core in a required amount, and is not particularly limited. The temperature at the time of winding is prevented from being scratched by shrinkage after winding. It is preferable to cool to room temperature, and it is preferable to use it to cool to room temperature. The coiler to be used is not particularly limited, and a general-purpose machine can be used, and a constant tension method, a constant torque method, a gradient tension method, and an internal portion can be used. The winding method is performed by a winding method such as a constant tension control method. The composition of the resin solution (coating material) used in the present embodiment will be described below. The resin solution used in the present embodiment is as described above. The acrylic resin and the cellulose ester resin -20-201213098 may be dissolved in a solvent at a mass ratio of 9 5 : 5 to 30: 70, and the β (acrylic resin) is not particularly limited. The resin which is formed into a film shape by using a coating material which is contained in the form of a film of the above-mentioned cellulose ester-based resin is not particularly limited, and is specifically, for example, The obtained film may be one which has a high mutual solubility with the acrylic resin which is contained in a mutually soluble state with the cellulose ester-based resin. By using the above-mentioned acrylic resin having high mutual solubility and the cellulose ester-based resin in combination, The properties of the respective resins complement each other, and the physical properties or qualities necessary for the optical film can be achieved. Here, the inclusion of the acrylic resin and the cellulose ester resin in a mutually soluble state means that the respective resins are mixed. (Polymer), the result is a state of mutual dissolution. Further, whether or not the acrylic resin and the cellulose ester resin are in a mutually soluble state can be determined, for example, by measuring the glass transition temperature T g . For example, it can be judged by the following. Even in the case where the glass transition temperatures of the two resins are different, when the mutual solubility of the two resins is high, only one glass transition temperature is measured. That is, the glass transition temperature inherent to each resin disappears and is measured as one glass transition temperature. On the other hand, when the mutual solubility of the two resins is low, the glass transition temperature of each resin is still present, so that the glass transition temperature of the mixture is measured to be two or more. In addition, the glass transition temperature is measured by a differential scanning calorimeter (DSC-7 model manufactured by PerkinElmer Co., Ltd.) at a temperature elevation rate of 20 ° C /min, in accordance with JIS K7121 (-21 - 201213098 1 987). The intermediate point glass transition temperature (Tmg) obtained by the standard. In addition, the acrylic resin is not particularly limited as long as it is an acrylic resin as described above. Specifically, for example, a resin obtained by polymerizing a monovalent body containing an acrylic monomer such as a methacrylate such as a methyl methacrylate or a methyl methacrylate may be mentioned. More specifically, for example, a methyl acrylic acid resin such as polymethyl methacrylate may be mentioned. Further, as the above-mentioned monomer, it is preferably from 1 to 50% by mass based on 55 to 99% by mass of methyl methacrylate and from the other monomer which can be copolymerized with methyl methacrylate. Therefore, as the acrylic resin, a resin obtained by polymerizing a monomer in an amount of from 55 to 99% by mass of methyl methacrylate and from 1 to 50% by mass of another monomer which can be copolymerized with methyl methacrylate It is better. Other monoliths which are copolymerizable with the methyl methacrylate are not particularly limited, and examples thereof include an alkyl methacrylate having an alkyl group having 2 to 18 carbon atoms and an alkyl carbon group. An alkyl acrylate of 1 to 18, an α,β-unsaturated acid such as acrylic acid or methacrylic acid, maleic acid (maleic acid), fumaric acid (fumaric acid), methylene An aromatic vinyl compound such as an unsaturated group containing a divalent carboxylic acid such as succinic acid, styrene or α-methylstyrene, an α,β-unsaturated nitrile such as acrylonitrile or methacrylonitrile, or a anhydrous Malay Acid, maleimide, hydrazine-substituted maleimide, glutaric acid anhydride, and the like. Further, these may be used alone or in combination of two or more. Further, among them, from the viewpoint of heat decomposition resistance or fluidity of the copolymer, methyl acrylate, ethyl acrylate, n-propyl acrylate, propylene-22-201213098 n-butyl acrylate, sec-butyl acrylate, acrylic acid 2-Ethylhexyl ester or the like is preferred, and methyl acrylate or n-butyl acrylate is particularly preferred. Further, as the acrylic resin, a commercially available product can be used. Specifically, Delpet 60N (transliteration) manufactured by Asahi Kasei Chemical Co., Ltd., Delpet 80N (transliteration) manufactured by Asahi Kasei Chemical Co., Ltd., Dyanile BR52 (transliteration) manufactured by Mitsubishi Rayon Co., Ltd., and Dyanile BR80 manufactured by Mitsubishi Rayon Co., Ltd. (transliteration) ), Dyanile BR83 (transliteration) manufactured by Mitsubishi Rayon, Dyanile BR85 (transliteration) manufactured by Mitsubishi Ray on, Dyanile BR88 (transliteration) manufactured by Mitsubishi Rayon, and KT7 5 manufactured by Electric Chemical Industry Co., Ltd. In addition, one type of the above-mentioned acrylic resin may be used, and two or more types may be used in combination. The acrylic resin is preferably a weight average molecular weight (Mw) of from 110,000 to 1,000,000, from the viewpoint of improving the brittleness of the protective film of the liquid crystal polarizing film and improving the transparency when it is miscible with the cellulose ester resin. It is more preferably 1 50,000 to 400,000. Further, the weight average molecular weight can be measured by gel permeation chromatography. The measurement conditions include, for example, the following conditions. Solvent: Dichloromethane Column: Connected to Shodex K806 manufactured by Showa Denko Co., Ltd., Shodex K805 manufactured by Showa Denko Co., Ltd., and Shodex K803G manufactured by Showa Denko Co., Ltd.

Column temperature: 25°C Sample concentration: 〇·1 mass percentage -23- 201213098 Detector: RIModel504 manufactured by GLScience Pump: L6000 manufactured by Hitachi, Ltd. Flow rate: 丨.Oml/min Calibration curve: 13 samples used A calibration curve prepared by standard polystyrene STKstandard polystyrene (to Mw = 2,800,000 to 500) manufactured by TOSOH Co., Ltd. (13 samples: use M w is almost equally spaced, preferably as the above). The production method is not particularly limited as long as the acrylic resin can be obtained. Specifically, for example, a monomer having an acrylic acid-based monomer such as acrylate or methacrylate as described above can be produced by polymerization by a known lipid polymerization method. The polymerization method is not particularly limited, and examples thereof include suspension polymerization, emulsion polymerization, bulk polymerization, and solution polymerization. Here, the polymerization initiator to be used in the polymerization method is not particularly limited as long as the polymerization reaction can be started, and examples thereof include a peroxide polymerization initiator, an azo polymerization initiator, and a redox system. A polymerization initiator or the like. Further, the polymerization temperature as the polymerization method is not particularly limited as long as it is a temperature at which the polymerization reaction can proceed. Specifically, for example, in the case of suspension polymerization or emulsion polymerization, it is preferably 8 〇 to 16 〇 t in the case of 3 〇 〜 1 〇 较佳 preferably ‘block polymerization or solution polymerization. Further, in order to control the reduction viscosity of the obtained copolymer, it is also possible to use an alkyl mercaptan or the like as a chain shifting agent. (Cellulose ester-based resin) -24-201213098 The cellulose ester-based resin is a resin film which can be formed into a film shape by using a coating material which is contained together with the acrylic resin, similarly to the above-mentioned acrylic resin. The transparent resin is not particularly limited. Specifically, for example, from the viewpoint of improvement in brittleness or transparency at the time of miscibility with an acrylic resin, the total degree of substitution (T) of the fluorenyl group is 2 to 3, and the number of carbon atoms is 3 to 7. A cellulose ester-based resin having a degree of substitution of 1.2 to 3 is preferred. Further, the degree of substitution of the fluorenyl group having 3 to 7 carbon atoms is preferably 2 to 3. That is, a cellulose ester-based resin which is substituted with a fluorenyl group having a carbon number of 3 to 7 is particularly preferable because the degree of substitution is 2 to 3. In addition, as the sulfhydryl group, for example, a propyl fluorenyl group and a butyric acid butyl acid group can be mentioned, and a fluorenyl group can be suitably used. When the total degree of substitution (T) of the thiol group of the cellulose ester-based resin is too low, that is, when the residual degree of the hydroxyl group at the 2, 3, and 6 positions of the cellulose ester molecule is too high, the acrylic resin is used. The mutual solubility is insufficient, and the obtained haze of the optical film tends to be high. Further, even if the total degree of substitution (T) of the fluorenyl group is high, when the degree of substitution of the fluorenyl group having 3 to 7 carbon atoms is too low, the mutual solubility with the acrylic resin may be insufficient or obtained. The tendency of the optical film to be brittle. Specifically, for example, even when the total substitution degree of the fluorenyl group is 2 or more, the substitution ratio of the fluorenyl group having a carbon number of 2, for example, the thiol group is high, and the substitution ratio of the fluorenyl group having 3 to 7 carbon atoms is low. In the case of 1.25, the mutual solubility is lowered and the ambiguity is increased. In addition, even when the total degree of substitution of the fluorenyl group is 2 or more, the degree of substitution of the fluorenyl group having 8 or more carbon atoms is high, and when the degree of substitution of the fluorenyl group having 3 to 7 carbon atoms is less than 1.2, brittleness is deteriorated. , the tendency to get the desired characteristics. -25-201213098 In addition, as described above, the total degree of substitution (T) is 2 to 3, and the degree of substitution of the fluorenyl group having 3 to 7 carbon atoms is preferably 1.2 to 3, but it is preferable. The total of the substitution ratio of the fluorenyl group other than the carbon number of 3 to 7, that is, the oxime group or the fluorenyl group having a carbon number of 8 or more is preferably 1.3 or less. Further, the total degree of substitution (T) of the thiol group of the cellulose ester-based resin is more preferably in the range of 2.5 to 3. The above mercapto group is not particularly limited, and may be an aliphatic mercapto group or an aromatic mercapto group. In the case of an aliphatic sulfhydryl group, it may be a straight chain or a divergent one, and further a substituent may be used. Further, the carbon number of the above mercapto group is the carbon number of the substituent group including a mercapto group. Further, in the case where the cellulose ester-based resin has an aromatic fluorenyl group as a substituent, the number of the substituents X substituted with an aromatic ring is preferably 0 to 5. In this case, the degree of substitution of the fluorenyl group having a carbon number of 3 to 7 in the carbon number of the substituent is preferably 1.2 to 3. Further, for example, when the benzyl group has a carbon number of 7 and has a carbon-containing substituent, the benzyl group has a carbon number of 8 or more and is not contained in the ruthenium group having 3 to 7 carbon atoms. Further, when the number of substitution groups substituted with an aromatic ring is two or more, they may be the same or different. Further, they are linked to each other to form, for example, naphthalene, indene, indan, phenanthrene, quinoline, isoquinoline, chromene, chromane. A condensed polycyclic compound such as phthalazine, acridine, indole or indoline may also be used. In addition, the cellulose ester-based resin is not particularly limited as long as it is a fiber of the above-mentioned fiber -26-201213098. Specifically, for example, cellulose acetate propionate resin, cellulose acetate butylate resin, cellulose acetate benzoate resin, cellulose propionate resin And cellulose butyrate (cellulose butylate) resin can be used. Namely, a cellulose ester-based resin having a fluorenyl group having 3 or 4 carbon atoms as a substituent is preferable. Among them, cellulose acetate propionate resin or cellulose propionate resin is particularly preferred. Further, a portion which is not substituted with a thiol group usually has a hydroxyl group. The cellulose ester-based resin can be synthesized by a known method. Further, the degree of substitution of the thiol group or the degree of substitution of other thiol groups is determined by the method specified in the ASTM-D8 17-9 6 standard. The weight average molecular weight (Mw) of the cellulose ester-based resin is preferably 75,000 or more, more preferably 75,000 to 300,000, and more preferably 100,000 to 250,000, and further, from the viewpoint of improving compatibility with the acrylic resin and brittleness. Jia's is especially good for 1 60000~240000. When the weight average molecular weight (Mw) of the cellulose ester-based resin is too small, the effect of improving heat resistance or brittleness tends to be insufficient. Further, the cellulose ester-based resin may be used in combination of two or more kinds of cellulose ester-based resins. Further, the weight average molecular weight (Mw) of the cellulose ester-based resin can be measured in the same manner as the above-mentioned acrylic acid-based resin. The content ratio of the acrylic resin to the cellulose ester resin is 95: 5 to 30: 70, preferably 95: 5 to 50: 50, and more preferably 90: 10 to 60: 40. . When the content of the acrylic resin is too large as the above-mentioned cellulose ester-based resin of -27 to 201213098, the effect of the cellulose ester-based resin may not be sufficiently exhibited. In addition, when the content of the acrylic resin is too small, the effect of the acrylic resin may not be sufficiently exhibited, and for example, the moisture resistance of the obtained optical film may be insufficient. tendency. (Solvent) The solvent to be used in the present embodiment is not particularly limited as long as it is a solvent capable of dissolving the above-mentioned acrylic resin and the cellulose ester resin. Specifically, for example, a chlorine-based organic solvent such as dichloromethane, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3 - two may be mentioned. Dioxolane, 1,4 - dioxane, cyclohexanone, ethyl formate, 2,2,2·trifluoroethanol, 2,2,3,3 -hexafluoro-1-propanol, 1,3·difluoro-2-propanol, 1,1,1,3,3,3·hexafluoro-2-methyl-2-propanol, 1,1, A non-chlorine organic solvent such as 1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol or nitroethane (Nitroethane). Among them, dichloromethane, methyl acetate, ethyl acetate, acetone, and the like are preferred. Further, in the above solvent, an aliphatic alcohol having a linear or branched chain having 1 to 4 carbon atoms is preferred. The content 'is preferably from 1 to 40% by mass based on the total amount of the above solvent. When the content ratio of the above-mentioned alcohol in the coating material is high, the net gels and the metal support is easily peeled off. In addition, when the content ratio of the alcohol is low, the non-chlorinated organic solvent system is promoted. 28- 201213098 The effect of dissolution of acrylic resin and cellulose ester resin. Further, the acrylic resin and the cellulose ester resin are mixed with the acrylic in advance in a solvent containing dichloromethane and a linear or branched chain aliphatic alcohol having 1 to 4 carbon atoms. Three kinds of the mixture of the particles and the surfactant are preferably at least a coating composition in which a total of 15 to 45 mass% is dissolved. Further, examples of the linear or divalent chain aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, and t-butanol. (Additive) In addition, various additives may be appropriately blended in order to adjust the chemical, mechanical, and electrical properties of the optical film obtained by using the above-mentioned coating material. Examples of the additive include acryl particles, a plasticizer, an oxidation inhibitor, and an ultraviolet absorber. The acryl particles are not particularly limited as long as they are insoluble in the solvent, unlike the acrylic resin. Specifically, for example, in the optical film in which the acrylic resin and the cellulose ester resin are contained in a mutually soluble state, particles of an acrylic resin which are present in a particulate state, that is, in an immiscible state are preferable. More specifically, for example, a specific amount of the obtained optical film is used, and a solution which is stirred in a solvent to sufficiently dissolve a component dissolved in the solvent is used, and an aperture having a volume average particle diameter which is less than the acryl particles is used. The filtration membrane made of PTFE is filtered, and the weight of the insoluble matter collected by filtration is preferably 90% by mass or more based on the acryl particles -29 to 201213098 added to the optical film. The acryl particles are not particularly limited as long as they are acryl particles as described above. Specifically, for example, acryl particles which are formed of a layer having two or more layers are preferable, and in particular, a granule-like granular composite having a multilayer structure as described later is preferable. The multilayer structure acryl-type granular composite refers to an innermost hard layer polymer having a central portion facing the outer peripheral portion, a bridged soft layer polymer exhibiting rubber elasticity, and an outermost hard layer polymer, which are formed to overlap each other. A particulate acrylic polymer having a layered structure. In other words, the multi-layer structure acryl-type granular composite body is a multi-layer structure acrylic-like granular composite body composed of an innermost hard layer, a bridged soft layer, and an outermost hard layer from the center portion toward the outer peripheral portion. . Such a three-layer core-shell structure of a multi-layer structure of an acrylic-based granular composite is suitable for use. The preferred embodiment of the multi-layer structure acryl-based granular composite exemplifies the following. That is, each layer may be formed as described below. The above-mentioned innermost hard layer polymer may, for example, be an alkyl methacrylate having a methyl methacrylate content of 80 to 98.9 mass%, and an alkyl acrylate having an alkyl group having a carbon number of 1 to 8 of 1 to 20 mass%. And a multi-functional grafting agent of 0.01 to 0.3% by mass of a mixture of a single body of a polymer, and the like. In addition, as the bridging soft layer polymer, for example, 75 to 98.5 mass% of an alkyl acrylate having an alkyl group having 4 to 8 carbon atoms in the presence of the innermost hard layer polymer, polyfunctionality The bridging agent 0.01 -30- 201213098 ~ 5 mass percentage 'and multi-functional grafting agent 〇 · 5 ~ 5 菅 percentage of the composition of the single-body mixture is polymerized and so on. Further, as the outermost hard layer polymer, for example, methyl methacrylate 80 is present in the presence of a polymer composed of the innermost hard layer and the bridged soft layer. 99 parts by mass, and a mixture of a single amount of the alkyl acrylate having an alkyl group having an alkyl group of 1 to 8 and a mass percentage of 1 to 20 by mass. Then, the content ratio of each layer is 5 to 40% by mass of the innermost hard layer polymer, 30 to 60% by mass of the soft layer polymer, and 20 to 50% by mass of the outermost hard layer polymer. It is preferred that the force is a granular composite. Further, it is more preferable that the insoluble portion is treated with acetone, and the multi-layer structure acrylic-like granular composite having a methyl ethyl ketone oxime degree of 1.5 to 4 in the insoluble portion is more preferable. Further, by not only specifying the composition or particle diameter of each layer of the multi-layer structure acrylic-like granular composite, but also the tensile modulus of the multilayer structure of the acrylic-like granular composite or the acetone-insoluble portion When the degree is set within a specific range, a balance between more sufficient impact resistance and stress whitening resistance can be achieved. The range of the tensile modulus of the multi-layered structure of the acrylic-based granular composite or the methyl ethyl ketone penetration of the acetone-insoluble portion is not particularly limited in this embodiment, but as an example, it may be exemplified by - 1 7 406, and the scope disclosed in Japanese Patent Publication No. 3 - 3 9 0 9 5. As the innermost hard layer polymer, for example, a methyl methacrylate having a methyl methacrylate content of 80 to 98.9 mass%, an alkyl acrylate having a carbon number of 1 to 8 in a yard base of 1 to 20% by mass, and a polyfunctional group -31 - 201213098 It is more preferable to polymerize a mixture of a single amount of a grafting agent of 0·01 to 0.3 mass%. Here, examples of the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, and 2-ethyl acrylate. Ethyl hexyl ester or the like, and methyl acrylate or n-butyl acrylate is suitable for use. Further, when the content ratio of the alkyl acrylate of the innermost hard layer polymer is too low, the thermal decomposition property of the innermost hard layer polymer obtained tends to be large. In addition, when the content ratio of the alkyl acrylate is too high, the glass transition temperature of the innermost hard layer polymer is lowered, and the impact resistance imparting effect of the three-layer structure acryl-type force composite tends to be lowered. Further, examples of the polyfunctional grafting agent include polyfunctional monoliths having different polymerizable functional groups, such as acrylic acid, methacrylic acid, maleic acid, allyl fumarate, and the like. And allyl methacrylate is suitable for use. The above polyfunctional grafting agent is used for chemically bonding the innermost hard layer polymer to the soft layer polymer. The compounding ratio of the above-mentioned polyfunctional grafting agent used in the polymerization of the innermost hard layer is preferably from 0. 01 to 0.3 mass%. As the bridging soft layer polymer, for example, in the presence of the innermost hard layer polymer, an alkyl acrylate having an alkyl group having a carbon number of 1 to 8 is 75 to 98.5 mass%, and a polyfunctional bridging agent is 0.01 to 5 It is preferred that the mass percentage, and the mixture of the individual components of the multi-functional grafting agent 0.5 to 5 mass% are polymerized. Here, the alkyl group has an alkyl acrylate having a carbon number of 4 to 8, and is suitably used as -32 to 201213098 n-butyl acrylate or 2-ethylhexyl acrylate. Further, together with these polymerizable unitary bodies, it is also possible to copolymerize with other monofunctional monoliths which are 25 mass% or less copolymerizable. Other monofunctional monoliths which can be copolymerized include styrene and a substituted styrene inducer. The ratio of the alkyl acrylate having a carbon number of 4 to 8 to styrene is the lower the glass transition temperature of the bridging soft layer polymer, i.e., softening. On the other hand, from the viewpoint of the transparency of the resin composition, the refractive index of the soft layer polymer at normal temperature is close to the innermost hard layer polymer, the outermost hard layer polymer, and the acrylic system. The resin is advantageous in terms of 'the ratio of the two is taken into consideration. The polyfunctional grafting agent herein may be the same as the polyfunctional grafting agent used in the production of the innermost rigid polymer. The polyfunctional grafting agent used herein is used for chemically bonding the aforementioned soft layer polymer to the aforementioned outermost hard layer polymer. The blending ratio of the above-mentioned polyfunctional grafting agent used in the polymerization of the innermost hard layer is preferably from 0.5 to 5 mass% from the viewpoint of imparting impact resistance. As the polyfunctional bridging agent, a conventionally known bridging agent such as a diene ethyl compound, a diallyl compound, a diacrylic compound, or a dimethacrylic compound can be used, but a glycol diacrylate (molecular weight 200) can be used. ~600) Suitable for use. The polyfunctional bridging agent ' used herein generates a bridging structure at the time of polymerization of the bridging soft layer polymer' to exhibit an impact resistance imparting effect. However, when the previous polyfunctional grafting agent is used in the polymerization of the above-mentioned bridge soft layer-33-201213098, the bridging structure of the bridged soft layer polymer is generated to some extent, so the polyfunctional bridging agent is not an essential component. . When the polyfunctional bridging agent is used, the mixing ratio of the polyfunctional bridging agent used in the polymerization of the bridging soft layer polymer is from the viewpoint of the impact imparting effect, and the mass is 〇. The percentage is better. In the outermost hard layer polymer, methyl methacrylate is 80 to 99% by mass and the carbon number of the alkyl group is 1 in the presence of the innermost hard layer polymer and the soft layer polymer. It is preferable to polymerize a mixture of a monomer of 1 to 20% by mass of the alkyl acrylate of ～8. As the alkyl acrylate, the above-mentioned one is used, but methyl acrylate or ethyl acrylate is used. The alkyl acrylate unit of the outermost hard layer polymer has a unit ratio of preferably 1 to 20% by mass. Further, in the polymerization of the outermost hard layer polymer, it is possible to use an alkylthiol or the like as a chain shifting agent for the purpose of adjusting the molecular weight for the purpose of improving the mutual solubility with the acrylic resin. In particular, in the outermost hard layer, a gradient in which the molecular weight is gradually changed from the inner side to the outer side is set, and the balance between the stretchability and the impact resistance can be improved. As a specific method, by forming a mixture of a single body for forming the outermost hard layer into two or more portions, the method of adding the interlocking moving dose to each time is sequentially increased, and the polymerization of the outermost hard layer can be formed. The molecular weight of the body is reduced from the inner side to the outer side of the multi-layered structure acrylic composite. The molecular weight formed at this time can be investigated by polymerizing the mixture of the individual components used in each of the same conditions under the same conditions, and measuring the molecular weight of the obtained poly-34-201213098 complex. In the above-mentioned multilayer structure, the acryl-type granular composite body is not particularly limited in mass ratio between the core and the shell. Specifically, for example, when the entire multilayer structure acryl-type granular composite is 100 parts by mass, the core layer is preferably 50 parts by mass or more and 90 parts by mass or less, and more preferably 60 parts by mass or more and 80 parts by mass or less. . Further, the core layer here is the innermost hard layer. Specific examples of the commercially available product of the multi-layered structure of the acryl-based granulated composite include METABLEN manufactured by Mitsubishi Rayon Co., Ltd., Kane Ace manufactured by Kaneka Co., Ltd., Paraloid manufactured by Kureha Co., Ltd., Acryloid (transliteration) manufactured by RohmandHaas, Stafiloid manufactured by Ganz Chemical Co., Ltd., and ParapetSA manufactured by Kuraray. These may be used alone or in combination of two or more. Further, as the aforementioned acryl particles, grafted copolymer particles are also suitable for use. Specifically, the graft copolymerized particles include, in the presence of a rubbery polymer, an unsaturated carboxylic acid monomer, an unsaturated carboxylic acid monovalent, and an aromatic vinyl single. A grafting copolymer particle obtained by copolymerizing a mixture of a monomer and a monomer of another vinyl monomer which is copolymerized as necessary. Specific examples of the rubbery polymer include particles containing a rare rubber, an acryl-based rubber, and an ethylene-based rubber. More specifically, for example, polybutadiene, styrene-butadiene copolymer styrene-butadiene bulk copolymer, acrylonitrile-butadiene copolymer, butyl acrylate-butyl Alkene copolymer, polyisoprene-35- 201213098 (polyisoprene), butadiene-methyl methacrylate butyl methacrylate-methyl methacrylate copolymer, butadiene-copolymer, ethylene propylene A copolymer, an ethylene-propylene-dimer, an ethylene/isoprene copolymer, and an ethylene-acrylic acid. These rubbery polymers can be used singly or in combination of two or more kinds. In addition, as the acryl particles, for example, 341 manufactured by Mitsubishi Rayon Co., Ltd., Chemisnow MR-2G manufactured by Ivy Chemical Co., Ltd., C hemis η 〇w MS - 3 0 0 X manufactured by Sisei Chemical Co., Ltd., etc. may be used. . Further, the content of the acryl particles is not particularly specific, for example, 0.5 to 30% by mass of the resin constituting the optical film, and 1 to 15% by mass of the acryl particles. There is no particular limitation. For example, it is preferably 10 nm or more and 100 nm or less, more preferably 500 nm or less, and 50 nm or more and 400 nm or less. Further, the refractive index of the acryl particles is close to the refractive index of the resin or the foregoing. The refractive index of the mixture of the acrylic resin and the above-mentioned fibrin is preferable in that a film having high transparency can be obtained. Specifically, for example, the difference in refractive index between the acryl particles and the resin is preferably 0.05 or less, more preferably 0, more preferably 0.01 or more. In order to satisfy the above-mentioned conditions of the refractive index, the acrylic resin may be known as a method of polymerizing a single unit body composition ratio, a copolymer of a polymer of ethylene acrylate or a copolymer of methyl acrylate, or a combination of two products. Specific Metablen W - Comprehensive Chemicals Special Limited. The total quality is better. set. Specifically, more than 4 2 0 nm: better. In the case of the above-mentioned acrylic acid ester, the composition ratio of the rubbery polymer or the monolith of the acrylic particles is adjusted to be the same as the above-mentioned acrylic acid 02. By doing so, the refractive index difference can be reduced, and a protective film for a liquid crystal polarizing plate which is excellent in visibility can be obtained. In addition, the refractive index difference referred to herein means an acrylic resin in a solvent, and the protective film for a liquid crystal polarizing plate according to the present invention is sufficiently dissolved in a suitable material to form a white turbid solution, which is separated by centrifugation or the like. The difference between the measured solvent (23 ° C, measurement wavelength: 550 nm) after the solvent soluble portion and the insoluble portion were respectively purified from the soluble partial olefinic resin and the insoluble portion (acrylic particles). The plasticizer is not particularly limited, and may be added for imparting appropriate flexibility to the obtained optical film. Specifically, for example, an ester-based plasticizer, a phosphate-based plasticizer, a phthalic acid phthalate plasticizer, a benzoic acid-based plasticizer, a benzenetetracarboxylic acid plasticizer, a glycol ester plasticizer, a citric acid ester plasticizer, And the above-described glycol-based plastic plastomer as the ester-based plasticizer, and specific examples thereof include a basic acid such as a dibasic acid, an alicyclic dibasic acid, and an aromatic dibasic acid, and a glycol. The formation of multivalent alcohols. Further, the above-mentioned succinic acid may be used without particular limitation, and specific examples thereof include adipic acid (adipic acid), seic acid, and phthalic acid. ), terephthalic acid, 1,4-cyclohexyl adipate, and the like. Specific examples of the phosphate-based plasticizer include, for example, a triphenyl phosphate or a tricresyl phosphate method to dissolve a strip, and the acrylic acid is obtained by a refractive index. Fat multivalent side such as bac ic acid (Azerbaijan, A-37-201213098 phenol diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl Phosphate ester, etc. As the above-mentioned phthalate ester plasticizer, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate may be mentioned. , dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, etc. as the benzoic acid ester plasticizer, Specifically, for example, Tributyl Trimellitated, Triphenyl Trimellitated, Triethyl Trimellitated, etc. may be mentioned. The aforementioned benzoic acid ester plasticizer, For example, tetrabutylbenzenetetracarboxylic acid ester, tetraphenylbenzene tetracarboxylic acid ester, tetraethylbenzene tetracarboxylic acid ester, etc. are mentioned. As said glycolate type plasticizer, specifically, For example, hydrazine triacetate, tributyrin, ethyl phthalate, methyl phthalic acid ethyl hydroxyacetate, butyl phthalic acid butyl hydroxyacetate or the like may be mentioned. The citrate-based plasticizer, specifically, for example, triethyl citrate (Triethy 丨 Citrate ), tri-n-butyl citrate, ethyl triethyl citrate, tri-n-butyl citrate β, such as acetonitrile tri-n-ethyl 2-ethylhexyl ester, as the above-mentioned glycol-based plasticizer, for example, ethylene glycol, diethylene glycol, 1,3-propanediol '丨, 2· propylene glycol, hydrazine, 4 _Butanediol, hydrazine, 3-butanediol, -38-201213098 1,2-butanediol, etc. The above-mentioned plasticizers may be used singly or in combination of two or more kinds thereof. There is no particular limitation, for example, a hindered phenol) compound can be suitably used. Specifically, for example Taking 2,6-di-t-butyl-P-cresol, pentaerythritol-tetrakis3,5·di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis [ 3-(: yl-5-methyl-4_phenyl)propionic acid vinegar], 1,6-hexanediol-bis-[3-di-t-butyl-4-hydroxyphenyl)propionic acid Ester], 2,4-bis-(η-octylsulfuric acid (4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, 2,2-thioglycol Bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], deca, 3-(3,5-di-1-butyl-4-hydroxyphenyl)propane Acid ester], 1>^-hexamethylene (3,5-di-t-butyl-4-hydroxy-hydroxycinnamamine), 1,3,5-tri 2,4,6-11*13 ( 3,5-Di-1-butyl-4-hydroxyphenyl)benzene, 1^3-(3,5-butyl-4-hydroxybenzyl)-isocyanurate, and the like. In particular, it may be tl di-t-butyl-P-cresol, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-yl)propionate], triethylene glycol-bis [ 3-(3-t-butyl-5-methyl-4-hydroxy)propionate]. Further, a hydrazine-based metal such as N,N'-bis[3-(3,5-butyl-4-hydroxyphenyl)propanyl] hydrazine or the like may be used as the non-living or Tris (2, A phosphorus-based processing agent such as 4-di-t-butylphenyl phosphite. The optical film produced by the coating method according to the present embodiment can be used for a protective film for a polarizing plate or the like. Here, in order to prevent deterioration of a polarizing plate or a liquid crystal, it is preferable to use ultraviolet rays "combination L. Phenol (丨[3-( 丨-1 · butyl(3,5-)-6-substituted-dioctayl) bismethyl-di-t- ii 2,6-hydroxyphenylphenyl di- In the case of the above-mentioned ultraviolet absorber, it is preferably used for the wavelength of 370 nm or less and has good liquid crystal display properties. The absorption of visible light of 400 nm or more is rare. Specifically, the transmittance of 3 80 ηη is preferably less than 10%, particularly preferably less than 5%. As the ultraviolet absorber, specifically, for example, Examples thereof include an oxybenzophenone-based compound, a Benzotriazole-based compound (benzotriazole-based ultraviolet absorber), a salicylate-based compound, and an benzophenone-based compound (benzophenone). UV absorber) A cyanoacrylate-based compound, a nickel-salted salt-based compound, a triazine-based compound, etc. Among the above-mentioned ultraviolet absorbers, a Benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber is preferred. Specific examples of the benzotriazole-based ultraviolet absorber or the benzophenone-based ultraviolet absorber are not limited thereto. The benzotriazole-based ultraviolet absorber may specifically be, for example, 2-) 2'-hydroxy-5.-methylphenyl)benzotriazole, 2-(2.-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole , 2-( 2,-hydroxy-3,-tert-butyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3,5'-di-tert.butyl Phenyl)-5-chloro-benzotriazole, 2-( 2'-hydroxy-3'-( 3",4",5",6"-tetrahydrophthalene iminomethyl)- 5'-Methylphenyl)benzotriazole, 2,2-methylenebis(4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole- 2- yl)phenol, 2·(2'-hydroxy-3'-tert-butyl-5,-methyl-40-201213098-phenyl)-5-chlorobenzotriazole, 2. (2Η -benzotriazole-2-yl)-6-(linear and side chain dodecyl)-4-methylphenol (TINUVIN 1 71, manufactured by Chiba Specialty Chemicals Co., Ltd.), octyl-3-[3 -tert-butyl-4-hydroxy-5-(chloro-2H-benzotriazol-2-yl)phenyl]propionate with 2-ethylhexyl-3-[3-tert-butyl-4 a mixture of -hydroxy-5·(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate (TINUVIN 119, manufactured by Chiba Specialty Chemicals Co., Ltd.). Specific examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4·methoxybenzoquinone, and 2-hydroxy-4. -Methoxy-5-benzophenone, bis (2-methoxy-4-hydroxy-5-benzimidylphenylmethane), and the like. Further, a resin solution (coating) can be obtained by mixing the above respective components. Further, it is preferred that the obtained coating material be filtered by using an appropriate filter medium such as filter paper. (Optical film) The optical film obtained as described above is an optical film containing a cellulose ester resin in order to improve moisture resistance, heat resistance, etc., and is transparent and processable. Excellent in flatness. Specifically, for example, it differs depending on the composition and the like, but the haze of the obtained optical film is preferably 0.3 or less, more preferably 0.1 or less. Here, the measurement of the haze of the optical film can be measured in accordance with the ISK7136 standard. Specifically, for example, measurement can be carried out using a ambiguity meter (NDH2000 type manufactured by Nippon Denshoku Industries Co., Ltd.) or the like. In addition, the width of the optical film is preferably 1000 to 4000 mm in view of the use of a large liquid crystal display device, the use efficiency of an optical film during processing of a polarizing plate, and production efficiency. Further, the film thickness of the optical film is preferably from 30 to 90 μm from the viewpoint of downsizing of the liquid crystal display device and stabilization of production of the optical film. Here, the film thickness means an average film thickness, and a film thickness of 20 to 200 is measured in a wide direction of the optical film by a contact film thickness meter manufactured by Mitsutoyo (transliteration). The average enthalpy of the enthalpy is measured as a film thickness (polarizing plate). Further, the optical film can be used as a transparent protective film for a polarizing plate for protecting a polarizing element of a polarizing plate. The polarizing plate is specifically provided with, for example, a polarizing element and a transparent protective film disposed on the surface of the polarizing element. Next, as the transparent protective film, the above resin film can be used. The above-mentioned polarizing element is an optical element that changes incident light into polarized light and emits it. It is preferable that the polarizing plate is immersed in at least one surface of a polarizing element which is formed by immersing a polyvinyl alcohol-based film in an iodine solution, and is bonded to the optical film using a fully alkalized polyvinyl alcohol aqueous solution. . Further, the other surface of the polarizing element may be formed by laminating the optical film or laminating a transparent protective film for other polarizing plates. As the transparent protective film for the polarizing plate, for example, as a commercially available cellulose ester, it is preferable to use KC8UX2M, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC8UY-HA, KC8UX-RHA (above is Konica -42- 201213098)

Minolta Opto (manufacturing) and so on. Alternatively, a resin film such as a cyclic olefin resin, an acrylic resin, a polyester or a polycarbonate other than the cellulose ester film may be used. In this case, since the enthalpy is low in suitability, it is preferable to bond it to the polarizing plate through a suitable adhesive layer. As described above, the polarizing plate is used as a transparent protective film laminated on the surface side of at least one of the polarizing elements. In this case, when the optical film described above functions as a retardation film, the slow axis of the resin film is preferably arranged so as to be substantially parallel or orthogonal to the absorption axis of the polarizing element. Further, as a specific example of the above-mentioned polarizing element, for example, a polyvinyl alcohol-based polarizing film can be given. The polyvinyl alcohol-based polarizing film may be one in which iodine is dyed on a polyvinyl alcohol-based film and dyed with a dichroic dye. As the polyvinyl alcohol film, a modified polyvinyl alcohol film which is denatured with ethylene is preferably used. The polarizing element ' can be obtained, for example, as follows. First, an aqueous solution is used for film formation. The obtained polyvinyl alcohol-based film is dyed after being uniaxially stretched, or uniaxially stretched after dyeing. Next, it is preferred to apply a durability treatment to the boron compound. The film thickness of the polarizing element is preferably 5 to 40 μm, more preferably 5 to 30 μm, and most preferably 5 to 20 μm. On the surface of the polarizing element, the field of the cellulose ester-based resin film is preferably bonded by a water-based adhesive which is a basic alkali metal hydroxide or the like as a main component. Further, in the case of a resin film other than the cellulose ester resin film, it is preferable to bond the film to a polarizing plate through a suitable adhesive layer. The polarizing plate as described above is used as a transparent protective film, and the optical film of the present embodiment is an optical film excellent in transparency, moisture resistance, and processability by using the optical film of the present embodiment. Therefore, for example, a polarizing plate suitable for use in a screen-type liquid crystal display device can be obtained. Specifically, even if it is a polarizing plate for a liquid crystal display device having a large screen, deformation or the like is caused. Further, since a processed optical film is used as the transparent protective film, the use of a large film suppresses the occurrence of damage. (Liquid crystal display device) The polarizing plate including the optical film can be used as a polarizing plate provided in a liquid device, and a liquid crystal display device can be used, for example, a liquid crystal cell and a liquid crystal cell are trapped. A polarizer. Next, as the polarizing plate to which the two polarizing plates are placed, the polarizing plate can be used. In addition, when a liquid crystal cell is filled with a liquid crystal material between the electrodes, a liquid crystal is applied to the electrode, and the liquid crystal is aligned, so that the amount of transmitted light is suppressed, and the liquid crystal is used as a transparent protective film for a polarizing plate. The optical film according to the present aspect is provided with the optical film, and is an optical film excellent in transparency, heat-resistant moisture, and workability. Therefore, even if it is a large screen, it is possible to provide an optical film disposed in the image display region. A liquid crystal display device that is suppressed. Further, since the optical film is applied to the liquid crystal display device which is suitable for a large screen, the liquid crystal display device having a large screen is prevented from being damaged during the production. In the above, the embodiment of the present invention is described in detail, but the heat resistance is large, and the hygroscopicity is good, and the arrangement is less than that of the pair of liquid display devices. The shape of the machine is very large in size and can be described in the above-mentioned -44 - 201213098. All the embodiments are merely illustrative, and the invention is not limited to these types. Numerous modifications not illustrated are to be construed as being presumed without departing from the scope of the invention. [Examples] Hereinafter, the present invention will be specifically described by way of Examples, but the present invention is not limited thereto. [Example 1] (Acrylic resin) The acrylic resin was prepared as follows. First, in the reactor, 5 parts by mass of methyl acrylate, 95 parts by mass of methyl methacrylate, 1.2 parts by mass of t-dodecyl mercaptan, 2, 2'-azoisobutyronitrile 0.4 parts by mass, while stirring, the temperature of the liquid in the reactor was raised to 70 °C. Thereafter, it was maintained at 70 ° C while stirring for 1 80 minutes. Thereafter, the liquid in the reactor is cooled in accordance with a usual method, and thereafter, the solid component is precipitated from the cooled liquid. Next, the precipitated solid component was washed with water and then dried. By doing so, a beaded copolymer can be obtained. Further, the obtained copolymer had a polymerization ratio of 97% and a weight average molecular weight of 300,000. Next, the obtained copolymer was blended with NaOCH3 as an additive in an amount of 0.2% by mass. The complex was placed in a 2-axis extruder (manufactured by Sakamoto Steel Co., Ltd., ^30, 1^/〇 = 44.5), and the hopper portion of the 2-axis-45-201213098 extruder was used to make nitrogen. The mixture was rinsed at a rate of 10 L/min, and the auger was rotated at a number of 100 rpm, and the amount of the raw material (complex) supplied was 5 kg/hr. By doing so, a resin in the form of a tablet can be obtained. Next, the obtained ingot was vacuum dried at 80 ° C for 8 hours. Thus, an acrylic resin can be obtained. Further, the obtained acrylic resin is one in which the above complex is subjected to intramolecular cyclization. Further, the obtained acrylic resin had a weight average molecular weight of 300,000 and a glass transition temperature (Tg) of 130 °C. Further, the weight average molecular weight herein is measured by a GPC 'gel permeation chromatography, and the Tg is measured by a differential scanning calorimeter (D S C ). (Preparation of Coating Material 1) First, 40 parts by mass of methylene chloride and a mixed solvent of methanol and n-butanol (methanol: n-butanol (mass ratio) = 9:1) were dissolved in 40 parts by mass. 'As an acrylic resin, 70 parts by mass of the acrylic resin produced by the above-mentioned production method was added, and cellulose acetate propionate resin was added as a cellulose ester-based resin (the total substitution degree of the thiol group was 2.75, and the degree of substitution of the thiol group was 0.19). 'Propanyl substitution degree: 2.56, Mw: 200000) 30 parts by mass. In other words, the content ratio of the acrylic resin to the total amount of the acrylic resin and the cellulose ester resin (acrylic resin/acrylic resin + cellulose ester resin: A mass percent) , is 70 mass%. Then, after the liquid temperature was raised to 8 〇, the mixture was stirred for 3 hours. By doing so, a resin liquid can be obtained. Thereafter, the stirring was terminated and the temperature was lowered to 43 C. Then, the obtained resin solution was filtered by a filter paper having a furnace accuracy of -46 - 201213098 0.0 0 5 m, and the bubble in the resin solution was defoamed by leaving the filtered resin solution overnight. The resin solution thus obtained was used as a coating material to produce an optical film as follows. (Manufacture of optical film) First, the temperature of the obtained coating material was adjusted to 35 °C to adjust the temperature of the endless belt support to 25 °C. Next, using the optical film manufacturing apparatus shown in Fig. 1, an endless cylindrical support body composed of a stainless steel cylinder made of stainless steel and honed to a super-mirror surface by a casting die was cast to a conveying speed of 60 m/min. . As a result, a web is formed on the endless cylindrical support body, and dried and transported. Next, the web is peeled off from the endless cylinder support into a film. Thereafter, the peeled film is extended in the MD direction by the first stretching means, and extends in the TD direction by the second stretching means. Next, both ends of the film were cut and removed by a cutting device. Thereafter, the film in which both end portions are removed is extended in the MD direction by the third stretching means. Next, an optical film wound into a roll shape was obtained by winding the film to a length of 8000 m. The obtained film had a width of 2300 mm > a thickness of 40 μm. In the above-described production, the elongation of the first stretching device and the third stretching device is adjusted so as to exhibit the elongation shown in Table 1, and the stretching conditions such as the conveying tension of the film are adjusted. Specifically, the total elongation (first elongation) of the first stretching device and the elongation (third elongation) of the third stretching device (total elongation in the MD direction) and relative to the MD The ratio of the first elongation of the total elongation in the direction (the total elongation in the first elongation/MD direction) is the elongation of 値 shown in Table 1, and the transfer of the film is adjusted to -47-201213098. Extended conditions. In the elongation rate of the second extension device, the temperature of the conveyance roller in the first extension device is set to 35 °C, and the temperature of the conveyance roller is not particularly controlled. [Examples 2 to 4 and Comparative Examples 1 to 4] In addition to the total elongation in the MD direction of the first stretching device and the third stretching device, and the extension of 値 shown in Table 1 of the first elongation/MD direction In the same manner as in the first embodiment, the light was produced in the same manner as in the first embodiment, and the light was produced in the same manner as in the example 1 except that the temperature of the conveyance roller in the first extension device was changed. , manufacturing optical film. [Example 6] An optical film was produced in the same manner as in Example 2 except that the atmosphere temperature in the first stretching device was set. [Example 7] The elongation of the first stretching device, the total elongation in the MD direction, and the total elongation in the first direction were made into the elongation β film of the crucible shown in Table 1, except that the coating material 2 described later was used. An optical film was produced in the same manner as in the examples except for the extension conditions such as the conveyance tension. 10% » Next, the first extensional elongation becomes the extension of the elongation to the tension: film.

It is set to -1 5 °C to 60 °C and the third extension 1 elongation/MD J method, and change 1 to perform -48-201213098 (modification of coating 2). In addition to the acrylic resin, 70 mass is used instead. The acrylic resin produced by the above-mentioned production method is used in an amount of 3 parts by mass, and as a cellulose ester-based resin, 70 parts by mass of a cellulose acetate-based resin is used instead of 30 parts by mass. 2.75, acetonitrile substitution degree: 〇.19, acrylonitrile substitution degree: 2.56, Mw: 200000), and manufactured under the same conditions as the coating material j. Further, the A mass percentage (acrylic resin/acrylic resin + cellulose ester resin) of the coating was 30 mass%. [Example 8] The total elongation in the MD direction and the total elongation in the first elongation/MD direction in the elongation ratio of the first stretching device and the third stretching device were set as shown in Table 1 except that the coating material 3 to be described later was used. An optical film was produced in the same manner as in Example 1 except that the elongation of the film was changed, and the elongation of the film was changed. (Preparation of the coating material 3) In place of the acrylic resin, instead of using 70 parts by mass, 95 parts by mass of the acrylic resin produced by the above-described production method is used, and 30 parts by mass is used instead of the cellulose ester resin. The cellulose acetate propionate resin (the total substitution degree of thiol group 2.75, the substitution ratio of acetonitrile base · 0.19 , the substitution degree of propyl sulfhydryl: 2.56, Mw : 200000) is the same as that of the coating material 1 -49-201213098 The conditions to manufacture. Further, the A mass percentage (acrylic resin/acrylic resin + cellulose ester resin) of this coating was 95% by mass. [Comparative Example 5] The total elongation in the MD direction and the total elongation in the first elongation/MD direction in the elongation ratio of the first stretching device and the third stretching device were set as shown in Table 1 except that the coating material 4 to be described later was used. An optical film was produced in the same manner as in Example 1 except that the elongation of the film was changed, and the elongation of the film was changed. (Preparation of the coating material 4) The acrylic resin produced by the above-described production method is used instead of 70 parts by mass instead of the acrylic resin, and the same conditions as those of the coating material 1 are used except for the cellulose ester-based resin. Manufacturing. Further, the A mass percentage (acrylic resin/acrylic resin + cellulose ester resin) of the coating was 100% by mass. [Comparative Example 6] The total elongation in the MD direction and the total elongation in the first elongation/MD direction in the elongation ratio of the first stretching device and the third stretching device were set as shown in Table 1 except that the coating material 5 to be described later was used. In the same manner as in Example 1, except that the elongation of the film was changed, the optical film was produced in the same manner as in Example 1 except that the acrylic film was used instead of the acrylic resin. 70 parts by mass and 20 parts by mass of the acrylic resin produced by the above-mentioned production method, and as a cellulose ester-based resin, instead of using 30 parts by mass, 80 parts by mass of cellulose acetate propionate-based resin is used instead. The degree of substitution: 2.75, the substitution ratio of acetonitrile: 0.19, the degree of substitution of propyl thiol: 2.56, and Mw: 200000) were produced under the same conditions as those of the coating material 1. Further, the A mass percentage (acrylic resin/acrylic resin + cellulose ester resin) of the coating was 20 mass%. The above experimental data is included and compiled in Table 1. Further, when the surface temperature of the conveying roller of the first stretching device is not particularly controlled, "_" -51 - 201213098 is displayed. [1 巡«1 ι|Β 1 LD ^― 1 1 1 酗11„ 〇濉 alkali坩忉8 LO CO mc〇褂ll 1 Shanghai 2 LO 00 to 〇0 〇Τ—LO CO 00 Total elongation in MD direction (%) 〇〇8 〇Coating A (% by mass) 〇LO CD Ο 〇Type coating 1 Coating 2 Coating 3 Coating 1 Coating 4 Coating 5 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 | Example 8 Comparative Example 1 1 Comparative Example 2 1 Comparative Example 3 Comparative Example 4 Comparison Example 5 Comparative Example 6 - 52 - 201213098 Examples 1 to 8 and Comparative Examples 1 to 1 were evaluated as follows. (Haze) First, the obtained optical was measured in accordance with the n SK 7 1 3 6 standard. Specifically, the ambiguity of the film is measured using a ambiguity meter (NDH2000 type manufactured by Nippon Denshoku Industries Co., Ltd.). Then, if the measured ambiguity is 0.1 or less, the evaluation is "◎". ·1 and if it is below 〇.3, the evaluation is "〇j, if it exceeds 〇. 3, the evaluation is "X".(Cutting) The optical film obtained by the Toyo Seiki Co., Ltd. was used to pull the obtained optical film, and the cracked surface was visually confirmed. At this time, the cracked surface was very smooth, and it was split in a straight line. When the occurrence of the cut powder was not confirmed on the cracked surface, it was evaluated as "◎", and although the straight crack was opened, it was confirmed that the cut powder occurred on the cracked surface. It is evaluated as "〇". If the cracked surface is confirmed to have a burr, or if it is not torn in a straight line, or if a large amount of cut powder is formed on the cracked surface, it is evaluated as "X". (Planarity) First, a length of 2000 mm was cut out from the obtained optical film (width 2300 mm) in the longitudinal direction (transport direction) of the film. The cut film was visually observed from a position which constituted a 30 degree angle with the surface of the film. Then, when it was confirmed that wrinkles were not observed on the film, it was evaluated as "〇", and it was confirmed that wrinkles were present, but -53-201213098 was a wrinkle (a crepe which is not noticeable) which can be used as an optical film. When the evaluation is "△", it is confirmed that it is difficult to use the optical film, and the evaluation is "X". The evaluation results are shown in Table 2 below. [Table 2] Fuzziness Cutting Planar Example 1 0.3 〇 ◎ Example 2 0.2 〇 ◎ Example 3 0.2 〇〇〇 Example 4 0.2 〇〇〇 Example 5 0.1 ◎ ◎ 〇 Example 6 0.3 〇 Example 7 0.2 〇〇〇 Example 8 0.3 〇〇〇 Comparative Example 1 0.8 X ◎ 〇 Comparative Example 2 0.2 〇X 〇 Comparative Example 3 0.2 〇 ◎ X Comparative Example 4 0.2 〇X 〇 Comparative Example 5 0.2 〇X 〇Comparative Example 6 0.5 XX "〇", as shown in Table 1 and Table 2, as a coating material, a mass ratio of 95:5 to 30:70 (the content A of the acrylic resin is 3 Å to 95% by mass) contains an acrylic resin. The total elongation in the MD direction of the resin solution of the resin and the cellulose ester resin is a/3+i〇~a/5+4〇, and the ratio of the first elongation to the total elongation in the MD direction is 7〇~ In the case of 95% (Examples 1 to 8 -54 - 201213098), moisture resistance, heat resistance, and the like were improved as compared with the case where none of the conditions were satisfied (Comparative Examples 1 to 6), so that even the acrylic resin was used. It is also contained in cellulose ester-based resin and can also produce transparency such as haze. An optical film excellent in workability and planarity such as cutting property. The present specification discloses the various types of techniques as described above, but the main techniques are as follows. The optical film manufacturing method of one aspect of the present invention is characterized by And a casting step of forming a casting film by casting a resin solution containing an acrylic resin and a cellulose ester resin in a mass ratio of 95:5 to 30:70 to form a cast film, and casting the film The peeling step of peeling the support into a film, transporting the peeled film, and extending in the first extending step of the film transporting direction, transporting the film extending by the first extending step, and extending to the film In the second extending step of the direction in which the conveying direction is perpendicular, the film extending in the second extending step is conveyed, and both ends in the direction perpendicular to the conveying direction of the film are cut, and the cutting step of the cut end portion is removed. a third extension step of transporting the removed film at the end of the cutting and extending in the transport direction of the film; and an elongation of the film in the first extending step and the third In the total of the elongation of the film in the stretching step, when the content of the acrylic resin is A mass% of the total amount of the acrylic resin and the cellulose ester resin, it is expressed as a percentage in A/3 + 10~ In the range of A/5 + 40, the elongation of the film in the first stretching step is 70 to 95 in total of the elongation of the film in the first stretching step and the elongation in the film in the third stretching step. According to such a configuration, it is possible to provide transparency, workability, and planarity even when the acrylic resin is contained in the cellulose ester resin in order to improve the moisture resistance or the heat resistance of -55 to 201213098. A method of producing an optical film of an optical film. This situation can be presumed to be based on the following. First, the total elongation of the film in the direction of transport, and the total elongation of the film in the first stretching step and the elongation of the film in the third extending step are within the above range, and it is possible to suppress the film. The occurrence of whitening can also increase the film strength. In this case, first, when the elongation is insufficient, the alignment of the resin constituting the film may be insufficient. Further, the extension is too large, and it should be caused by the difference in the degree of orientation of the resin depending on the kind of the resin constituting the film, and the difference becomes large. In other words, in the above range, the alignment of the acrylic resin constituting the film and the cellulose ester resin is ensured to some extent, and the difference in the degree of alignment between the acrylic resin and the cellulose ester resin is not too large. Therefore, 'the reason why the total elongation in the direction of transport of the film is 'defined within the above range' is to improve the moisture resistance, the heat resistance, etc., even if the acrylic resin is contained in the cellulose ester resin. It can improve transparency and processability. Then, when the elongation of the film in the first stretching step is within the above range, the transparency and workability of the obtained film should be maintained in a high state, and the planarity should be improved. When the elongation of the film in the first stretching step is too low, the elongation of the film in the third stretching step may become too high. In the third stretching step, there is a direction in which the film is conveyed (long side) The direction) is caused by the tendency to form an extended line (vertical wrinkles). Further, -56-201213098, if the elongation of the film in the first extension step is too high, the elongation of the film in the third extension step becomes too low, which is formed in the second extension step, and extends The wrinkles (transverse wrinkles) perpendicular to the direction of the film transport direction (the short side direction) tend to be insufficiently removed even if the third extending step extends in the transport direction '. Therefore, the transparency and workability of the film obtained by setting the elongation of the film in the first stretching step within the above range should be maintained at a relatively high level, and the planarity can be improved. In the above, the optical film of an optical film excellent in transparency, workability, and planarity can be produced by allowing the acrylic resin to be contained in the cellulose ester-based resin in order to improve moisture resistance, heat resistance, and the like. Further, in the method for producing an optical film, when the ratio of the content of the acrylic resin to the total amount of the acrylic resin and the cellulose ester resin is A mass%, the film of the first extending step The total of the elongation and the elongation of the film of the third stretching step is preferably expressed by a percentage in the range of A/3+15 to A/5+30. According to such a configuration, an optical film having more excellent transparency and workability can be produced. In this case, it should be in the above range, and the alignment between the acrylic resin constituting the film and the cellulose ester resin is ensured to some extent, and the difference in the degree of alignment between the acrylic resin and the cellulose ester resin does not become too large. Large range. Further, in the method for producing an optical film, the elongation of the film in the first stretching step is 80% in relation to the elongation of the film in the first stretching step and the elongation in the film in the third stretching step. 95% are -57- 201213098. According to such a configuration, an optical film having more excellent planarity can be produced. In this case, the transparency and workability of the film obtained by setting the elongation of the film in the first stretching step within the above range are maintained high, and the planarity can be further improved. Further, in the method for producing an optical film, the ambient temperature of the first extending step is preferably 5 to 39 °C. According to such a configuration, the strength of the film can be further enhanced, and an optical film having more excellent workability can be produced. In this case, in the first stretching step, the resin constituting the film can be more appropriately aligned. In the method for producing the optical film, the first stretching step is such that the conveying roller is in contact with the conveying roller. Preferably, the surface temperature of the transfer roller is -20 to 0 ° C in the step of simultaneously rotating the film peeled off by the peeling step. According to such a configuration, the strength of the film can be further enhanced, and an optical film having more excellent workability can be produced. In this case, in the first stretching step, the resin constituting the film can be more appropriately aligned. Further, another aspect of the present invention is obtained by the method for producing the optical film. Optical film. According to such a configuration, the acrylic resin is contained in the optical film of the cellulose ester resin in order to improve moisture resistance, heat resistance, and the like, and is excellent in transparency, workability, and planarity. Then, since it is excellent in hygroscopicity, workability, and the like, it can be easily applied to a protective film for a polarizing plate for a liquid crystal display device of a large screen. In addition, the desired size is also available. Further, another aspect of the present invention provides a transparent plate which is polarized on a surface of at least one of the polarizing elements, wherein the transparent protective film is a transparent film which is a polarizing plate according to such an optical film. For example, it is excellent in heat resistance, heat resistance, transparency, workability, and planarity, and it is suitable for a liquid crystal display polarizing plate which is large screen. Specifically, even in the case of a liquid crystal polarizing plate having a large screen, deformation due to moisture absorption or the like is suppressed. Further, since the film is made of an optical film having good workability, the occurrence of a large flaw is used. Further, another aspect of the present invention is a liquid of two polarizing plates in which liquid crystal cells are provided in a liquid crystal, and at least one of the two polarizing plates is configured to be resistant to such a configuration. The polarizing plate of the optical film excellent in wetness, resistance, workability, and planarity can be screened, and a liquid crystal display device in which the problem of placement in the image display region is suppressed can be provided. Specifically, the large-screen liquid crystal display device ′ can also suppress the occurrence of deformation due to moisture absorption of the optical film in the matching region. In addition, since it is excellent in workability, even if it is a polarizing plate film which is easy to cut into a component and a polarizing feature in which a protective film is disposed, it is suitable for a display device used for a display device. The transparent protective film also suppresses the damage and the crystal display device, and the polarizing plate is thermally and transparent, so that even if it is a large optical film, for example, even if it is placed on an image display, the optical germanium crystal display device -59-201213098 A large-sized film suppresses the occurrence of damage of the optical film at the time of manufacture, so that a liquid crystal display device with a large screen can be provided. [Industrial Applicability] According to the present invention, it is possible to produce transparency, workability, and planarity even when an acrylic resin is contained in a cellulose ester resin in order to improve moisture resistance, heat resistance, and the like. A method of producing an optical film of an optical film. Further, an optical film obtained by the method for producing an optical film, a polarizing plate using the optical film as a transparent protective film, and a liquid crystal display device including the polarizing plate are provided. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the basic configuration of an apparatus 11 for manufacturing an optical film according to a solution casting film forming method according to an embodiment of the present invention. [Description of main component symbols] 12: Endless cylinder support body 1 3 : Casting die 1 4 : Peeling roller 1 5 : 1st extension device 16 : 2nd extension device 17 : Cutting device 18 : 3rd extension device 1 9 : Resin solution (paint) 20 : coiling device -60-

Claims (1)

201213098 VII. Patent application scope: 1. A method for producing an optical film, comprising: a resin solution containing a propionic acid resin and a cellulose ester resin in a mass ratio of 95: 5 to 30: 70; a casting step of forming a casting film on the supporting rubbing body, and a peeling step of peeling the casting film from the support into a film, and conveying the peeled film while extending the first conveying direction of the film In the extending step, the film extending by the first extending step is simultaneously extended in a second extending step in a direction perpendicular to the conveying direction of the film, and the film extending by the second extending step is conveyed while being perpendicular to the film a third extending step of removing the cut end portion and a film 'removed at the end portion of the film in the direction in which the film is conveyed, and extending the film in the transport direction of the film; The ratio of the elongation of the film in the stretching step to the elongation of the film in the third stretching step, the content of the acrylic resin to the acrylic resin and the fiber When the total amount of the ester-based resin is A mass percentage, it is expressed as a percentage in the range of A/3 + 10 to A/5 + 40; the elongation of the film in the first extension step is relative to the first extension The total elongation of the film in the step and the elongation of the film in the third stretching step are 70 to 95%. 2. The method for producing an optical film according to the first aspect of the invention, wherein the ratio of the content of the acrylic resin to the total amount of the acrylic resin and the cellulose-ester resin of -61 - 201213098 is A mass% In the case where the elongation of the film in the first stretching step and the elongation in the film in the third stretching step are expressed as a percentage in the range of A/3 + 15 5 to A/5 + 30. The method for producing an optical film according to the first aspect of the invention, wherein the elongation of the film in the first extending step is longer than the elongation of the film in the first extending step and the film in the third extending step The total rate is 80 to 95%. 4. The method of producing an optical film according to claim 1, wherein the ambient temperature of the first extending step is 5 to 39 °C. 5. The method for producing an optical film according to the first aspect of the invention, wherein the first extending step is a step of causing the conveying roller to be in contact with the film peeled off by the peeling step, wherein the surface temperature of the conveying roller is - 20~0 °C. An optical film obtained by the method for producing an optical film according to any one of claims 1 to 5. A polarizing plate comprising: a polarizing element; and a polarizing plate disposed on a surface of at least one of the polarizing elements; wherein the transparent protective film is in claim 6 The optical film described. 8. A liquid crystal display device as a liquid crystal display device comprising two liquid crystal cells and two polarizing plates arranged to sandwich the liquid crystal cell, wherein: -62 - 201213098 at least one of the two polarizing plates One party is a polarizing plate that applies for the seventh item of the patent scope. -63-