TW201107396A - Optical element - Google Patents

Abstract

Disclosed is a stable optical element which has excellent brittle properties, low birefringence, low photoelasticity, less haze and less odor, while being suppressed in birefringence changes which are caused by temperature/humidity changes. Specifically disclosed is an optical element containing 10-50 parts by mass of cellulose ester resins (B) per 50-90 parts by mass of an acrylic resin (A), which is characterized in that at least one kind of the cellulose ester resins (B) has a total degree of substitution of acyl groups (T) of 2.00-2.99 and a degree of substitution of acetyl groups (ac) of 0.10-1.89, with portions other than the acetyl groups being substituted by an acyl group having 3-7 carbon atoms at a degree of substitution (r) of 1.10-2.89. The optical element is also characterized in that a chain-transfer agent having a boiling point of not less than 165 DEG C at atmospheric pressure is contained in an amount of 0.1-0.5% by mass relative to the acrylic resin (A).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element which is excellent in exhibiting low birefringence and having a low change in luminosity or a change in temperature caused by a change in birefringence. [Prior Art] A description will be made regarding an optical film represented as an optical element. The demand for liquid crystal display devices in LCD TVs and computer LCD displays has expanded. Generally, a liquid crystal display device is a liquid crystal cell made of a glass electrode, a liquid crystal layer, a color filter, or the like, and two polarizing plates on both sides are formed, and each polarizing plate is protected by two polarizing plates to hold a polarizing photo ( Also known as a polarizing film). The polarizing plate protective film usually uses a cellulose film. On the other hand, due to advances in technology in recent years, the liquid has been accelerated and the liquid crystal display device has been used for various purposes. For example, as a large-scale display installed on a street or a storefront, a display device called a digital electronic signage is used. The use of advertising displays. Regarding such applications, since it is intended to be used outside the house, deterioration due to moisture absorption becomes a problem, and the polarizing plate is protected from a high moisture resistance. However, the cellulose tribride which has been used in the past is transparent and is provided on the optical film (the polarizing film triacetate thin crystal display device) by the use plate of the wet resin composition, such as the current problem display device. In the case of a polarizing film in a public place, it is difficult to obtain sufficient moisture resistance due to a cellulose ester film of a film having a higher acid ester film, such as -5,001,07,396, and if the film is thickened to obtain moisture resistance, the optical influence becomes large. In addition, in recent years, since the thickness of the device has been required to be thinned, the thickness of the polarizing plate itself has become a problem. On the other hand, as a low hygroscopic optical film material, polymethacrylic acid represented by an acrylic resin. The methyl ester (hereinafter abbreviated as PMMA) is preferably used for an optical film because it exhibits transparency and dimensional stability in addition to low hygroscopicity. However, as the liquid crystal display device as described above is enlarged, it is used outdoors. In order to fully recognize the image outdoors, it is necessary to increase the amount of backlight light and at the same time it can be used under more severe conditions, and it is required to Heat resistance at high temperature or heat resistance at a long time. However, PMMA film lacks heat resistance, and it has a problem of shape deformation at high temperatures and long-term use. This problem is not only an important issue for the physical properties of film monomers. In the liquid crystal display device, since the polarizing plate is curled by the deformation of the film, the entire panel is warped, which is caused by the deformation of the film. The problem is also a problem on the backlight side. However, when the position of the identification side surface is used, the phase difference of the design changes due to deformation, so that the problem of causing a change in the viewing angle or a change in the color tone occurs. Compared with the ester film and the like, the fragile property which is also ruptured is difficult to handle, and it is difficult to stably manufacture an optical film for a large liquid crystal display device. In view of the above problems, it is proposed to improve moisture resistance and heat resistance. C-6-201107396 Adding polycarbonate (hereinafter referred to as PC) to the olefin resin, but it is limited to use The solvent and the resin are insufficient in compatibility with each other and are easily opaque to be used as an optical film (for example, refer to Patent Document 1). As another method for improving heat resistance, there is disclosed a method of introducing an alicyclic alkyl group as a copolymerization component of an acrylic resin. The method or the method of performing an intramolecular cyclization reaction to form a cyclic structure of a molecular main chain (see, for example, Patent Documents 2 and 3). However, in these methods, although the heat resistance is improved, the film fragility is still insufficient, and it is difficult to manufacture a large liquid crystal. The optical film used in the display device. When the brittleness is insufficient, the optical film will deform the panel, and it is not possible to suppress the change in the final phase difference, and also causes a change in the viewing angle and a change in color tone. As a function for improving moisture resistance and heat resistance. As a technique, a resin in which an impact-resistant acrylic rubber-methyl methacrylate copolymer or a butyl-modified acetaminophen is combined in an acrylic resin is proposed (for example, see Patent Document 4). However, in the case of this document, since the structure of the maleic anhydride unit is copolymerized in the acrylic resin, since the ring structure of the maleic anhydride changes to a maleic acid unit in a water or a high humidity environment, it is optical. The disadvantage of increasing humidity. At the same time, fogging occurs at the same time, and when outdoor use is required with higher contrast, the contrast of the image is lowered. Further, a technique of mixing a plasticizer with a conventional cellulose ester film or an acrylic resin for controlling optical properties has been proposed (for example, refer to Patent Document 5). However, for these purposes, since the acrylic resin which can sufficiently improve the moisture resistance cannot be added, sufficient moisture resistance cannot be obtained, and deterioration of the polarizing plate or optical enthalpy change of the optical film occurs in the high humidity 201107396 environment. problem. In addition, in the case where a large amount of other resin for improving moisture resistance is added to the cellulose ester resin, it is considered that the transparency is lowered, and the moisture resistance cannot be improved to the extent that the optical enthalpy does not change in a high-humidity environment. Cellulose ester film. Under the above circumstances, with the recent expansion of the use of liquid crystal display devices, problems such as low moisture absorption, transparency, high heat resistance, and brittleness of optical films used have become more and more demanding. An optical element other than the optical film used in the above liquid crystal display device, a read head lens mounted on an optoelectronic device using a substrate or a coating layer of an information recording medium, an optical fiber, an optical connector, or a semiconductor laser, Fresnel lenses, lenticular sheets, iridium, light guide plates, and polarized optical elements used in display elements are also required to allow low humidity, transparency, and high heat resistance. Optical components. In particular, the quality of the material as an optical element is highly demanded, and in order not to obscure an optical signal or an image, the quality is small, and there is little foreign matter and there is no optical distortion or an external stress is hard to be optically deformed. Optical element with low birefringence and low photoelastic coefficient. Further, as an example of using an optical element by polarizing, a polarizing mirror or an analyzer of a polarizing microscope, a filter for detecting deformation of a deformation inspection device, a filter for attenuating a light-densing optical attenuating device, and a polarizing stereoscopic image device are exemplified. Polarized aperture or polarized glasses; polarized sunglasses lenses; polarized filters for cameras; liquid crystal displays for LCD TVs, PC monitors, digital cameras, 201107396 cameras, mobile phones, electronic computers, etc. Glass, etc. For example, in the above application, there are at least two or more polarizers, and the polarizer (polarizer) on the input side and the polarizer on the output side can be used as a photodetector (analyzer), but at this time, the polarizer is Between the analyzers, optical elements with significantly reduced or zero birefringence or stress birefringence are used, thereby faithfully communicating light as an optical design. However, if there is an alignment birefringence or a stress birefringence other than the design between the polarizer and the analyzer, since it is different from the design flaw, for example, in the case of a liquid crystal display, the brightness or color tone of the image changes, and analysis When the polarized glasses of the polarized three-dimensional image device are used, the brightness or color tone of the image cannot be faithfully reproduced. [PATENT DOCUMENT] [Patent Document 1] JP-A-2005-146084 (Patent Document 3) JP-A-2005-146084 [Patent Document 5] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. The finisher, whose purpose is to provide a stable optical element which is excellent in brittleness, exhibits low birefringence and low photoelasticity, and has a small change in birefringence due to a change in humidity or a change in humidity and a haze. [Means for Solving the Problem] The above-described problems of the present invention are achieved by the following constitution. An optical element comprising 10 to 50 parts by mass of a cellulose ester resin relative to 50 to 90 parts by mass of the acrylic tree, characterized in that the cellulose ester resin (B) is at least for the acrylic resin ( A), the degree of substitution (T) of 0.1 to 0.5% by mass is 2.00 to 2_99, and the degree of substitution (ac) of ethyl sulfonate is exemplified by a ratio of 3 to 7 carbon atoms. The optical element having the degree of substitution (r) of 1.10 to 2.89 and having a boiling point at a constant pressure j. The optical element according to the above 1, wherein the optical elastic modulus is -3 〇 xl (T12/Pa ~7. 〇xl (r12/Pa (23 ° C, ο 3. The optical element according to 1 or 2 above, wherein the aforementioned in-plane birefringence (i) is absolute 値' or thickness direction (ii) At least any of the absolute 满足 meets 2.0 x 1 0 _ 4 (23 ° C), (i) Δηο= ( nx-ny) (ii) Anth= ( ( nx + ny ) / 2-nz ) ( Wherein, nx is a light-type species in which the resin constituting the optical element is made into a thin inner maximum refractive index 'ny is in-plane and nx perpendicular direction, and the odor is less fat (A): B), and the phase 醯 base is taken as 0.10. -1.89 醯基换专用1 6 5 °C with component light 5 5% RH) Birefringence of optical element, face ratio of 5 5 % R Η film, ηζ is -10- 201107396 refractive index in the thickness direction of optical element 'each refractive index is for wavelength 590nm The optical element according to any one of the above 1 to 3, wherein the in-plane birefringence and the birefringence in the thickness direction of the optical element, and the birefringence of a temperature of 23 ° C and 20% RH The optical element of any one of the above-mentioned 1 to 4, wherein the in-plane double of the optical element is the same as the optical element of any of the above-mentioned optical elements. The birefringence in the direction of refraction and thickness, and the absolute 値 of the difference between the birefringence of temperature 35t: 27% RH and the birefringence of 55% RH at 23 ° C are both 1 · 〇χ 1 0 · 4 or less. [Effect of the invention] According to the invention, a stable optical element having excellent brittleness, low birefringence and low photoelasticity, small birefringence fluctuation due to humidity change or temperature change, and low haze and odor is provided. The form of the present invention will be described in detail, but the present invention is not limited thereto. The optical element of the invention is exemplified by a general camera lens, a viewfinder, a camera lens, a laser read head lens, a f0 lens for a laser printer, a cylindrical lens, an oregon mirror, and a projection television. Lens, multi-focal lens for liquid crystal projector, relay lens, capacitor lens, projection lens, lens for Fresnel lens, lens for glasses, etc., 11 - 201107396 Brain CD (CD, CD-ROM, etc.), mini Optical disc, DVD disc substrate, LCD substrate, organic EL substrate 'polarizing plate protective film, retardation film, zero retardation film, light diffusing film, liquid crystal element bonding adhesive, and the like, liquid crystal element member, projector screen , optical filters, optical fibers, optical waveguides, germanium, lenses for photoelectric conversion elements, and the like. The resin composition of the present invention can also be used for a pickup lens (an objective lens, a diffraction grating, a collimator lens, etc.) for a micro-disc and a read-head lens (an objective lens, a diffraction grating, a collimator lens, etc.) for a DVD, etc. In the optical component. In particular, the present invention is directed to an optical film used for a polarizing protective film, a retardation film, a zero retardation film, or the like in the above optical element, and the optical film used in the polarizing plate protective film is generally a cellulose ester film. However, the cellulose ester film has a disadvantage of being highly hygroscopic compared to the acrylic film. However, when an acrylate resin is mixed in a cellulose ester resin to improve moisture absorption, it is incompatible with each other to cause an increase in haze, and it is difficult to use it as an optical film. In particular, an acrylate resin having a large molecular weight is considered to be incompatible with the cellulose ester resin, and it is considered that it is difficult to improve hygroscopicity by mixing of the resin. In Patent Document 5, a lower molecular weight acrylate resin as a plasticizer is added to the cellulose ester resin. However, since the amount of addition is small, the hygroscopicity cannot be improved, and by adding an acrylate resin having a small molecular weight, The heat resistance is lowered, and the characteristics of the optical film used in a liquid crystal display device suitable for a large liquid crystal display device or an outdoor use cannot be obtained. On the other hand, the acrylic resin film lacks heat resistance and is used under high temperature -12-201107396. It is easy to deform and deteriorate in brittleness when used for a long time. In Patent Documents 1 to 3, although the characteristics of the acrylic resin are improved, the characteristics of the optical film are not sufficiently obtained. Patent Document 3 also proposes a technique of mixing a cellulose ester resin with an acrylic resin to improve heat resistance, but since a cellulose ester resin having a high molecular weight is considered to be incompatible with a acrylic acid resin, a cellulose ester having a low molecular weight is added. As a result of the positive review of the above-mentioned problems, the inventors of the present invention found that the cellulose ester resin having a specific degree of substitution exhibits high compatibility with the acrylate resin, and more unexpectedly, the higher molecular weight of the aliphatic fiber. The ester resin did not increase the haze and was judged to be compatible. Further, by blending the acrylic resin (A) with a cellulose ester resin (B) having a specific degree of substitution within a specific mixing ratio, it is dissolved and further contains a boiling point of 0.1 to 0.5 parts by mass at atmospheric pressure. The next is 165. (The above chain transfer agent was found to improve the disadvantages of the acrylic resin and the cellulose ester resin, and it was excellent in brittleness, low birefringence and low photoelasticity, and the birefringence variation due to humidity change or temperature change was small and The present invention has been completed in that the optical element of the present invention contains 10 to 50 parts by mass of the cellulose ester resin (50 to 90 parts by mass with respect to the acrylic resin (A). The optical element of B), characterized in that at least one of the cellulose ester resins (B) has a total degree of substitution (T) of from 0.1 to 0.5% by mass based on the acrylic resin (A) of from 2.00 to 2.99. The degree of substitution (ac) of acetamyl group is 〇.1〇~1.89 'The part other than acetyl group is substituted by thiol group consisting of 3~7 carbon numbers-13- 201107396 'The degree of substitution (r) is 1.10~2.89' and the boiling point is 165 at normal pressure. The chain transfer agent above 〇. The photoelastic coefficient of the optical element is preferably _3.0x10·12/P a~ 7.〇xl〇-, 2/ Pa ( 2 3〇C ' 5 5% RH), the absolute intrinsic birefringence (i), or the thickness direction At least one of the absolute defects of (ii) preferably satisfies 2·〇χ 1 0_4 (23° C., 55% RH ) or less, in-plane birefringence and birefringence in the thickness direction of the optical element, and a temperature of 23 ° The absolute 値 of the difference between the birefringence of C 20 % RH and the birefringence of 23° C. and 80% RH is preferably 1.5 XI (Γ4 or less 'in addition to the in-plane birefringence and birefringence of the thickness direction of the optical element, and the temperature 35 The absolute 値 of the difference between the birefringence of 27% RH and the birefringence of 23 °C and 55 % RH is 1.0 X 1 Ο·4 or less, which is preferable in terms of improving the effect of the present invention. The optical film of one form of the optical element of the present invention is used on at least one side of the polarizing plate to obtain a liquid crystal display device in which the viewing angle is changed or the color shift is reduced. The present invention will be described in detail below. <Acrylic Resin (A) The acrylate resin used in the present invention also contains a methacrylate resin. The resin is not particularly limited, but is preferably from 50 to 99% by mass of methyl methacrylate units and from 1 to 50% by mass. The other monomer unit of the polymerization. The other monomer units of the polymerization are exemplified by alkyl groups of 2 to 18 carbon atoms having an alkyl number, alkyl acrylates having an alkyl number of 1 to 18, propylene-14-201107396 acid, methyl propylene acid, etc. α,/3-3-unsaturated acid 'maleic acid, fumaric acid, itaconic acid, etc., unsaturated vinyl-containing divalent carboxylic acid, styrene 'α-methylstyrene, etc. Alpha, cold-unsaturated nitrile such as nitrile, methacrylonitrile, maleic anhydride 'maleimide, hydrazine-substituted maleimide, glutaric anhydride, etc., which can be used alone' or can be used Use with more than two monomers. Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, dibutyl acrylate, 2-ethyl acrylate are preferably used from the viewpoint of heat decomposition resistance or fluidity of the copolymer. Preferably, methyl acrylate or n-butyl acrylate is used for the hexyl hexyl ester or the like. In the structure of the acrylic resin, it is preferable from the viewpoint of heat resistance from the viewpoint that the unit of methyl methacrylate is large, but when it is used alone as the acrylate resin, a Zipper type occurs when heated. The case of depolymerization represented by decomposition. In particular, acrylic resins which are generally used have a double bond at the end of the polymer and a depolymerization from the terminal. The countermeasure for the depolymerization is to use a number of methyl acrylate units in an amount of from 1 to 5% by mass based on the acrylic resin in the resin, and to use a methyl methacrylate unit in the other to suppress depolymerization. However, the acrylic resin which has existed in the past is not suitable for use as an optical element because depolymerization still occurs. In the present invention, it is considered that the above-mentioned decomposition phenomenon due to the presence of the cellulose ester resin can be preferably suppressed by dissolving the cellulose ester resin in the acrylic resin. On the other hand, in the processing of the optical element, it is considered that the depolymerization can be suppressed by the presence of oxygen constituting the air. Therefore, it is understood that the resin constituting the optical element -15-201107396 is subjected to radical depolymerization. (chain transfer agent)

Since the optical element of the present invention is stabilized in order to suppress the depolymerization, the optical element is stabilized by the inclusion of a chain transfer agent. The chain transfer agent is used for the purpose of adjusting the molecular weight of the polymer, but in the present invention, the effect of stabilizing the optical element can be exhibited. Regarding the chain transfer agent, an appropriate type and addition amount can be selected depending on the type of the polymerizable monomer to be used. Among them, from the viewpoint of the processability and optical properties of the optical member to be produced, it is preferred to use a chain transfer constant of 0.1 to 10 for a monomer, and a chain transfer constant of 0.2 to 8 is more preferably used, and it is more preferably used. 0.3 to 4 people. The polymerizable composition of the present invention contains a plurality of polymerizable monomers, but the chain transfer agent has a chain transfer constant for each polymerizable monomer within the above range. The chain transfer constant of the chain transfer agent for each monomer can be referred to, for example, the 3rd edition of the Polymer Handbook (edited by J. BRANDRUP and E.H. IMMERGUT, issued by JOHN WILEY &amp; SON). In addition, the chain transfer agent constant can be referred to the chemical experiment of "Experimental Methods for Polymer Synthesis" by Otsu Takayuki and Katsuyuki Yasushi. It was published in the 47th year of Showa and can also be obtained through experiments. In the present invention, the aforementioned chain transfer agent is used as a radical replenisher for suppressing depolymerization of the acrylic resin (A). For example, the acrylic resin (A) constituting the optical element of the present invention mainly uses methyl methacrylate as a polymerizable monomer. The chain transfer agent is usually exemplified by alkyl mercaptans (n-butyl mercaptan, n-pentyl mercaptan, n-octyl mercaptan, n-lauryl mercaptan, tri-dodecyl mercaptan, etc.). , thiophenes (thiophene, m-bromothiophene, p-bromothiophene, m-toluenethiol, p-toluenesulfon 16 - 201107396 alcohol, etc.), etc., but in the present invention, used to shape or cast optical components When the solution is heated and dried, the chain transfer agent does not volatilize, contributing to the generation of odor during manufacture. From these viewpoints, the chain transfer agent of the present invention has a boiling point of 1 65 ° C or more, preferably 180 ° C, more preferably 250 ° C or more. When this is processed into an optical element, since the chain transfer agent does not volatilize or has a low amount of volatilization, it is possible to suppress the odor inherent to the chain transfer agent, especially the occurrence of an alkyl mercaptan odor. At the same time, since the chain transfer agent is not volatile or is less volatile, the chain transfer agent present in the optical element can effectively inhibit the depolymerization of the acrylic resin (A). For example, n-butyl mercaptan (boiling point: 98 °C) has the disadvantage of causing odor generation during the forming process. In the case of heat drying during molding or solution casting, if the boiling point of the chain transfer agent is low, the amount of the chain transfer agent in the resin is lowered due to volatilization from the resin, and the effects of the present invention cannot be obtained. The upper limit of the boiling point of the chain transfer agent is preferably 320 ° C or less. The chain transfer agent used in the present invention may be exemplified by n-octyl mercaptan (boiling point: 198 ° C), n-dodecyl mercaptan (266 ° C), α-methylstyrene dimer (boiling point) :3 1 6 °C), but not limited to these. The above chain transfer agent may be used in combination of two or more kinds. The chain transfer agent preferably contains 0. 10-0.50 mass% with respect to the acrylic resin (A). It is better to contain 〇15~〇3〇% by mass. When the amount of the chain transfer agent is less than the range of the present invention, the effect of the present invention cannot be obtained, and when the amount of the chain transfer agent exceeds the range of the present invention, the transparency of the optical element is lowered or the haze is increased, or plasticization is caused. It cannot be used as an optical element of the present invention. -17- 201107396 After performing the mass reduction measurement of the optical film of the optical element of the present invention using a thermal mass measuring device (TG/DTA200 manufactured by Seiko Electronics Co., Ltd.), the acrylic resin (A) containing no chain transfer agent was subjected to a nitrogen atmosphere. Heating at a heating rate of 20 ° C / min from 25 ° C, and confirming that the mass is significantly reduced around 1 60 ° C. After analyzing the volatile components at the same temperature by gas chromatography, it is known that the MMA monomer is volatilized. . On the other hand, an optical element containing a chain transfer agent satisfying the constitution of the present invention hardly confirmed a mass reduction at around 1 60 °C. Further, when the same heating is carried out under an oxygen atmosphere, the same mass is less reduced, and it is suggested that the thermal decomposition for forming and the thermal decomposition during use are suppressed. The optical element of the present invention can process the acrylic resin (A) and the cellulose ester resin (B) using a halogen-containing organic solvent which is generally used. At this time, an organic solvent containing a halogen can preferably use dichloromethane. Chlorine or bromine An organic solvent composed of a covalent bond with a hydrocarbon tends to cause a chain transfer reaction when the resin is synthesized, and is often hindered by the polymerization reaction. In the present invention, when it is processed into a structure as an optical element, in particular, methylene chloride is used as a halogen-based solvent, and it is considered that a radical which is generated by depolymerization of an acrylic resin can be used in a dichloromethane having high chain transfer property. It is preferred from the viewpoint of supplementing the depolymerized radical and transferring it. In general, the thermal decomposition of the resin can be suppressed in the low-temperature processing, and the solvent is dichlorinated in the presence of the cellulose ester resin compatible with the acrylic resin, compared to the melt molding which is liable to cause thermal decomposition. The presence of methane is preferred from the viewpoint of the constitution and processing of the optical element of the present invention. When the optical element of the present invention is used for an optical film, the acrylic resin (18-201107396 A)' is particularly effective as an improvement in the brittleness of the optical film and the improvement in transparency when it is compatible with the cellulose ester resin (B). The weight average molecular weight (Mw) is preferably more than 80,000. When the weight average molecular weight (Mw) of the acrylic resin (A) is less than 80,000, the brittleness is not sufficiently improved, and the compatibility with the cellulose ester resin (B) is deteriorated. The weight average molecular weight (Mw) of the acrylic resin (A) is more preferably in the range of 80,000 to 1,000,000, preferably in the range of 100,000 to 600,000, and preferably in the range of 150,000 to 400,000. The upper limit of the weight average molecular weight (Mw) of the acrylic resin (A) is not particularly limited, but it is preferably in the form of 1 〇 0 0 0 0 or less from the viewpoint of production. The weight average molecular weight of the acrylic resin of the present invention can be measured by a gel permeation chromatography. The measurement conditions are as follows. Solvent: Dichloromethane column: Shodex K806, K8 05 ' KL8 03 G (made by B and Electrician), column temperature: 2 5eC Sample concentration: 0.1% by mass Detector: RI model 504 (Manufactured by GL Sciences) Pump: L6000 (manufactured by Hitachi, Ltd.) Flow rate: 1. Oml/min Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by TOSHO Co., Ltd.), used by Mw = 2,800,000 A calibration curve obtained for 13 samples of -500. 1 3 samples are preferably used at almost equal intervals. The method for producing the acrylic resin (A) of the present invention is not particularly limited. Any one of conventional methods such as suspension polymerization, emulsion polymerization, bulk polymerization or solution polymerization can be used. Here, 'as a polymerization initiator, a general peroxide system or an azo group can be used, and a redox system can also be used. The polymerization temperature is in suspension or emulsion polymerization at 30~1 〇 〇. (: It is carried out in a block or solution polymerization system at 80 to 160 ° C. In order to control the reduction viscosity of the obtained copolymer, it is also possible to carry out polymerization using an alkyl mercaptan or the like as a transfer agent. The acrylic resin of the present invention can be used. Commercially available, for example, DELPET 60N, 80N ((Asahi Kasei Chemical Co., Ltd.), DIANAL BR73, BR80, BR83, BR85, BR88 (Mitsubishi snail), KT7 5 (Electrical Chemical Industry) (Production), etc. The acrylic resin may be used in combination of two or more. <Cellulose Ester Resin (B)> The cellulose ester resin (B) of the present invention is particularly useful for improving brittleness or compatibility with the acrylic acid (A). From the viewpoint of transparency, the total thiol group (T) is preferably 2.00 to 2.99, the acetyl group substitution degree (ac) is 〇·10 to 1.89, and the acetamino group is 3~ The thiol group consisting of 7 carbon numbers has a degree of substitution (r) of 1_1 〇 to 2.89. That is, the oxime ester resin of the present invention is a cellulose ester resin substituted with a fluorenyl group having 3 to 7 carbon atoms. Specifically, a propionyl group, a butyl group, etc. are preferably used, but a propyl fluorenyl group is preferably used. When the total substitution degree of the fluorenyl group of (B) is less than 2.0, that is, when the residual degree of the hydroxyl group at the 2, 3, and 6 positions of the fiber ester molecule is higher than 1.0, the acrylic acid (A) and the cellulose ester resin ( B) Insufficient compatibility. For -20-201107396, haze turbidity is a problem when used as an optical film. Further, the total substitution of sulfhydryl groups @ even if it is 2.0 or more, the substitution ratio of thiol groups at carbon number 3 to 7 is lower than At 1.1 ,, sufficient compatibility is still not obtained, and the brittleness is reduced. For example, when the total substitution degree of the fluorenyl group is 2.0 or more, the substitution ratio of the thiol group of the carbon number 2, that is, the thiol group is also high, and the carbon number is 3~ When the substitution ratio of the thiol group of 7 is less than 1.2, the compatibility decreases to increase the haze. Further, when the total substitution degree of the fluorenyl group is 2.0 or more, the substitution degree of the fluorenyl group having 8 or more carbon atoms is also high, and the carbon number is 3~ When the substitution degree of the fluorenyl group of 7 is less than n ,, the brittleness is deteriorated and the desired characteristics are not obtained. The degree of substitution of the thiol group of the cellulose ester resin (B) of the present invention is 2.0 to 2.99, if the total degree of substitution (T) is 2.0 to 2.99, The substitution ratio of the thiol group having a carbon number of 3 to 7 is 1.10 to 2.89. Although there is no problem, the sulfhydryl group having a carbon number of 3 to 7 or more is an ethyl group or a carbon number of 8 Further, the degree of substitution of the sulfhydryl group is preferably 1.3 or less. Further, the total thiol group (T) of the cellulose ester resin (B) is more preferably in the range of 2.5 to 2.99. The sulfhydryl group in the present invention is a fat. The sulfhydryl group may be an aromatic fluorenyl group. The aliphatic fluorenyl group may be linear or branched, and may further have a substituent. The carbon number of the fluorenyl group in the present invention is a substitution containing a fluorenyl group. When the cellulose ester resin (B) has an aromatic fluorenyl group as a substituent, the number of substituents X substituted on the aromatic ring is preferably from 〇 to 5. In this case, the degree of substitution of the fluorenyl group having a carbon number of 3 to 7 containing a substituent must be noted as 1.10 to 2.89. For example, when the carbon number of the benzamidine group is 7, when the substituent having carbon is contained, the carbon number of the benzamidine group is 8 or more, and it is not contained in the fluorenyl group having 3 to 7 carbon atoms. -21 - 201107396 In addition, when 'the number of substituents substituted on the aromatic ring is two or more', they may be the same or different, or may be bonded to each other to form a condensed polycyclic compound (for example, naphthalene, anthracene, and anthracene). , phenanthrene, quinoline, isoquineline, boring, chroman, pyridazine, aziridine, anthracene, porphyrin, etc.). The cellulose ester resin (B) of the present invention is preferably at least one selected from the group consisting of cellulose acetate propionate and cellulose acetate butyrate, that is, preferably having a carbon number of 3 or 4. The thiol group as a substituent ^ The moiety which is not substituted by a thiol group is usually a hydroxy group. These can be synthesized by conventional methods. Further, the degree of substitution of the thiol group or the degree of substitution of the other thiol groups is determined by the method specified in 331^-D 8 1 7 - 9 6 . The weight average molecular weight (Mw) of the cellulose ester resin of the present invention is 75,000 or more, preferably 75,000 or less, from the viewpoint of improving the compatibility and brittleness with the acrylic resin (A) when used in an optical film. Within the range of 300000, it is preferably in the range of 00000 to 240,000, preferably in the range of 160,000 to 470,000. When the weight average molecular weight (Mw) of the cellulose ester resin is less than 75,000, the effect of improving heat resistance or brittleness is insufficient, and the effect of the present invention cannot be obtained. In the present invention, two or more kinds of cellulose resins may be used in combination.

The optical film of the present invention contains 10 to 50 parts by mass of the resin composition of the cellulose ester resin (B) in an amount of 50 to 90 parts by mass based on the acrylic resin (A), and is contained in a compatible state, but is preferably relatively 60 to 80 parts by mass of the acrylic resin (A) containing 20 to 40 parts by mass of the cellulose ester resin (B-22-201107396, the mass ratio of the acrylic resin (A) to the cellulose ester resin (B) is more than 90 When the acrylic resin (A) of 10 is large, the effect by the cellulose ester resin (B) cannot be sufficiently obtained, and if the mass ratio of the acrylic resin is less than 50:50, the moisture resistance becomes insufficient. In the optical film of the present invention, it is necessary to contain the acrylic resin (A) and the cellulose ester resin (B) in a compatible state. The physical properties or qualities necessary as an optical film can be achieved by complementing each other by dissolving different resins. Whether or not the resin (A) and the cellulose ester resin (B) are in a compatible state can be determined by, for example, a glass transition temperature Tg. For example, when the glass transition temperatures of the two resins are different, when the two resins are mixed, the glass of each resin exists. Transfer temperature There are two or more glass transition temperatures in the mixture, but when the two resins are compatible, the glass transition temperature inherent to each resin disappears, becoming a glass transition temperature and becoming the glass transition temperature of the compatible resin. The transfer temperature was measured by a differential scanning calorimeter (Model DSC-7 manufactured by Perkin Elmer Co., Ltd.) at a temperature rising rate of 20 ° C /min, and the intermediate point glass transition temperature (Tmg) was determined according to JIS ΚΉΗ (1 9 8 7 ). The acrylic resin (A) and the cellulose ester resin (b) are preferably each a non-crystalline resin, and may be either a crystalline polymer or a polymer having partial crystallinity, but in the present invention, The acrylic resin (A) is compatible with the cellulose ester resin (B) to form a non-crystalline resin. [S1 The weight average molecular weight (Mw) or cellulose of the acrylic resin (A) in the optical film of the present invention. Weight average molecular weight of ester resin (B) (-23- 201107396

The Mw) or degree of substitution is obtained by using a difference in solubility of the two resins to the solvent, and after separation, by individual measurement. When the resin is separated, the resin which is dissolved in the solvent is dissolved in only one of the solvents, and the dissolved resin can be extracted and separated. In this case, heating or reflux can be carried out. The combination of these solvents in combination of two or more steps can also separate the resin. Filtration of the dissolved resin and the resin remaining as insolubles The separation of the resin can be carried out by evaporating the solvent and drying the solution containing the extract. These separated resins can be specified by the general structure analysis of the polymer. The optical film of the present invention can also be isolated in the same manner when it contains a resin other than the acrylic resin (A) or the cellulose vinegar resin (B). Further, when the weight average molecular weight (Mw) of the compatible resin is different, the gelation permeation chromatography (GPC) can be easily separated by dissolving the high molecular weight substance and the low molecular weight substance is dissolved for a long time. The molecular weight can also be determined. In addition, while measuring the molecular weight of the compatible resin by GPC, the resin composition of each of the different molecular weight fractions can be determined by quantitatively analyzing the dry resin of the resin solution obtained by separating the resin solution and distilling off the solvent per hour. A specific resin is specified. The resin which has been previously separated by the solubility of the solvent is each measured by GPC, and the resin which is compatible is also detected. In the present invention, the phrase "containing the acrylic resin (A) or the cellulose ester resin (B) in a compatible state means that the results of mixing the respective resins (polymers) become compatible, and do not include the monomer. The acrylic resin precursor such as a dimer or an oligomer is mixed with the state of the mixed resin by polymerization after -24 to 201107396 in the cellulose ester resin (B). For example, the step of obtaining a mixed resin by polymerization after mixing an acrylic resin precursor of a monomer, a dimer or an oligomer into the cellulose ester resin (B) is complicated in that the polymerization reaction is carried out by the method. It is difficult to control the reaction of the resin' and the adjustment of the molecular weight is also difficult. Moreover, when synthesizing a resin by such a method, a graft polymerization, a crosslinking reaction, or a cyclization reaction often occurs, and it is often not dissolved in a solvent or melted by heating, and it is difficult to dissolve the acrylic resin in the mixed resin. It is difficult to measure the weight average molecular weight (Mw). Therefore, it is difficult to control the physical properties and it is not possible to use a resin which is an optical film which is stably produced. The optical film of the present invention may be composed of a resin or an additive other than the acrylic resin (A) or the cellulose ester resin (B) as long as it does not impair the function as an optical film. When the resin other than the acrylic resin (A) or the cellulose ester resin (B) is contained, the resin to be added may be in a compatible state or may be mixed without being dissolved. The total mass of the acrylic resin (A) and the cellulose ester resin (B) in the optical film of the present invention is preferably 55 mass% or more, more preferably 60 mass% or more, and most preferably 7 0 of the optical film. More than % by mass. When a resin or an additive other than the acrylic resin (A) and the cellulose ester resin (B) is used, it is preferred to adjust the addition amount within a range not impairing the function of the optical film of the present invention. <Acrylic Particles (C)> The optical film of the present invention preferably contains acrylic particles-25-201107396 The so-called acrylic particles (c) used in the present invention are represented by a phase in a particle state (also referred to as "incompatible state"). The acrylic component (C) in the optical film containing the acrylic resin (A) and the cellulose ester resin (B) in a dissolved state is preferably an optical film produced by, for example, taking a specific amount, and is dissolved and stirred in a solvent. After being sufficiently dissolved and dispersed, it is filtered using a membrane filter made of PTFE having a pore diameter smaller than the average particle diameter of the acrylic particles (C), and the weight of the insoluble matter collected by filtration is the acrylic particles (C) added to the optical film. 90% by mass or more. The acrylate particles (C) used in the present invention are not particularly limited, but are preferably acrylic particles (C) having a layer structure of two or more layers, and are preferably an acrylic granular composite having a multilayer structure as described below. The multilayered acrylic granulated composite means a structure in which an innermost hard layer polymer is laminated layer by layer from the center portion toward the outer peripheral portion, a crosslinked soft layer polymer exhibiting rubber elasticity, and an outermost hard layer polymer are formed. A particulate acrylic polymer. In other words, the multi-layered structure acrylic-like granular composite body is a multilayer structure acrylic granular composite body composed of an innermost hard layer, a crosslinked soft layer, and an outermost hard layer from the center portion toward the outer peripheral portion. It is preferred to use the multilayered acrylic granulated composite having the three-layer core structure. The multilayer structure used in the acrylic resin composition of the present invention. The preferred form of the acrylic-based particulate composite is exemplified as follows. For example, it has 1 to 20% by mass of an alkyl acrylate having (a) a methyl methacrylate of 80 to 98.9 % by mass, an alkyl group having a carbon number of 1 to 8, and a polyfunctional grafting agent of 0.01 to 0.3. -26- 201107396 The innermost hard layer polymer obtained by polymerization of a mixture of monomers consisting of % by mass (b) Acrylic acid having a carbon number of 4 to 8 from an alkyl group in the presence of the innermost hard layer polymer described above Crosslinked soft layer polymerization obtained by polymerizing a mixture of alkyl esters 7 5 to 9 8.5% by mass, polyfunctional crosslinking agent 0.01 to 5 mass %, and polyfunctional grafting agent 〇 5 to 5 mass % And (c) an acrylic acid having a carbon number of from 80 to 99% by mass of methyl methacrylate and from 1 to 8 carbon atoms of the alkyl group in the presence of a polymer composed of the innermost hard layer and the crosslinked soft layer a three-layer structure composed of a mixture of monomers composed of 1 to 2% by mass of an alkyl ester to obtain an outermost hard layer polymer, and the obtained three-layer structure polymer is composed of the innermost hard layer polymer (a) 5 ~40% by mass, soft layer polymer (b) 30~60% by mass and outermost hard layer polymer (c) 20~50 % Of the composition, the insoluble portion is separated from acetone, methyl ethyl ketone and the insoluble portion of the degree of swelling of an acrylic granular complex 1.5~4.0. Further, as disclosed in Japanese Patent Publication No. Sho 60-17406 or Japanese Patent Publication No. Hei No. 3-39095, not only the composition or particle diameter of each layer of the multilayered acrylic granulated composite is specified, but also the multilayered acrylic granulated composite is The tensile modulus of elasticity or the methyl ethyl ketone swelling degree of the acetone-insoluble portion is set within a specific range, and the balance between sufficient impact resistance and stress whitening resistance can be further achieved. Among them, the innermost hard layer polymer (a) constituting the multilayer structure acrylic granular composite is preferably an alkyl acrylate 1 having a methyl group of 80 to 98.9 mass% of an alkyl group having a carbon number of 1 to 8. A mixture of ~20% by mass and a monomer of a polyfunctional grafting agent of 0.01 to 0.3% by mass is polymerized. Among them, alkyl acrylates having an alkyl group having a carbon number of 1 to 8 are exemplified by methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, propane -27-201107396 enedic acid second butyl ester, acrylic acid. As the 2-ethylhexyl ester or the like, methyl acrylate or n-butyl acrylate is preferably used. The ratio of the alkyl acrylate unit in the innermost hard layer polymer (a) is 1 to 2% by mass, and when the unit is less than 1% by mass, the thermal decomposition property of the polymer becomes large, and on the other hand, the unit exceeds When the amount is 2% by mass, the glass transition temperature of the innermost hard layer polymer (c) is lowered, and the effect of imparting impact resistance to the three-layer structure acrylic granular composite is lowered, and thus either one is not preferable. The polyfunctional grafting agent is exemplified by a polyfunctional monomer having different polymerizable functional groups, such as acrylic acid, methacrylic acid, maleic acid, allyl fumarate, etc., and allyl methacrylate is preferably used. . The polyfunctional grafting agent is used to chemically bond the innermost hard layer polymer to the soft layer polymer, and the ratio of the innermost hard layer to be polymerized is 0.01 to 0.3% by mass. The crosslinked soft layer polymer (b) constituting the acrylic granular composite is preferably an alkyl acrylate having a carbon number of from 1 to 8 in the presence of the innermost hard layer polymer (a). A mixture of 75 to 98.5% by mass, a polyfunctional crosslinking agent of 0.01 to 5% by mass, and a polyfunctional grafting agent of 0.5 to 5% by mass of a monomer is obtained by polymerization. Among them, an alkyl acrylate having an alkyl group having a carbon number of 4 to 8 is preferably n-butyl acrylate or 2-ethylhexyl acrylate. Further, these polymerizable monomers may be copolymerized with 25% by mass or less of other monofunctional monomers copolymerizable. Other monofunctional monomers which are copolymerizable are exemplified by styrene and substituted styrene. The alkyl group has a carbon number of 4 to 8 and the ratio of the alkyl acrylate to the styrene. If the former is more, the lower the glass transition temperature of the polymer (b), the softer the -28-201107396. On the other hand, from the viewpoint of the transparency of the resin composition, the refractive index of the soft layer polymer (b) at normal temperature is closer to the innermost hard layer polymer (a) and the outermost hard layer polymer (c). The more advantageous the hard thermoplastic acrylic resin is, the ratio of the two is selected in consideration of the above. A polyfunctional grafting agent can be used as listed in the item of the aforementioned innermost layer of the hard polymer (a). The polyfunctional grafting agent used therein is used for chemically bonding the soft layer polymer (b) to the outermost hard layer polymer (c), and the ratio of the innermost hard layer is used to impart impact resistance. From the viewpoint of the sexual effect, it is preferably from 0.5 to 5% by mass. As the polyfunctional crosslinking agent, a generally known crosslinking agent such as a divinyl compound 'diallyl compound, a diacrylic compound, a dimethacrylic compound, etc.' can be used, but polyethylene glycol diacrylate (molecular weight 200) is preferably used. ～600) ° The polyfunctional crosslinking agent used herein is used to produce a crosslinked structure during polymerization of the soft layer (b) and exhibits an impact resistance imparting effect. However, if the prior polyfunctional grafting agent is used in the polymerization of the soft layer, the crosslinked structure of the soft layer (b) is generated to some extent, so the polyfunctional crosslinking agent is not an essential component, but when the soft layer is polymerized, The ratio of the polyfunctional crosslinking agent is preferably from 观点 to 5% by mass in terms of the impact resistance imparting effect. The outermost hard layer polymer (c) constituting the multilayer structure acrylic granular composite is preferably made of methacrylic acid in the presence of the innermost hard layer polymer (a) and the soft layer polymer (b). A monomer consisting of 8 to 99% by mass of methyl ketone and 1 to 2% by mass of an acrylic acid ester having a carbon number of 1 to 8 is a -29-201107396 mixture obtained by polymerization. Among them, the alkyl acrylate is used as described above, but methyl acrylate or ethyl acrylate is preferably used. The proportion of the alkyl acrylate unit in the outermost hard layer (C) is preferably from 1 to 20% by mass. Further, in the polymerization of the outermost hard layer (c), in order to improve the compatibility with the acrylic resin (A), an alkylthiol or the like for adjusting the molecular weight may be used as a chain transfer agent. In particular, it is preferable to provide a gradient in which the molecular weight gradually decreases from the inner side toward the outer side on the outermost hard layer, thereby improving the balance between elongation and impact resistance. The specific method is that the molecular weight of the polymer forming the outermost hard layer can be made from the multilayer structure by dividing the mixture of the monomers for forming the outermost hard layer into two or more portions and sequentially increasing the amount of the chain transfer agent added each time. The inner side of the acrylic granular composite gradually becomes smaller toward the outer side. The molecular weight formed at this time can also be investigated by polymerizing the mixture of monomers used each time under the same conditions alone and measuring the molecular weight of the obtained polymer, and the particle size of the acrylic particles (C) which are preferably used in the present invention is not investigated. Although it is particularly limited, it is preferably from 1 nm to 100 nm, more preferably from 20 nm to 500 nm, even more preferably from 50 nm to 400 nm. In the acrylic granular composite in which the multilayer structure polymer is preferably used in the present invention, the mass ratio of the core to the shell is not particularly limited, but when the multilayer structure polymer is 100 parts by mass, the core layer is preferably 5 parts by mass or more and 90 parts by mass or less 'more preferably 60 parts by mass or more and 80 parts by mass or less. Here, the core layer is the innermost hard layer. -30- 201107396 Examples of commercially available products of the multilayered acrylic granulated composites are, for example, "ME TAB LEN" manufactured by Mitsubishi Corporation, "KANE ACE" manufactured by Kaneka Chemical Industry Co., Ltd., and Wu Yu Chemical "PARALOID" manufactured by Industrial Co., "ACRYLOID" manufactured by Rohm and Haas Company, "STAPHYLOID" manufactured by GANZ Chemical Industry Co., Ltd., and "PARAPET SA" manufactured by KURARAY Co., Ltd., etc., may be used alone or in combination of two or more. Further, a specific example of the acrylic acid particles (c-1) which is suitable for use as a graft copolymer of the acrylic particles (C) which is preferably used in the present invention is exemplified by an unsaturated carboxylic acid ester in the presence of a rubbery polymer. A graft copolymer in which a monomer, an unsaturated carboxylic acid monomer, an aromatic vinyl monomer, and optionally a mixture of monomers which are copolymerized with other vinyl monomers are copolymerized. The rubbery polymer used in the acrylic particles (c-1) of the graft copolymer is not particularly limited, and a diene rubber, an acrylic rubber, a vinyl rubber or the like can be used. Specifically, it is exemplified by polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer , polyisoprene, butadiene-methyl methacrylate copolymer, butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene - A propylene-diene copolymer, an ethylene-isoprene copolymer, and an ethylene-methyl acrylate copolymer. These rubbery polymers may be used alone or in combination of two or more. Further, when the acrylic particle (C) is added to the optical film of the present invention, the mixture of the acrylic resin (A) and the cellulose ester resin (B) is folded -31 - 201107396 and the refractive index of the acrylic particle (C) When it is close, it is preferable to obtain a film having high transparency. Specifically, the difference in refractive index between the acrylic particles (C) and the acryl phenol resin (A) is preferably 〇 5 or less, more preferably 〇 〇 2 or less, and particularly preferably 〇 〇 1 or less. In order to satisfy the refractive index conditions, the composition ratio of each monomer unit of the acrylic resin (A) is adjusted, and/or the composition ratio of the rubbery polymer or monomer used in the acrylic particle (C) is adjusted. According to the method, the refractive index difference can be reduced, and an optical film excellent in transparency can be obtained. Further, the term "refractive index difference" means that the optical film of the present invention is sufficiently dissolved in a solvent soluble in the acrylic resin (A) to form a white turbid solution, which is separated into a solvent by centrifugation or the like. The soluble fraction (acrylic resin (A)) and the insoluble fraction (acrylic acid particle (C)) were respectively purified by the soluble fraction and the insoluble fraction, and the measured refractive index (2 3 ° C, measurement wavelength: 5 50 nm) )Difference. In the present invention, the method of formulating the acrylic particles (C) in the acrylic resin (A) is not particularly limited, and it is preferably used after pre-blending the acrylic resin (A) with any other components, usually at 200 to 3 50. At a temperature of ° C, a method of uniformly melting and kneading a uniaxial or biaxial extruder while adding acrylic particles (C). Further, a method in which a solution in which acrylic particles (C) are dispersed in advance is added to a solution (dopant) in which an acrylic resin (A) and a cellulose ester resin (B) are dissolved and mixed may be used, or a connection may be added. A method of dissolving and mixing an acrylic particle (C) and any other additives. The acrylic particles of the present invention can also be used commercially. It can be exemplified by, for example, -32-201107396 METABLEN W-341 (C2) (manufactured by Mitsubishi Rayon Co., Ltd.), KEMISUNO-MR-2G (C3), MS-3 0 0 X (C 4 ) (Comprehensive Chemistry) ) Manufacturing) and so on. The optical film of the present invention preferably contains 0.5 to 30% by mass of the acrylic particles (C), more preferably 1.0 to 15% by mass, based on the total mass of the resin constituting the film. <Other Additives> In the optical film of the present invention, a plasticizer may be used to improve the fluidity or flexibility of the composition. The plasticizer is exemplified by a phthalate type, a fatty acid vinegar type, a trimellitic acid ester type, a phosphate ester type, a polyester type, or an epoxy type. Among them, a plasticizer of a polyacetal or a phthalate type is preferably used. The polyester-based plasticizer is superior to the phthalate-based plasticizer such as dioctyl phthalate in non-migration property and extraction resistance, but has a slightly poor plasticizing effect or compatibility. Accordingly, the plasticizers are selected depending on the use, or are suitable for a wide range of applications by use. The polyester-based plasticizer is a monovalent to tetravalent carboxylic acid and a monovalent to hexavalent alcohol reactant' but mainly used to obtain a reaction between a divalent carboxylic acid and a diol. Representative divalent carboxylic acids are exemplified by glutaric acid, itaconic acid, adipic acid, phthalic acid, azelaic acid, sebacic acid and the like. In particular, if adipic acid, phthalic acid or the like is used, excellent plasticization properties can be obtained. The diols are exemplified by ethylene glycol, propylene glycol, 1,3-butylene glycol, 14-butanediol, hydrazine, 6-hexanediol, neopentyl glycol, diethylene glycol, and triethylene di-33-201107396. a diol such as an alcohol or a dipropylene glycol. These divalent carboxylic acids and diols may be used singly or in combination. The ester-based plasticizer may be any of an ester, an oligoester or a polyester, and has a molecular weight of preferably from 100 to 10,000, preferably from 600 to 3,000, and has a plasticizing effect. Moreover, the viscosity of the plasticizer is related to the molecular structure or molecular weight, but the relationship between the compatibility and the plasticizing efficiency of the adipic acid plasticizer is preferably in the range of 200 to 5000?4?3.3 (25??). . Furthermore, several polyester-based plasticizers can be used. The plasticizer is preferably added in an amount of from 0.5 to 30 parts by mass based on 100 parts by mass of the optical film of the invention. When the amount of the plasticizer added exceeds 30 parts by mass, the surface is sticky, so it is practically unsatisfactory. The optical film of the present invention preferably contains an ultraviolet absorber, and the ultraviolet absorber to be used is exemplified by a benzotriazole type, a 2-hydroxybenzophenone type or a phenyl salicylate type. It can be exemplified by, for example, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(dimethylbenzyl)phenyl]-2H-benzo Triazoles such as triazole, 2-(3,5·di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxyl a benzophenone such as 4_octyloxybenzophenone or 2,2,-dihydroxy-4-methoxybenzophenone. Among the ultraviolet absorbers, the ultraviolet absorber having a molecular weight of 400 or more is difficult to volatilize at a high boiling point, and is difficult to fly at the time of high-temperature molding. Therefore, it is possible to effectively improve weather resistance by adding it in a small amount. As for the ultraviolet absorber having a molecular weight of 400 or more, it is exemplified as 2_[2_hydroxy-34-201107396-based, 3,5-bis(α,α-dimethylbenzyl)phenyl]-2-benzotriazole, 2 , 2-extended methyl bis[4-(1,1,3,3-tetrabutyl)-6-(211-benzotriazol-2-yl)phenol], etc., benzotriazole, double (2 , 2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, etc. Hindered amine, further 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl 4-piperidinyl)ester, 1-[2-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propenyloxy]ethyl]-4-[3-( 3,5-di-t-butyl-4-hydroxyphenyl)propanoxy]-2,2,6,6-tetramethylpiperidine and the like have a mixture of hindered phenol and hindered amine structure in the molecule. The system 'can be used alone or in combination of two or more. Among these, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2-benzotriazole or 2,2-extension methyl bis[4- (1,1,3,3-tetrabutyl)-6-( 2Η-benzotriazol-2-yl)phenol] is optimal. Further, in the optical film of the present invention, various antioxidants may be added to improve thermal decomposition property or thermal coloring property during molding processing. An antistatic agent may also be added to impart antistatic properties to the optical film. A flame-retardant acrylic resin composition containing a phosphorus-based flame retardant can also be used in the optical film of the present invention. The phosphorus-based flame retardant used herein may be selected from the group consisting of red phosphorus, triaryl phosphate, diaryl phosphate, monoaryl phosphate, arylphosphonic acid compound, arylphosphine oxide compound, and condensed aryl phosphate. One or a mixture of two or more of an ester, a halogenated alkyl phosphate, a halogen-containing condensed phosphate, a halogen-containing condensed phosphonate, a halogen-containing phosphite, and the like. Specific examples are triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphine-35-201107396 phenanthrene-oxide, phenylphosphonic acid, ginseng (wan-chloroethyl) Phosphate vinegar 'dichloropropyl) phosphate, ginseng (tribromoneopentyl) phosphate, and the like. According to the optical film of the present invention, it is possible to simultaneously achieve the improvement of low hygroscopicity, transparency, high heat resistance and brittleness which cannot be achieved by the conventional resin film. The brittleness index in the present invention is whether or not "does not cause ductile damage". The basis of the optical film is judged. When an optical film which does not cause ductile damage or brittleness is obtained, when a polarizing plate for a large-sized liquid crystal display device is produced, cracking or cracking at the time of production does not occur, and an optical film excellent in handleability can be obtained. Among them, the ductile fracture is a fracture caused by a stress greater than the strength of a material, and is defined as a failure accompanied by significant elongation or contraction of the material before the final fracture. The ruined surface has the characteristics of a myriad of recesses called depressions. Whether or not the present invention is "an optical film which does not cause ductile damage" is evaluated by breaking or the like under the stress of bending the film twice. When an optical film which does not cause ductile fracture is applied even if such a large stress is applied, even when a polarizing plate protective film for a large-sized liquid crystal display device is used, problems such as breakage during production can be sufficiently reduced, and even if When the optical film is used again after the temporary bonding, the film is not broken, and the thickness of the optical film can be sufficiently reduced. In the present invention, a tension softening point is used as an index of heat resistance. In addition to the increase in the size of liquid crystal display devices and the increasing brightness of backlight sources, the use of outdoor applications such as digital signage requires higher brightness. Therefore, optical films are required to withstand higher temperatures, but the tension is softened.

-36- 201107396 If the point is 1 〇5 °C ~ 1 45 °c, it can be judged that it shows sufficient heat resistance. Especially better controlled at 110 ° C ~ 130 ° C. For the specific measurement method of the temperature at which the tension softening point of the optical film is displayed, for example, a universal material testing machine (manufactured by ORIENTEC, RTC-1225A) can be used to cut the optical film into 120 mm (length) x 10 mm (width) under a tension of 10 N. The stretched edge was continuously heated at a temperature increase rate of 30 ° C /min, and the temperature at the time point of 9 N was measured three times, and the average enthalpy was obtained. Further, from the viewpoint of heat resistance, the glass transition temperature (Tg) of the optical film is preferably ll 〇 ° or more. Better for 12CTC or above. It is preferably 150 ° C or more. In addition, the glass transfer temperature here is measured by a differential scanning calorimeter (DSC-7 model manufactured by Perkin Elmer Co., Ltd.) at a temperature increase rate of 20 ° C /min. 'According to JIS K 7 1 2 1 (1 9 8 7) The intermediate point glass transition temperature (T mg ) is obtained. (Photoelastic coefficient) The birefringence generated when stress is applied to the optical element, and the photoelastic constant is obtained as follows. The sample was prepared into a long strip film of a film having a width of lcm width x 10 cm and a thickness of 40 μm. The measurement direction was the film transport direction when the film was formed, that is, the width direction was cut into l 〇 cm for the longitudinal direction. For the film which was conditioned for 24 hours at 23 t: · relative humidity of 55%, the phase lag measurement for 590 nm light was carried out as follows. Using KOBRA-31PRW, stress is applied along the length direction (10 cm length) with a 1 〇 point stress in the range of 1N to 15N, and the measurement of the stagnation phase exhibited at this time is performed. , using its -37-201107396 slope and film thickness 値 calculated. The horizontal axis is plotted as the stress (based on the cross-sectional area of the film), and the photoelastic system 1 /P a ) is obtained from the slope. This measurement selects the stress range in the range where no birefringence is exhibited. The optical elastic modulus of the optical element of the present invention is preferably -3.0 xlO·1 7.0 x 10'12/Pa (23 〇C '5 5% RH). More preferably -1.〇χ1(Γ12/Ρ^ 1 (the range of TI2/Pa, and preferably close to zero, preferably zero. When the photoelastic coefficient is increased in positive or negative, when an external force is applied to the optical element, It is not good to obtain a change in light transmittance in an optical element having a birefringence other than the design flaw, especially in a birefringent system. The birefringence optical element is represented by a liquid crystal display device. The optical member is subjected to stress or birefringence due to heat or humidity caused by shrinkage or expansion of the polyvinyl alcohol polarizer in the polarizer as a function of temperature, and the stress is applied to the adjacent polarizing plate protective film. The elastic coefficient is defined by showing the exhibitivity of the stress birefringence. The recovery is close to zero, and the stress birefringence is less likely to be applied when the stress is applied. The decrease of the photoelastic coefficient can reduce the liquid crystal display corresponding to the environmental change. (Birefringence) (Birefringence) In the present invention, a film-like sample optical element prepared by measuring photoelasticity has a small birefringence during molding, and has the following in-plane bifold i) or thickness. To the absolute divergence divisor of at least one of the birefringence (ii) (appropriate [/Pa~ -3.0 X part of the light board point in the middle of the table, so it appears as light easy to display as a shot (required -38 - 201107396 is 2.0χ 1 Ο·4 ( 23 °C, 5 5% RH, 24-hour tuning characteristics. Glass has the advantage of being isotropic, but it is easy to break into resin, it is not easy to break and it is also light weight 1) or The birefringence (ii) in the thickness direction is preferably at least 1.0xxO·4 or less, more preferably 5.0xl 〇·5 or less (i) Δηο= ( nx-ny) (ii ) Anth= ( ( nx + ny ) /2-nz (wherein nx is an optical element having a plane ratio 'ny" as a refractive index in the direction of the refractive index in the in-plane and nx perpendicular directions, and each refractive index is for the wave $ 〇 In the present invention, the optical element In-plane birefringence, and temperature 23 ° C 20% RH (birefringence placed in the environmental chamber and 2 3 ° C 80 % R Η (the absolute difference between the birefringence placed in the environmental chamber is expressed as a birefringent element) The birefringence in the plane and the double-folding in the thickness direction are less than the above. The liquid crystal display device is easy to generate temperature unevenness due to image driving and application of heat. The TAC film and the polarizer of the polarizer have moisture permeability, and the difference between the moisture in and out caused by the addition of the moisture and the external humidity surface are also generated as an optical element depending on the location, and if the birefringence changes, the light advances. There is a change in the aspect, so birefringent wetness is required. The following is a disadvantage of the preferred crack, by setting i. In-plane birefringence (i is the absolute refraction of the absolute refraction in the in-plane, nz is the optical element thickness I590nm The temperature of the light and the thickness of the two-fold sample within 2 hours of the test)) The temperature change of the sample is 2 χ1〇_4 from the backlight of the back side and the protective film of the board The heat is uneven and the heat does not change, and the liquid crystal display is different. With the design flaws, the changes with the environment are small. -39- 201107396 In the present invention, as for the humidity variation of the birefringence defined above, the absolute 値 of the difference between the birefringence of the temperature 23 ° C 20% RH and the birefringence of 23 ° C 80% RH is preferably 1. 0 χ 1 (Γ4 or less, more preferably 5.〇xl〇_5 or less. The in-plane birefringence of the optical element and the birefringence in the thickness direction are defined as the temperature change at a fixed absolute humidity, and the temperature of the birefringence fluctuates from the temperature. The absolute enthalpy of the difference between the birefringence of 27 °R 27% RH and the birefringence of 23 °C and 55 % RH is 1.0x1 〇·4 or less. The temperature variation of birefringence is preferably 7·Οχ1 (Γ5, more preferably 4.0X10·5 or less. If it is larger than this range, it becomes non-optical isotropic, with the transmission of light other than the design, especially regarding liquid crystal display, using the optical element of the present invention as a polarizing plate protection held in two polarizers In the case of a film, the liquid crystal screen becomes dull or color uneven. In the present invention, the fact that the birefringence is close to zero means close to optical isotropy, and the birefringence variation with the heat or with the change of heat and humidity is small, even if it is accompanied by environmental changes. , also means that the birefringence changes little. Close to optical isotropic, other optical elements are also similar to isotropic or isotropic, and the purpose of the present invention is to use haze (turbidity) as an indicator for judging the transparency of the optical film of the present invention. In the liquid crystal display device for outdoor use, in order to obtain sufficient brightness or high contrast in a bright place, it is necessary to have a haze of 1.0% or less, more preferably 0.5% or less. According to the acrylic resin (cellulose) and cellulose. The optical film of the present invention of the ester resin can obtain high transparency, but when acrylic particles are used for the purpose of improving other physical properties, by using a resin (acrylic resin (A) and cellulose ester resin (Β)) Birefringence with acrylic particles (C) -40, 201107396 The difference in rate is small, which prevents fogging and haze from rising. Also, since the surface roughness also affects haze as a surface haze, acrylic particles (C) are used. The particle size or the addition amount is suppressed within the above range, and the surface roughness of the film contact portion at the time of film formation is also effective. Further, the hygroscopicity of the optical film of the present invention is also effective. The evaluator is used for the dimensional change of the humidity change. As for the dimensional change evaluation method for the humidity change, the following method is used. In the casting direction of the produced optical film, a mark (cross) is applied at two places, at 60 °c 9 0 % R Η Treatment for 1 hour, the distance (%) of the mark (cross) before and after the treatment was measured with an optical microscope, and the dimensional change rate (%) was determined by the following formula. Dimensional change rate (%) = [(al-a2) / al] xlOO al: distance before heat treatment a2: distance after heat treatment When an optical film is used as a protective film for a polarizing plate of a liquid crystal display device, as a result of moisture absorption The dimensional change causes unevenness in the optical film or a change in phase difference ,, which causes a problem of contrast reduction or color unevenness. The above problem becomes remarkable if it is a polarizing plate protective film used in a liquid crystal display device which is used outdoors. However, if the dimensional change ratio (%) in the above conditions is less than 0.5%, it can be evaluated as an optical film exhibiting sufficient low humidity. Further, it is preferably less than 0.3%. Further, the optical film of the present invention preferably has a defect of 5 μm or more in the in-plane diameter of the film of 1/10 cm square or less. Better for 0.5 /10 cm square below -41 - 201107396, and better for 0.1/10 cm square. Here, the defect diameter indicates the diameter when the defect is circular, and the range of the defect when it is not circular is determined by microscopic observation according to the following method, and is the maximum diameter (diameter of the circumscribed circle). The scope of the shortcomings is the size of the shadow when the shortcomings of the microscope are observed by the differential interference microscope. Disadvantages: Light scratches When the surface shape of a transfer or scratch is changed, the shortcomings of the differential interference microscope are used to observe the defects and confirm the size. Further, when observing the reflected light, if the size of the defect is not clear, aluminum or uranium is vapor-deposited on the surface for observation. High-precision filtration of the polymer solution before casting, or increase the cleanliness of the periphery of the casting machine', and setting the drying time after casting stepwise, drying efficiently and inhibiting foaming, and effectively producing good productivity A film of excellent quality expressed by the frequency of such defects is obtained. When the number of the defects is more than one/1 0 c m square, when the tension is applied to the film, for example, when the processing is performed as described later, the film may be broken due to the defect, and the productivity may be lowered. In addition, when the diameter of the defect is 5 μm or more, there is a case where the use of the polarizing plate or the like can be visually confirmed and used as an optical member. Further, even when it is impossible to visually confirm, there is a case where the uniform coating agent cannot be formed when the hard coat layer is formed on the film (coating off). Here, the term "disadvantage" means a cavity (foaming defect) which occurs in the film due to rapid evaporation of the solvent in the solution film drying step, or a foreign matter caused by the film forming solution or foreign matter mixed in the film forming process. Foreign matter in the film -42- 201107396 (foreign defect). Further, the optical film of the present invention has an elongation at break in at least one direction of 10% or more, more preferably 20% or more, in accordance with JIS-K7 1 27-1999, and is not particularly limited. In reality, it is about 250%. The increase in elongation at break can effectively suppress disadvantages caused by foreign matter or foamed film. The optical film of the present invention preferably has a total light transmittance of 90% or more, more preferably 93% or more. Moreover, the upper limit in reality is about 99%. The excellent transparency of the total light transmittance can be effectively achieved by not introducing an additive or a copolymerized component that absorbs visible light, or by filtering a foreign matter in the polymer with high precision to reduce light diffusion or absorption inside the film. Moreover, the surface roughness of the film contact portion (the cooling roll, the calender roll, the roll, the coated substrate in the film forming solution, the transfer roll, etc.) at the time of film formation is reduced, and the surface roughness of the film surface is reduced. Small, or by reducing the refractive index of the acrylic resin, can effectively reduce light diffusion or reflection on the surface of the film. When the optical film of the present invention satisfies the above physical properties, a polarizing plate protective film for a large-sized liquid crystal display device or a liquid crystal display device for outdoor use can be particularly preferably used. (Film film formation of optical film) Although an example of a film forming method of an optical film is described, the present invention is not limited thereto. As for the film forming method of the optical film of the present invention, a blow molding method, a -43-201107396 τ-mold method, a calender method, a cutting method, a casting method, an emulsion method, a hot pressing method, or the like can be used. From the viewpoints of suppression, suppression of foreign matter defects, suppression of optical defects such as impression lines, and the like, it is preferred to form a film by a solution of a casting method. (Organic solvent) An organic solvent which can be used to form a dopant when the optical film of the present invention is produced by a solution casting method, as long as it is capable of simultaneously dissolving an acrylic resin, a cellulose ester resin (Β), and other additives, it is not limited. Use. For example, a halogen-based organic solvent is exemplified by dichloromethane, and a non-halogen-based solvent is exemplified by methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, and 1,4. _Dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol 1,1,1,3,3,3-hexafluoro-2.methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2, 3, 3,3-pentafluoro-1-propanol, nitroethane, etc., and preferably dichloromethane, methyl acetate, ethyl acetate or acetone. The dopant preferably contains, in addition to the above organic solvent, 1 to 40% by mass of a linear or branched aliphatic alcohol having 1 to 4 carbon atoms. When the ratio of the alcohol in the dopant is high, the web will gel, and the peeling from the metal support becomes easy. Further, when the ratio of the alcohol is decreased, the acrylic resin is promoted by dissolving the non-halogen organic solvent ( A), the role of cellulose ester resin (B). In particular, it is preferred to dissolve the acrylic resin (A), cellulose-44 - 201107396 ester resin (B) and acrylic acid in a solvent containing dichloromethane and a linear or branched aliphatic alcohol having 1 to 4 carbon atoms. Three at least a few % of the dopant composition of particles (C). A linear or branched aliphatic alcohol having 1 to 4 carbon atoms may be ethanol, n-propanol, isopropanol, n-butanol or second butanol. Among these, the stability and doping of the doping are also low, and ethanol is preferred for drying. The preferred film forming method for the optical film of the present invention is as follows: in the dissolution vessel, the olefin resin is stirred in an organic solvent mainly for the acrylic resin (the ester resin (B) is a good solvent ( A), cellulose ester resin (B), optionally (C), other additives, a step of forming a dopant, acrylic particles in a solution of an enoic acid resin (A), a cellulose ester resin (B) (C) a step of a solution, a solution of other additives, and a dopant of the liquid. The method of performing the method of the acrylic resin (A) and the cellulose ester resin (B) under normal pressure, and above the boiling point of the main solvent below the boiling point of the main solvent A method of performing a pressurization, a method of performing a cooling and dissolving method as described in Japanese Unexamined Patent Publication No. Publication No. Publication No. Publication No. No. No. No. No. No. No. No. No. No. No. The method of carrying out the method, etc., but the acrylic resin (Α) and the cellulose ester ribs in the square dopant which are pressurized above the boiling point of the main solvent are enumerated as methanol and third. Alcohol is also good, etc. to explain A), fiber edge Dissolving the acrylic acrylic particles or forming the main dissolution in the case of the mixture may be carried out by a method such as, for example, a special method, such as a flat-opening 9- 9 5 5 3 8 丨 开 Π - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The gluten (B) -45- 201107396 is preferably in the range of 15 to 45 mass%. Additives are added to the viscous during or after the dissolution and are dissolved and dispersed, and then 'filtered by the filter material' to be defoamed and pumped to the next step by liquid feeding. For the filtration, it is preferable to use a filter medium having a particle size of 〇·5 to 5 μm and a filtration time of 10 to 25 sec/100 ml. In this method, the aggregates remaining when the particles are dispersed or the aggregates generated when the main dopant is added are used to remove only the agglomerates by using a filter medium having a particle diameter of 〇5 to 5 μm and a drainage time of 10 to 25 sec/100 ml. Things. Since the main dopant is also sufficiently thinner than the additive liquid, the aggregates do not stick to each other during filtration and do not cause a sharp rise in the filtration pressure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing an example of a dopant preparation step, a casting step and a drying step of a preferred solution casting film forming method of the present invention. If necessary, the large agglomerates are removed from the acrylic acid particles into the kettle 41 by the filter 44, and fed to the stock tank 42. Subsequently, an acrylic particle addition liquid is added from the storage tank 42 to the main dopant dissolution vessel 1. The main dope is then filtered by the main filter 3, and an ultraviolet absorber addition liquid is added thereto from the 16 line. In many cases, the main dopant may contain about 1 to 50% by mass of recycled material. The recovered material may contain acrylic particles. In this case, it is preferable to add the amount of the recovered material to control the addition amount of the acrylic particle-added liquid. The additive liquid containing the acrylic particles preferably contains 0.5 to 10% by mass of acrylic particles, and more preferably contains 1 to 10% by mass, preferably 1 to 5% by mass. If it is within the above range, since the addition liquid is low in viscosity and easy to handle, -46-201107396 can be easily added to the main dopant, which is preferable. The recycled material is a finely pulverized material of an optical film, which is an optical film raw material which is produced by filming an optical film and which is cut off on both sides of the film, or scratched, etc., which does not conform to specifications. Further, it is also possible to preferably use a pre-kneaded acrylic resin, a cellulose ester resin, and optionally acryl particles. 2) The casting step feeds the doping liquid into the pressurized die nozzle 30 by a liquid feeding pump (for example, a pressurized quantitative gear pump), and the annular metal strip 3 1, such as a stainless steel belt or rotating, is transferred infinitely. A step of casting a dopant from a pressurized die slit in a casting position on a metal support such as a metal sump. Preferably, it is a slit shape in which the mold portion of the nozzle can be adjusted, and the pressure die having a uniform film thickness is easily obtained. The pressurizing die can be preferably used in any one of a coat-hanger die or a T die. The surface of the metal support is mirrored. In order to increase the film forming speed, two or more press nozzles may be provided on the metal support, and the amount of the dopant may be divided into overlapping layers. Alternatively, it is preferred to obtain a film of a laminated structure by a co-casting method in which a plurality of kinds of dopants are simultaneously cast. 3) Solvent evaporation step A step of heating a web (a dopant film formed by casting a dopant onto a support for casting) into a support for casting, and evaporating the solvent. Evaporating the solvent by a method of blowing from the side of the sheet and/or by means of liquid heat transfer from the back side of the support, by means of radiant heat transfer from the back of the surface, etc. -47-201107396 'But drying by back liquid heat transfer method Good and better. Further, a method of combining these methods can also be preferably used. Preferably, the sheet on the support after casting is dried on the support under an atmosphere of 40 to 100 °C. It is maintained at an atmosphere of 4 Torr to 100 ° C. It is preferred to contact the upper surface of the sheet at a temperature of this temperature or by means of infrared rays or the like. From the viewpoint of the surface quality, moisture permeability, and peelability, the sheet is preferably peeled off from the support within 30 to 12 seconds. 4) Peeling step A step of peeling off a thin film on a metal support by evaporating a solvent at a peeling position. The peeled flakes are sent to the next step. The temperature at the peeling position on the metal support is preferably from 10 to 40. (:, preferably 1 1 to 3 0 ° C. Also, the amount of residual solvent at the time of peeling off the sheet on the metal support at the time of peeling is better depending on the strength of the drying condition, the length of the metal support, etc. in the 50~ When it is peeled off in the range of 120% by mass, when the amount of residual solvent is large, the sheet is excessively soft, and the flatness at the time of peeling is impaired, and surface unevenness or vertical streaks are likely to occur due to peeling tension. The amount of residual solvent at the time of peeling is determined in consideration of the economic speed and quality. The amount of residual solvent in the flakes is defined by the following formula: The amount of residual solvent (%) = (the mass before the heat treatment of the sheet, the mass after the heat treatment of the sheet) / (mass after heat treatment of the sheet) X 100 Further, the heat treatment in the case of measuring the amount of residual solvent means heat treatment at 1 15 ° C for 1 hour. -48- 201107396 When peeling off the metal support and the film The peeling tension is usually 19 6 to 2 4 5 N/m, but when the peeling is likely to occur, the peeling is preferably performed under a tension of 190 N/m or less, more preferably the lowest tension of the peelable ~1 6 6 · 6N/m, its Preferably, the peeling is preferably carried out at a minimum tension of 133 N/m, preferably at a minimum tension of 1.00 N/m. In the present invention, the temperature at the peeling position on the metal support is preferably _50. ～40°C, preferably 1〇~4〇t:, preferably 15~30°C. 5) After the drying and stretching steps are peeled off, the sheets are alternately passed through a plurality of rollers arranged in the drying device and transported. The drying device 35 and/or the tenter stretching device 34 conveyed at both ends of the sheet by a jig to dry the sheet. The drying method generally blows hot air to both sides of the sheet, but there is also a method of heating by using a contact microwave instead of the wind. The result of excessive rapid drying easily damages the planarity of the film. It is preferred to use a high-temperature drying system so that the residual solvent is slightly less than 8% by mass. The entire dry sorghum is carried out at 40 to 250 °C. It is best to dry at 40~160 °C. When the tenter stretching device is used, it is preferable to use a device which can control the holding length of the film (the distance from the start of gripping to the end of gripping) independently by the left and right gripping mechanisms of the tenter. In the tentering step, it is also preferable to form a partition having deliberately different temperatures for improving planarity. Moreover, it is also preferred to provide a neutral zone between different temperature zones so that the zones do not cause interference. Further, the stretching operation can be divided into multi-stage implementations, and it is also preferable to perform biaxial stretching in the casting direction and the width direction. In addition, when performing biaxial stretching, simultaneous biaxial stretching can also be carried out at -49-201107396. In this case, the gradation may be extended in different directions, for example, or may be performed by dividing the extension in the same direction into a plurality of stages and extending the directions in any one of the stages. That is, it may be, for example, an extension step as follows. • Extension in the casting direction - Extension in the width direction - Extension in the casting direction - Extension in the casting direction - Extension in the width direction - Extension in the width direction - Extension in the casting direction - Extension in the casting direction, so-called simultaneous biaxial stretching is also included One direction extends while the other side relaxes the tension and causes it to contract. At the same time, the preferred extension ratio of the biaxial stretching is in the range of xl.01 times to xl.5 times in the width direction and the length direction. The amount of the residual solvent of the sheet at the time of the tentering is preferably from 20 to 100% by mass at the start of the tentering, and is dried while applying a tenter to the amount of the residual solvent of the sheet to be less than 1% by mass. It is preferably 5% by mass or less. The drying temperature at the time of tentering is preferably from 30 to 160 ° C, more preferably from 50 to 150 ° C, most preferably from 70 to 140 ° C. In the tentering step, the temperature distribution in the width direction of the atmosphere is less preferably from the viewpoint of improving the uniformity of the film, and the temperature distribution in the width direction of the tentering step is preferably within ±5 ° C, preferably. Within ±2 ° C, preferably within ± 1 ° C. 6) The winding step is such that the amount of residual solvent in the sheet is 2% by mass or less, and the winding step is taken up by the coiler 37 as an optical film, and the solvent residual amount is -50 to 201107396. Below %, a film having good dimensional stability can be obtained. In particular, it is preferably wound up at 0 · 0 0 to 0 · 10% by mass. The winding method can be used as long as it is a general user, and there are a fixed torque method, a fixed tension method, a gradual tension method, a stylized tension control method with a constant internal stress, and the like. The optical film of the present invention is preferably a long film, and specifically, it is a form which is usually provided in the form of a roll, which is about 100 m to 5000 m. Further, the film width is preferably from 1.3 to 4 m., more preferably from 1.4 to 2 m. The film thickness of the optical film of the present invention is not particularly limited, and is preferably from 20 to 200 μm, more preferably from 25 to 100 μm, even more preferably from 30 to 80 μm, as used in the polarizing plate protective film described later. [Polarizing Plate] When the optical film of the present invention is used as a protective film for a polarizing plate, the polarizing plate can be produced by a general method. Preferably, the optical film of the present invention is provided with an adhesive layer on the back side thereof, and is bonded to at least one side of a polarizer produced by immersing and stretching in an iodine solution. The optical film of the present invention can be used on the other side, and other polarizing plates can be used to protect the film. For example, it is preferred to use a commercially available cellulose ester film (for example, KONICA MINOLTA TAC KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC8UE 'KC4UE, KC4FR-3, KC4FR- 4. KC4HR-1, KC8UY-HA 'KC8UX-RH A, the above is ICONIC A MINOLTA OPTO (share) system). -51 - 201107396 The polarizer of the main component of the polarizing plate is a component that passes only the light of the deflecting surface in a certain direction. The currently known representative polarizing film is a polyvinyl alcohol-based polarizing film. The film has iodine dyed on the film. Among the polyvinyl alcohol-based films and those dyed with dichroic dyes. The polarizer is preferably formed by forming a film of a polyvinyl alcohol aqueous solution, stretching it by uniaxial stretching, or performing uniaxial stretching after dyeing, and then preferably treating it with a boron compound. As for the adhesive used in the above adhesive layer, at least a part of the adhesive layer is preferably used in an adhesive having a storage modulus of from 1.0 X 1 〇 4 p a to 1.0 x 1 〇 9 Pa at 25 ° C. A hardening type adhesive which forms a high molecular polymer or a crosslinked structure by various chemical reactions after applying an adhesive and bonding them. Specific examples thereof include, for example, a urethane-based pressure-sensitive adhesive, an epoxy-based pressure-sensitive adhesive, a water-based polymer-isocyanate-based pressure-sensitive adhesive, a thermosetting acrylic adhesive, and the like, and a moisture-curing amine group. An anaerobic adhesive such as a formate adhesive, a polyether methacrylate type, an ester methacrylate type, an oxidized polyether methacrylate, or a decane acrylate-based instant adhesive 'acrylate and A two-liquid instant adhesive such as a peroxide. The above adhesive may be of a single liquid type, or may be a mixture of two or more liquids before use. Further, the above-mentioned adhesive may be a solvent system using an organic solvent as a medium, or may be an emulsion type, a colloidal dispersion type, or a water solution type which uses water as a main component medium, or may be a solventless type. The concentration of the above-mentioned adhesive liquid is -52 to 201107396, and may be appropriately determined depending on the film thickness after adhesion, the coating method, the coating conditions, and the like, and is usually 0.1 to 50 mass%/〇. [Liquid Crystal Display Device] By assembling a polarizing plate to which the optical film of the present invention is bonded to a liquid crystal display device, various liquid crystal display devices having excellent visibility can be produced, and can be preferably used for, in particular, a large liquid crystal display device or A liquid crystal display* device for outdoor use such as digital electronic signage. The polarizing plate of the present invention is bonded to the liquid crystal cell through the adhesive layer. The polarizing plate of the present invention can be preferably of a reflective type, a transmissive type, a transflective type LCD or a TN type, an STN type, an OCB type, a HAN type, a VA type (PVA type, MVA type), or an IPS type (including an FFS method). ) and other various driving methods of the LCD. In particular, the large-screen display device of the 30-inch type or the above-mentioned screen, especially the 30-inch type to the 5th-inch type, does not fall off and white, etc., and can maintain its effect for a long time. In addition, uneven color, glare, or uneven fluctuations have an effect of not being tired even if the eyes are appreciated for a long time. [Examples] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. The acrylic resin (A) used in the examples is the following. Acrylic resin A1 Mw8 5 000 (methyl methacrylate/acrylic acid [v } ester ratio = 98/2) ° -53- 201107396 Acrylic resin A2 Mw95000 (methyl methacrylate / methyl acrylate ratio = 97 / 3 ) Acrylic resin A3 Mw40000 (methyl methacrylate / methyl acrylate ratio = 95/5) Acrylic resin A4 M w2 80000 (methyl methacrylate / methyl acrylate ratio = 99 / 1) Acrylic resin A5 M w4 8 0000 ( Methyl methacrylate / methyl acrylate ratio = 9 8 / 2 ) Acrylic resin A6 Mw 100000 (methyl methacrylate / methyl acrylate ratio = 97 / 3 ) Acrylic resin A7 Mw 100000 (methyl methacrylate / acrylic acid Methyl ester ratio = 97/3) Synthesis of acrylic resin A6 First, a methyl methacrylate/acrylamide copolymer suspension was prepared as follows. Methyl methacrylate 20 parts by mass of acrylamide 80 parts by mass of potassium persulfate. 3 parts by mass of ion-exchanged water 1 500 parts by mass. The above is fed into the reactor while maintaining the reactor at 70 while replacing the reactor with nitrogen. The reaction was carried out at ° C until the monomer was completely converted into a polymer. The resulting aqueous solution is a suspending agent. A solution obtained by dissolving 5 parts by mass of the above suspension agent in 165 parts by mass of ion-exchanged water was supplied to a 5-liter stainless steel autoclave equipped with a buffer plate and a faudler type stirring blade, with nitrogen- 54- 201107396 The inside of the gas displacement system is stirred at 400 rpm. Next, while stirring the reaction system, a mixture of the following feed components was added. 4 parts by mass of 96 parts by mass of 〇-5 mass 0.4 mass of methyl acrylate methyl methacrylate n-dodecyl mercaptan fraction 2,2'-azobisisobutyronitrile fraction, and then heated to 70 ° C When the internal temperature reached 70 ° C, the polymerization start time was maintained for 180 minutes. Subsequently, the reaction system was cooled, the polymer was separated, washed, and dried according to a usual method to obtain a bead copolymer. The copolymer had a polymerization ratio of 97% and a weight average molecular weight of 10,000. Acrylic resins A 1 to A5 were synthesized by suspension polymerization as in the case of acrylic resin A6 to obtain an acrylic resin shown in Table 1. The acrylic resin A was the same as A6 except that n-dodecyl mercaptan and 2,2'-azobisisobutyronitrile were 0.25 parts by mass, and the polymerization reaction time was adjusted to synthesize the weight average molecular weight to 100,000. [Production of optical film] <Production of optical film 1> (Doping composition 1) Acrylic resin A4 70 parts by mass -55- 201107396 Cellulose ester (cellulose acetate propionate thiol total substitution degree 2.75 'B The thiol substitution degree was 0.19, the propyl thiol group substitution degree was 2.56, Mw = 200000) 30 parts by mass of dichloromethane, 300 parts by mass of ethanol, 40 parts by mass, and the above composition was completely dissolved while heating to prepare a doping solution. The chain transfer agent necessary for the optical element of the present invention is such that the chain transfer agent contained in the acrylic resin (A) is insufficient for the optical element so as to have a quantitative amount of ruthenium as shown in Table 1, The amount of dissolved addition is simultaneously adjusted in the case of the liquid to obtain an optical element. The content of the chain transfer agent was determined by liquid chromatography to determine the quantitative amount of the chain transfer agent in the optical element. The results are shown in Table 1. (Film formation) Using the casting apparatus, the doping liquid prepared above was uniformly cast on a stainless steel belt support at a temperature of 22 ° C and a width of 2 m. The solvent was evaporated on a stainless steel belt support until the amount of residual solvent became 100%, and the peeling tension was 16 2 N/m and peeled off from the stainless steel belt support. The peeled sheet was subjected to evaporation of the solvent at 35 ° C, and cut into a width of 1.6 m, followed by drying at a drying temperature of 140 ° C by a tenter extending 1.3 times in the width direction. At this time, the amount of residual solvent when the tenter was stretched was 10%. After stretching with a tenter, after relaxing at 1 10 °C for 1 〇 second, it was transported at 1 1 〇 °c for 5 minutes and applied with a transport tension of 30 N/m to the film, and then -56-201107396, The drying was carried out at a temperature of 50 ° C for 5 minutes at a temperature of 50 ° C and a transporting tension of 50 N/m. The film was cut into 1.5 m width and a width of 5 μm was applied to both ends of the film. Knurling processing, at an initial tension of 220 N/m, and a final tension of 110 N/m, coiled to a core of an inner diameter of 15.24 cm to obtain an optical film 1 containing an acrylic resin (A) / cellulose ester resin (B) . The stretching ratio in the longitudinal direction calculated from the rotation speed of the stainless steel support and the running speed of the tenter was 1.1 times. The amount of residual solvent of the optical film 1 described in Table 1 was 0.1%, the film thickness was 40 μm, and the roll length was 4000 m. (Preparation of Optical Film 2-31) In the preparation of the optical film 1, the amount and composition ratio of the acrylic resin (A) and the cellulose ester resin (B), and the type and amount of the chain transfer agent were changed to those in Table 1. The optical films 2 to 31 were prepared in the same manner as described above. Further, in the thiol group of the cellulose ester resin described in Table 1, ac represents an ethyl group, pr represents a fluorenyl group, and bu represents a butyl group. [Preparation of Acrylic Particles] <Preparation of Acrylic Particles (C)> 8.2 liters of ion-exchanged water and 11.1 g of sodium dioctylsuccinate were placed in a reactor equipped with a reflux of 60 liters of internal volume. In the middle, the temperature was raised to 75 t in a nitrogen atmosphere while stirring at a number of revolutions of 250 rpm, and it was in a state of being virtually unaffected by oxygen. Put APS 0.36g, stir for 5 minutes, add -57- 201107396 once and add a monomer mixture consisting of MMA 1657g, BA 21.6g and ALMA 1.68g, and then check the starting heat peak for 20 minutes to complete the innermost hard Polymerization of layers.

Then, 'APS 3.48g was put in, and after stirring for 5 minutes, the force was continuously added in 120 minutes [3] A monomer mixture consisting of BA 8105g 'PEGDA (200) 31.9g and ALMA 264.0g was kept for 120 minutes after the end of the addition. Complete the polymerization of the soft layer. Then, 1.32 g of APS was charged, and after stirring for 5 minutes, a monomer mixture consisting of 2,106 g of MMA and 201.6 g of BA was continuously added over 20 minutes, and after completion of the addition, the polymerization was continued for 20 minutes to complete the polymerization of the outermost hard layer 1. Then, 1.32 g of APS was charged, and after 5 minutes, a monomer mixture consisting of MMA 3148g, BA 201.6g, and n-OM 10g was continuously added for 20 minutes, and the addition was continued for 20 minutes. The temperature was then raised to 95 ° C for 60 minutes to complete the polymerization of the outermost hard layer 2 . The polymer latex thus obtained was placed in a 3 mass% sodium sulfate warm water solution, salted out and solidified, and then dehydrated, washed, and dried to obtain a three-layer structure of acrylic particles (C1). The average particle diameter was determined by the absorbance method to be 1 〇〇 nm. The above abbreviations are respectively the following materials. MMA: methyl methacrylate MA: methyl acrylate BA: n-butyl acrylate ALMA: allyl methacrylate PEGDA: polyethylene glycol diacrylate (molecular weight 200) -58- 201107396 n-OM : n-octyl Mercaptan AP S : ammonium persulfate The sample containing acrylic particles described in Table 1 was prepared so as to have the composition shown in Table 1, and the composition was completely dissolved while heating to prepare a dopant liquid, and an optical film was also prepared. . The comparison 1 in Table 1 is the same as the result of evaluating the commercial product KM-4UE (manufactured by Konica-minolta Opto Co., Ltd.), and the comparison 3 is the same evaluation of the commercial product KM-4UY (manufactured by Konica-minolta Opto Co., Ltd.). result. The comparison 2 in Table 1 is a result of similarly evaluating a Z-TAC film (manufactured by Fujifilm) of a commercially available triethylenesulfonated cellulose film. -59- 201107396

[I谳J Remarks The present invention 1 invention 1 comparison 1 invention 丨 comparison 1 invention 1 invention invention 1 invention 丨 comparison 1 invention invention 1 invention 1 comparison 丨 comparison 1 1 comparison 丨 1 invention invention 1 Invention 1 1 invention 1 1 invention 1 1 invention 丨 1 invention 丨 1 comparison 丨 | the invention | 1 invention 1 1 invention 1 I invention 1 1 invention invention 丨 1 invention 丨丨The present invention 丨丨 1 invention 1 丨 comparison 1 1 comparison 1 1 comparison I ※ &lt;N 〇ts d CS d (N 〇 &lt;N 〇&lt;N d 0.11 I 045 1 00 〇dd μ ο CM Ο 〇d 〇〇〇&lt;N 〇td cs o ο fS Ο 〇〇〇(S 〇(N 〇(Ν U 〇— - - - — — — - — — — 一一- 〇v-&gt; 〇| KM&quot;4UE(KONICA MINOLTA OPTO) | Z-TAC (Fuji Film Co., Ltd.) | KM-4UY (K0NICA MINOLTA OPTO (share) system) im cs V© CO tTi in PO r*-i • λ v-&gt; ΓΟ in m ν&gt; ν〇*〇m *〇ΓΟ «Λ ro IT) m tn m Π 〇σ\ s SS ss S VO CN 〇\ 〇\ s W) «ο s 5 5 s 5 Ss Os VO 〇\ \〇Os s〇ω am πυ喂 喂 击 M M M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 200000 1 1 200000 ! 1 200000 1 200000 1 200000 | 70000 1 85000 | 220000 1 130000 1 120000 1 150000 1 150000 1 120000 1 110000 Total substitution 丨 2.75 | 2.75 1 2.75 1 2.75 | 2.75 1 2.75 1 2.75 | 2.75 | 2.75 1 2.75 1 1_^_I 1___1 1__^_1 1_2J1__! | 2.92 | 1_2^5__I 1_2^5_1 1__2^5__1 1__1 1 2.75 ! 1 2.75 1 2.75 | 2.75 | 2.75 1 2.75 1 2.75 1 2.75 | 2.75 1 2.75 1 2.75 1 2.75 1 * - 1 • • 1 &lt; • • • * • 1 1 • - * &gt; m Ξ. 2.56 | 2.56 1 2.56 1 2.56 | 2.56 1 2.56 1 2.56 | 2.56 | 2.56 1 2.56 1 | 2.56 | 256 1 256 1 1 2.56 1 • | 2.56 I 1 2.56 1 1 2.56 1 1 2.56 1 1 2.56 1 1 2·56 1 2.56 1 | 2.56 ! 1 2.56 | 2.56 | 2.56 1 2.56 1 2.56 1 2.56 | 2.56 1 2.56 0.19 | 0.19 1 0.19 1 0.19 | 0.19 1 0.19 1 Q\ 〇1_^__I 11 1__1 !_^_1 1_^_1 1_0^__1 1_^_I 1___1 1_^_1 1___1 1__1 1__1 1 0.19 1 0.19 1 | 0.19 | 0.19 | 0.19 | 0.19 | 0.19 丨0.19 1 0.19 | 0.19 1 0,19 Acrylic Resin (A) 1 Chain Transfer Agent | n-Dodecyl Mercaptan I | Orthodox 12-mercaptothiol n-dodecyl mercaptan 1 n-dodecyl mercaptan | Orthodecyl mercaptan | n-dodecyl mercaptan | n-dodecyl mercaptan 1 | n-Dodecyl mercaptan | | α-methylstyrene dimer i 1 n-octylmethyl mercaptan 1 1 n-butyl methyl mercaptan 1 1 n-dodecyl mercaptan I 1 n-dodecyl Thiol 1 1 n-dodecyl mercaptan | | n-dodecyl mercaptan | 1 n-dodecyl mercaptan i 1 n-dodecyl mercaptan i 1 n-dodecyl mercaptan 1 Dialkyl mercaptan • 1 n-dodecyl mercaptan 丨 n-dodecyl mercaptan I n-dodecyl mercaptan 1 n-dodecyl mercaptan 1 n-dodecyl mercaptan | Alkyl mercaptan 丨 n-dodecyl mercaptan 1 n-dodecyl mercaptan | n-dodecyl mercaptan 1 n-dodecyl mercaptan Mw | 280000 1 280000 | 280000 | 280000 I 280000 | 280000 I 280000 | 280000 | 280000 | 280000 I 280000 1 ,280000 1 1 280000 1 1 28 0000 I 1 280000 I | 85000 I | 280000 | 1 280000 1 | 280000 丨1 100000 | 100000 I 40000 1 95000 1 480000 1 280000 1 280000 1 280000 | 280000 1 280000 | 280000 | 280000 Acrylic 丨 5 5 &lt; 5 ΙΛ &lt; Optical film number - (N inch 4Λ V© 〇〇〇 〇〇〇 \ o two r4 Ρ〇Ό 〇〇 Os (N &lt;Ν fS m tN ID &lt;N Ό 00 CS σ\ CM | comparison Example 1 I Comparative Example 2 | Comparative Example 3 - (%¥»N(V)S5M via iiMM^&lo_M#sii^-fl-#: Old Linmi: e※(φ}_»)u)rf3⁄4氍亵^E:cs※(φs_)chain i&amp;莸:I※

201107396 "Evaluation" <Measurement of Photoelastic Constant> The sample film was cut to a length of 1 cm wide x l 〇 cm (the measurement direction was 10 cm with respect to the width direction of the film forming conveyance direction). For the film which was humidity-conditioned for 24 hours at 23 ° C and a relative humidity of 55%, the phase-deterioration of light at 59 〇 nm was carried out as follows. Using KOBRA-31PRW, stress was applied along the length direction (l〇cm length) in the range of 1N-15N with 1〇 point stress, and the hysteresis phase exhibited at this time was measured, and the tension and hysteresis of each point were plotted. , calculated using the slope of the film and the thickness of the film. It is shown that the horizontal axis represents the stress (the load is divided by the cross-sectional area of the film), and the photoelastic coefficient (1 /Pa) is obtained from the slope. This assay selects the appropriate stress range in the range where no birefringence is exhibited. <Measurement of variation of birefringence 値 and birefringence> The average refractive index of the film sample was measured using an Abb e refractometer (1 T ) and a spectroscopic light source. Further, the thickness of the optical film was measured using a commercially available micrometer, and an automatic birefringence meter Κ Ο BRA - 2 1 AD Η (manufactured by Oji Scientific Instruments Co., Ltd.) was used, and an environment of 23 ° C, 5 5 % R Η was used. The film was placed under a pressure of 24 hours, and the phase of the film at a wavelength of 589 nm was measured in the same environment. The above average refractive index and film thickness were placed in the following formula, and the three-dimensional refractive index 〇 in-plane birefringence Δ no and the thickness direction birefringence Δ nth were calculated by the following equation. [S ] -61 - 201107396 (i) Δηο= ( nx-ny) (ii) Δ nth= ( ( nx + ny ) /2-nz ) where ' nx is the in-plane maximum refractive index when the optical element is plane , ny is the refractive index in the in-plane and nx perpendicular direction, nz is the refractive index in the thickness direction of the optical element, and each refractive index is relative to the wavelength of 5 9 Onm. In addition, for measuring 23 ° The film which was placed in the environment of C 20% environment and the in-plane birefringence and the birefringence in the thickness direction of the environment at 23 ° C for 80 hours was also subjected to hysteresis measurement, and the humidity variation of in-plane birefringence was performed. The measurement of the absolute enthalpy of the absolute enthalpy and the change in the humidity of the birefringence in the thickness direction is shown in Table 2. On the other hand, the film was also subjected to hysteresis measurement for the film placed in an environment of 23 ° C 5 5% and 35 ° C 27% environment in the in-plane birefringence and thickness direction birefringence. The measurement results of the absolute enthalpy of the temperature change in the in-plane birefringence and the absolute temperature 双 of the birefringence in the thickness direction are considered in Table 2. <Extension damage> At 23 °C, In the air-conditioned room of 55 % RH, the film containing acrylic resin was conditioned for 24 hours under the same conditions and cut into l〇0mm (length) xl0mm (width) 'in the center of the length direction' with a radius of curvature of 0mm' bending angle of 180 . The film was bent in such a manner that the films were tightly overlapped, and the evaluation was performed three times, and the evaluation was performed as follows. Further, the -62-201107396 evaluated here means that the fracture is separated into two or more pieces. 〇· · · Three times without breaking X ··· At least one of three times broken -63- 201107396 "Evaluation results" [Table 2] Thick 1 The 2 double fold 1 s値裱3 j«4 The turbidity extension destroys the odor Remarks to 5 cold 6 资 7 裱 8 8C9 1 53⁄4 8 effect 10 (Χ10·6) (xi〇's) (X.10·6) (Χ:1〇·5) 1 1 *46: 1.6 1.9 1.3 2.2 1.7 2.0 ο Ο _ _ _| · 2 —厶01 一3·5 -6,7 3.0 2'8 3.2 0.5 ο Ο 〇♦Settings* η 口 Port 3 _3.62 -5.2 -9.6 5.0 0.3 4.9 0.3: 〇 X 〇4 4.87 6.6 Π.Ό 6.3 8.0 6.1 5.5 ο 〇〇5 5.62 7.7 12,0 8.0 16.0 7.3 6.5 ο Ο ο 6 2.41 3.0 4.3 2-8 3.5 2,7 3.0 〇〇〇7 2.39 3.0 4.3 2.8 3.2 2.6 3,1 ο. 〇〇8 2.44 3,1 4,3 2.8 3.4 2.7 3.4 ο 〇〇9 2.49 3.2 4.3 2.9 4.8 2.8 5·2 X 〇〇10 2.49 3.2 4·3 2.7 3.0 2-5 2vl 〇〇〇 η 2.49 3.2 4.3 2,9 3.4 2.6 2.9 〇ο 〇12 2.49 3.2 4.3 2.9 5.1 2.9 7.3 X 〇χ 13 8,04 1,1 19.0 11,0 17,0 11.0 11.0 〇X Mutual 14 9,54 1.4 23.0 14.0 22.0 13.0 13.0 ο X &quot;〇15 0;00 1.6 1,9 1.8 2.0 1.2 1·8 ο 〇Ο £^!i| EHH E@H g^ IUl @0] 16 1.48 1.6 1.9 1.3 2.1 1 .2 2.1 ο 〇&quot;〇&quot; Τ7 2.40 3.0 4.3 3.0 5.1 2.7 5.7 〇〇18 2.41 3.0 4.3 3.0 3.3 2.9 3.8 ο 〇&quot;〇~ 19 2.43 3.0 4.3 3.0 3.3 2,9 4.1 〇ο 20 1 .47 3.0 4.3 3.3 3.5 2;7 3,7 ο ο 21 1.48 3.1 4.2 3.2 3.4 2.7 7.0 〇X _ 22 2.46 3.0 4.3 2.8 3.7 3.2 3.2 ο 〇23 2.44 3,0 4.3 2:7 3.7 2.9 3.1 ο Ο 24 2.43 3.0 4.3 3,1 3.7 2.7 3.1 ο ο 25 25 2.41 3.0 4.3 3,1 3.5 2.7 3.0 〇〇26 2.43 3.0 4.3 3.1 3.5 2.9 3.0 | | | 27 2.43 3V0 4.3 3.1 3.6 3·0 3.1 〇ο 〇28 2.42 3,0 4.3 3·0 3.5 3.0 3.1 ο 〇29 1.48 1.6 1,9 1.8. 3.5 1.6 3,0 〇〇~rT 30 ..1. 47 1.6 1.9 1.5 3, 6 1 .5 .3.1 〇〇~〇&quot; 31 1.47 1.6 1.9 1.5 3.6 1.5 3.1 〇〇Compare 1 8.00 5.0 1.3 4.8 34.0 4.8 20.0 〇〇Comparative comparison 2 9.52 2.8 4.0 28.0 35.0 27.0 &quot;21.0 〇〇Comparison|Compare 3 1 11.02 | 2.5 75.0 20.0 43.0 45.0 22.0 〇〇ο: Comparison ※l : Optical film number ※2 : Photoelastic coefficient xlO_12 (l/Pa) *3 : Under wet motion Absolute 双 of birefringence difference (temperature is constant, relative humidity change) ※ Bucket: Absolute 双 of birefringence difference under temperature fluctuation (temperature change, absolute humidity) *5: In-plane birefringence Ληο 23°C 55% ( Xl0·6) *^ : Birefringence in the thickness direction Anth 23°C 55% (xl0·5) ※: In-plane birefringence (Δηο) *8: Thickness direction birefringence (Anth) ※Today: (23°C20% -23°C80%) ※Chuan: (23°C 55%-35°C27%) -64- 201107396 <Confirmation of compatibility state> Use a non-difference scanning calorimeter (DSC-7 model manufactured by Perkin Elmer) 'After the measurement at a temperature rising rate of 20 ° C /min, the temperature of the sample of the present invention in the vicinity of the volume average of the glass transition temperatures of the acrylic resin (A) and the cellulose ester resin (B) Endothermic peak. In the present invention, a resin having a relationship between a glass transition temperature inherent to the acrylic resin (A) and a glass transition temperature inherent to the cellulose ester resin (B) is selected. From these results, it was confirmed that the heat was uniform. When incompatible, even if blended together, the glass transition temperature derived from the acrylic resin (A) and the cellulose ester resin (B), respectively, appears to exhibit two glass transition temperatures, but in the sample of the present invention. Since the two glass transition temperatures were not observed, they were judged to be compatible. Further, in such a configuration, from the viewpoint of the acrylic resin, the heat resistance is improved by blending the cellulose ester resin. <Measurement of haze> Each of the above-prepared film samples was conditioned for 24 hours in an air-conditioned room at 23 ° C and 55% RH, and a haze meter (NDH20 00 type, Nippon Electric Industrial Co., Ltd.) was used in accordance with JIS K-7136. (Stock)) A sample of a film was measured under the same conditions, and it was judged to be 〇 after 0.4% or less, and the sample which was higher than 〇. 4% was judged as x and shown in Table 2. The optical film of the present invention is transparent to 0.4% or less, and is considered to be compatible from the viewpoint of optics. The cellulose resin of cellulose triethyl fluorenyl cellulose (total degree of substitution 2 · 94) outside the scope of the present invention is also subjected to the acrylate resin of the range of the present invention -65-201107396 After the evaluation of the compatibility with the acid-soluble domain, the film having 15 parts by mass of tridecyl cellulose present in an amount of 85 parts by mass of acrylic tree DIANAL BR85 (manufactured by Mitsubishi) was white turbid. 4 The 雾μηι thick film has a haze of 3. and exhibits extensibility and destructiveness due to breakage after bending. Accordingly, it has been clarified that the haze which is thermally and optically compatible is also improved. <Odor> The film was heated to 140 ° C and the sample was placed in a dry box for 2 hours to confirm whether or not there was a thiol odor. When three or more of the five observers judged that there was sulfur odor, it was judged as X, and when it was three or less, it was judged as 〇. The optical thin of the present invention has no mercaptan odor. The acrylic resin (A) used in the present invention was confirmed by a spectrum of sub-NMR according to a usual method to have a high composition of methyl methacrylate. The methyl methacrylate in the acrylic resin of the present invention is a copolymer of 80 parts by mass or more based on 100 parts by mass. The acrylic resin used in the present invention has a high composition of methyl methacrylate, so that it is a negative birefringence for stretching and a negative birefringence for the film. Further, since the composition of methyl methacrylate is high, the photoelastic coefficient is negative. On the other hand, the cellulose ester resin (B) used in the present invention selects a substituent composition in the field of the present invention from the viewpoint of phase compatibility, and the alignment birefringence of the cellulose ester resin (B) in the collar is positive. And the photoelastic refraction is positive. The acrylic resin (A) and the cellulose ester resin (B) are dissolved. -66-201107396 The resin is such that the negative birefringence is different from the positive resin and the birefringence of the compatible resin becomes near zero. At the same time, the photoelastic coefficient is also a negative and positive resin of different signs, and the photoelasticity of the compatible resin becomes close to zero. The resin composition of the present invention shown in Table 1 is as shown in Table 2, and it is known that the birefringence and the photoelasticity are remarkably close to zero. The moisture permeability can be measured in accordance with the method described in JIS Z 〇 2〇8. When the acrylic resin (A) used in the table alone has a moisture permeability of 40 μm, it is in the range of 40 to 11 〇g/m 2 · 24 h at 40 ° C and 90% RH. When the cellulose ester resin (B) used in the other watch is used as a film of 40 μm, it is in the range of 700 to 1 600 g. When the ratio of the cellulose ester resin (B) used in the present invention exceeds 50 parts by mass, the birefringence fluctuation is large as the optical element enters and exits with moisture having a high moisture permeability and a change in humidity or temperature. On the other hand, when the ratio of the acrylic resin (A) used in the present invention exceeds 90 parts by mass, the moisture permeability of the cellulose ester resin (B) is low, and the moisture ingress and egress with the corresponding humidity or temperature change causes The birefringence changes little, but the brittleness deteriorates. The resin composition of the present invention used as an optical element, from such a viewpoint, a system in which more than 90 parts by mass of the acrylic resin (A) or a system in which the cellulose ester resin (B) exceeds 50 parts by mass, The change in birefringence caused by the ingress and egress of water having a change in temperature and humidity is particularly excellent. In the compatibility system of the acrylic resin (A) and the cellulose ester resin (B), the acrylic particles (C) have an impact resistance within a range having little optical influence, and are also not affected by elongation. Preferably. The acrylic resin (A) used in the present invention is subjected to differential thermal mass measurement -67-201107396 apparatus (TG/DTA200 manufactured by Seiko Electronics Co., Ltd.), and is heated to a temperature of 160 ° C at a temperature increase rate of 20 ° C / min. After 30 minutes at 160 ° C, it was reduced by 15% by mass under a nitrogen atmosphere. The results of the same conditions as described for the optical film sample 1 of Table 1 were reduced by 5% by mass. On the other hand, the optical film sample 1 of Table 1 was measured while blowing air, and the mass reduction was less than 1%. Therefore, when the optical element is processed, the processing quality in the air is rarely reduced. This shows that the inherent thermal decomposition property of the acrylic resin is compatible with the cellulose ester resin and can be more stable in the air processing than in the nitrogen atmosphere. machining. The optical film sample of the present invention described in Table 1 was 1.3 times in the width direction and 1.1 times in the transport direction, but the birefringence was low and excellent. Further, an optical film having a smaller birefringence can be obtained by reducing the stretching ratio. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a doping preparation step, a casting step and a drying step of a solution casting film forming method used in the present invention. [Explanation of main component symbols] 1.: Dissolving kettle 3, 6, 12' 15: Filter 4, 13: Storage tank 5, 14: Liquid feeding pump 8, 16: Catheter 10: UV absorber feeding kettle 20 : Confluence pipe -68- 201107396 2 1 : Mixer 3 0 : Mold nozzle 31 : Metal support body 3 2 : Sheet material 3 3 : Peeling position 34: Tenter extender 3 5 : Drying device 4 1 : Particle feed Into the kettle 42: Storage tank 43: Pump 44: Filter - 69

Claims (1)

201107396 VII. Patent application range: 1. An optical element which is an optical element containing 10 to 50 parts by mass of the cellulose ester resin (B) with respect to 50 to 90 parts by mass of the acrylic resin (A), which is characterized in that The at least one of the cellulose ester resin (B) has a total degree of substitution (T) of from 0.1 to 0.5% by mass based on the acrylic resin (A) of from 2.00 to 2.99, and the degree of substitution (ac) of the ethyl thiol group is 〇.1. 〇~1_89, the part other than the acetamidine group is substituted with a thiol group consisting of 3 to 7 carbon numbers, and the degree of substitution (r) is 1.10 to 2.89, and the boiling point is 165 ° C or more under normal pressure. Chain transfer agent. 2. The optical component of claim 1, wherein the optical element has a photoelastic coefficient of -3. 〇χ 10_12 / Pa 〜 7 · 〇χ 1 (T12 / Pa (23 ° C, 5 5 % R Η 3. The optical component according to claim 1 or 2, wherein the optical element has at least an absolute 値 of the in-plane birefringence (i) or an absolute 値 of the thickness direction (ii) One satisfies 2·〇χ10·4 (23°C, 55%RH), (i) Δηο= ( nx-ny ) (ii) Anth= ( ( nx + ny ) /2-nz ) (where nx is The in-plane maximum refractive index when the resin constituting the optical element is formed into a thin film, ny is a refractive index in the in-plane direction perpendicular to nx, and nz is a refractive index in the thickness direction of the optical element, and each refractive index is a wavelength of 5 9 〇 nm. 4. The optical component according to any one of claims 1 to 3, wherein the in-plane birefringence and the birefringence in the thickness direction of the optical component, and -70- 201107396 Temperature 2 3 °C 2 0 % R The birefringence of Η and the absolute 値 of the difference between the birefringence of 2 3 °C and 8 0 % RH are both 1.5 X 1 (Γ4 or less. 5 · Apply for patent The optical component of any one of items 1 to 4, wherein the in-plane birefringence and the birefringence in the thickness direction of the optical element, and the birefringence at a temperature of 35 ° C 2 7 % RH and 23 ° C 5 5 The absolute 値 of the difference between the birefringences of % R 値 is 1 · 〇X 1 〇·4 or less. -71 -