TW578016B - Optical film, its process and polarizing sheet - Google Patents

Abstract

An optical film is formed by extrusion process of an amorphous thermoplastic resin, the film having a thickness of less than 100 mum, a residual phase difference of 10nm, and an optical axial deviation of less than ±10 DEG. The temperature of optical film immediately before the film comes in contact with a cooling roll after the optical film formed by the amorphous thermoplastic resin is extruded with the die installed on the excluder is set at above Tg+50 DEG C, wherein Tg is a glass transition temperature of the amorphous thermoplastic resin.

Description

578016 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to an optical film, a manufacturing method thereof, and a polarizing plate used in the field of optical applications or displays; more specifically, it relates to the use of melt extrusion An optical film obtained by molding and having less optical distortion, a manufacturing method thereof, and a polarizing plate using the optical film. [Prior Art] In recent years, a film having excellent transparency and a small residual phase difference has been required for optical applications or displays. However, when a film manufactured by melt extrusion is used, stress deformation occurs with the deformation during film formation, and the problem of residual optical deformation occurs. This optical distortion is left in the film in order to make it a phase difference. Therefore, when the film is used for a disc substrate or a liquid crystal display, it causes a large problem. As a means for reducing optical distortion, as disclosed in Japanese Patent Laid-Open No. 4-2 7 5 1 2 9, a polycarbonate resin is used at a resin temperature of 300 to 330 ° C, that is, a glass transition temperature. (Tg) + 150 ° C to Tg + 18 (TC, set the air gap to 80 to 100mm, and set the cooling roller temperature to 100 to 140 ° C A method for manufacturing a formed optical film is provided, in which the deformation shear during extrusion and the cooling shrinkage force of the film are in a balanced state, thereby obtaining an optical film with an optical deformation of 5 × 10- slave. In addition, Japanese Patent Laid-Open No. 2000-208 0 268 discloses a method for manufacturing a sheet having a residual phase difference of 10 nm or less. When the glass transition temperature of the resin constituting the sheet is set to T g, the tape for extrusion molding and

3l3 ^ 6.ptd Page 11 578016 State of the Invention (2) A method for manufacturing an optical film by extruding the roller at a temperature of Tg to Tg + 50 ° C. Here, a membrane with a thickness of 0.1 to 2 mm can be obtained. However, the method disclosed in Japanese Patent Application Laid-Open No. 4-27.5 2 1 9 cannot be applied to other resins other than polycarbonate. When it is used, for example, saturated norbornene resin For example, in the case of a resin containing a large number of tertiary carbons on the molecular skeleton, the resin may be deteriorated because the formation temperature is too high. Furthermore, Japanese Patent Laid-Open No. 2000- 2 0 8 268 does not describe a method for manufacturing a thin optical film of less than 100 // m. In addition, when the film is peeled off, there is a concern that an optical distortion may remain as the film is stretched. If optical distortion remains in the film, a phase difference will occur when light passes through the film, so it is not suitable for optical applications or display fields. _ The phenomenon of residual phase difference (optical distortion) in the diaphragm is caused when the molecules in the diaphragm are oriented in one direction. Residual phase difference occurs when the resin is deformed at a temperature above Tg, and its proportion is caused by the stress during deformation. Because the stress during deformation depends on the temperature and the amount of deformation of the resin, if the amount of deformation is the same, the stress will change with the temperature of the resin. When a film is obtained by an extrusion molding method, the Θ resin usually extruded from the mold is pulled down in the air gap in a manner to form the target film thickness, and the resin temperature will decrease at this time. If the temperature of the resin is lowered, the lower the temperature, the greater stress will be generated during deformation, and a large phase difference will remain depending on the stress. ‘In addition, optical films used in optical applications or displays

313926.ptd Page 12 578016 V. Description of the invention (3) The film will not only cause a residual phase difference indicating the magnitude of optical distortion, but also the optical axis of the optical distortion direction will cause an error problem. Conventionally, in order to stabilize the contact between the cooling roller and the resin and suppress the occurrence of the optical axis deviation, the air cavity, contact roller, and full-surface pin rolling are generally used to press the film on the cooling roller. . However, when these methods are used, in the above-mentioned contacts, since a larger stress is applied to the diaphragm, a larger residual phase difference is caused. In addition, in optical applications, although amorphous thermoplastic resins are mainly used, saturated norbornene-based resins have superior heat resistance and transparency, and have a unique complex refractive index and a photoelastic coefficient. Also smaller advantages. Therefore, a film made of a saturated norbornene-based resin is quite suitable for an optical film. Therefore, in an optical film made of a saturated norbornene-based resin, it is actively sought to reduce the residual phase difference and suppress it. Optical axis shift. In addition, in recent years, in the field of optical applications or displays, not only have small residual phase differences, small optical axis shifts, but also optical films with superior thickness accuracy have been required. However, when an optical film is produced by melt-extrusion of a thermoplastic resin, since the deformation during film formation is not uniform, there is a problem that the thickness accuracy deteriorates. Therefore, since the magnitude of the stress stored in the diaphragm is distributed in the width direction, there is a problem that the residual phase difference cannot be uniform. In addition, especially in a narrow range, when the thickness accuracy is poor, thick or thin in a certain thickness range not only the residual phase difference, but also the optical axis in the direction of optical deformation also has a scattered distribution problem. In addition, the polarizing plate used in the liquid crystal display device (LCD) is

313926.ptd Page 13 578016 i. Description of the invention (4) A polarizing plate composed of a polarizer and a protective film laminated on both sides thereof. For the polarizer, a polyvinyl alcohol film extended by adsorbing iodine or a dichroic dye, and a protective film using an untreated cellulose triacetate (TAC) film or a choline-treated TAC film. ^ The optical film, such as the protective film, can be obtained by a casting method because a film with better physical properties such as optical properties can be obtained. However, the TAC film obtained by the casting method is used as a polarizer for the protective film of polarizers. Because the TAC film has a large photoelastic coefficient, the complex refractive index and optical axis shift will become larger. Problems with polarizing characteristics such as light production when orthogonally polarized. In order to solve such problems, various methods have been tried. For example, Japanese Patent Laid-Open No. 6-5 1 120 has proposed a transparent protection with a retardation value of 3 nm or less on one or both sides of the polarizing film. Layer of polarizer. ^ However, the method for manufacturing a transparent protective film proposed in the above publication is not specifically disclosed in the publication. In addition, in the obtained polarizing plate, although the light leakage observed from the front in the orthogonal polarization state was slightly improved, it was difficult to eliminate the light leakage observed from the oblique direction. [Summary of the Invention] Φ The purpose of the present invention is to provide an optical film composed of an amorphous thermoplastic resin that has a small residual phase difference and a small optical axis error, in view of the current state of the conventional technology. , And its manufacturing method. Another object of the present invention is to provide a melt extrusion using an amorphous thermoplastic resin which has not only excellent optical characteristics but also excellent thickness accuracy.

313926.ptd Page 14 ^ 016

The obtained oblique observing observation of the present invention is superior to the polarized optical film. Another object is to provide a polarizing plate that can obtain a smaller phase difference from the normal direction, less optical axis, and less leakage from the front, even from orthogonal polarization. Optical film, manufacturing method thereof, and polarizing plate used.

Plastic tree month purpose # f ^ Ming series of optical films, using non-crystalline heat can be combined with the optical extrusion molding, the residual phase difference is flat 1 n, especially the film thickness is less than 1 〇 0 // m, residual 10. The second invention below 3nm and the optical axis shifted in the soil case is an optical film plastic tree moon dagger 4 pre-film 'is made of amorphous, the remaining phase difference is squeezed at T' The optical film with a thickness of less than 10 to 2 nu, the second invention of the spleen and the secret formula / the difference of lnmU will not cause the problem of optical axis shift error. In the special inventions of the first and second inventions, the phase is shifted forward in the direction of the axis and the retardation Rs (4 ()) A is measured on the extension axis of the normal line of the two discs, the optical capture film, from the tilt 40. Fang Leng Another special feature of the first and second inventions is the use of saturated norbornene-based resins. II: Amorphous thermoplastic resins mentioned above 丨 Isobornene-based resins, so the dimorphic thermoplastic resins have a complex refractive index and photoelastic transmission; Z is superior in heat resistance and transparency, Can provide the characteristics of the residual phase of the borneol dilute resin. The driver is small, and the light car

578016 to the description of the invention (6), in the feature of the first invention, the manufacturing method of the optical film of the first invention is provided, which includes: an amorphous thermoplastic resin having a glass transition temperature Tg, The step of extruding the die on the machine to form a sheet to obtain a film composed of an amorphous thermoplastic resin; and a step of closely adhering the film composed of the amorphous thermoplastic resin described above to a cooling roller; _The temperature of the diaphragm just before the cooling roller and the diaphragm are in contact is set to Tg + 5 ot or more. Thus, an optical film with a residual phase difference of 10 nm or less can be obtained. It is best to set the temperature of the diaphragm just before the contact between the cooling roller and the diaphragm when the diaphragm is in close contact with the cooling unit, so that the residual phase difference can be less than 3nm. Another feature of the first invention is to provide a method for manufacturing the optical film according to the first invention, which includes: applying an amorphous thermoplastic resin from a mold mounted on an extruder, A step of extruding a thin sheet to obtain a film sheet composed of the above-mentioned amorphous thermoplastic resin; and a step of closely contacting the film sheet composed of the above-mentioned amorphous thermoplastic resin to cooling Xingkun; The thickness immediately after the contact with the diaphragm is set to A, and if the die gap of the mold is set to B, the B / A value is above the thickness of the above-mentioned die is 70 // m and less than 100 // m When it is less than 10, it is less than 15 when it is 5 // ^^ and 70 // m, and when it is less than 50 // m, it is less than Λ 2 0. And if the glass transition temperature of the amorphous thermoplastic resin is set to Tg, when the film is in close contact with the cooling light In cooling - about to be film roll and the film temperature before contact is set Tg + 3〇〇c invention to provide a ^ 2 in accordance with the case wherein the second invention, the optical system of the

3] 3926.ptd

578016 V. Description of the invention (7) '~~-The method for making cymbals includes: extruding an amorphous thermoplastic resin having a glass transition temperature from a mold installed on an extruder, A step of obtaining a film sheet made of the above-mentioned amorphous thermoplastic resin; and a step of closely contacting the film sheet made of the above-mentioned amorphous thermoplastic resin to a cooling roller, wherein the temperature of the resin immediately after extruding the mold is set to Tg + 130t or more, and the temperature of the diaphragm from the die exit right before the diaphragm contacts the cooling roller, which is lower than Tg + i 00. The method of 〇 is maintained, and at the same time, the temperature difference between the film width direction of the film just before the extrusion die Ϊ ϋ ϋ ϋ ϋ 接触 d before contacting the cooling roller 疋 is less than 10 ℃.

The first, the second, and the other—feature 'are at the contact point of the cooling roller and the diaphragm into the lamp, by the gland {cake)% + m, U Η, you press ^ 7 ° P roller Press, or by cooling from side to side, the diaphragm can be tightly attached to the cooling roller. At the time of the gust wind of the first and second inventions, in the round, from the installation of the extruder ;: the specific method of manufacturing the grate: from the die exit to the cooling rod and film: directly connected to the cooling roller: 'Insulate the diaphragm. θ is in the air gap just before the contact ’, the third invention of this case is an optical

Plastic resin, and melted and extruded to open / ^, win the film 'is using amorphous thermal film, in which the retardation value in the direction of the normal direction ^^ the thickness of the optical film is less than 100 # m towards the optical axis The shift is ± i 〇. Where) is 3nm or less and the length is or (b). The degree of accuracy is as follows (a) (a) When the average thickness is 60% // below 10% of the average thickness, wide households / phenes, the thickness accuracy of the entire width & average thickness of 2cm in the direction

578016 i. Description of the invention (8) The degree is less than 5% of the average thickness. In the thickness curve in the width direction, the difference between the adjacent top and concave bottom is less than 7% of the average thickness. (b) When the average thickness is less than 60 // m, the thickness accuracy of the entire width is below '6 # m, and the thickness accuracy of the average length of 2 cm in the width direction is below 3 // m. The difference between the adjacent top and concave bottom is 4 // in or less. In the third aspect, the non-crystalline thermoplastic resin is a norbornene-based resin. The optical films according to the first to third aspects are related The sheet is a protective film suitable for protecting photons. Furthermore, still another feature of the present invention is to provide a polarizing plate, which is a layer of at least the optical film of the first to third inventions that is polarized. The first invention of this case is an optical film, which is an optical film made of an amorphous thermoplastic resin and extruded, wherein the thickness is less than 100 / m and the residual phase difference is Below 1 Onm, preferably below 3 nm, and the optical axis shift is below ± 10 °. Furthermore, the second invention of this case is an optical film, which uses an amorphous 1 plastic resin and is extruded. Optical film, where the thickness is less than Λ 0 // m, and the residual phase difference is within 1 nm . Optical film with a residual phase difference below 10nm (preferably a residual phase difference below 3nm, especially below 1nm) is suitable for optical applications such as optical discs or liquid crystal displays. It is particularly suitable for When manufacturing liquid crystal displays, such as the front and back films of a retardation plate or the protective film of a polarizing plate, especially

313926.ptd Page 18 578016 V. Description of the invention (9) A low phase difference can be obtained. Therefore, 'the optical film of the present invention is very effective for such applications because the residual phase difference is very small'. Furthermore, when the optical axis of the optical film is shifted by ± i0. In the following, when the optical film of the present invention is used for optical applications, the yield rate can be improved. For example, when a protective film that is a polarizer is used, the offset of the optical axis of the polarizer can be set to ± 10, and display unevenness can be suppressed. In addition, since the thickness of the optical film is less than 1000 // m, it can achieve miniaturization effects such as optical discs and liquid crystal displays. Furthermore, in the second invention, since the residual phase difference is less than inm, the optical axis shift caused by the use of a film having a residual phase difference of more than 1 nm, as is conventionally known, can be ignored, And can provide a special simplified conventional manufacturing process that integrates the optical axis, at the same time can eliminate the defects caused by the optical axis shift, and improve product yield, and even eliminate the epoch-making optical film of the inspection step. In the specific layout of the first and second inventions, the phase of the normal direction of the above-mentioned optical film is moved forward from the axis direction and the retarded phase. Two: first ;, = of: t ^ to the measured delay Rs (40) And the retardation Rf (40) will be the value obtained by the difference between the refractive index and the thickness of the birefringence at R (the meaning of the product of ζ i and the retardation) at 0H6nm. 1 Using the rotation analyzer method, measured by light with a wavelength of 590 nm, the system shown in Figure 5 ~ R (〇), and the retardation measured from the normal direction of the optical and optical film is 40 ° The normal direction of the media is a three-dimensional schematic diagram of the delay RS (40) from the oblique phase forward axis direction.

578016 V. Description of the invention (10) As shown in FIG. 5, the delay R (0) in the present invention is a delay value measured from the normal direction of the optical film, and the delay in the present invention R s (4 0) is a retardation value measured from the normal direction of the optical film by 40 degrees from the oblique phase forward axis direction. -Further, "the retardation value R f (40) of the present invention" means a retardation value measured from the normal direction of the optical film 'from the direction of the inclined phase retardation axis direction at 40 degrees. In addition, the phase delay axis is usually in the plane of the die, and it is consistent with the direction of maximum refractive index ', and the phase forward axis is aligned with the direction orthogonal to the phase delay axis. • The optical film system of the first invention must have the above-mentioned retardation R (0) below 10 nm ', preferably below 5 nm, particularly preferably below 3 nm, and more preferably below 1 nm. If the above-mentioned R (〇) of the optical film exceeds 丨 0 nm, the contrast when the LCD is viewed from the front will be reduced. -Furthermore, in the optical films of the first and second inventions, it is preferable that the retardation Rs (40) and the retardation Rf (4〇) are equal to or less than the aforementioned R (〇) + 6 nm, especially R (〇) + 5 nm. Preferably, R (0) + 2nm is more preferred. If any one or both of the above Rs (40) and the optical film exceeds R (0) + 6nm, the contrast when the LCD is viewed obliquely will be reduced. The optical film of the first and second inventions can be used as a protective film for protecting polarized photons and vice versa. In general, polarized photons are prone to cracking if they are pulled by a tearing force. In addition, under high humidity, it is easier to produce discoloration or deformation. Therefore, for the purpose of protecting polarized photons, _ laminated protection Diaphragm. However, if the protective film is made of the TAC film as described above, problems such as poor polarization characteristics such as light leakage will occur. but

P.20 578016 5. Description of the invention (11) In the first and second inventions, when the delays Rs (40) and Rf (40) are within the above specific range, the above-mentioned light leakage can be effectively suppressed. Defective polarization characteristics. Therefore, if the polarizing plate produced by using this optical film is arranged in a orthogonal polarization state, there will be less leakage when viewed from the front and oblique directions, and superior polarization characteristics will be exhibited. In addition, because the thickness of this optical film is less than 100 ° // m and the optical axis is shifted below 10 °, a polarizing plate made using the optical film or an LCD using the polarizing plate can be used. To achieve the effect of thinning or miniaturization, the LCD does not cause display unevenness. In other words, the light film of the present invention has the above-mentioned superior characteristics and is quite suitable for the production of polarizing plates. The manufacturing method of the optical film of the first invention is not particularly limited, and for example, various methods including the following first to third methods can be adopted. In the first method, as shown in Fig. 1, the temperature of the film extruded from the die before the contact with the cooling roller is set to Tg + 50 ° C or more. Therefore, in this state, even if the diaphragm is deformed, the stress deformation of the resin will be reduced, and the residual phase difference in the diaphragm can be set below 10 nm. In addition, in the second method, if the glass transition temperature of the amorphous thermoplastic resin is set to Tg, when a sheet-like film is extruded from a die mounted on an extruder, it is brought into close contact with a cooling roll At this time, the temperature of the diaphragm just before the cooling roller and the diaphragm are in contact is set to Tg + 80 ° C or more. As shown in Figure 2, a thin film is extruded from a die mounted on the extruder, and the temperature of the film is set to Tg +8 0 ° just before contact with the cooling roller and the film. C or more. Therefore, in this state, even if the diaphragm changes

313926.ptd Page 21 578016 i. Description of the invention (12) The resin stress will be significantly reduced. Therefore, the residual phase difference in the film can be formed below 1 Onm, and of course, it can also be formed below 3 nm. This is because the higher the temperature of the amorphous thermoplastic resin-based resin, the less stress is generated during deformation. Therefore, when deforming the resin during molding, by applying appropriate temperature control, the stress deformation of the resin can be reduced, and it is difficult to produce a residual phase difference. However, even if the temperature of the film just before the cooling roller and the film are brought into contact is controlled to be Tg + 50 ° C or more, or Tg + 80 ° C or more, if the temperature error occurs in the width direction of the film, the resin is deformed. There is an error in the stress of 1 #, because the residual resin of 1 # may cause an error of the residual phase difference, and the optical axis may be shifted with the stress concentration on a specific part. Therefore, it is best to set the temperature error in the width direction of the die just before the cooling roller and the film are in contact with each other within 10 ° C. _ The specific method of setting the temperature of the die just before the cooling roller and the membrane are in contact, such as the method of controlling the temperature of the die, can be set to Tg + 50 ° C or more. In this case, if the mold temperature is too high, thermal degradation will occur with the resin, but by using temperature conditions that are not thermally degraded, an optical film that can meet the above-mentioned residual phase difference can be reliably obtained. In addition, since the temperature of the diaphragm immediately before the above contact is set to _ + 50 ° C or higher or Tg + 80 ° C or higher, a method of narrowing the air gap can be adopted. In this case, it is only necessary to set the air gap size in consideration of the accuracy of the mold line and diaphragm thickness. Although there is no particular limitation on the air gap distance, it is best to set it to 30 to 150 mm in consideration of the mold quality and heat preservation efficiency. In addition, the film width direction before the cooling roller and the film formally contact each other

313926.ptd Page 22 578016 V. Description of the invention (13) There is no particular limitation on the specific method for setting the temperature error within 1 o ° c. For example, the temperature accuracy of the mold can be improved, or the width can be adjusted in the air gap. Directional output variable heater, the method of keeping the resin temperature in the width direction uniform, or the method of using a thermal insulation box to prevent the disturbance. The third method of the method for manufacturing an optical film according to the first invention is that a film made of a thin sheet of amorphous thermoplastic resin extruded from a die mounted on an extruder is tightly adhered. The thickness after the cooling roller is set to A, and if the die gap is set to B, the value of B / A is when the thickness of the film is above 70 // m and below 100 // m In the case of the thickness, it is 10 or less, when the thickness is 50 // m or more and less than 70 // m, it is 15 or less, and in the case of thickness less than 50 // m, it is 20. In the following, if the glass transition temperature of the amorphous thermoplastic resin is set to Tg, when the film is in close contact with the cooling roller, the temperature of the film immediately before the cooling roller and the film are in contact is set to Tg + 30 ° C or more. As shown in Fig. 4, in this manufacturing method, a molten resin composed of an amorphous thermoplastic resin is extruded from a mold 11 having a die gap of B and supplied to a cooling roll 13. The temperature of the film just before the film 12 is in close contact with the surface of the cooling roller 13 is set to Tg +3 0 ° C or higher if the amorphous thermoplastic resin glass transition temperature is Tg. In addition, when the thickness of the diaphragm immediately after the above-mentioned cooling roller is set to A, the B / A value is set as described above. In setting the above B / A to the above specific range, a method of adjusting the die gap G of the mold 11 according to the target optical film thickness can be adopted. Originally, when extruding amorphous thermoplastic resins with high melt viscosity,

313926.ptd Page 23

: = The resin pressure gap B suspended from the die opening of the die A 1 i is reduced. Α 情; my brother called Xiong Lianya: the method of raising the sound and reducing the viscosity of the melt, hey, to reduce Ke Zhi 'the degree can be reduced. In the method of reducing ... the amount of extrusion, if B / A (that is, the elongation ratio) is greater than the above-specified value, if medium: grease temperature 'and stretching the resin, then: the residual phase difference of the film will change: For quite big. As mentioned above, if the B / A ratio is set below the specific value as described above, and when the film is in close contact with the cooling roller, the temperature of the contact die is set by the cooling roller and the film. Above T g + 3 0 C, 'in the air gap, the stress generated in the resin will be reduced, thereby providing an optical film with a smaller residual phase difference. '' Next, a method for manufacturing an optical phosphine sheet according to the second invention, which can obtain a residual phase difference of 1 nm or less, will be described. The method for manufacturing the optical film of the second invention with a residual phase difference of 1 nm or less is not limited to the following method. In other words, in the method of manufacturing an optical film of the second invention, a film made of a thin sheet of an amorphous thermoplastic resin is extruded from a die mounted on an extruder, and is brought into close contact with a cooling roll ' The Hk degree of the tree immediately after the extrusion die is set to Tg + 1 3 (TC or more, and the diaphragm immediately after the extrusion die is about to contact the temperature of the diaphragm before cooling Xingkun to keep it not low At T g + 100 ° C, at the same time, the temperature error in the width direction of the diaphragm immediately after extruding from the die and immediately before contacting the cooling light is set within 10 ° C. &Quot; The resin temperature after the mold is set to TG + 1 3 0 c

578016 5. In the description of the invention (15), at the same time, the temperature of the diaphragm just before contacting the cooling roller is maintained above Tg + 10 o ° c. In this state, even if it is made of amorphous thermoplastic resin The formed diaphragm is deformed, and the stress stored in the resin can also be reduced. At the same time, the temperature error in the width direction of the diaphragm is set to within 10 ° c, which can avoid the phenomenon of localized stress concentration. As a result, there is almost no residual stress in the film, and the residual phase difference with the residual stress can be minimized. In the manufacturing method of the optical film of the second invention, the resin temperature immediately after the extrusion die is set to Tg + For specific methods above 130 ° C, methods such as controlling mold temperature can be considered. In this case, if the mold temperature is too high, the chance of thermal degradation with the resin will increase. However, by using the temperature conditions without thermal degradation, an optical film with less optical distortion can be obtained. In addition, by narrowing the air gap, it is possible to effectively suppress the heat radiation phenomenon at the resin outlet. In addition, the method of setting the temperature of the diaphragm just before contacting the cooling roller to Tg + 10 o ° c or higher can be, for example, predicting a decrease in temperature by using heat radiation in the air gap, and setting a method of increasing the mold temperature in advance. , Or a method of narrowing the air gap as described above, or a method of suppressing a decrease in the resin temperature by keeping the air gap warm and actively heating it. In order to achieve such a method, it is only necessary to surround the air gap with a box body or install a heater beside the air gap diaphragm, and it is not limited to these methods. Although the distance of the air gap at this time is not particularly limited, it is best to set it to 30 to 150 mm on the premise of considering the quality of the mold and the thermal insulation efficiency. Furthermore, in the method for manufacturing an optical film of the second invention, the film is

313926.ptd Page 25 578016 i. Description of the invention (16) There is no particular limitation on the method of maintaining the temperature error in the width direction within 10 ° C. For example, the accuracy of the temperature of the mold can be increased, or in the air gap, A variable heater that can output in the width direction, a method of keeping the temperature of the resin in the width direction uniform, or a method of enclosing with a thermal insulation box, etc., and a method of preventing disturbance. In the second invention, in order to obtain an optical film having a residual phase difference of 1 nm or less, it is possible to disregard the problems caused when the conventional use of a mold such as a residual phase difference of more than 1 nm is used for optical applications. Optical axis shift phenomenon. This means that the optical axis can be integrated and the more complicated air-conditioning operations in the conventional manufacturing process can be particularly simplified. In addition, because there are no defects caused by the offset of the optical axis in the conventional technology, the product yield can be greatly improved, and even inspection steps are not necessary. It can provide epoch-making optical films. _ It is preferable that the manufacturing method of the optical film according to the first and second inventions (the present invention) is to extrude a sheet made of an amorphous thermoplastic resin from a die installed on an extruder. When the diaphragm is in close contact with the cooling head, the diaphragm is held in an air gap from the die exit to immediately before contacting the cooling roller. In other words, the temperature control of the die just before it comes into contact with the cooling roller can be performed by holding the diaphragm in an air gap. In this case, as shown in Fig. 3, compared with the case of Fig. 1, the temperature change of the diaphragm can be eased, and compared with the method of changing the mold temperature, high-precision temperature control can be performed, reducing Temperature error in the width direction of the diaphragm, especially with high precision to perform temperature control of norbornene-based resin, for the required resin

313926.ptd Page 26 578016 V. Description of the invention (17) is particularly effective. In addition, because the mold temperature does not need to be raised excessively, it also has the advantage of controlling resin degradation. The heat preservation in the air gap is preferably set to a temperature of Tg + 30 ° C or more of the resin, particularly Tg + 50 ° C or more, particularly Tg + 80 ° C or more, and more preferably Tg + 1 0 (above TC is the best. In particular, by setting the above temperature to Tg +8 0 ° C or higher, the residual phase difference of the optical film can be suppressed to less than 3nm, and by setting it to Tg + 1 00 Above 1 ° C, it can be suppressed to less than 1 nm. The above-mentioned air-gap insulation method does not need to change the mold or air-gap conditions. It is only necessary to install an appropriate heating source such as a heater or a heat-insulation box or The thermal insulation device is sufficient. The length of the air gap for thermal insulation usually only needs to be appropriately set within the range of 30 to 150 mm. The manufacturing method of the optical film according to the first and second inventions is preferably cooled with the above. In the contact between the rollers, the diaphragm is pressed against the cooling roller, or the cooling roller is used to attract the film, so that the diaphragm can be closely contacted with the cooling roller. In this way, in the contact between the cooling roller and the diaphragm, it is mandatory By making the film tightly contact the cooling roller, the contact surface of the cooling roller to the entire surface of the film can be stabilized. As a result, the error of the optical axis can be further reduced. In the manufacturing method of the optical film according to the first and second inventions, the molten resin extruded from the mold is pulled out and forcedly adhered to the cooling roller, There is no particular limitation on the method of stabilizing the contacts during film formation. For example, a universal device such as an air cavity, a vacuum nozzle, an electrostatic pin rolling, and a contact roll can be used, which can impart a uniform force in the width direction. In the manufacturing method of the optical film of the second invention,

313926.ptd Page 27 578016 V. Description of the invention (18) Although the temperature of the cooling roller varies with the resin used, in general, it is best to set the resin's T g to T g-1 0 o ° c range. Next, the third invention will be described in detail. '' The optical film of the third invention is an optical film using an amorphous thermoplastic resin and melt-extruded to a thickness of less than 1 0 0 // m, wherein the retardation value in the normal direction R (0) The thickness is 3 nm or less, and the optical axis shift in the longitudinal direction is ± 10 ° or less. The thickness accuracy is as described in (a) or (b) above. In the third invention, the thickness accuracy of the full width of the diaphragm refers to the difference between the maximum thickness and the minimum thickness in the width direction. In addition, although the #th optical film has the thickness accuracy shown in (a) or (b) above, in this case, it may be added at the two ends in the width direction of the optical film, and the thickness does not meet the above thickness. The area of precision. In other words, at the time of melt extrusion, the film extruded from the die does not conform to (a) or (b) in the area of 10% from the width direction end to the width direction, but if It suffices that the portion between the ends conforms to the thickness accuracy shown in (a) or (b) above. By removing the two end portions that do not meet this thickness accuracy, it can be used as an optical film. In addition, the thickness accuracy of the average length in the width direction of 2 cm refers to the difference between the maximum thickness minus the minimum thickness when an arbitrary 2 cm portion is cut from the width dimension. ® In the so-called thickness curve in the width direction, the difference between the vertex and the concave bottom is the difference in the thickness curve in the width direction as shown in FIG. 8. In addition, the adjacent top and concave bottoms are in addition to a slight amplitude of less than 1 # m, and deviate by more than 20 m in the width direction. An optical film according to the third invention, via an amorphous thermoplastic resin

313926.ptd Page 28 578016 V. Description of the invention (19) can be obtained by melt extrusion. This specific method is not particularly limited, and can be obtained, for example, according to the following manufacturing method. The amorphous thermoplastic resin is supplied to a melt extruder, and the optical film of the third invention is obtained by extruding from a mold mounted in the melt extruder. In this case, in terms of integrated thickness accuracy, it is best to make the clearance at the die exit uniform. If the gap error of the original die exit with respect to the film thickness accuracy is 1/10 or less, an optical film having the thickness accuracy of the third invention can be obtained. Furthermore, although the air gap length varies with the viscosity or final thickness of the resin, it usually only needs to be between 30 and 100 nm. In addition, if the die gap is set to B and the final thickness of the diaphragm is set to A, B / A is not particularly limited, but only needs to be 20 or less. There is no particular limitation on the method for reducing the residual phase difference. For example, when the glass transition temperature of the amorphous thermoplastic resin is set to Tg, when a film made of the amorphous thermoplastic resin is extruded from a mold, the In the case of close contact with the cooling roller, it is only necessary to set the temperature of the film just before the cooling roller and the film are contacted to Tg + 80 ° C or more. In addition, the temperature error of the film just before the cooling roller and the film are in contact is preferably within 10 ° C in the width direction, so that the thickness accuracy of the film can be improved. When manufacturing the optical film according to the third invention, when the molten resin extruded from the mold is pulled out, and the film is brought into close contact with a cooling roller, the contact stabilization method only needs to meet the thickness accuracy described above. OK, nothing special

313926.ptd Page 29 578016 V. Description of the invention (20) Other restrictions, such as ordinary devices such as electrostatic pin rolling, which can impart force to the ends. In the optical film according to the third invention, since the retardation value β (0) in the normal direction is less than 3 nm, and the residual phase difference is small, the optical axis shift to the longitudinal direction is less than ± 10 °, and the thickness is less than 1 0 0 // m, and the thickness accuracy conforms to the above (a) or (b), so the residual phase difference is small, the optical axis shift is small, and the thickness accuracy is also superior. Therefore, for example, when used as a protective film for protecting polarizers, a polarizing plate having excellent optical characteristics can be provided. In addition, since the optical distortion is small, it can also be suitably used as a single-axis, double-axis, or oblique extension and deflection film formed by the uniaxial or biaxial films. The amorphous thermoplastic resin used in the optical film of the present invention (1st to 3rd inventions) refers to a polymer that has almost no crystalline structure and maintains an amorphous state. Although its Tg varies with the resin, it does not have Special restrictions, but generally above 100 ° C. Examples of the amorphous thermoplastic resin include polymaple, polymethyl methacrylate, polystyrene, polycarbonate, polyethylene gas, and norbornene-based resin. Among them, saturated norbornene-based resins are preferred for the reasons described above. These amorphous thermoplastic resins can be used alone or in combination. Examples of the saturated norbornene-based resin include ring-opening polymer hydrogenates of norbornene-based monomers, addition polymers of norbornene-based monomers and olefins, and addition of norbornene-based monomers. Polymers, and such derivatives. These saturated norbornene-based resins can be used alone or in combination.

313926.ptd Page 30 578016 V. Description of the invention (21) Use above. Specific examples of the above norbornene-based monomers include, for example, bicyclic bodies such as norbornene and norbornadiene; tricyclic bodies such as dicyclopentadiene and dihydroxypentadiene; and tetracyclododecane Tetracycles such as ene; Pentacyclic bodies such as cyclopentadiene; Heptacyclic bodies such as tetracyclopentadiene; Alkyl substitutes such as methyl, ethyl, propyl, butyl, etc., etc. Alkenyl substitutes, alkylidene substitutes such as ethylene, aryl substitutes such as phenyl, tolyl, naphthyl; even such ester, ether, cyano, i atom, alkoxycarboxyl, pyridyl , Hydroxyl group, carboxylic acid group, amino group, acid anhydride group, silyl group, epoxy group, propenyl group, methacryl group and other groups containing elements other than carbon and hydrogen; all substituents having polar groups and the like. Among them, from the standpoint of ease of acquisition and excellent heat resistance to obtain a highly reactive shaped product, it is preferable to use a norbornene-based monomer such as a tricyclic body, a tetracyclic body, or a pentacyclic body. These norbornene-based monomers may be used alone or in combination of two or more. The ring-opening polymer hydrogenation system of the norbornene-based monomer is widely used. After the above-mentioned norbornene-based monomer is subjected to ring-opening polymerization according to a known method, the remaining double bonds are hydrogenated. This may be a single polymer of a norbornene-based monomer or a copolymer, or a copolymer of a norbornene-based monomer and another cyclic olefin-based monomer. The addition polymer of the norbornene-based monomer and an olefin may be, for example, an addition polymer between a norbornene-based monomer and an α-olefin. The α-olefin is an α-olefin having a carbon number of 2 to 20 (preferably 2 to 10), and examples thereof include ethylene, acrylic, 1-butane, 3 -fluorenyl-1-butane, 1 -Pentene, 3-methyl-1-pentene, 4-fluorenyl-1-pentene, buxene, bucinene, butonene,

313926.ptd Page 31 578016 X. Description of the invention (22) JL-decene,: 1-tetradecene,: 1-hexadecene, etc. Among them, ethylene is preferred in terms of high copolymerizability. Even when other α-olefins are copolymerized as norbornene monomers, high copolymerizability can be achieved if ethylene is present. These norbornene-based resins are well known and commercially available. Specific examples of well-known norbornene-based resins are described in Japanese Patent Laid-Open No. 1-2 0 5 1 7 and specific examples of commercially available norbornene 1 resins, such as Zheyi (Company name, transliteration) series product name "Aton" (trade name, transliteration) series, Japan Ruiwang company (common name, transliteration) product name "Ruiwangneng" (product name, transliteration) ) Series, "Apel" (trade name, transliteration) series made by Mitsui Chemicals, etc. -The amorphous thermoplastic resin used in the present invention can meet the needs of the present invention and prevent the deterioration of the amorphous thermoplastic resin in the molding process or the improvement of the optical film formed on the premise that it does not hinder the achievement of the present invention. Heat resistance, UV resistance, smoothness, etc. Antioxidants such as benzene S-based, dish-based, etc .; anti-heat deterioration agents such as internal fat-based; Absorbent; lubricants such as esters of aliphatic alcohols, partial esters or polyols of polyhydric alcohols; antistatic agents such as ammonia; and various additives, such as one or two or more. The optical film of the present invention, which is formed by melt-extruding the above-mentioned amorphous thermoplastic resin, must have a thickness of less than 100 // m. If the optical thickness is more than 100 // in, when the polarizing plate produced by using this optical film is used for LCD, it will be difficult to achieve LCD thinness or miniaturization.

313926.ptd Page 32 578016 V. Description of the invention (23) The optical film of the present invention can be used in various optical applications, for example, in a polarizing plate of a liquid crystal display device, it can be suitably used as a film for protecting polarizers. In this case, a polarizing plate can be constructed by laminating the optical film of the present invention on at least one side of a polarizer. When the optical film of the present invention is laminated only on one side of the polarizer, when the LCD is assembled, the optical film of the present invention is preferably disposed on the liquid crystal cell side. This can reduce the phenomenon of light leakage when viewed from the front and oblique direction, not only from the front, but also from oblique direction, and a high contrast LCD can also be obtained. Furthermore, on the other side of the polarizer (the backside polarizer on the liquid crystal cell side), a resin film having higher transparency other than the optical film of the present invention may be laminated. Examples of the resin include olefin resin, Acrylic resin, polyester resin, polycarbonate resin, polyamide resin, polymaple resin, polyimide resin, cellulose resin, etc. These resin films can be formed by any method such as melt extrusion molding and solution casting molding, and can also be uniaxially or biaxially stretched. The above-mentioned polarized photosystems can be used as long as they belong to a film (including a thin film) having a polarized photonic function, and there are no other special restrictions. For example: after the iodine is adsorbed on the polyvinyl alcohol resin (PVA) film, the PVA · iodine-based polarized photon that is uniaxially extended in the boric acid bath is diffused and adsorbed on the PVA film, and the direct dye with higher dichromaticity is absorbed and Axially-extended PVA · Dye-based polarizers; uniaxially-extended PVA dehydrated products or uniaxially-extended polyacetal resins, such as dehydrochlorination, and other polyfluorenes are biased toward polarized photons. The above PVA is not only obtained by alkalizing a polyvinyl acetate resin polymerized with polyvinyl acetate, but also can be used in

313926.ptd Page 33 578016 V. Description of the invention (24) The amount of unsaturated wei acid (also includes: salts, esters, donkey amines, nitriles, etc.), dilute hydrocarbons, vinyl ethers, unsaturated sulfonates, etc. Polymerization components are copolymerized and tested. The method of laminating the optical film and the polarizer of the present invention is not particularly limited. "Generally used methods include, for example, a wet lamination (wet 1 am i na ti on) method." The above wet lamination method Taking into consideration the thickness after drying, the smoothness of the coating, and the like, for example, the adhesive can be formulated with water to an appropriate concentration (for example, 0.01 to 50% by weight) to prepare a coating solution, and then Use well-known coating β (for example: gravure coater, micro gravure coater, etc.), after coating or dripping on the film, use a pair of rollers to glue the excess coating liquid while rolling dry, and then A method of drying by hot air or the like. _ The above-mentioned adhesive is not particularly limited as long as it shows a transparent adhesive or adhesive after drying. For example, urethane-based adhesives, Or PVA-based adhesives, etc., have higher adhesion performance and durability, so they are better. Furthermore, when the above-mentioned optical film is laminated, in order to further improve the adhesion of the film, it is best to Diaphragm application General surface treatments, such as halo discharge treatment or line irradiation treatment. The polarizing plate of the present invention is characterized in that the above-mentioned optical film of the present invention is laminated on at least one side of a polarizer, so it can exhibit excellent polarization characteristics, and can obtain LCDs with uneven display and thin or miniaturized effect are quite suitable for LCD production.

313926.ptd page 34, description of the invention (25) embodiment] # # 2 Z, the present invention will be made clearer by explaining the relevant light segment # 本 of the present invention. % Pre-film real agricultural compound = Xi Bu, in the following, I extends the light residual measurement, 1 ^ dynamic 啜 refractometer, the trade name "Residual value of the wavelength of 5 90nm. And ^ direction of the sepal width, spleen eight In terms of planting, 4-〇 will be the two ends respectively toward the width too-measured at a distance of 5 Omm, the new ancient Si direction value. 丄, lm distance measured 4 3 points, and shows the angular sound, optical axis offset It is the value with the largest absolute value within the phase angle $ of the deflection angle of the diaphragm. The company (eight resins used ... will be saturated norbornene name, made \ transliteration) produced by the trade name "made by Swiss company. ) 'Tg = 1 68c), Jufeng resin (the name of the emperor, = f company name, transliteration), the product name "Youde & translator" Tg = 193 ° C) for the pre-dryer to come out ... Inner diameter 5 〇 Li, l / d = 28, single ★ _ soft & f 疋 is from 2 70 to 3 2 (TC 〇® T-die ... use a hanger type with a width of 500 mm. On. ④ cooling rollers ... Air cavity person, Wen Wu's specific embodiment of the tablet

It uses the prince measuring machine KOBRA-21ADH ", and the delay is cut by 10% of the obtained ^ size! ^ f + direction of flow & V moxibustion and other measured values + Aj for diaphragm flow = 糸 resin (Japan% Wang Neng 1 6 0 0 ″ Amo ^ f is plastic °° 3 5 0 0 ”(quotient 0 g t3Q helical shaft extruder, with the degree of masking set at 1 4 〇c 4 The above-mentioned device is used to make and thickness 4 mm in the following examples and comparative examples.

Page 35 578016 V. Description of the invention (26) (Example 1) Extrusion was performed by using a saturated norbornene-based resin, setting the mold temperature to 3 1 0 ° C, and the air gap to 80 mm. A radiation thermometer was used to measure the temperature of the diaphragm just before the contact of the i-cooling roller. The result was 220 ° C, the average residual phase difference was 9.50 nm, and the optical axis was shifted by 7 °. (Example 2) A saturated norbornene-based resin was extruded using a die temperature of 3 10 ° C and an air gap of 70 mm. The temperature of the diaphragm immediately before the contact with the cooling roller is 250 ° C, the residual phase difference is an average of 2.75 mm, and the optical axis is shifted by 7 °. Example 3) Extrusion was performed using a saturated norbornene-based resin, setting the mold temperature to 290 ° C, and setting the air gap to 80 mm. In the air gap, a heater was provided at a position containing 0 mm from the diaphragm. The temperature of the diaphragm was maintained before the contact with the cooling roller was 23 2 ° C, the average residual phase difference was 9. 0 nm, and the optical axis was shifted by 7 °. (Example 4) A saturated norbornene-based resin was used, and the die temperature was set to 290 ° C, and the air gap was set to 70 mm, and extrusion was performed. The air gap was set at a distance of 30 mm from the diaphragm. The heater and the membrane were kept warm. As a result, the temperature of the membrane before contacting the cooling roller jP was 258 ° C, the average residual phase difference was 2.50 nm, and the optical axis was shifted by 7 °. (-Example 5) Extrusion was performed using a saturated norbornene-based resin, setting the mold temperature to 3 1 0 ° C, and setting the air gap to 80 mm.

313926.ptd Page 36 578016 V. Description of the invention (27) A heater was installed at a position of 30mm, and the membrane was insulated. As a result, the temperature of the membrane just before the contact with the cooling roller was 2 50 ° C, and the residual The phase difference is 8.9 nm on average, and the optical axis is shifted by 7 °. (Example 6) Extrusion was performed using a saturated norbornene-based resin, setting the mold temperature to 320 ° C and the air gap to 70 mm, and setting the air gap at a distance of 30 mm from the diaphragm. The heater and the film were kept warm. As a result, the temperature of the film immediately before the contact with the cooling roller was 278 ° C, the average residual phase difference was 2.90 nm, and the optical axis was shifted by 7 °. (Example 7) The die gap was set to 50 0 // m, and the thickness of the diaphragm after being closely contacted with the cooling roller was set to 50 / zm (elongation ratio B / A = l 0). The rest was the same as in Example 1. To get the diaphragm. The residual phase difference of the obtained diaphragm is 5.20 nm on average, and the optical axis is shifted by 4 °. In addition, the temperature of the diaphragm before the contact with the cooling roller was 212t :. (Embodiment 8) The die gap was set to 50 0 " m, and the thickness of the diaphragm after being closely contacted with the cooling roller was set to 30 // m (elongation ratio B / A = 17), and the rest was the same as in Embodiment 1. Obtain a diaphragm. The residual phase difference of the obtained diaphragm is 8.8 nm on average, and the optical axis is shifted by 3 °. In addition, at this time, the temperature of the diaphragm immediately before the contact with the cooling roller was 230 ° C. (Example 9) Using the resin used in Example 5, the die gap was set to 5 0 0 // m, and the thickness of the diaphragm after close contact with the cooling roller was set to 5 0 // m (elongation ratio

313926.ptd page 37 5. Description of the invention (28) B / A = 1. ), The rest is the same as in the embodiment. The residual phase difference is an average of 6.0 mm, and the smoothing is shifted by 5: slices. In this case, the temperature of the diaphragm immediately before the contact with the cooling light is 宂. (Comparative Example 1) The mold temperature was set to 'result'. The resin used in Example 1 was used to average the positive residual phase difference from the cooling roll, 290C, and the air gap was set to 80 mm. The front diaphragm temperature is 207 ° C, 1 2 · 1 Onm, and the optical axis is shifted by 7. . (Comparative Example 2) The gap of the die was set to use the resin used in Example 1, i0 0 0 2 Γ,!, And the thickness of the diaphragm after being densely packed in the cooling rod was set to 2 extension = 2 mesh Γ difference The rest of A is the same as in Example 1 to obtain a membrane. The residual phase difference of the obtained film is 1160nnl on average, light

At the eve of the contact with the cooling concept, this example should be 10 to 1 ... ^^ 3 to 6 with a shirt of 195C. 1. Amorphous thermoplastic resin used ① Norbornene tree moon dagger Meng oral sex "mountain name transliteration" business deduction ^ Wang Neng 1 6 0 0 "(commodity name #), Tg 168c, Japan's Ruiwang Company (company name, transliteration rang ② norbornene series tree υ ru ... 1A-shaped G62, ° C, manufactured by Jie Yiersi (Gong Yi Li Chi ^ company name, tone #). ③ thin smoke-N-hospital Jimin, maleic anhydride imide resin ... Name g · 1 4 0 C 'Dongsu company (company name, transliteration) produced by "ΤΙ-160α system

Tg: 173

313926.ptd Page 38 578016 V. Description of the invention (29) ④ TAC cast film ... Product name "Fuji Texkeria", thickness: 8 0 " m, manufactured by Fuji Photo Film Co., Ltd. 2 · Melt extrusion molding device used ① Extruder ... p 50mm, single-shaft extruder with L / D = 28, the die temperature (extrusion temperature) is adjusted to 2 8 5 to 3 2 0 ° C. ② τ mold ... Use a hanger type with a width of 500 mm. ③ Air gap ... Adjust to 70 to 85mm. ④ Cooling roller ... Those who use a temperature of l4 (rc and have an air cavity installed. (Example 10)) The amorphous thermoplastic resin is a norbornene-based resin "Ruiwang. 1 6 0 0" and the above melt extrusion is used. Out of the molding device, at the mold temperature: 30CT type, mold die gap: 8000 # m, air gap: § 〇mm, the temperature of the diaphragm before entering the contact point with the cooling roller · Tg of the resin + 55 ° C, f sheet thickness immediately after the cooling roll: 50 // m, the above norbornene-based resin is melt-extruded from a τ die to produce a thickness of 50 // m and a width of 43omm (Example 11) Except for the amorphous thermoplastic resin, a norbornene-based resin "Aton = 6 2" was used, and the mold temperature was 3200c, and the mold gap of the τ-type mold was 80%. 〇 // m, Air gap: 70mm, Diaphragm temperature before contact with the cooling roller: Tg + 60 ° C of the resin, the rest are the same as in the case of Example 丨. Optical film with a width of 430mm. (Example 1 2) Excluding mold temperature: 3 1 5 ° C, T-die die gap: 8 0 0 # m, gas

313926.ptd Page 39 578016 V. Description of the invention (30) '一 ^-Gap: 80mm, a heater is placed in the air gap from the diaphragm 3〇_ and the diaphragm is put into the thermal insulation' and the cooling roller The temperature of the film before the contact: Except for Tg + 110 ° C of the resin, the rest are the same as in Example 丨. An optical film with a thickness of 50m and a width of 43Omm was produced. (Example 1 3) ^ Except for the gap of the die of the 7-type mold: 50 0 // m, the temperature of the diaphragm before the contact with the cooling roller: the resin's Tg + 78t :, the rest are the same as the example 丨 丨In the case of an optical film having a thickness of 50 // in and a width of 430 ·. (Example 14) The clearance of the T-die die opening was eliminated: 500 // ^, the temperature of the diaphragm before the contact with the cooling roller: Tg of the resin + 60 ° C, immediately after the cooling roller was in close contact with the cooling roller. Film thickness: Except for 40 // m, the rest are the same as those in the embodiment, and an optical film with a thickness of 40 # m and a width of 430mm is produced. C Example 15 5) The non-crystalline thermoplastic resin is a norbornene-based resin "ene-N-alkyl-maleic anhydride imide resin" (τ 丨 — 丨 6 0α :), which is connected to the cooling transfer. Diaphragm temperature before the point: Tg of the resin +88. (Except for the rest, as in Example 10, an optical film with a thickness of 50 // m and a width of 43.0 mm was made., G Comparative Example 3) '' A TAC cast film "Fujitecria ". (Comparative Example 4)-A norbornene-based resin "Alton G 6 2" was dissolved in toluene, and a norbornene-based resin solution having a resin content of 35 wt% was prepared. Next, this norbornene-based resin solution was cast onto a smooth surface of polyparaben

313926.ptd Page 40 578016 V. Description of the invention (31) and carried out at 80 ° C This peeled and dried at 100 ° C, 130 ° C to obtain a thick ethylene glycol resin (PET) film After being dried on the sheet (thickness: 125 // m) for 5 minutes, the sheet was peeled from the pet sheet. Next, the norbornene-based resin film is washed in the casting film line and 16 (TC three stages, respectively, and washed for 5 minutes at 5 0 // m. (Comparative Example 5) except the mold temperature: 28 5 ° C, Air gap: 85mm, Diaphragm temperature before contact with the cooling roller: Tg of resin +42. (Except for the rest, it is the same as in Example 11, the thickness is 50 # m and the width is 43 0mm optical film. (Comparative Example 6) Except for T die die gap: 1 0 0 0 / / m, the cymbals before contact with the cooling roller ΐ Tg + 35 ° c of the second resin In the same manner as in the case of Example π, an optical film having a thickness of 50 // m and a width of 430 mm, Examples 10 to 5 and Comparative Examples 3 to 3 were produced. The retardation of the sheet and the shift of the optical axis were as follows: Enter the example shown in the following example: (6), (2), and (2) the order. The results are shown in Table 1. [Measurement method of delay and optical axis offset] The "-0" "KOBRA-21ADH" manufactured by Oji Measurement Co., Ltd. is used. Light with a wavelength of 590 nm, =, radiometer, ::

Delay R (0), forward from the normal direction of the diaphragm = H oblique direction of the diaphragm, Rs (40), inclined 40 ° from the normal direction of the diaphragm = tilt to 40 ° The delay R f (4 〇),: the phase delay = the measurement of the delay described above, for the width of the diaphragm, will be -I axis. In addition, after cutting 10% of the size, all ends were measured in the width direction at 50mm intervals, and I | 11PMAw

313926.ptd Page 41 578016 V. Description of the invention (32) ^^ _ The length (flow direction) of the diaphragm is separated by 1 m. The distance = love to find the relevant R (0), R s (4 0), R f ( 4 〇) test densities: enter the amount of bamboo, and the system is calculated as in Example 1. The average value. The optical axis is shifted next. 'Using these films, the following is done. Method of polarizing plate [Manufacture of polarized photons] m After washing un-stretched PVA (basicity: 99 mol%) with room temperature water, perform ^ (thickness: 75 // ^ extension) in this state In the case, immersed in a 5 times aqueous solution of Kazuki • 5% by weight potassium potassium, and then again: 0.5% by weight iodine and potassium iodide in 5% rc aqueous solution, / t boric acid 10% by weight and a polarized photon is obtained. Cross-linking treatment of a heart knife clock, [production of a polarizing plate] ♦ β First, the polarized photon obtained by the above-mentioned electro-discharge treatment is laminated. The surface of the diaphragm is treated by corona discharge The operating antenna is 42 to 44 degrees. In addition, a water-based adhesive (trade name "EL-43 6A / B", Toyo _ 1 / Tylanimate-based tone) Production of A agent / B agent = 10/3 (weight ratio of the meaning, the company (company name, the amount of the amount of the * formula 'diluted with the second substance using water') according to the solid form is divided into 5, using a coated bar # 8 The above adhesive is a solution of 4 adhesives. 箪 Discharge the treated surface and attach it to the polarizers. Secondly, apply the same operation to each film. The other operation is performed on the other surface. (Polarized photon): Then 'protect this laminate in a 45t constant temperature bath: laminate and dry each film to make a polarizing plate.', Hours, and apply 578016 V. Description of the invention (33) [No Evaluation of light] The absorption axis of one of the two polarizing plates in the orthogonal polarization state shown in Fig. 7 is tilted 40 degrees from the normal direction within 45 degrees of the rotating soil within the plane of the polarization axis. A perspective view of the incident direction. As shown in FIG. 7, the absorption axis of one of the two polarizing plates arranged in a orthogonal polarization state is tilted from the normal direction within a rotation direction of ± 45 degrees within the plane of the polarization axis. Visual observation was made in two directions of the incident angle of 40 degrees to evaluate the amount of light leakage.

313926.ptd Page 43 578016 V. Description of Invention (34) Table 1

CN a u > U) 20 Aton G62 Aton G62 Aton G62 TAC casting TM60a Aton G62 Aton G62 Aton G62 Aton G62 Rui Wang Neng 1600 ^ > ωσ 洚 渰 寐 4 m U) 1,) 〇to 00 Ln 1 1 OJ U) U) WU) Ui LO U) Mold temperature (° c) oo U \ 1 1 (X air gap (mm) Tg + 35 Tg + 42 1 1 Tg + 88 | Tg + 60 + Tg + 110 Tg + 60 Tg + 55 QS SST Yima hemp price 5; 1 1 a \ ίο 3 ON ON w > Thickness of the film for the heat preservation note of the casting heater 丨 degree (Mm) to o two b bo u & gt ON 1— »b; L〇Os R (0) (nm) ΪΟ 〇v〇b K b On b VO 00 io SO as oo I〇oo Rs (40) (nm)! · Ί_ v〇u > o u > k) bo o OO K) ON Rf (40) (nm) 00 Ό Ul · 00 oo W job, 菡 Vt very little | Vt Vt V o o Polarizer Vt Vt Vt Vt Vt +45 degrees Vt Vt Vt Vt -45 degree

313926.pid Page 44 578016 V. Description of the invention (35) It is known from Table 1 that the polarizing plate manufactured by using the optical films of Examples 5 to 5 of the present invention is not only from the front, but also from the Observed obliquely, there is less leakage under orthogonal polarization, and it shows superior polarization characteristics. In contrast, in Comparative Example 3, the polarized light produced by using the TAC cast film has less light leakage when viewed from the front, but has more light leakage when viewed from an oblique direction, and has poor polarization characteristics. In addition, in the optical film of Comparative Example 4 which was film-formed and removed, R (0) exceeded 100 nm, and the optical axis shifted more than ± 10. Each of the optical film of Comparative Example 5 and the polarizing plate of Comparative Example 6 with R (0) exceeding 1〇_ exhibited more light leakage when viewed from the front and oblique directions, and the polarization characteristics Worse. 16 and 17 and Comparative Examples 7 and 1 The manufacturing equipment was adopted as shown below. • Extruder: A uniaxial extruder with an inner diameter of 50mm and L / D = 28. The extrusion temperature can be adjusted within the range of 270 to 320 ° C. • Mold: hanger-type τ mold with a width of 500 mm. Poor 430, • Cooling roller: The temperature is set at and the side pin rolling is installed. Using the above-mentioned device, the following examples and comparative examples were used to manufacture a wide-sounding film with a thickness of 40 # m, and the residual phase of the obtained film was measured in the same manner as in Example 1. (Example 16) _The crystalline thermoplastic resin is a norbornene-based resin (manufactured by Japan Moss (company name, transliteration), trade name "Ruiwang 1 6 0", Tg = U8 ° C), After pre-drying, the mold temperature: 30 (rc, air gap

㈣ 26, PUi Page 45

578016 • V. Description of the invention (36) 70 mm, a heater with a width of 400 mm is placed 30 mm away from the diaphragm in the air gap, and the diaphragm is extruded while holding the heat, just extruded from the die exit The resin temperature after exit is 298 to 303 ° C, and the temperature of the diaphragm before contact with the cooling roller is' 270 to 274 ° C. In addition, the diaphragm temperature was measured using a radiation thermometer. In addition, the residual phase difference of the obtained film averaged 0.85 nm (maximum 0.90 nm). 〇 (Example 17) In addition to the amorphous thermoplastic resin, a norbornene-based resin (Teijin ΐφ Mok) was used. Produced by Engineering Plastics Company (company name, transliteration), trade name "Yo Deer 3 5 0 0" (trade name, transliteration), Tg = 193cc), and mold temperature ... except for 325 0 C, the rest are the same as the implementation Example 16 Extruded film. At this time, the temperature of the resin immediately after extrusion from the outlet of the puller is 3 3 1 to 3 3 4 ° C, and the temperature of the diaphragm before contacting with the cooling roller is 3 3 0 to 3 6 ° C. In addition, the average retardation of the obtained diaphragm was 0.89 nm (maximum 0.95 nm). 〇 (Comparative Example 7) ^ Except for the mold temperature set to 2 8 (TC, the rest are the same as in Example 1 6 At this time, the temperature of the resin immediately after extrusion from the die exit is 5 to 2 9 1 C 'The temperature of the film before contacting the cooling roller is 2 5 8 to 2 6 5 ° 'The average retardation of the obtained film was 2.05 nm. (Comparative Example 8) The resin used in Example 17 was used, and the phase was the same as that in Example 16

578016 V. Description of the invention (37) Extrusion under the same conditions. At this time, try to make the mold temperature error as much as possible after the resin temperature immediately after it is extruded from the die exit is 303 to 32 It: As a result, the temperature of the diaphragm before the contact with the cooling roller is 270 to 2 8 1. In addition, the residual phase difference of the obtained diaphragm was 0.9 nm on average, and there were individual sites exceeding 1 nm. Example 19 and Comparative Examples 9 and 10 An apparatus having the following extruder, T die, and cooling roll was used to produce an optical film. ~ (1) Extruder ... The diameter of the uniaxial extruder is 100mm, L / D ratio = 32, and the extrusion temperature is adjusted within the range of 270 to 320 ° C. (2) Ding die ~ hanger type with a width of 170〇111111, the die gap is 800 // m ° (3) cooling rollers ... using two-end installation of electrostatic pin rolling, the roller temperature is set at 140 ° C. (Example 18) A thermoplastic norbornene-based resin (produced by Ruiwang Co., Ltd. (trade name of the company), product name: Ruiwang 1660, Tg = 168t) was prepared at 11 ° C, Under the condition of 3 hours, a pre-dryer is implemented. This thermoplastic norbornel dilute resin was extruded under the conditions of a mold temperature of 31 ° C and an air gap of 70 mm, and was then cooled by cooling lightly to obtain an optical film. The temperature of the diaphragm before the diaphragm was brought into contact with the cooling roller was 25 ° C. An optically clean film with a width of 15 0 mm and a thickness of 4 0 // m was obtained as described above. For the 1 200 mm film except the two ends in the width direction, the residual phase difference, optical axis shift, and thickness accuracy were evaluated in the following manner. In addition, the above-mentioned optical film is carried out in the following manner.

313926.ptd Page 47 578016 5. Description of the invention (38) Adhesion test attached to polarized photons and evaluated. (a) Delay value, optical axis offset, and thickness accuracy in the normal direction ... Adopt the product name "KOBRA-21ADH" manufactured by Wang Zizi Measuring Machinery Co., Ltd., and measure according to the measurement wavelength # 59 0 n m. When measuring the retardation value in the normal direction, the optical axis offset, and the thickness accuracy, the two ends in the width direction are cut off at 10% of the width dimension as described above, and then the points are measured at a distance of 5 mm apart in the width direction. In addition, the optical axis offset system sets the average direction of the optical axis to 0 ° and displays the maximum value of the absolute value of the offset average direction. The thickness measurement is a trade name manufactured by Mahr Co. 2N ", and R 3 0mm super hard spherical measuring device, according to the measurement pressure 0. 2N to measure. (b) Adhesion test: Corona treatment is performed on the side of the polarized photon adhesion surface of the optical film, and then the water-based amino urethane adhesive (manufactured by Toyo Motor Corporation (Company name, transliteration)) is produced, product number EL -4 3 6) The main agent and hardener (mixing ratio main agent: hardener = 1 0: 3), which is prepared by diluting with water in a way that the solid content is divided into 10% by weight, using a coated rod # 8 Apply the coating and attach it to the polaron, and then confirm the bonding state visually. In the optical film obtained in Example 18, the retardation value in the normal direction was at most 2.8 nm, and the optical axis shift was 9 °. In addition, the thickness accuracy at this time is 5.3 // m, and the maximum thickness difference between the adjacent top and the concave bottom cloth is 3.8 // m. In addition, the average thickness accuracy of 2 c m is up to 2. 4 1 // m. In the above-mentioned adhesion test, it was confirmed that the optical film 'sheet was tightly adhered to the polaron over the entire area in the width direction.

313926.ptd Page 48 578016 V. Description of the Invention (39) (Example 19) The name of the product is "Yu Deer 3 5 0 0" (Shang Mo Si) Production system (company name, ° C), 1 1 (3 hours of pre-drying at TC), 93 is 320 ° C, air gap is set to 70mm. The cooling film is used to obtain an optical film. The above resin is extruded, and the temperature of the film before the contact is 2 78t. From the top of the film / film and cooling roller, enter the 15,000-thick, thick film, and go to get The width is divided into 'for an optical film with a width of 1200mm'a. It is estimated to 鳊 1. The joint Λ is evaluated as in Example 18. The average retardation value is 29nm, and the optical axis is shifted by 7 The thickness is 7.5 ", the adjacent top and concave bottom "= ·: Λ is _8". In addition, the average is 2 Å, and in the adhesion test with the polaron, there is no problem in the entire area in the width direction: (Comparative Example 9) Λ⑴ is connected to a polarized photon. 31 OtV gas ~ 2nd example J2: The resin used 'Set the mold temperature to change, but make the mold 2 in the width direction: "4〇" The thickness of the film with poor accuracy. According to the film temperature of the second two is 25 ° ° c. As a result, the normal square = Erhu optical film, as implemented The evaluation was performed on Example 18. In addition, the thickness at this time; the average value of dream production is 2. 8 nm, and the optical axis is shifted by 19. The X-cut degree is 6 · 9 // m, between the adjacent top and the concave bottom. thick

313926.pid Page 49 578016 V. Description of the invention (40) The maximum degree difference is 5.2 // m. In addition, the thickness accuracy with an average width of 2 cm is at most 4 // m. In the adhesion test with the polarizer, it was confirmed that the% optical film was not in close contact with the polarizer in the part with a large thickness difference. (Comparative Example 10) A commercially available norbornene resin extruded film (manufactured by Ruiwang Co., Ltd. (company name, transliteration), model: ZF-16-7 5 batch number: 0 0 6 9), Evaluation was performed as in Example 18. As a result, the retardation value in the normal direction was 3.2 nm, and the optical axis was shifted by 34 °. In addition, as a result of measuring the thickness, the result as shown in Fig. 9 was obtained. In other words, for an average thickness of 75 // m, the thickness accuracy is 8. 5 5 // m, and the maximum thickness difference between adjacent tops and concave bottoms in the width direction is 7.0 // m. In addition, the thickness accuracy in the width direction averaged 2 cm was a maximum of 4.33 // m. „As in Example 18, an adhesion test with the polarizer was performed, and it was confirmed that the optical film was not in close contact with the part of the polarizer in the part with a large thickness difference.

313926.ptd Page 50 578016 Brief description of the drawings [Schematic description] The first diagram in the present invention is the relationship between the distance from the die exit and the diaphragm temperature. Fig. 2 is a graph showing the relationship between the distance from the die exit and the temperature of the diaphragm in the present invention. Fig. 3 is a graph showing the relationship between the distance from the die exit and the temperature of the diaphragm when the diaphragm is held in the air gap in the present invention. Fig. 4 is a schematic cross-sectional view for explaining the optical film forming step between the die and the cooling roll in the manufacturing method of the present invention. Figure 5 shows the retardation value R (0) measured from the normal direction of the optical diaphragm, and the retardation value R measured from the normal direction of the optical diaphragm by 40 degrees inclined to the phase forward axis direction Schematic diagram of s (40). Fig. 6 is a schematic cross-sectional view of the optical film forming step between the die and the cooling roller. Fig. 7 is an absorption axis of one of the two polarizing plates in an orthogonally polarized state. A three-dimensional schematic diagram of the direction of in-plane rotation of ± 45 degrees, and an angle of 40 degrees that is inclined to the normal direction. Fig. 8 is an explanatory diagram for explaining the top portion and the concave bottom portion appearing in the width direction thickness curve in the third invention. Fig. 9 is a graph of the thickness of the optical film in the width direction obtained in Comparative Example 10 〇 1,.] L 1 mold 2, 12 film 3,.] 3 Cooling roller A film thickness

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Claims (1)

578016 Case No. 91117736_ Naiyin // Month 7th Amendment_ VI. Patent application scope 1. An optical film is an optical film made of amorphous thermoplastic resin and extruded; wherein the thickness is less than 1 0 0 // in, the residual phase difference is below 1 Onm, and the optical axis offset is below ± 10 °. 2. For example, the optical film of the scope of patent application, wherein the residual phase difference is below 3nm. 3. For example, the optical film of the scope of patent application, wherein the retardation R s is measured from the direction of the normal phase of the optical film month, the direction of the phase forward axis, and the phase delay axis from a direction inclined by 40 ° ( 4 0) and the delay R f (4 0) are below R (0) + 6 nm. 4 · The optical film according to item 1 of the patent application scope, wherein the amorphous thermoplastic resin is a saturated norbornene dilute resin. 5. An optical film, which is an optical film made of an amorphous thermoplastic resin and extruded; wherein the thickness is less than 100 / m and the residual phase difference is less than 1 nm. 6. The optical film according to item 5 of the patent application, wherein the retardation R s is measured from the direction of the normal phase of the optical film, the direction of the phase advance axis and the phase delay axis from a direction inclined by 40 ° ( 4 0) and the delay R f (4 0) are below R (0) + 6 nm. 7. The optical film according to item 5 of the application, wherein the amorphous thermoplastic resin is a saturated norbornene dilute resin. 8. A method for manufacturing an optical film, comprising: extruding an amorphous thermoplastic resin having a glass transition temperature Tg into a sheet shape from a die mounted on an extruder to obtain amorphous thermoplasticity A step of a resin-made diaphragm; and 33 3926.pi c Page 53 578016 _Case No. 91117736_Corner Two Years // Month 7 Amendment_ Sixth, the scope of patent application ^ The step of tightly adhering the film composed of the amorphous thermoplastic resin to the cooling roller; The temperature of the diaphragm before the contact between the cooling roller and the diaphragm is set above Tg + 50 ° C, so that the thickness is less than 100 // m, the residual phase-the difference is less than 1 Onm, and the optical axis is off Optical film moved below ± 10 °. 9. The manufacturing method of the optical film according to item 8 of the patent application range, wherein the temperature of the film before the cooling roller is in contact with the film is set to Tg + 80 ° C or more, so that An optical film with a residual phase difference of 3 ηι or less is obtained. A method for manufacturing an optical film includes: extruding an amorphous thermoplastic resin into a sheet shape from a die mounted on an extruder, and A step of obtaining a film composed of the amorphous thermoplastic resin; and a step of closely adhering a film composed of the amorphous thermoplastic resin to a cooling roller; wherein the thickness of the cooling roller and the film after contacting the film Let A be the A, and if the die gap of the mold is set to B, the value of B / A will be 10 or less when the thickness of the die is more than 70 // m and less than 100 // in; When it is 50 // m or more and less than 70 // m, it is 15 or less; when '_ is less than 50 # m, it is 20 or less; and if the amorphous thermoplastic resin is When the glass transition temperature is set to Tg, when the film is in close contact with the cooling roller, The temperature of the diaphragm before the contact is set to Tg + 30 ° C or more, which can obtain a thickness of less than 100 / m, a residual phase difference of 10 nm or less, and an optical axis deviation of ± 1 Optical below 0 ° 313926. Page 54 578016 _ Case No. 91117736_ for the year // month 7 Amendment _ 6. Scope of patent application Diaphragm. 1 1. A method for producing an optical film, comprising: extruding an amorphous thermoplastic resin having a glass transition temperature Tg from a mold mounted on an extruder to obtain the amorphous thermoplastic resin A step of forming a film made of a resin; and a step of closely adhering a film made of an amorphous thermoplastic resin to a cooling roll; wherein the temperature of the resin immediately after extruding the mold is set to Tg + 130 ° C or more, and comply The temperature of the film from the exit of the die until the film just contacts the cooling roller is not kept below Tg + 100 ° C. At the same time, the film just after extruding from the die exit and just before contacting the cooling roller The temperature error in the width direction of the sheet is set within 10 ° C, thereby obtaining an optical film with a thickness of less than 10 m and a residual phase difference of 1 nm or less. 1 2. The method for manufacturing an optical film according to any one of items 8 to 11 of the scope of application for a patent, wherein when the cooling roller contacts the film, the film is squeezed by the cooling roller through the film, Alternatively, the film is brought into close contact with the cooling roller by suction from the cooling roller side. 1 3. The method for manufacturing an optical film according to any one of claims 8 to 11 in the scope of patent application, wherein the film-shaped amorphous is extruded from a die mounted on an extruder When the film made of thermoplastic resin is in close contact with the cooling roller, the film is held in the air gap from the die exit to the point where the cooling roller and the film are just in contact. 1 4. An optical film, which uses an amorphous thermoplastic resin and is melt-extruded to form an optical film with a thickness of less than 100 #m; 313926.pic Page 55578016 _ Case No. 91117736 " Amended on July 7_ Sixth, the scope of patent application ^ The retardation value R (0) in the normal direction is less than 3nm, and the optical axis offset to the length direction is soil Below 10 °, the thickness accuracy is (a) or (b) below; ^ (a) when the average thickness is more than 60 // m, the thickness accuracy of the entire width is less than 10% of the average thickness, The thickness accuracy of the average length of 2cm in the width direction is less than 5% of the average thickness. In the thickness curve of the width direction, the difference between the adjacent top and the concave bottom is less than 7% of the average thickness; (b) when the average thickness When it is less than 6 0 // m, the thickness of the entire width is less than 0 // m, and the thickness accuracy of the average width of 2 cm in the width direction is less than 3 // m. In the thickness curve of the width, the adjacent top and The drop between the concave bottoms is below 4 // m. 15. The optical film according to item 14 of the scope of patent application, wherein the amorphous heat „plastic resin-based norbornene-based resin. 1 6. Such as the scope of application for patents, items 1 to 7, and item 14 Or the optical film of any one of item 15 is a protective film for protecting polarizers. 1 7. —A kind of polarizing plate, which will apply for patents No. 1 to No. 7 and No. 1 4 The optical film of any one of items 15 or 15 is laminated on at least one side of a polarizer. 3] 3926.pic Page 56