WO2014064736A1 - 長尺延伸フィルムの製造方法、長尺延伸フィルム、該長尺延伸フィルムを用いた円偏光板および有機elディスプレイ - Google Patents
長尺延伸フィルムの製造方法、長尺延伸フィルム、該長尺延伸フィルムを用いた円偏光板および有機elディスプレイ Download PDFInfo
- Publication number
- WO2014064736A1 WO2014064736A1 PCT/JP2012/006841 JP2012006841W WO2014064736A1 WO 2014064736 A1 WO2014064736 A1 WO 2014064736A1 JP 2012006841 W JP2012006841 W JP 2012006841W WO 2014064736 A1 WO2014064736 A1 WO 2014064736A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- film
- long
- stretched film
- gripping tool
- long stretched
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
- B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
- B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
- B29C55/16—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial simultaneously
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D7/00—Producing flat articles, e.g. films or sheets
- B29D7/01—Films or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2069/00—Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
Definitions
- the present invention relates to a method for producing a long stretched film, a long stretched film obtained by the production method, a circularly polarizing plate using the long stretched film, and an organic EL display.
- a stretched film formed by stretching a resin is used as an optical film that performs various optical functions in various display devices by utilizing its optical anisotropy.
- the stretched film is used as an optical compensation film for optical compensation such as anti-coloring and viewing angle expansion, or by bonding the stretched film and a polarizer, It is known to use as a retardation film that also serves as a polarizing plate protective film.
- a self-luminous display device such as an organic electroluminescence display device has attracted attention as a new display device.
- the self-luminous display device has a room for suppressing power consumption compared with a liquid crystal display device whose backlight is always lit, and further, a self-luminous display in which a light source corresponding to each color such as an organic EL display is lit.
- the contrast can be further increased.
- a reflector such as an aluminum plate is provided on the back side of the display in order to increase the light extraction efficiency. Therefore, there is a problem that the external light incident on the display is reflected by this reflector, thereby reducing the contrast of the image. Therefore, it is known to use a circularly polarizing plate on the surface side of a display by bonding the stretched film and a polarizer in order to improve contrast of light and darkness by preventing reflection of external light. Moreover, such a circularly polarizing plate may be used also in what is called a 3D liquid crystal display device which displays a three-dimensional image.
- the above circularly polarizing plate needs to be bonded in such an arrangement that the in-plane slow axis of the stretched film is inclined at a desired angle with respect to the absorption axis of the polarizer.
- the absorption axis of the polarizer and the ⁇ / 4 retardation film are used.
- the angle formed by the slow axis is about 45 °, high antireflection performance can be obtained.
- a general polarizer (polarizing film) is obtained by stretching at a high magnification in the transport direction, and its absorption axis coincides with the transport direction.
- a conventional retardation film is produced by longitudinal stretching (stretching in the conveying direction) or lateral stretching (stretching in the width direction), and usually the stretched film is delayed in a direction parallel to or perpendicular to the stretching direction. Since the phase axis appears, the in-plane slow axis is in principle 0 ° or 90 ° with respect to the longitudinal direction of the film.
- a long polarizing film and a stretched film can be rolled tow instead of the conventional batch-type bonding.
- -It becomes possible to manufacture a circularly polarizing plate by laminating with a roll.
- productivity can be improved dramatically and yield can be greatly improved.
- the bending-type oblique stretching device has a bent shape for the gripper transport rail on which the left and right grippers travel, and provides a difference in the movement trajectory length between the inner peripheral gripper and the outer peripheral gripper.
- This is a method for producing a long obliquely stretched film by stretching the resin film in an oblique direction by preceding the grasping tool that travels on the circumferential gripper transport rail.
- the straight-line speed difference type oblique stretching apparatus grips both ends of a resin film with a pair of gripping tools, and while transporting the resin film, the traveling speed of one gripping tool is gradually increased from the traveling speed of the other gripping tool.
- the film is stretched in an oblique direction by making one gripping tool ahead of the other gripping tool at a high speed, thereby producing a long obliquely stretched film.
- the straight stretching difference type oblique stretching device stretches in the oblique direction due to the difference in the traveling speed of the gripping tools at both ends, it can be a device having the same shape as the conventional longitudinal stretching and transverse stretching equipment. Conventional manufacturing facilities and sites can be used, and manufacturing is possible with a relatively small installation space. Further, since the orientation angle of the film can be adjusted by changing the traveling speed of the gripping tool without changing the shape of the gripping tool transport rail, the orientation angle setting can be easily changed.
- the present inventors manufactured a long stretched film using such a linearly traveling speed difference type oblique stretching apparatus, and studied the production of an optical film used for a circularly polarizing plate of an organic EL display.
- the self-luminous display device in which the light source corresponding to each color such as an organic EL display is turned on has few members such as a color filter which causes a reduction in contrast, and the contrast is very high, It was found that a slight variation in optical characteristics is recognized as a problem because it is observed as color unevenness.
- the long stretched film produced by the above-mentioned conventional straight-line speed difference type oblique stretching apparatus has the slow axis angle (orientation angle) continuously fluctuating in the longitudinal direction of the film.
- the present invention has been made in view of the above-mentioned conventional problems, and in an oblique stretching apparatus of a straight traveling speed difference method, it is possible to suppress the deviation of the optical axis of the obtained long stretched film, and to achieve a very high contrast such as an organic EL display.
- Method for producing a long stretched film capable of suppressing the occurrence of color unevenness even when used in a circularly polarizing plate used in a high image display device, a long stretched film obtained by the production method, and the long stretch An object is to provide a circularly polarizing plate and an organic EL display using a stretched film.
- FIG. 1A is a schematic diagram schematically illustrating a neck-in N that occurs in a long film F in conventional transverse stretching
- FIG. 1B illustrates a neck that occurs in the long film F in oblique stretching of a straight speed difference method. It is a schematic diagram which illustrates in N roughly.
- neck-in refers to contraction in the width direction of the long film that occurs in a portion of the end of the long film that is not gripped by the gripping tool.
- the conventional lateral stretching method (stretching method in the width direction) will be described as an example.
- the line L1 connecting the neck-in N portions at both ends of the film and the gripping portion by the gripping tool C are connected.
- Both lines L2 are parallel to the film width direction, and the same degree of neck-in occurs at both ends in the width direction. Therefore, an optical axis can be easily formed along the stretching direction, and a long stretched film with suppressed axial displacement can be obtained.
- FIG. 1A the conventional lateral stretching method in the width direction
- the gripping tool C ⁇ b> 1 which is the gripping tool on the side preceded by the slow axis during oblique stretching, is downstream in the transport direction of the long film F after gripping. Accelerates gradually toward the grip, and precedes the gripper C2 that grips the long film in pairs at the grip start position. At this time, as shown in FIG. 1B, the film end on the side gripped by the gripping tool C1 generates a large stress due to stretching, while the gap between gripping tools not held by the gripping tool C1 increases.
- the neck-in (neck-in N1) generated at the end of the film gripped by the gripping tool C1 is the film on the side gripped by the gripping tool C2. It becomes larger than the neck-in (neck-in N2) generated at the end.
- neck-in N2 the neck-in generated at the end.
- the location where the large neck-in occurs is not sufficiently stretched compared to the location that is sufficiently stretched by being gripped by the gripping tool, and therefore, when neck-ins of different sizes occur at both ends of the film.
- the direction of the slow axis changes between the position gripped by the gripper and the position not gripped.
- a method for producing a long stretched film according to one aspect of the present invention for solving the above-described problem is to grip both ends of a long film made of a thermoplastic resin with a plurality of grippers that move at a constant speed. By moving the gripping tool that grips one end in the transporting direction, the moving speed in the transporting direction is gradually made faster than the gripping tool that grips the other end.
- the gripping is preceded in at least a step of obliquely stretching so that the slow axis direction of the long film is an angle larger than 0 ° and smaller than 90 ° with respect to the longitudinal direction.
- the neck-in rate represented by the following formula at the end of the long film held by the tool is adjusted to be greater than 0 and 5% or less.
- Neck-in rate (d / W) x 100 (%) (Where d is the neck-in distance (mm), and W is the length (mm) in the width direction of the long film in the oblique stretching step)
- FIG. 1A is a schematic diagram schematically illustrating neck-in that occurs in a long film in conventional transverse stretching.
- FIG. 1B is a schematic diagram schematically illustrating neck-in that occurs in a long film in the straight-line speed difference method oblique stretching.
- FIG. 2 is a schematic diagram for explaining an oblique stretching apparatus used in a method for producing a long stretched film in one embodiment of the present invention.
- FIG. 3 is a schematic diagram for explaining neck-in that occurs in a stretched long film.
- FIG. 4 is a schematic diagram for explaining a method for adjusting the temperature of the film end to be lower than the stretching temperature in one embodiment of the present invention.
- FIG. 1A is a schematic diagram schematically illustrating neck-in that occurs in a long film in conventional transverse stretching.
- FIG. 1B is a schematic diagram schematically illustrating neck-in that occurs in a long film in the straight-line speed difference method oblique stretching.
- FIG. 2 is a schematic diagram for explaining an
- FIG. 5 is a schematic view for explaining a method of fixing the film end with a pin tenter in an embodiment of the present invention.
- FIG. 6 is a schematic diagram for explaining a method of bonding a protective film or the like to the film end in one embodiment of the present invention.
- FIG. 7 is a schematic diagram illustrating a method for adjusting the distance between gripping tools to be short in an embodiment of the present invention.
- FIG. 8 is a schematic diagram schematically illustrating the configuration of an organic EL display according to an embodiment of the present invention.
- FIG. 9 is a schematic diagram for schematically explaining the configuration of the stretching apparatus used in the reference example.
- the present inventor has determined that the neck-in rate at the end where the slow axis of the film represented by the following formula precedes the neck-in ratio in a predetermined range in an oblique stretching apparatus of a linear speed difference method. It has been found that the above-mentioned purpose can be achieved by adjusting inward. And this inventor advanced further examination, and came to complete this invention based on these knowledge.
- the gripping tool grips one end while gripping and transporting both ends of a long film made of a thermoplastic resin with a plurality of gripping tools moving at a constant speed.
- the direction of the slow axis of the long film is 0 with respect to the lengthwise direction.
- the following formula is used at the end of the long film gripped by the preceding gripping tool. It is the manufacturing method of a elongate stretched film which adjusts the represented neck-in rate so that it may become larger than 0 and 5% or less.
- Neck-in rate (d / W) x 100 (%) d is the neck-in distance (mm), and W is the length (mm) in the width direction of the long film in the oblique stretching step.
- d is the length from the top of the neck-in (maximum contracted portion) to the film end indicated by a broken line in FIG. 3 described later (see reference symbol d), and W is the neck.
- W is the neck. It is the width
- the present invention is characterized by the oblique stretching process as described above, the oblique stretching process will be described in detail.
- the long length refers to a film having a length of at least about 5 times the width of the film, preferably a length of 10 times or more, specifically It may be a roll (film roll) having a length enough to be wound or stored or transported.
- the oblique stretching step is a step of stretching the formed long film in a direction oblique to the longitudinal direction.
- a long stretched film can be manufactured to desired arbitrary length by manufacturing a long stretched film continuously.
- the manufacturing method of a elongate stretched film may be made to wind up to a core once after forming a elongate film, and to supply it to a diagonal stretch process after making it into a wound body, You may supply to a diagonal stretch process continuously from a film forming process, without winding up a long film. It is preferable to perform the film forming step and the oblique stretching step continuously, because the film forming conditions can be changed by feeding back the film thickness after stretching and the optical value result, and a desired long stretched film can be obtained.
- a long stretched film having a slow axis at an angle of more than 0 ° and less than 90 ° with respect to the longitudinal direction of the long film can be produced.
- the angle with respect to the long direction of a long film is an angle in a film plane, and is also called an orientation angle. Since the slow axis is usually expressed in the stretching direction or a direction perpendicular to the stretching direction, in the production method of the present embodiment, an angle of substantially greater than 0 ° and less than 90 ° with respect to the longitudinal direction of the long film.
- a linear stretching speed type oblique stretching apparatus In order to impart an oblique orientation to the long film to be stretched in the present embodiment, a linear stretching speed type oblique stretching apparatus is used.
- the oblique stretching apparatus used in the present embodiment includes gripping tool travel support tools on which a plurality of gripping tools that grip both ends of the long film travel on both ends of the traveling long film.
- This oblique stretching apparatus grips both ends of a long film sequentially supplied to the inlet of the apparatus with a gripping tool, guides the long film into a heating zone, and at an arbitrary temperature at which the long film can be stretched. By heating, a gripping tool that grips one end of the long film is preceded by a gripping tool that grips the other end of the long film, so that the film can be stretched in an oblique direction.
- the stretching speed of the film can be selected as appropriate, but is preferably 10 to 20000% / min. If the stretching speed of the film is slower than 10% / min, it takes too much time for stretching and stress necessary for orientation is relaxed, so that the desired orientation angle does not appear, and if it is faster than 20000% / min, the film When the local stretching stress applied to the neck-in portion at the end is increased, the film tends to be wrinkled or shifted, or the film is torn and causes breakage during conveyance.
- the gripping tool that travels on one gripping tool travel support tool precedes the gripping tool that travels on the other gripping tool travel support tool only in some sections. Travel speed is accelerated. Except for this accelerated section, at least the difference in travel speed between the gripper pair holding the long film is usually 1% or less, preferably 0.5% or less, more preferably 0.1% of the travel speed. And can be adjusted at substantially constant speed.
- the distribution of the orientation angle may be uneven in the longitudinal direction of the produced long film, wrinkles at the stretching process exit, This is because the difference between the speeds of the left and right gripping tools constituting the gripping tool pair is required to be substantially constant because a shift occurs.
- the method of the oblique stretching apparatus is not particularly limited as long as it is a straight speed difference method, and for example, an apparatus as described in Patent Document 2 described above can be used.
- the long film sequentially passes through a heating zone having a preheating zone, a stretching zone, and a heat fixing zone of an oblique stretching apparatus.
- the preheating zone refers to a section where the distance between the gripping tools gripping both ends is kept constant at the heating zone entrance.
- the stretching zone refers to the interval until the gap between the gripping tools that grips both ends of the long film starts and reaches a predetermined interval.
- the gripping tool gripping one end of the long film precedes the gripping tool gripping the other end of the long film in an oblique direction.
- the travel speed of the gripping tool after the gripping tool gripping both ends of the long film in the stretching zone is run at a constant speed and stretched in the width direction. May be stretched obliquely with a difference between the two, and may be further stretched in the width direction in a state where the traveling speed of the gripping tool at both ends is returned to a constant speed after the oblique stretching.
- the heat setting zone refers to the section in which the gripping tools at both ends run parallel to each other during the period when the spacing between the gripping tools after the stretching zone becomes constant again. You may pass through the area (cooling zone) by which the temperature in a zone is set to below the glass transition temperature Tg degreeC of the thermoplastic resin which comprises a elongate film, after passing through a heat setting zone. At this time, in consideration of the shrinkage of the long stretched film due to cooling, a rail pattern that narrows the gap between the opposing grippers in advance may be used.
- transverse stretching and longitudinal stretching may be performed as necessary in the steps before and after introducing the long film into the oblique stretching apparatus.
- the temperature in each zone is Tg to Tg + 30 ° C. in the preheating zone, Tg to Tg + 30 ° C. in the stretching zone, and Tg ⁇ Tg + 30 ° C. in the cooling zone, with respect to the glass transition temperature Tg of the thermoplastic resin constituting the long film. It is preferably set to 30 to Tg ° C.
- a temperature difference in the width direction may be applied in the stretching zone in order to control thickness unevenness in the width direction.
- a method of adjusting the opening degree of the nozzle for sending warm air into the temperature-controlled room so as to make a difference in the width direction, or controlling the heating by arranging the heaters in the width direction is known. Can be used.
- the draw ratio in the drawing step is preferably 1.2 to 3.0, more preferably 1.5 to 2.8. If the draw ratio is in this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the oblique stretching tenter, if the stretching temperature is differentiated in the width direction, the thickness unevenness in the width direction can be further improved.
- FIG. 2 is a schematic diagram for explaining an oblique stretching apparatus T used in the method for producing a long stretched film of the present embodiment.
- this is an example, and the present embodiment is not limited to this.
- the long film F is the entrance of the oblique stretching device T (the gripping tool is a gripping start point for gripping the long film F, and a straight line connecting the gripping start points is denoted by reference symbol A. 2), both ends thereof are gripped by the left and right gripping tools (a pair of gripping tools), and are conveyed as the gripping tool travels.
- the gripping tool is a gripping start point for gripping the long film F, and a straight line connecting the gripping start points is denoted by reference symbol A. 2
- both ends thereof are gripped by the left and right gripping tools (a pair of gripping tools), and are conveyed as the gripping tool travels.
- the gripper pair is composed of left and right grippers C1 and grippers C2 which are opposed to a direction substantially perpendicular to the transport direction of the long film at the entrance of the oblique stretching apparatus T.
- the left and right gripping tool C1 and gripping tool C2 travel along the gripping tool travel support tool R1 and gripping tool travel support tool R2 formed substantially in contrast, respectively, and the position at the end of stretching (the gripping tool releases gripping).
- the long stretched film gripped by the grip release point and indicated by the reference sign B) is released.
- the gripping tool C1 and the gripping tool C2 each grip both ends of the long film F at the grip start point A, and start conveying the long film F. .
- the gripping tool C1 travels to the position indicated by the reference symbol P1
- the gripping tool C1 is accelerated to precede the gripping tool C2.
- a mechanism for accelerating the gripping tool C1 will be described later.
- the acceleration of the gripper C1 is continued up to the position indicated by the reference symbol P2. While the gripping tool C1 is accelerating, the traveling speed of the gripping tool C2 is maintained.
- the gripping tool C1 travels on the gripping tool travel support tool R1 prior to the gripping tool C2, and moves to the downstream side in the transport direction of the long film F.
- Reference sign P3 indicates the position of the gripping tool C2 when the gripping tool C1 reaches P2.
- the gripping tool C1 that has reached P2 travels to the grip release point B while maintaining the speed.
- the gripping tool C2 that has reached P3 is accelerated in the same manner as the gripping tool C1.
- a mechanism for accelerating the gripping tool C2 will be described later.
- the acceleration of the gripping tool C2 is continued until P4.
- the speed of the gripping tool C2 reaching P4 is the same as the speed of the preceding gripping tool C1.
- the gripping tool C2 that has reached P4 travels to the grip release point B while maintaining the speed.
- the gripping tools C1 and C2 that grip the film F at the gripping start point A are positioned obliquely with respect to the longitudinal direction of the film F at the gripping release point B. As a result, the long film F is tilted in the oblique direction. It will be stretched.
- the gripping tool C1 and the gripping tool C2 move at a constant speed from the gripping start point A to P1, and only the gripping tool C1 is accelerated at P1.
- the configuration is not limited to this. That is, the position where acceleration is started and the acceleration can be appropriately set so that a desired orientation angle can be obtained.
- the gripping tool C1 may start to be accelerated at the gripping start point A, or the gripping tool C1 may be accelerated at a constant acceleration from the gripping start point A to the gripping release point B.
- the traveling speed of the gripping tool C2 may not be adjusted in this way. That is, in order to give the long film F an oblique orientation, the gripping tool C1 may reach the grip release point B in advance. Therefore, it is not necessary to accelerate the gripping tool C2, and even when accelerating, it is not always necessary to accelerate the gripping tool C2 until it becomes the same speed as the gripping tool C1.
- the method of accelerating the gripping tool C1 and the gripping tool C2 is not particularly limited, and is a method that can change the pitch of the continuous gripping tool C1 or the gripping tool C2 (the distance between the gripping tools in the transport direction of the long film F). I just need it.
- a method for changing the pitch for example, a method using a pantograph mechanism or a linear guide mechanism can be employed.
- FIG. 3 is a schematic diagram for explaining neck-in occurring in the long film F being stretched.
- the neck-in occurs between gripping tools (for example, the gripping tool C1) traveling on the gripping tool travel support tool (for example, the gripping tool travel support tool R1).
- the gripping tool C1 precedes the gripping tool C2. Therefore, the contraction force in the width direction (stress in the width direction of the long film F) generated at the film end gripped by the gripping tool C1 is larger than the contraction force generated at the film end gripped by the gripping tool C2. Become. As a result, the size of the neck-in (indicated by reference numeral N1) formed between the gripping tools C1 is larger than the size of the neck-in (indicated by reference numeral N2) formed between the gripping tools C2. .
- the gripping tool C1 is accelerated as it travels.
- the separation distance from the gripping tool C ⁇ b> 1 increases as the length of the long film F advances toward the downstream side.
- the neck-in N1 becomes larger on the downstream side in the transport direction of the long film F.
- the location where the neck-in occurs can be insufficient in the stretching in the width direction of the film as compared with the location gripped by the gripping tool. Therefore, in the obtained long stretched film, an optical axis oriented in a desired direction is not formed, and a periodic axial shift of the optical axis occurs in the longitudinal direction of the film.
- the neck-in rate (hereinafter simply referred to as the neck-in rate) of the neck-in N1 formed on the side of the gripping tool C1 preceding the gripping tool C2 represented by the following formula is 0. It is characterized by being adjusted so as to be largely 5% or less.
- Neck-in rate (d / W) x 100 (%) Note that d and W can vary depending on the size of the neck-in as a reference.
- the neck-in rate is adjusted to be greater than 0 and 5% or less, the occurrence of neck-in is remarkably suppressed. Therefore, the portion not gripped by the gripper is sufficiently stretched and the optical axis is misaligned. Is suppressed to less than 0.6 °. As a result, the obtained long stretched film is formed in a circularly polarizing plate used for an image display device having a very high contrast, such as an organic EL display, because the optical axis is formed in substantially the same direction along the longitudinal direction. Even in this case, it is possible to suppress the occurrence of color unevenness regardless of the part to be used.
- the neck-in rate is preferably adjusted to be larger than 0 and 3% or less from the viewpoint of further suppressing the axial shift of the optical axis.
- the method for adjusting the neck-in rate within the above range is not particularly limited.
- a method for preventing deformation of the long film by adjusting the temperature of the film end to be lower than the stretching temperature, between the gripping tools A method for preventing the deformation of the long film by fixing the film end with a pin, a method for preventing the deformation of the long film by bonding a protective film or the like to the film end, and the distance between the gripping tools is By adjusting the length to be shorter, a method for preventing the deformation of the long film can be employed.
- FIG. 4 is a schematic diagram for explaining a method for adjusting the temperature of the film end to be lower than the stretching temperature
- FIG. 4A is a schematic diagram for explaining the state of the neck-in before the temperature adjustment.
- FIG. 4B is a schematic diagram for explaining the neck-in state after the temperature adjustment.
- region shown with a broken line has shown the area
- the long film F shown in FIG. 4 (a) is stretched obliquely without adjusting the temperature of the film end. Therefore, a large neck-in occurs on the downstream side in the transport direction of the long film F. As a result, the obtained long stretched film causes an optical axis misalignment in the longitudinal direction.
- the long film F shown in FIG. 4B since only the film end is adjusted to a temperature lower than the stretching temperature, the elasticity of the film end is lowered and the neck-in is reduced. .
- the neck-in rate is adjusted to be larger than 0 and 5% or less, and the portion not gripped by the gripping tool is sufficiently stretched in the same manner as the portion gripped by the gripping tool.
- the obtained long stretched film is oriented in a desired direction, and the axial displacement of the optical axis in the longitudinal direction is suppressed.
- the temperature at the end of the film is not particularly limited as long as it is lower than the stretching temperature and can stretch the long film F.
- the stretching temperature is 150 to 200 ° C.
- the temperature at the end of the film can be adjusted to 140 to 195 ° C.
- the method for adjusting the temperature of the film end is not particularly limited.
- a method of blowing warm air adjusted to a temperature lower than the stretching temperature, or a cooling device that cools the gripping tool immediately before entering the stretching device It is possible to employ a method for suppressing an increase in the temperature of the grip portion inside.
- the embodiment is not limited to this. That is, in the low temperature region, it is only necessary to cool at least the film end gripped by the gripping tool C1, and it is not necessary to cool both ends of the long film F.
- FIG. 5 is a schematic diagram for explaining a method of fixing the film end with a pin tenter (pin), and FIG. 5 (a) is a schematic diagram for explaining a neck-in state when the film end is not fixed with a pin.
- FIG. 5B is a schematic diagram for explaining the neck-in state when the film end is fixed with a pin.
- the long film F shown in FIG. 5 (a) is stretched obliquely without the film end being fixed with a pin. Therefore, a large neck-in N occurs on the downstream side in the transport direction of the long film F. As a result, the obtained long stretched film causes an optical axis misalignment in the longitudinal direction.
- the long film F shown in FIG. 5 (b) is obliquely stretched with the film ends fixed with pins P, the occurrence of neck-in N is suppressed.
- the neck-in rate is adjusted to be larger than 0 and 5% or less, and the portion not gripped by the gripping tool is sufficiently stretched in the same manner as the portion gripped by the gripping tool.
- the obtained long stretched film is prevented from shifting in the longitudinal direction of the optical axis.
- the method for fixing the film end portion with the pin P is not particularly limited, and for example, a mechanism for piercing the end portion of the long film F to be conveyed with the pin P can be employed. Specifically, the method described in JP-A-6-160623 can be employed.
- the pin P may be provided on a gripping tool travel support tool on which the gripping tool travels, or may be provided as a separate member along the gripping tool travel support tool.
- the diameter, length, pitch, arrangement, and the like of the pins P are not particularly limited, and can be selected as appropriate.
- the pin P may stab and hold the long film F, and may pierce and penetrate it. The film end deformed or broken by piercing the pin P is preferably excised after oblique stretching.
- FIG. 6 is a schematic diagram illustrating a method of bonding a protective film or the like to the film end
- FIG. 6 (a) is a schematic diagram illustrating a neck-in state when the protective film is not bonded
- FIG.6 (b) is a schematic diagram explaining the state of the neck-in in the case of bonding with a protective film.
- the long film F shown in FIG. 6A is obliquely stretched in a state where a protective film is not bonded to the film end. Therefore, a large neck-in N occurs on the downstream side in the transport direction of the long film F. As a result, the obtained long stretched film causes an optical axis misalignment in the longitudinal direction.
- the long film F shown in FIG. 6B is obliquely stretched in a state where the protective film Fa is bonded to the end of the film, the occurrence of neck-in N is suppressed.
- the neck-in rate is adjusted to be larger than 0 and 5% or less, and the portion not gripped by the gripping tool is sufficiently stretched in the same manner as the portion gripped by the gripping tool.
- the obtained long stretched film is oriented in a desired direction, and the axial displacement of the optical axis in the longitudinal direction is suppressed.
- the type of the protective film Fa bonded to the film end is not particularly limited, and for example, a stretchable film such as a propylene film or a polyimide film can be employed. Especially, it is preferable to employ
- a protective film Fa to the film edge part of the elongate stretched film F
- a protective film is laminated
- the process of pasting by grasping can be adopted.
- the present embodiment in the present embodiment, the case where both ends of the film are fixed with the protective film Fa is illustrated, but the present embodiment is not limited to this. That is, it is only necessary to bond the protective film Fa to at least the film end held by the holding tool C1, and it is not necessary to bond the protective film Fa to both ends of the long film F.
- FIG. 7 is a schematic diagram illustrating a method for adjusting the distance between the gripping tools to be short
- FIG. 7A is a schematic diagram illustrating a state of the neck-in before the distance between the gripping tools is adjusted.
- FIG. 7B is a schematic diagram for explaining the state of the neck-in after adjusting the distance between the gripping tools.
- the long film F shown in FIG. 7A is stretched obliquely in a state where the distance between the holding tools is not adjusted. Therefore, a large neck-in N occurs on the downstream side in the transport direction of the long film F. As a result, the obtained long stretched film causes an optical axis misalignment in the longitudinal direction.
- the long film F shown in FIG. 7B is stretched obliquely in a state where the distance between the gripping tools is adjusted to be shorter than the distance between the gripping tools shown in FIG. Yes. Therefore, since the stress applied to the center direction of the long film F between gripping tools becomes small, generation
- the method for shortening the distance between the gripping tools is not particularly limited.
- a method of adjusting the acceleration of the preceding gripping tool C1 or a method of reducing the distance from the subsequent gripping tool by decelerating after high acceleration can be employed.
- the present embodiment in the present embodiment, the case where the distance between the gripping tools C1 is shortened by increasing the number of gripping tools C1, but the present embodiment is not limited to this. . That is, at least the distance between the gripping tools C1 may be shortened, and at the same time, the distance between the gripping tools C2 may be adjusted.
- the film forming step is a step of forming a long film made of a thermoplastic resin.
- the long film formed in this embodiment is not particularly limited as long as it is a long film made of a thermoplastic resin.
- a film made of a resin having a property transparent to a desired wavelength is preferable.
- resins include polycarbonate resins, polyether sulfone resins, polyethylene terephthalate resins, polyimide resins, polymethyl methacrylate resins, polysulfone resins, polyarylate resins, polyethylene resins, polyvinyl chloride resins.
- resins include resins, olefin polymer resins having an alicyclic structure, and cellulose ester resins.
- polycarbonate resins, olefin polymer resins having an alicyclic structure, and cellulose ester resins are preferable from the viewpoints of transparency and mechanical strength.
- ⁇ Polycarbonate resin> Various polycarbonate resins can be used without particular limitation, and aromatic polycarbonate resins are preferred from the viewpoint of chemical properties and physical properties, and bisphenol A polycarbonate resins are particularly preferred. Among these, those using a bisphenol A derivative in which a benzene ring, a cyclohexane ring, an aliphatic hydrocarbon group and the like are introduced into bisphenol A are more preferable. Furthermore, a polycarbonate resin having a structure in which the anisotropy in the unit molecule is reduced, obtained by using a derivative in which the functional group is introduced asymmetrically with respect to the central carbon of bisphenol A, is particularly preferable.
- a polycarbonate resin for example, two methyl groups in the center carbon of bisphenol A are replaced by benzene rings, and one hydrogen of each benzene ring of bisphenol A is centered by a methyl group or a phenyl group.
- a polycarbonate resin obtained by using an asymmetrically substituted carbon is particularly preferable.
- 4,4′-dihydroxydiphenylalkane or a halogen-substituted product thereof can be obtained by a phosgene method or a transesterification method.
- 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl Examples include ethane and 4,4'-dihydroxydiphenylbutane.
- JP 2006-215465 A, JP 2006-91836 A, JP 2005-121813 A, JP 2003-167121 A, JP 2009-126128 A, JP Examples thereof include polycarbonate resins described in 2012-31369, JP 2012-67300 A, International Publication No. 00/26705, and the like.
- the polycarbonate resin may be used by mixing with a transparent resin such as polystyrene resin, methyl methacrylate resin, and cellulose acetate resin. Moreover, you may laminate
- the polycarbonate resin preferably has a glass transition point (Tg) of 110 ° C. or higher and a water absorption rate (measured under conditions of 23 ° C. water and 24 hours) of 0.3% or less. Yes. Moreover, Tg is 120 degreeC or more, and a water absorption rate is 0.2% or less more preferable.
- the polycarbonate-based resin film that can be used in the present embodiment can be formed by a known method, and among them, the solution casting method and the melt casting method are preferable.
- alicyclic olefin polymer-based resin examples include cyclic olefin random multi-component copolymers described in JP-A No. 05-310845, hydrogenated polymers described in JP-A No. 05-97978, and JP-A No. 11
- the thermoplastic dicyclopentadiene ring-opening polymer and hydrogenated product thereof described in JP-A-124429 can be employed.
- the alicyclic olefin polymer resin is a polymer having an alicyclic structure such as a saturated alicyclic hydrocarbon (cycloalkane) structure or an unsaturated alicyclic hydrocarbon (cycloalkene) structure.
- the number of carbon atoms constituting the alicyclic structure is not particularly limited, but when it is usually in the range of 4 to 30, preferably 5 to 20, more preferably 5 to 15, the mechanical strength, The properties of heat resistance and formability of the long film are highly balanced and suitable.
- the proportion of the repeating unit containing the alicyclic structure in the alicyclic olefin polymer may be appropriately selected, but is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight. That's it.
- the ratio of the repeating unit having an alicyclic structure in the alicyclic polyolefin resin is within this range, the transparency and heat resistance of an optical material such as a retardation film obtained from the long stretched film of the present embodiment are improved. Therefore, it is preferable.
- olefin polymer resin having an alicyclic structure examples include norbornene resins, monocyclic olefin resins, cyclic conjugated diene resins, vinyl alicyclic hydrocarbon resins, and hydrides thereof.
- norbornene-based resins can be suitably used because of their good transparency and moldability.
- Examples of the norbornene-based resin include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, a hydride thereof, and a norbornene structure. And an addition copolymer of a monomer having a norbornene structure and an addition copolymer of another monomer or a hydride thereof.
- a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability and lightness. Can be used.
- melt extrusion method As a method for forming a long film using the above preferred norbornene-based resin, a solution casting method or a melt extrusion method is preferred.
- melt extrusion method include an inflation method using a die, but a method using a T die is preferable in terms of excellent productivity and thickness accuracy.
- the extrusion molding method using a T-die is a method for maintaining retardation and orientation by a method of keeping a molten thermoplastic resin in a stable state when closely contacting a cooling drum as described in JP-A-2004-233604.
- a long film with small variations in optical properties such as corners can be manufactured.
- a sheet-like thermoplastic resin extruded from a die is brought into close contact with a cooling drum under a pressure of 50 kPa or less; 2) melting When producing a long film by extrusion, the enclosure member covers from the die opening to the first cooling drum that is in close contact, and the distance from the enclosure member to the die opening or the first contact cooling drum is 100 mm or less.
- Method 3 Method of heating the temperature of the atmosphere within 10 mm to a specific temperature from the sheet-like thermoplastic resin extruded from the die opening when producing a long film by the melt extrusion method; A sheet-like thermoplastic resin extruded from a die so as to satisfy the above condition is taken into close contact with a cooling drum under a pressure of 50 kPa or less; A method in which a wind having a speed difference of 0.2 m / s or less from the cooling speed of the cooling drum that is first brought into close contact with the sheet-like thermoplastic resin extruded from the die opening is produced. It is done.
- This long film may be a single layer or a laminated film of two or more layers.
- the laminated film can be obtained by a known method such as a coextrusion molding method, a co-casting molding method, a film lamination method, or a coating method. Of these, the coextrusion molding method and the co-casting molding method are preferable.
- cellulose ester-based resin examples include those characterized by containing a cellulose acylate satisfying the following formulas (i) and (ii) and containing a compound represented by the following general formula (A). It is done.
- Formula (ii) 0.5 ⁇ X (In Formula (i) and Formula (ii), Z1 represents the total acyl substitution degree of cellulose acylate, and X represents the sum of the propionyl substitution degree and butyryl substitution degree of cellulose acylate)
- L 1 and L 2 each independently represent a single bond or a divalent linking group.
- L 1 and L 2 include the following structures. (R below represents a hydrogen atom or a substituent)
- L 1 and L 2 are preferably —O—, —COO—, and —OCO—.
- R 1 , R 2 and R 3 each independently represent a substituent.
- R 1 and R 2 are preferably a substituted or unsubstituted phenyl group or a substituted or unsubstituted cyclohexyl group. More preferred are a phenyl group having a substituent and a cyclohexyl group having a substituent, and further preferred are a phenyl group having a substituent at the 4-position and a cyclohexyl group having a substituent at the 4-position.
- R 3 is preferably a hydrogen atom, halogen atom, alkyl group, alkenyl group, aryl group, heterocyclic group, hydroxyl group, carboxyl group, alkoxy group, aryloxy group, acyloxy group, cyano group, amino group, More preferably, they are a hydrogen atom, a halogen atom, an alkyl group, a cyano group, and an alkoxy group.
- Wa and Wb represent a hydrogen atom or a substituent, (I) Wa and Wb may be bonded to each other to form a ring; (II) At least one of Wa and Wb may have a ring structure, or (III) At least one of Wa and Wb may be an alkenyl group or an alkynyl group.
- Wa and Wb are bonded to each other to form a ring, it is preferably a nitrogen-containing 5-membered ring or a sulfur-containing 5-membered ring, particularly preferably represented by the following general formula (1) or general formula (2). It is a compound.
- a 1 and A 2 each independently represent —O—, —S—, —NRx— (Rx represents a hydrogen atom or a substituent) or CO—.
- Rx represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.
- X represents a nonmetallic atom belonging to Groups 14-16. X is preferably ⁇ O, ⁇ S, ⁇ NRc, ⁇ C (Rd) Re.
- Rc, Rd, and Re represent substituents, and examples thereof are synonymous with specific examples of the substituents represented by Wa and Wb.
- L 1, L 2, R 1 , R 2, R 3, n is L 1, L 2, R 1 , same meanings as R 2, R 3, n in the general formula (A).
- Q 1 is —O—, —S—, —NRy— (Ry represents a hydrogen atom or a substituent), —CRaRb— (Ra and Rb represent a hydrogen atom or a substituent) or Represents CO-.
- Ry, Ra, and Rb represent substituents, and examples thereof are synonymous with the specific examples of the substituents represented by Wa and Wb.
- Y represents a substituent.
- substituent represented by Y it is synonymous with the specific example of the substituent represented by said Wa and Wb.
- Y is preferably an aryl group, a heterocyclic group, an alkenyl group, or an alkynyl group.
- the aryl group represented by Y include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a biphenyl group.
- a phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.
- Q 3 represents ⁇ N— or ⁇ CRz— (Rz represents a hydrogen atom or a substituent), and Q 4 represents a nonmetallic atom belonging to Groups 14-16.
- Z represents a nonmetallic atom group forming a ring together with Q 3 and Q 4 .
- the ring formed from Q 3 , Q 4 and Z may be further condensed with another ring.
- the ring formed from Q 3 , Q 4 and Z is preferably a nitrogen-containing 5-membered ring or 6-membered ring condensed with a benzene ring.
- L 1, L 2, R 1 , R 2, R 3, n is L 1, L 2, R 1 , same meanings as R 2, R 3, n in the general formula (A).
- Wa and Wb is an alkenyl group or an alkynyl group
- a vinyl group having a substituent and an ethynyl group are preferable.
- the compound represented by general formula (3) is particularly preferable.
- the compound represented by the general formula (3) is superior in heat resistance and light resistance to the compound represented by the general formula (1), and is an organic solvent compared to the compound represented by the general formula (2).
- the solubility with respect to and the compatibility with a polymer are favorable.
- the compound represented by the general formula (A) of the present embodiment can be contained by appropriately adjusting the amount for imparting desired wavelength dispersibility and anti-bleeding property.
- the content is preferably 1 to 15% by mass, and particularly preferably 2 to 10% by mass. If it is in this range, sufficient wavelength dispersibility and bleeding resistance can be imparted to the cellulose derivative of the present embodiment.
- general formula (A), general formula (1), general formula (2), and general formula (3) can be performed with reference to a known method. Specifically, it can be synthesized with reference to Journal of Chemical Crystallography (1997); 27 (9); 512-526) JP 2010-31223 A, JP 2008-107767 A, and the like.
- the cellulose acylate film that can be used in the present embodiment contains cellulose acylate as a main component.
- the cellulose acylate film that can be used in the present embodiment preferably contains cellulose acylate in the range of 60 to 100% by mass with respect to 100% by mass of the total mass of the film.
- cellulose acylate examples include esters of cellulose and aliphatic carboxylic acids and / or aromatic carboxylic acids having about 2 to 22 carbon atoms, and in particular, esters of cellulose and lower fatty acids having 6 or less carbon atoms. Preferably there is.
- the acyl group bonded to the hydroxyl group of cellulose may be linear or branched, and may form a ring. Furthermore, another substituent may be substituted.
- the degree of substitution is the same, birefringence decreases when the number of carbon atoms described above is large. Therefore, the number of carbon atoms is preferably selected from acyl groups having 2 to 6 carbon atoms.
- the degree of propionyl substitution and the degree of butyryl substitution are preferred. Is a sum of 0.5 or more.
- the cellulose acylate preferably has 2 to 4 carbon atoms, more preferably 2 to 3 carbon atoms.
- cellulose acylate includes propionate group, butyrate group or phthalyl group in addition to acetyl group such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate or cellulose acetate phthalate.
- Bound cellulose mixed fatty acid esters can be used.
- the butyryl group forming butyrate may be linear or branched.
- cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate is particularly preferably used as the cellulose acylate.
- the cellulose acylate according to this embodiment preferably satisfies the following mathematical formulas (iii) and (iv).
- Y represents the degree of substitution of the acetyl group
- X represents the degree of substitution of the propionyl group or butyryl group or a mixture thereof.
- the mixing ratio is preferably 1:99 to 99: 1 (mass ratio).
- cellulose acetate propionate is particularly preferably used as the cellulose acylate.
- cellulose acetate propionate 0 ⁇ Y ⁇ 2.5 and 0.5 ⁇ X ⁇ 3.0 (where 2.0 ⁇ X + Y ⁇ 3.0) are preferable, and 0 More preferably, 0.5 ⁇ Y ⁇ 2.0 and 1.0 ⁇ X ⁇ 2.0 (where 2.0 ⁇ X + Y ⁇ 3.0).
- the substitution degree of the acyl group can be measured according to ASTM-D817-96.
- cellulose as a raw material for cellulose acylate, but examples include cotton linters, wood pulp, and kenaf. Moreover, the cellulose acylate obtained from them can be mixed and used at an arbitrary ratio.
- Cellulose acylate can be produced by a known method. Specifically, for example, it can be synthesized with reference to the method described in JP-A-10-45804.
- the long stretched film obtained according to the present embodiment may be obtained by appropriately mixing polymer components other than the cellulose ester described later.
- the polymer component to be mixed is preferably one having excellent compatibility with the cellulose ester, and the transmittance when formed into a long stretched film is 80% or more, more preferably 90% or more, and further preferably 92% or more. preferable.
- Additives that can be added include plasticizers, UV absorbers, retardation modifiers, antioxidants, deterioration inhibitors, peeling aids, surfactants, dyes, and fine particles.
- additives other than the fine particles may be added during the preparation of the cellulose ester solution, or may be added during the preparation of the fine particle dispersion. It is preferable to add a plasticizer, an antioxidant, an ultraviolet absorber, or the like that imparts heat and moisture resistance to a polarizing plate used in an image display device such as an organic EL display.
- These compounds are preferably contained in an amount of 1 to 30% by mass, preferably 1 to 20% by mass, based on the cellulose ester.
- a compound having a vapor pressure at 200 ° C. of 1400 Pa or less is preferable.
- These compounds may be added together with the cellulose ester and the solvent during the preparation of the cellulose ester solution, or may be added during or after the solution preparation.
- Retardation adjuster As the compound to be added for adjusting the retardation, an aromatic compound having two or more aromatic rings as described in EP 911,656 A2 can be used.
- the aromatic ring of the aromatic compound includes an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring. Particularly preferred is an aromatic heterocycle, and the aromatic heterocycle is generally an unsaturated heterocycle. Of these, a 1,3,5-triazine ring is particularly preferred.
- the cellulose ester film in the present embodiment has a cellulose ester and a substituent selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, and a sulfo group, and has a weight average molecular weight in the range of 500 to 200,000. It is preferable to contain a polymer or oligomer of a certain vinyl compound.
- the mass ratio of the content of the cellulose ester and the polymer or oligomer is preferably in the range of 95: 5 to 50:50.
- fine particles can be contained in the long stretched film as a matting agent, whereby when the stretched film is long, conveyance and winding can be facilitated.
- the particle size of the matting agent is preferably primary particles or secondary particles of 10 nm to 0.1 ⁇ m.
- a substantially spherical matting agent having a primary particle acicular ratio of 1.1 or less is preferably used.
- silicon dioxide is particularly preferable.
- Preferred fine particles of silicon dioxide for this embodiment include, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) manufactured by Nippon Aerosil Co., Ltd. And commercially available products such as Aerosil 200V, R972, R972V, R974, R202, and R812 can be preferably used.
- Examples of polymer fine particles include silicone resin, fluorine resin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. Examples include Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.). Can do.
- heat stabilizers such as inorganic fine particles such as kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, and alumina, and alkaline earth metal salts such as calcium and magnesium may be added.
- a surfactant, a peeling accelerator, an antistatic agent, a flame retardant, a lubricant, an oil agent and the like may be added.
- the cellulose ester resin film that can be used in the present embodiment can be formed by a known method, and among them, the solution casting method and the melt casting method are preferable.
- the solution casting method is preferable from the viewpoints of suppression of film coloring, suppression of foreign matter defects, suppression of optical defects such as die lines, excellent film flatness, and transparency.
- organic solvents useful for forming the dope include chlorinated organic solvents such as methylene chloride, and non-chlorinated organic solvents such as methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, and 1,3-dioxolane.
- the dope preferably contains 1 to 40% by mass of a linear or branched aliphatic alcohol having 1 to 4 carbon atoms.
- linear or branched aliphatic alcohol having 1 to 4 carbon atoms examples include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Ethanol is preferred because of the stability of these dopes, the relatively low boiling point, and good drying properties.
- the metal support in the casting process is preferably a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support.
- the surface temperature of the metal support in the casting process is set to ⁇ 50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate.
- the melt casting method is a preferable film forming method from the viewpoint that it is easy to reduce the retardation Rt in the thickness direction after oblique stretching, the amount of residual volatile components is small, and the dimensional stability of the film is excellent.
- the melt casting method refers to heating and melting a composition containing an additive such as a resin and a plasticizer to a temperature exhibiting fluidity, and then casting the melt. Methods formed by melt casting can be classified into melt extrusion molding methods, press molding methods, inflation methods, injection molding methods, blow molding methods, stretch molding methods, and the like. Among these, the melt extrusion method is preferable, in which a long film having excellent mechanical strength and surface accuracy can be obtained.
- the long film formed by the above method is conveyed to the above stretching apparatus and stretched in an oblique direction.
- the thickness of the long film is preferably 20 to 400 ⁇ m, more preferably 30 to 200 ⁇ m.
- the thickness unevenness ⁇ m in the flow direction of the long film supplied for stretching keeps the take-up tension of the long film at the above-described oblique stretching tenter inlet constant, and stabilizes the optical characteristics such as the orientation angle and retardation. From the viewpoint of reducing the thickness, it is preferably less than 0.30 ⁇ m, preferably less than 0.25 ⁇ m, more preferably less than 0.20 ⁇ m. When the thickness unevenness ⁇ m in the flow direction of the long film is 0.30 ⁇ m or more, variations in optical properties such as retardation and orientation angle of the long stretched film are remarkably deteriorated.
- a long film having a thickness gradient in the width direction may be supplied as the long film.
- the gradient of the thickness of the long film was experienced by stretching a long film with various thickness gradients experimentally so that the film thickness at the position where the stretching of the subsequent process was completed could be the most uniform. Can be obtained.
- the gradient of the thickness of the long film can be adjusted, for example, so that the end portion on the thicker side is thicker by about 0.5 to 3% than the end portion on the thinner side.
- the width of the long film is not particularly limited, but can be 500 to 4000 mm, preferably 1000 to 2000 mm.
- the preferable elastic modulus at the stretching temperature at the time of oblique stretching of the long film is 0.01 Mpa or more and 5000 Mpa or less, more preferably 0.1 Mpa or more and 500 Mpa or less, expressed as Young's modulus. If the modulus of elasticity is too low, the shrinkage rate during stretching and after stretching will be low, and wrinkles will be difficult to disappear. If it is too high, the tension applied during stretching will increase, and the part that holds both side edges of the long film will be It is necessary to increase the strength, and the load on the tenter in the subsequent process increases.
- a non-oriented film may be used, or a long film having an orientation in advance may be supplied. Further, if necessary, the width distribution of the orientation of the long film may be bowed, so-called bowing. In short, the orientation state of the long film can be adjusted so that the orientation of the long stretched film at the position where stretching in the subsequent step is completed can be made desirable.
- the oblique stretching process has already been described above.
- the long stretched film that has undergone the oblique stretching step is stretched obliquely in a direction greater than 0 ° and less than 90 ° with respect to the width direction of the long film.
- the stretched long stretched film is wound up by a subsequent winding process.
- a winding process is a process of winding the elongate stretched film which passed through the extending process in roll shape.
- the winding device used in the winding process is provided at the outlet of the oblique stretching device.
- the take-up tension T (N / m) of the stretched long film is adjusted to 100 N / m ⁇ T ⁇ 300 N / m, preferably 150 N / m ⁇ T ⁇ 250 N / m. Is preferred.
- the take-up tension When the take-up tension is 100 N / m or less, slack and wrinkles of the long stretched film are likely to occur, and the retardation and the profile in the width direction of the orientation axis tend to deteriorate. On the other hand, when the take-up tension is 300 N / m or more, the variation in the orientation angle in the width direction is deteriorated, and the width yield (taking efficiency in the width direction) tends to be deteriorated.
- the fluctuation of the take-up tension T it is preferable to control the fluctuation of the take-up tension T with an accuracy of less than ⁇ 5%, preferably less than ⁇ 3%.
- the fluctuation of the take-up tension T is ⁇ 5% or more, the variation in the optical characteristics in the width direction and the flow direction becomes large.
- Examples of the method for measuring the load include a method in which a load cell is attached to a bearing portion of a roll and a load applied to the roll, that is, a tension of a long stretched film is measured.
- a load cell a known tensile type or compression type can be used.
- the long stretched film is released from the tenter outlet after being grasped by the gripping tool, and is sequentially wound on a winding core (winding roll) to form a wound body.
- a winding core winding roll
- both ends (both sides) of the long stretched film may be trimmed for the purpose of excising grip marks on both sides of the long stretched film held by the tenter gripping tool or obtaining a desired width. desirable.
- the above trimming may be performed at once or may be performed in a plurality of times.
- the long stretched film is fed out again as necessary, trimming both ends of the long stretched film, and winding up again as a wound body of the long stretched film. Good.
- the masking film may be overlapped and wound up at the same time, or at least one of the long stretched films, preferably tapes or the like at both ends. You may wind up while bonding.
- the masking film is not particularly limited as long as it can protect the long stretched film, and examples thereof include a polyethylene terephthalate film, a polyethylene film, and a polypropylene film.
- the long stretched film obtained by the production method of the present embodiment is formed by the orientation angle in the film plane, that is, the direction of the slow axis in the film plane and the film winding direction (long film direction).
- the angle is greater than 0 ° and less than 90 °. Specific values can be appropriately selected depending on the application, and examples thereof include values such as 15 °, 22.5 °, 45 °, 67.5 °, and 75 °.
- the value of the in-plane retardation of the long stretched film obtained by the production method of the present embodiment is preferably 120 nm or more and 160 nm or less, and more preferably 130 nm or more and 150 nm.
- the variation in the orientation angle in the width direction of the long stretched film obtained by the production method of the present embodiment is preferably less than 0.6 °, more preferably 0.4 ° or less, in a width of at least 1300 mm.
- a long stretched film with an orientation angle variation of 0.6 ° or more is bonded to a polarizer to obtain a circularly polarizing plate.
- a self-luminous image display device such as an organic EL display device
- a black image is displayed. Sometimes color unevenness occurs.
- the dispersion of the in-plane retardation of the long stretched film obtained by the production method of the present embodiment is preferably 3 nm or less, more preferably 1 nm or less, at least 1300 mm in the width direction.
- the optimum value of the in-plane retardation of the long stretched film obtained by the production method of the present embodiment is selected according to the design of the display device used.
- the in-plane retardation of the film is obtained by multiplying the difference between the refractive index nx in the in-plane slow axis direction and the refractive index ny in the direction perpendicular to the slow axis by the average thickness da of the long stretched film. Value ((nx ⁇ ny) ⁇ da).
- the film thickness of the long stretched film obtained by the production method of the present embodiment is, for example, preferably 10 to 200 ⁇ m, and more preferably The thickness is 10 to 60 ⁇ m, more preferably 10 to 35 ⁇ m.
- the thickness unevenness in the width direction is preferably 3 ⁇ m or less, and more preferably 2 ⁇ m or less, because it affects the availability of winding.
- the circularly polarizing plate of this embodiment has a polarizing plate protective film, a polarizer, a ⁇ / 4 retardation film (long stretched film obtained in the above embodiment), and an adhesive layer laminated in this order.
- the angle formed between the slow axis of the / 4 retardation film and the absorption axis of the polarizer is 45 °.
- a long polarizing plate protective film, a long polarizer, and a long ⁇ / 4 retardation film are laminated in this order.
- the circularly polarizing plate of this embodiment is manufactured by using a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and laminating with a configuration of ⁇ / 4 retardation film / polarizer. Can do.
- the film thickness of the polarizer is 5 to 40 ⁇ m, preferably 5 to 30 ⁇ m, and particularly preferably 5 to 20 ⁇ m.
- the polarizing plate can be produced by a general method.
- the ⁇ / 4 retardation film subjected to the alkali saponification treatment is preferably bonded to one surface of a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution.
- the polarizing plate can be constituted by further bonding a release film on the opposite surface of the polarizing plate protective film of the polarizing plate.
- the protective film and the release film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate, product inspection, and the like.
- the ⁇ / 4 plate using the long stretched film of the present embodiment is particularly preferably used as a circularly polarizing plate used for antireflection of a self-luminous display device such as an organic EL display.
- the long stretched film of the present embodiment is excellent in uniformity in the direction of the slow axis in the width direction (orientation angle). Therefore, when used in an organic EL display, it is particularly excellent in color uniformity. It can be a display device.
- FIG. 8 shows an example of the configuration of the organic EL display D of the present embodiment, but the present embodiment is not limited to this.
- FIG. 8 is a schematic diagram for schematically explaining the configuration of the organic EL display of the present embodiment.
- the organic EL display D has an organic EL display having a metal electrode F2, a light emitting layer F3, a transparent electrode (ITO etc.) F4, and a sealing layer F5 on a substrate F1 made of glass, polyimide, or the like.
- an organic EL display is configured by providing a circularly polarizing plate with a polarizer F8 sandwiched between a ⁇ / 4 retardation film F7 and a protective film F9 via an adhesive tank F6. It is preferable that a cured layer is laminated on the protective film F9. The cured layer not only prevents scratches on the surface of the organic EL display but also has an effect of preventing warpage due to the circularly polarizing plate. Further, an antireflection layer may be provided on the cured layer.
- the thickness of the organic EL element itself is about 1 ⁇ m.
- the light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or Structures with various combinations such as a laminate of such a light-emitting layer and an electron injection layer composed of a perylene derivative, and / or a laminate of these hole injection layer, light-emitting layer, and electron injection layer are known. ing.
- holes and electrons are injected into the light emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the fluorescent material, It emits light based on the principle that it emits light when the excited fluorescent material returns to the ground state.
- the mechanism of recombination on the way is the same as that of a general diode, and as can be expected from this, the current and the light emission intensity show strong nonlinearity with rectification with respect to the applied voltage.
- an organic EL display in order to extract light emitted from the light emitting layer, at least one of the electrodes must be transparent, and a transparent electrode usually formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. ing.
- ITO indium tin oxide
- metal electrodes such as Mg—Ag and Al—Li are used.
- the light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the light emitting layer transmits light almost completely like the transparent electrode. As a result, the light that is incident from the surface of the transparent substrate when not emitting light, passes through the transparent electrode and the light emitting layer, and is reflected by the metal electrode again exits to the surface side of the transparent substrate.
- the display surface of the EL display looks like a mirror surface.
- the circularly polarizing plate made of a long stretched film manufactured using this embodiment is suitable for an organic EL display in which such external light reflection is particularly problematic.
- a method for producing a long stretched film according to one aspect of the present invention includes gripping one end of a long film made of a thermoplastic resin while gripping and transporting both ends of the long film with a plurality of grippers moving at a constant speed.
- the direction of the slow axis of the long film is the long direction by submerging one gripping tool by gradually increasing the moving speed in the transport direction of the gripping tool faster than the gripping tool gripping the other end.
- the neck-in rate represented by the following formula is adjusted to be greater than 0 and 5% or less.
- Neck-in rate (d / W) x 100 (%) (Where d is the neck-in distance (mm), and W is the length (mm) in the width direction of the long film in the oblique stretching step)
- the neck-in rate is preferably adjusted to be greater than 0 and 3% or less.
- the neck-in rate By adjusting the neck-in rate to be greater than 0 and 3% or less, it is possible to further suppress the deviation of the optical axis of the obtained long stretched film. Therefore, even when the obtained long stretched film is used for a circularly polarizing plate used in an image display device having a very high contrast such as an organic EL display, the occurrence of color unevenness can be remarkably suppressed. Possible long stretched films can be produced.
- the photoelastic coefficient of the long film made of the thermoplastic resin is 1.0 ⁇ 10 ⁇ 11 (Pa ⁇ 1 ) or more and 1.0 ⁇ 10 ⁇ 10 (Pa ⁇ 1 ) or less. preferable.
- the deformation stress propagating from the film edge to the center due to neck-in can be reduced, so that the photoelastic modulus of the long film is 1.0 ⁇ 10 ⁇ 11 ( Even in the case of Pa ⁇ 1 ) or more and 1.0 ⁇ 10 ⁇ 10 (Pa ⁇ 1 ) or less, the effect of suppressing the deviation of the optical axis is particularly obtained.
- thermoplastic resin is preferably a polycarbonate resin.
- a long stretched film obtained by using a polycarbonate-based resin has high transparency and mechanical strength, and can improve the functions of an organic EL display and the like.
- a long stretched film according to another aspect of the present invention is characterized by being produced by the above-described method for producing a long stretched film.
- a circularly polarizing plate according to another aspect of the present invention is manufactured using the above-described long stretched film.
- this circularly polarizing plate is produced using the above-mentioned long stretched film in which the misalignment of the orientation axis is suppressed, for example, when bonded to an organic EL display or the like, the effect of improving the contrast of light and dark is excellent. ing.
- An organic EL display according to another aspect of the present invention is manufactured using the circularly polarizing plate.
- this organic EL display is produced using the above-mentioned long stretched film with a small misalignment of the orientation axis, the contrast between light and dark is particularly improved.
- long films A to C were prepared by the following method.
- the long film A is a cellulose ester resin film and was produced by the following production method.
- Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by mass Ethanol 89 parts by mass The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.
- ⁇ Fine particle additive solution Based on the following composition, the fine particle dispersion was slowly added to a dissolution tank containing methylene chloride while sufficiently stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution. 99 parts by mass of methylene chloride 5 parts by mass of fine particle dispersion 1
- a main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose acetate was added to a pressurized dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No.
- the main dope solution was prepared by filtration using 244.
- combined by the following synthesis examples was used for the sugar ester compound and the ester compound. Moreover, the following were used for the compound (B).
- Composition of main dope solution Methylene chloride 340 parts by mass Ethanol 64 parts by mass Cellulose acetate propionate (acetyl group substitution degree 1.39, propionyl group substitution degree 0.50, total substitution degree 1.89) 100 parts by mass Compound (B) 5.0 parts by mass Sugar ester compound 5.0 parts by mass Ester compound 2.5 parts by mass Particulate additive solution 1 1 part by mass
- the inside of the Kolben was depressurized to 4 ⁇ 10 2 Pa or less, and after excess pyridine was distilled off at 60 ° C., the inside of the Kolben was depressurized to 1.3 ⁇ 10 Pa or less and the temperature was raised to 120 ° C. Most of the acid and benzoic acid formed were distilled off.
- LC section Equipment Column oven (JASCO CO-965) manufactured by JASCO Corporation, detector (JASCO UV-970-240 nm), pump (JASCO PU-980), degasser (JASCO DG-980-50) Column: Inertsil ODS-3 Particle size 5 ⁇ m 4.6 ⁇ 250 mm (manufactured by GL Sciences Inc.) Column temperature: 40 ° C Flow rate: 1 ml / min Mobile phase: THF (1% acetic acid): H 2 O (50:50) Injection volume: 3 ⁇ l 2) MS unit Device: LCQ DECA (manufactured by Thermo Quest Co., Ltd.) Ionization method: Electrospray ionization (ESI) method Spray Voltage: 5 kV Capillary temperature: 180 ° C Vaporizer temperature: 450 ° C
- the ester compound had an ester of benzoic acid at the end of the polyester chain formed by condensation of 1,2-propylene glycol, phthalic anhydride and adipic acid.
- the acid value of the ester compound was 0.10, and the number average molecular weight was 450.
- the main dope solution was uniformly cast on a stainless steel belt support.
- the solvent is evaporated until the residual solvent amount in the cast (cast) long film reaches 75%, peeled off from the stainless steel belt support, and transported by many rolls. Drying was terminated, and a long film A having a width of 1000 mm was obtained.
- the film thickness of the long film A was 80 ⁇ m and the photoelastic coefficient was 2.0 ⁇ 10 ⁇ 12 Pa ⁇ 1 .
- the long film B is a polycarbonate film and was produced by the following production method.
- ⁇ Dope composition Polycarbonate resin (viscosity average molecular weight 40,000, bisphenol A type) 100 parts by mass 2- (2′hydroxy-3 ′, 5′-di-t-butylphenyl) -benzotriazole 1.0 part by mass Methylene chloride 430 parts by mass Methanol 90 parts by mass
- the above composition was put into a sealed container, kept at 80 ° C. under pressure, and completely dissolved with stirring to obtain a dope composition.
- the dope composition was then filtered, cooled and kept at 33 ° C., cast evenly on a stainless steel band, and dried at 33 ° C. for 5 minutes. Thereafter, the drying time was adjusted so that the retardation was 5 nm at 65 ° C., and after peeling from the stainless steel band, drying was completed while being conveyed by a large number of rolls, the film thickness was 80 ⁇ m, and the photoelastic coefficient was 2.5 ⁇ 10 ⁇ 11. A long film B with Pa ⁇ 1 and a width of 1000 mm was obtained.
- the long film C is a cycloolefin resin film and was produced by the following production method.
- DCP dicyclopentadiene
- MTF 9a-tetrahydrofluorene
- MTD 8-methyl-tetracyclo [4.4.0.12, 5.17,10] -dodec-3-ene
- a norbornene-based monomer mixture composed of parts and 40 parts by mass of tungsten hexachloride (0.7% toluene solution) were continuously added over 2 hours for polymerization.
- 1.06 parts by mass of butyl glycidyl ether and 0.52 parts by mass of isopropyl alcohol were added to deactivate the polymerization catalyst and stop the polymerization reaction.
- a soft polymer manufactured by Kuraray Co., Ltd .; Septon 2002
- an antioxidant manufactured by Ciba Specialty Chemicals Co., Ltd .; Irganox 1010
- cyclohexane and other volatile components which are solvents, are removed from the solution using a cylindrical concentration dryer (manufactured by Hitachi, Ltd.), and the hydrogenated polymer is extruded in a strand form from an extruder in a molten state. After cooling, it was pelletized and collected.
- the obtained pellets of the ring-opened polymer hydrogenated product were dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated to remove moisture.
- the pellets were melted by using a short-shaft extruder having a coat hanger type T die (manufactured by Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip member quality is tungsten carbide, peel strength 44N from molten resin).
- Extrusion molding produced a cycloolefin polymer film having a thickness of 80 ⁇ m.
- Extrusion is a long film with a width of 1000 mm and a photoelastic coefficient of 5.0 ⁇ 10 ⁇ 12 Pa ⁇ 1 under a molding condition of a molten resin temperature of 240 ° C. and a T-die temperature of 240 ° C. in a clean room of class 10,000 or less. C was obtained.
- the method for measuring the photoelastic coefficient of the long films A to C was carried out by the following procedure.
- the obtained long films A to C were cut into a sample size of 30 mm ⁇ 50 mm, and the film thickness was measured using a cell gap inspection device (RETS-1200, measurement diameter: diameter 5 mm, light source: 589 nm) manufactured by Otsuka Electronics Co., Ltd.
- a sample with a d (nm) was sandwiched between supports and a stress ⁇ (Pa) of 9.81 ⁇ 10 6 was applied in the longitudinal direction.
- the phase difference R1 (nm) under this stress was measured.
- the photoelastic coefficient C ⁇ (Pa ⁇ 1 ) was obtained by substituting the phase difference before applying stress as R0 (nm) into the following equation.
- C ⁇ (Pa ⁇ 1 ) (R1 ⁇ R0) / ( ⁇ ⁇ d)
- the long films A to C were stretched and wound into a roll.
- the conveyance speed of the long film F was 20 m / min.
- the gripping tool C1 precedes the gripping tool C2.
- the gripping tool C2 was accelerated from P3 to P4, and the gripping tool C1 and the gripping tool C2 were set to release the long stretched film at a constant speed.
- the end trimming process of the long stretched film discharged from the stretching apparatus was performed, and the final long stretched film was adjusted to have a film width of 1600 mm. Then, it wound up in roll shape with the take-up tension
- Example 1 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 10 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 12 m / min.
- the preheating zone was adjusted to 180 ° C
- the stretching zone was adjusted to 180 ° C
- the heat setting zone was adjusted to 177 ° C
- the cooling zone was adjusted to 90 ° C.
- the film edge was adjusted to 170 ° C.
- the long stretched film obtained had an in-plane retardation Re of 137 nm, an orientation angle ⁇ of 45 °, and a neck-in rate of 1%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- the long stretched film produced as described above was bonded to one side of the polarizer using a 5% aqueous solution of polyvinyl alcohol as an adhesive. At that time, bonding was performed so that the absorption axis of the polarizer and the slow axis of the ⁇ / 4 retardation film were oriented at 45 °.
- a Konica Minolta-tack film KC6UA manufactured by Konica Minolta Opto Co., Ltd. was similarly subjected to alkali saponification treatment to form a circularly polarizing plate.
- a reflective electrode made of chromium having a thickness of 80 nm is formed on a glass substrate by sputtering, ITO (indium tin oxide) is formed as a positive electrode on the reflective electrode to a thickness of 40 nm by sputtering, and a polyelectrolyte is formed on the anode as a hole transport layer.
- ITO indium tin oxide
- PEDOT polystyrene sulfonate
- red light emitting layer tris (8-hydroxyquinolinate) aluminum (Alq 3 ) as a host and a light emitting compound [4- (dicyanomethylene) -2-methyl-6 (p-dimethylaminostyryl) -4H-pyran] (DCM ) Were co-evaporated (mass ratio 99: 1) to form a thickness of 100 nm.
- the green light-emitting layer was formed with a thickness of 100 nm by co-evaporating Alq 3 as a host and the light-emitting compound coumarin 6 (mass ratio 99: 1).
- the blue light-emitting layer was formed as a host by co-evaporating BAlq shown below and a light-emitting compound Perylene (mass ratio 90:10) with a thickness of 100 nm.
- first cathode having a low work function so that electrons can be efficiently injected onto the light-emitting layer calcium is deposited to a thickness of 4 nm by a vacuum deposition method, and a second cathode is formed on the first cathode.
- Aluminum was formed to a thickness of 2 nm.
- the aluminum used as the second cathode has a role to prevent the calcium as the first cathode from being chemically altered when the transparent electrode formed thereon is formed by sputtering.
- an organic light emitting layer was obtained.
- a transparent conductive film with a thickness of 80 nm was formed on the cathode by sputtering.
- ITO was used as the transparent conductive film.
- 200 nm of silicon nitride was formed on the transparent conductive film by a CVD method (chemical vapor deposition method) to obtain an insulating film.
- the circularly polarizing plate 1 was fixed with an adhesive so that the surface of the ⁇ / 4 retardation film faced the surface of the insulating film, and an organic EL display was produced.
- Example 2 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 10 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 12 m / min.
- the temperature conditions of the tenter oven were adjusted to 160 ° C for the preheating zone, 160 ° C for the stretching zone, 157 ° C for the heat setting zone, and 80 ° C for the cooling zone.
- the film edge was adjusted to 155 ° C.
- Example 3 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 10 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 12 m / min.
- the temperature conditions of the tenter oven were adjusted to 140 ° C for the preheating zone, 140 ° C for the stretching zone, 137 ° C for the heat setting zone, and 80 ° C for the cooling zone.
- the film edge was adjusted to 138 ° C.
- the long stretched film obtained had an in-plane retardation Re of 140 nm, an orientation angle ⁇ of 45 °, and a neck-in rate of 5%.
- the film thickness of the long stretched film at this time was 35 ⁇ m. Further, an organic EL display was produced in the same manner as in Example 1.
- Example 4 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration is 10 m / min
- the traveling speed of the gripping tool C1 after acceleration is 10 m / min
- the traveling speed of the gripping tool C2 is 11 m / min.
- a long stretched film was obtained in the same manner as in Example 1.
- the in-plane retardation Re of the obtained long stretched film was 137 nm
- the orientation angle ⁇ was 20 °
- the neck-in rate was 1%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 5 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration is 10 m / min
- the traveling speed of the gripping tool C1 after acceleration is 10 m / min
- the traveling speed of the gripping tool C2 is 11 m / min.
- a long stretched film was obtained in the same manner as in Example 2.
- the in-plane retardation Re of the obtained long stretched film was 138 nm
- the orientation angle ⁇ was 20 °
- the neck-in rate was 3%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 6 Using the oblique stretching device T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration is 10 m / min
- the traveling speed of the gripping tool C1 after acceleration is 10 m / min
- the traveling speed of the gripping tool C2 is 11 m / min.
- a long stretched film was obtained in the same manner as in Example 3.
- the obtained long stretched film had an in-plane retardation Re of 140 nm, an orientation angle ⁇ of 20 °, and a neck-in rate of 5%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 7 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 10 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 15 m / min.
- a long stretched film was obtained in the same manner as in Example 1.
- the in-plane retardation Re of the obtained long stretched film was 137 nm
- the orientation angle ⁇ was 70 °
- the neck-in rate was 1%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 8 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 210 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 15 m / min.
- a long stretched film was obtained.
- the in-plane retardation Re of the obtained long stretched film was 138 nm
- the orientation angle ⁇ was 70 °
- the neck-in rate was 3%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 9 Using the oblique stretching apparatus T, the long film A was stretched in an oblique direction by adjusting the acceleration of the gripping tool C1 and the gripping tool C2.
- the traveling speed of the gripping tool C1 and the gripping tool C2 before acceleration was 10 m / min
- the traveling speed of the gripping tool C1 after acceleration was 10 m / min
- the traveling speed of the gripping tool C2 was 15 m / min.
- a long stretched film was obtained in the same manner as in Example 3.
- the obtained long stretched film had an in-plane retardation Re of 140 nm, an orientation angle ⁇ of 70 °, and a neck-in rate of 5%.
- the film thickness of the long stretched film at this time was 35 ⁇ m.
- an organic EL display was produced in the same manner as in Example 1.
- Example 10 to Example 18 A long stretched film and an organic EL display were produced in the same manner as in Examples 1 to 9 except that the long stretched film B was used.
- Example 19 A long stretched film and an organic EL display were produced in the same manner as in Examples 1 to 9 except that the long stretched film C was used.
- Example 1 (Comparative Example 1) Using the above-described oblique stretching apparatus T, the long film A is obliquely formed by the same method as in Example 1 except that a treatment such as blowing cold air to the film end is not performed in the stretching zone in the oblique stretching apparatus.
- the film was stretched to produce a long stretched film and an organic EL display.
- the in-plane retardation Re of the obtained long stretched film was 137 nm, the orientation angle ⁇ was 44 °, and the neck-in rate was 7%. Further, an organic EL display was produced in the same manner as in Example 1.
- the long film B is obliquely formed by the same method as in Example 10 except that a treatment such as blowing cold air to the film end is not performed in the stretching zone in the oblique stretching apparatus.
- the film was stretched to produce a long stretched film and an organic EL display.
- the in-plane retardation Re of the long stretched film obtained at this time was 138 nm, the orientation angle ⁇ was 44 °, and the neck-in rate was 7%. Further, an organic EL display was produced in the same manner as in Example 10.
- FIG. 9 is a schematic diagram for schematically explaining the configuration of the stretching apparatus used in the present reference example.
- the traveling speeds of the gripping tool Ci and the gripping tool Co that travel on the gripping tool travel support tool Ri and the gripping tool travel support tool Ro were set to 10 m / min.
- the end trimming process of the long stretched film discharged from the stretching apparatus was performed, and the final long stretched film was adjusted to have a film width of 1600 mm. Then, it wound up in roll shape with the take-up tension
- the in-plane retardation Re of the obtained long stretched film was 137 nm, the orientation angle ⁇ was 44 °, and the neck-in rate was 1%. Further, an organic EL display was produced in the same manner as in Example 1.
- the orientation angle of the produced long stretched film was measured using a phase difference measuring device (manufactured by Oji Scientific Co., Ltd., KOBRA-WXK). As an evaluation method, measurement was performed at an interval of 50 mm of the long stretched film in the film width direction of the long stretched film, and an average of all data was taken. In addition, the difference between the maximum value and the minimum value of all the measured values was evaluated as an axis shift of the optical axis.
- In-plane retardation and lateral distribution of in-plane retardation In-plane retardation of the produced long stretched film was measured using a phase difference measuring device (manufactured by Oji Scientific Co., Ltd., KOBRA-WXK). As an evaluation method, measurement was performed at an interval of 50 mm of the long stretched film in the film width direction of the long stretched film and evaluated.
- Color unevenness In the created organic EL display, color unevenness on the entire display surface when black was displayed was visually evaluated according to the following criteria.
- Tables 1 to 5 summarize the various elongated stretched films and organic EL displays and the results of various evaluations.
- the elongated stretched films produced in Examples 1 to 27 have an optical axis misalignment of less than 0.6 °, and the color tone is reduced when an organic EL display is produced. It was good.
- the optical axis misalignment is suppressed to less than 0.4 °, and the color tone is particularly good when an organic EL display is manufactured. It was.
Abstract
Description
(式中、dはネックイン距離(mm)であり、Wは斜め延伸工程における長尺フィルムの幅方向の長さ(mm)である)
dはネックイン距離(mm)であり、Wは斜め延伸工程における長尺フィルムの幅方向の長さ(mm)である。本明細書において、dは、ネックインの頂点(最大収縮した箇所)から、後述する図3の破線で示したフィルム端部までの長さであり(参照符号dを参照)、Wは、ネックインの頂点を通過する長尺フィルムFの幅(後述する図3の、破線で示したフィルム両端部を結ぶ直線の長さWを参照)である。
(斜め延伸工程)
斜め延伸工程は、製膜された長尺フィルムを長尺方向に対して斜めの方向に延伸する工程である。長尺フィルムの製造方法では、長尺延伸フィルムを連続的に製造することにより、所望の任意の長さに長尺延伸フィルムを製造し得る。なお、長尺延伸フィルムの製造方法は、長尺フィルムを製膜した後に一度巻芯に巻き取り、巻回体にしてから斜め延伸工程に供給するようにしてもよいし、製膜後の長尺フィルムを巻き取ることなく、製膜工程から連続して斜め延伸工程に供給してもよい。製膜工程と斜め延伸工程を連続して行うことは、延伸後の膜厚や光学値の結果をフィードバックして製膜条件を変更し、所望の長尺延伸フィルムを得ることができるので好ましい。
本実施形態における延伸に供される長尺フィルムに斜め方向の配向を付与するために、直進速度差方式の斜め延伸装置を用いる。本実施形態で用いられる斜め延伸装置は、走行する長尺フィルムの両端に、長尺フィルムの両端部を把持する複数の把持具が走行する把持具走行支持具を備える。この斜め延伸装置は、装置の入口部に順次供給される長尺フィルムの両端を、把持具で把持し、加熱ゾーン内に長尺フィルムを導いて、長尺フィルムを延伸し得る任意の温度に加熱しつつ、長尺フィルムの一方の端部を把持した把持具を長尺フィルムの他方の端部を把持した把持具よりも先行させることにより、斜め方向に延伸し得る。
なお、dおよびWは、基準とするネックインの大きさにより変化し得る。
次に、本実施形態が採用し得るその他の工程について説明する。なお、本実施形態は、上記した斜め延伸工程を有していればよく、その他の工程については特に限定されない。そのため、以下に説明するその他の工程は、例示であり、適宜設計変更を行うことができる。
製膜工程は、熱可塑性樹脂からなる長尺フィルムを製膜する工程である。
ポリカーボネート系樹脂としては、特に限定なく種々のものが使用でき、化学的性質および物性の点から芳香族ポリカーボネート樹脂が好ましく、特にビスフェノールA系ポリカーボネート樹脂が好ましい。その中でも、ビスフェノールAにベンゼン環、シクロヘキサン環、および脂肪族炭化水素基等を導入したビスフェノールA誘導体を用いたものがより好ましい。さらに、ビスフェノールAの中央の炭素に対して、非対称に上記官能基が導入された誘導体を用いて得られた、単位分子内の異方性を減少させた構造のポリカーボネート樹脂が特に好ましい。このようなポリカーボネート樹脂としては、たとえば、ビスフェノールAの中央の炭素の2個のメチル基をベンゼン環に置き換えたもの、ビスフェノールAのそれぞれのベンゼン環の一の水素をメチル基やフェニル基などで中央炭素に対し非対称に置換したものを用いて得られるポリカーボネート樹脂が特に好ましい。具体的には、4,4′-ジヒドロキシジフェニルアルカンまたはこれらのハロゲン置換体からホスゲン法またはエステル交換法によって得られるものであり、たとえば、4,4′-ジヒドロキシジフェニルメタン、4,4′-ジヒドロキシジフェニルエタン、4,4′-ジヒドロキシジフェニルブタン等が挙げられる。また、この他にもたとえば、特開2006-215465号公報、特開2006-91836号公報、特開2005-121813号公報、特開2003-167121号公報、特開2009-126128号公報、特開2012-31369号公報、特開2012-67300号公報、国際公開第00/26705号等に記載されているポリカーボネート系樹脂が挙げられる。
脂環式オレフィンポリマー系樹脂としては、特開平05-310845号公報に記載されている環状オレフィンランダム多元共重合体、特開平05-97978号公報に記載されている水素添加重合体、特開平11-124429号公報に記載されている熱可塑性ジシクロペンタジエン系開環重合体およびその水素添加物等を採用することができる。
セルロースエステル系樹脂としては、下記式(i)および(ii)を満たすセルロースアシレートを含有し、かつ、下記一般式(A)で表される化合物を含有することを特徴とするものが好ましく挙げられる。
式(i) 2.0≦Z1<3.0
式(ii) 0.5≦X
(式(i)および式(ii)において、Z1はセルロースアシレートの総アシル置換度を表し、Xはセルロースアシレートのプロピオニル置換度およびブチリル置換度の総和を表す)
以下、一般式(A)について詳細に説明する。
(I)WaおよびWbが互いに結合して環を形成してもよく、
(II)WaおよびWbの少なくとも一つが環構造を有してもよく、または
(III)WaおよびWbの少なくとも一つがアルケニル基またはアルキニル基であってもよい。
本実施形態で用いることができるセルロースアシレートフィルムは、セルロールアシレートを主成分として含有する。
式(iii) 2.0≦X+Y<3.0
式(iv) 0.5≦X
式中、Yはアセチル基の置換度を表し、Xはプロピオニル基もしくはブチリル基またはその混合物の置換度を表す。
本実施形態により得られた長尺延伸フィルムは後述するセルロースエステル以外の高分子成分を適宜混合したものでもよい。混合される高分子成分はセルロースエステルと相溶性に優れるものが好ましく、長尺延伸フィルムにした時の透過率が80%以上、さらに好ましくは90%以上、さらに好ましくは92%以上であることが好ましい。
リタデーションを調整するために添加する化合物は、欧州特許911,656A2号明細書に記載されているような、二つ以上の芳香族環を有する芳香族化合物を使用することができる。
本実施形態におけるセルロースエステルフィルムは、セルロースエステルと、カルボキシル基、ヒドロキシル基、アミノ基、アミド基、およびスルホ基から選ばれる置換基を有しかつ重量平均分子量が500~200,000の範囲内であるビニル系化合物のポリマーまたはオリゴマーとを含有することが好ましい。当該セルロースエステルと、当該ポリマーまたはオリゴマーとの含有量の質量比が、95:5~50:50の範囲内であることが好ましい。
本実施形態では、マット剤として微粒子を長尺延伸フィルム中に含有させることができ、これによって、延伸フィルムが長尺の場合、搬送や巻き取りをしやすくすることができる。
その他、カオリン、タルク、ケイソウ土、石英、炭酸カルシウム、硫酸バリウム、酸化チタン、アルミナ等の無機微粒子、カルシウム、マグネシウム等のアルカリ土類金属の塩等の熱安定剤を加えてもよい。さらに界面活性剤、剥離促進剤、帯電防止剤、難燃剤、滑剤、油剤等も加えてもよい。
フィルムの着色抑制、異物欠点の抑制、ダイラインなどの光学欠点の抑制、フィルムの平面性、透明度に優れるなどの観点からは溶液流延法が好ましい。
ドープを形成するのに有用な有機溶媒としては、たとえば、塩素系有機溶媒として、塩化メチレン、非塩素系有機溶媒としては、酢酸メチル、酢酸エチル、酢酸アミル、アセトン、テトラヒドロフラン、1,3-ジオキソラン、1,4-ジオキサン、シクロヘキサノン、ギ酸エチル、2,2,2-トリフルオロエタノール、2,2,3,3-ヘキサフルオロ-1-プロパノール、1,3-ジフルオロ-2-プロパノール、1,1,1,3,3,3-ヘキサフルオロ-2-メチル-2-プロパノール、1,1,1,3,3,3-ヘキサフルオロ-2-プロパノール、2,2,3,3,3-ペンタフルオロ-1-プロパノール、ニトロエタン等を挙げることが出来、塩化メチレン、酢酸メチル、酢酸エチル、アセトンを好ましく使用し得る。
溶液流延法では、樹脂および添加剤を溶剤に溶解させてドープを調製する工程、ドープをベルト状もしくはドラム状の金属支持体上に流延する工程、流延したドープをウェブとして乾燥する工程、金属支持体から剥離する工程、延伸または幅保持する工程、さらに乾燥する工程、仕上がった長尺延伸フィルムを巻き取る工程により行われる。
溶融流延法は、斜め延伸後の厚み方向のリタデーションRtを小さくすることが容易となり、残留揮発性成分量が少なくフィルムの寸法安定性にも優れる等の観点から好ましい製膜法である。溶融流延法は、樹脂および可塑剤などの添加剤を含む組成物を、流動性を示す温度まで加熱溶融し、その後、溶融物を流延することをいう。溶融流延によって形成される方法は、溶融押出成形法、プレス成形法、インフレーション法、射出成形法、ブロー成形法、延伸成形法などに分類できる。これらの中で、機械的強度および表面精度などに優れる長尺フィルムが得られる、溶融押出し法が好ましい。
斜め延伸工程は、すでに上記したとおりである。斜め延伸工程を経た長尺延伸フィルムは、長尺フィルムの幅手方向に対して0°より大きく90°未満の方向に斜め延伸されている。延伸された長尺延伸フィルムは、後続する巻き取り工程により巻き取られる。
巻き取り工程は、延伸工程を経た長尺延伸フィルムをロール状に巻き取る工程である。巻き取り工程で使用される巻き取り装置は、斜め延伸装置の出口に設けられている。巻き取り装置は、延伸装置に対して所定角度で長尺延伸フィルムを引き取れるように配置することにより、長尺延伸フィルムの引き取り位置および角度を細かく制御することが可能となり、膜厚、光学値のばらつきが小さい長尺延伸フィルムを巻き取ることが可能となる。そのため、長尺延伸フィルムのシワの発生を有効に防止することができるとともに、長尺延伸フィルムの巻き取り性が向上するため、延伸フィルムを長尺で巻き取ることが可能となる。本実施形態において、延伸後の長尺フィルムの引取り張力T(N/m)は、100N/m<T<300N/m、好ましくは150N/m<T<250N/mの間で調整することが好ましい。
本実施形態の製造方法により得られた長尺延伸フィルムは、フィルム面内における配向角、すなわち、フィルム面内における遅相軸の方向とフィルムの巻取方向(フィルムの長尺方向)とがなす角度が、0°より大きく90°未満の範囲となる。具体的な値は用途によって適宜選択することができるが、たとえば15°、22.5°、45°、67.5°、75°などの値が挙げられる。
本実施形態の円偏光板は、偏光板保護フィルム、偏光子、λ/4位相差フィルム(上記実施形態で得られた長尺延伸フィルム)、粘着層がこの順で積層されており、前記λ/4位相差フィルムの遅相軸と偏光子の吸収軸とのなす角度が45°である。
また、本実施形態の長尺延伸フィルムを用いたλ/4板は、有機ELディスプレイのような自発光型表示装置の反射防止の用途に用いられる円偏光板として特に好ましく用いられる。本実施形態の長尺延伸フィルムは、幅手方向における遅相軸の方向(配向角)の均一性に優れる為、有機ELディスプレイに用いられた場合には、特に色味の均一性に優れた表示装置とすることができる。
(式中、dはネックイン距離(mm)であり、Wは斜め延伸工程における長尺フィルムの幅方向の長さ(mm)である)
製膜工程では、以下の方法により、長尺フィルムA~Cを作製した。
長尺フィルムAは、セルロースエステル系樹脂フィルムであり、以下の製造方法により作製した。
微粒子(アエロジル R972V 日本アエロジル(株)製)11質量部
エタノール 89質量部
以上をディゾルバーで50分間攪拌混合した後、マントンゴーリンで分散を行った。
以下の組成に基づいて、メチレンクロライドを入れた溶解タンクに充分攪拌しながら、上記微粒子分散液をゆっくりと添加した。さらに二次粒子の粒径が所定の大きさとなるようにアトライターにて分散を行った。これを日本精線(株)製のファインメットNFで濾過し、微粒子添加液を調製した。
メチレンクロライド 99質量部
微粒子分散液1 5質量部
下記組成の主ドープ液を調製した。まず加圧溶解タンクにメチレンクロライドとエタノールを添加した。溶剤の入った加圧溶解タンクにセルロースアセテートを攪拌しながら投入した。これを加熱し、攪拌しながら、完全に溶解し。これを安積濾紙(株)製の安積濾紙No.244を使用して濾過し、主ドープ液を調製した。なお、糖エステル化合物およびエステル化合物は、以下の合成例により合成した化合物を用いた。また、化合物(B)は、以下のものを用いた。
メチレンクロライド 340質量部
エタノール 64質量部
セルロースアセテートプロピオネート(アセチル基置換度1.39、プロピオニル基置換度0.50、総置換度1.89) 100質量部
化合物(B) 5.0質量部
糖エステル化合物 5.0質量部
エステル化合物 2.5質量部
微粒子添加液1 1質量部
以下の工程により、糖エステル化合物を合成した。
1)LC部
装置:日本分光(株)製カラムオーブン(JASCO CO-965)、ディテクター(JASCO UV-970-240nm)、ポンプ(JASCO PU-980)、デガッサ-(JASCO DG-980-50)
カラム:Inertsil ODS-3 粒子径5μm 4.6×250mm(ジーエルサイエンス(株)製)
カラム温度:40℃
流速:1ml/min
移動相:THF(1%酢酸):H2O(50:50)
注入量:3μl
2)MS部
装置:LCQ DECA(Thermo Quest(株)製)
イオン化法:エレクトロスプレーイオン化(ESI)法
Spray Voltage:5kV
Capillary温度:180℃
Vaporizer温度:450℃
以下の工程により、エステル化合物を合成した。
長尺フィルムBは、ポリカーボネート系フィルムであり、以下の製造方法により作製した。
ポリカーボネート樹脂(粘度平均分子量4万、ビスフェノールA型)
100質量部
2-(2′ヒドロキシ-3′,5′-ジ-t-ブチルフェニル)-ベンゾ
トリアゾール 1.0質量部
メチレンクロライド 430質量部
メタノール 90質量部
長尺フィルムCは、シクロオレフィン系樹脂フィルムであり、以下の製造方法により作製した。
Cσ(Pa-1)=(R1-R0)/(σ×d)
図2に示される斜め延伸装置Tを用いて、長尺フィルムA~Cを延伸し、ロール状に巻き取った。長尺フィルムFの搬送速度は20m/分とした。P1からP2において把持具C1を加速させることにより、把持具C1を把持具C2よりも先行させた。また、P3からP4において把持具C2を加速させ、把持具C1と把持具C2とが等速で長尺延伸フィルムを解放するように設定した。延伸装置から排出された長尺延伸フィルムの端部トリミング処理を施し、最終的な長尺延伸フィルムのフィルム幅が1600mmとなるように調整した。その後、出口に設けられた巻き取り装置により、引取り張力200(N/m)でロール状に巻き取った。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は12m/分とした。テンターオーブンの温度条件としては、予熱ゾーンは180℃、延伸ゾーンは180℃、熱固定ゾーンは177℃、冷却ゾーンは90℃に調整した。延伸ゾーンでは、把持具部の走行部分に冷却風を当てることにより、フィルム端部を170℃に調整した。得られた長尺延伸フィルムの面内リタデーションReは137nmであり、配向角θは45°であり、ネックイン率は1%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は12m/分とした。テンターオーブンの温度条件としては、予熱ゾーンは160℃、延伸ゾーンは160℃、熱固定ゾーンは157℃、冷却ゾーンは80℃に調整した。延伸ゾーンでは、把持具部の走行部分に冷却風を当てることにより、フィルム端部を155℃に調整した。得られた長尺延伸フィルムの面内リタデーションReは、138nmであり、配向角θは45°であり、ネックイン率は3%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は12m/分とした。テンターオーブンの温度条件としては、予熱ゾーンは140℃、延伸ゾーンは140℃、熱固定ゾーンは137℃、冷却ゾーンは80℃に調整した。延伸ゾーンでは、把持具部の走行部分に冷却風を当てることにより、フィルム端部を138℃に調整した。得られた長尺延伸フィルムの面内リタデーションReは、140nmであり、配向角θは45°であり、ネックイン率は5%あった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は11m/分とした他は、実施例1と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、137nmであり、配向角θは20°であり、ネックイン率は1%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は11m/分とした他は、実施例2と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、138nmであり、配向角θは20°であり、ネックイン率は3%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は11m/分とした他は、実施例3と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、140nmであり、配向角θは20°であり、ネックイン率は5%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は15m/分とした他は、実施例1と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、137nmであり、配向角θは70°であり、ネックイン率は1%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は210m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は15m/分とした他は、実施例2と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、138nmであり、配向角θは70°であり、ネックイン率は3%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを使用して、把持具C1および把持具C2の加速度を調整して斜め方向に長尺フィルムAを延伸した。加速前の把持具C1および把持具C2の走行速度は、10m/分とし、加速後の把持具C1の走行速度は10m/分および把持具C2の走行速度は15m/分とした他は、実施例3と同様にして長尺延伸フィルムを得た。得られた長尺延伸フィルムの面内リタデーションReは、140nmであり、配向角θは70°であり、ネックイン率は5%であった。また、このときの長尺延伸フィルムの膜厚は35μmであった。また、実施例1と同様に、有機ELディスプレイを作製した。
長尺延伸フィルムBを使用した以外は、実施例1~9と同様の方法により長尺延伸フィルムおよび有機ELディスプレイを作製した。
長尺延伸フィルムCを使用した以外は、実施例1~9と同様の方法により長尺延伸フィルムおよび有機ELディスプレイを作製した。
上記斜め延伸装置Tを利用して、斜め延伸装置内の延伸ゾーンにおいて、フィルム端部に冷風を吹き付ける等の処理を行わなかったほかは、実施例1と同様の方法より長尺フィルムAを斜め延伸し、長尺延伸フィルムおよび有機ELディスプレイを作製した。得られた長尺延伸フィルムの面内リタデーションReは、137nmであり、配向角θは44°であり、ネックイン率は7%であった。また、実施例1と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを利用して、斜め延伸装置内の延伸ゾーンにおいて、フィルム端部に冷風を吹き付ける等の処理を行わなかったほかは、実施例10と同様の方法より長尺フィルムBを斜め延伸し、長尺延伸フィルムおよび有機ELディスプレイを作製した。このとき得られた長尺延伸フィルムの面内リタデーションReは、138nmであり、配向角θは44°であり、ネックイン率は7%であった。また、実施例10と同様に、有機ELディスプレイを作製した。
上記斜め延伸装置Tを利用して、斜め延伸装置内の延伸ゾーンにおいて、フィルム端部に冷風を吹き付ける等の処理を行わなかったほかは、実施例19と同様の方法より長尺フィルムCを斜め延伸し、長尺延伸フィルムおよび有機ELディスプレイを作製した。得られた長尺延伸フィルムの面内リタデーションReは、140nmであり、配向角θは43°であり、ネックイン率は7%であった。また、実施例19と同様に、有機ELディスプレイを作製した。
図9に示される屈曲式の斜め延伸装置を用いて、長尺フィルムAを延伸して長尺延伸フィルムを作製した。図9は、本参考例で使用する延伸装置の構成を概略的に説明する模式図である。それぞれの把持具走行支持具Riおよび把持具走行支持具Roを走行する把持具Ciおよび把持具Coの走行速度は、10m/分とした。延伸装置から排出された長尺延伸フィルムの端部トリミング処理を施し、最終的な長尺延伸フィルムのフィルム幅が1600mmとなるように調整した。その後、出口に設けられた巻き取り装置により、引取り張力200(N/m)でロール状に巻き取った。得られた長尺延伸フィルムの面内リタデーションReは、137nmであり、配向角θは44°であり、ネックイン率は1%であった。また、実施例1と同様に、有機ELディスプレイを作製した。
得られた長尺延伸フィルムについて、以下の評価を行った。
作成した長尺延伸フィルムの配向角を位相差測定装置(王子計測(株)製、KOBRA-WXK)を用いて測定した。評価方法としては、長尺延伸フィルムのフィルム幅方向に長尺延伸フィルムの50mmの間隔で測定を行い、全データの平均をとった。また、全測定値の最大値と最小値との差を光学軸の軸ズレとして評価した。
(配向角の幅手ばらつきの評価基準)
◎:光学軸の軸ズレが0.4°未満であった。
○:光学軸の軸ズレが0.4°以上0.6°未満であった。
△:光学軸の軸ズレが0.6°以上1.0°未満であった。
×:光学軸の軸ズレが1.0°以上であった。
作成した長尺延伸フィルムの面内リタデーションを位相差測定装置(王子計測(株)製、KOBRA-WXK)を用いて測定した。評価方法としては、長尺延伸フィルムのフィルム幅方向に長尺延伸フィルムの50mmの間隔で測定を行い、評価した。
上記作成した有機ELディスプレイにおいて、黒表示した際のディスプレイ全面における色ムラを、以下の基準で目視評価した。
◎:作成した有機ELディスプレイにおいて、箇所ごとの色味に違いは見られなかった。
○:作成した有機ELディスプレイにおいて、箇所ごとに色味に違いが見られるが使用に際して問題がない程度であった。
△:作成した有機ELディスプレイにおいて、箇所ごとに色味に違いが見られ、製品として使用できない程度であった。
×:作成した有機ELディスプレイにおいて、箇所ごとに色味違いが大きく、製品として使用できない程度であった。
Claims (7)
- 熱可塑性樹脂からなる長尺フィルムの両端部を、等速で移動する複数の把持具で把持して搬送しつつ、一方の端部を把持した把持具の搬送方向における移動速度を他方の端部を把持した把持具よりも徐々に早くすることで一方の把持具を先行させることにより前記長尺フィルムの遅相軸の方向が長尺方向に対して0°よりも大きく90°より小さい角度となるように斜め延伸する工程を少なくとも有する長尺延伸フィルムの製造方法において、
先行させた前記把持具が把持する前記長尺フィルムの端部における、下記式で表されるネックイン率を、0より大きく5%以下となるよう調整する、長尺延伸フィルムの製造方法。
ネックイン率=(d/W)×100(%)
(式中、dはネックイン距離(mm)であり、Wは斜め延伸工程における長尺フィルムの幅方向の長さ(mm)である) - 前記ネックイン率が0より大きく3%以下となるよう調整される、請求項1記載の長尺延伸フィルムの製造方法。
- 前記熱可塑性樹脂からなる長尺フィルムの光弾性係数が、1.0×10-11Pa-1以上1.0×10-10Pa-1以下である、請求項1または2記載の長尺延伸フィルムの製造方法
- 前記熱可塑性樹脂がポリカーボネート系樹脂である、請求項1~3のいずれか1項に記載の長尺延伸フィルムの製造方法。
- 請求項1~4のいずれか1項に記載の長尺延伸フィルムの製造方法で作製した、長尺延伸フィルム。
- 請求項5記載の長尺延伸フィルムを用いて作製した、円偏光板。
- 請求項6記載の円偏光板を用いて作製した、有機ELディスプレイ。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020157007110A KR101723318B1 (ko) | 2012-10-25 | 2012-10-25 | 긴 연신 필름의 제조 방법, 긴 연신 필름, 상기 긴 연신 필름을 사용한 원편광판 및 유기 el 디스플레이 |
JP2013516884A JP5333699B1 (ja) | 2012-10-25 | 2012-10-25 | 長尺延伸フィルムの製造方法 |
CN201280076650.3A CN104755251B (zh) | 2012-10-25 | 2012-10-25 | 长条拉伸膜的制造方法、长条拉伸膜、使用该长条拉伸膜的圆偏振片和有机el 显示器 |
PCT/JP2012/006841 WO2014064736A1 (ja) | 2012-10-25 | 2012-10-25 | 長尺延伸フィルムの製造方法、長尺延伸フィルム、該長尺延伸フィルムを用いた円偏光板および有機elディスプレイ |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2012/006841 WO2014064736A1 (ja) | 2012-10-25 | 2012-10-25 | 長尺延伸フィルムの製造方法、長尺延伸フィルム、該長尺延伸フィルムを用いた円偏光板および有機elディスプレイ |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014064736A1 true WO2014064736A1 (ja) | 2014-05-01 |
Family
ID=49679045
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/006841 WO2014064736A1 (ja) | 2012-10-25 | 2012-10-25 | 長尺延伸フィルムの製造方法、長尺延伸フィルム、該長尺延伸フィルムを用いた円偏光板および有機elディスプレイ |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP5333699B1 (ja) |
KR (1) | KR101723318B1 (ja) |
CN (1) | CN104755251B (ja) |
WO (1) | WO2014064736A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107405822A (zh) * | 2015-03-31 | 2017-11-28 | 日本瑞翁株式会社 | 拉伸膜的制造方法及拉伸膜 |
JP2019174636A (ja) * | 2018-03-28 | 2019-10-10 | コニカミノルタ株式会社 | 斜め延伸フィルム、偏光板、異形表示装置および斜め延伸フィルムの製造方法 |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5755675B2 (ja) * | 2013-03-29 | 2015-07-29 | 日東電工株式会社 | 位相差フィルムの製造方法および円偏光板の製造方法 |
JP5755674B2 (ja) | 2013-03-29 | 2015-07-29 | 日東電工株式会社 | 位相差フィルムの製造方法および円偏光板の製造方法 |
JP5755684B2 (ja) | 2013-06-10 | 2015-07-29 | 日東電工株式会社 | 位相差フィルムの製造方法および円偏光板の製造方法 |
JP6009024B2 (ja) | 2014-04-09 | 2016-10-19 | 日東電工株式会社 | 位相差フィルムの製造方法および円偏光板の製造方法ならびにフィルム延伸装置 |
JP6050881B2 (ja) * | 2014-07-16 | 2016-12-21 | 日東電工株式会社 | 積層体の製造方法 |
KR102543171B1 (ko) * | 2015-10-27 | 2023-06-14 | 미쯔비시 케미컬 주식회사 | 폴리비닐 알코올계 필름 및 이를 사용한 편광막, 편광판, 및 폴리비닐 알코올계 필름의 제조 방법 |
EP3670146B1 (en) * | 2018-12-21 | 2023-04-12 | Essilor International | Method and system for producing a gradient polarisation film |
JP7012179B1 (ja) * | 2021-03-24 | 2022-02-15 | 日東電工株式会社 | 延伸フィルムの製造方法 |
JP7039757B1 (ja) * | 2021-03-24 | 2022-03-22 | 日東電工株式会社 | 延伸フィルムの製造方法 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2000009912A (ja) * | 1998-06-25 | 2000-01-14 | Nitto Denko Corp | 延伸フィルムの製造方法及び位相差板 |
JP2006224618A (ja) * | 2005-02-21 | 2006-08-31 | Jsr Corp | フィルム加工方法 |
JP2006255892A (ja) * | 2005-02-21 | 2006-09-28 | Jsr Corp | フィルム加工方法 |
JP2008023775A (ja) * | 2006-07-19 | 2008-02-07 | Toshiba Mach Co Ltd | シート・フィルムの斜め延伸方法およびクリップ式シート・フィルム延伸装置 |
JP2012025167A (ja) * | 2011-10-07 | 2012-02-09 | Nippon Zeon Co Ltd | 長尺の延伸フィルム、長尺の積層フィルム、偏光板及び液晶表示装置 |
WO2012017639A1 (ja) * | 2010-08-02 | 2012-02-09 | 株式会社日本触媒 | 位相差フィルムの製造方法および位相差フィルムロール |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3920805B2 (ja) * | 2003-04-10 | 2007-05-30 | 五洋紙工株式会社 | 光学用フィルムの製造法 |
WO2007111313A1 (ja) * | 2006-03-24 | 2007-10-04 | Zeon Corporation | 長尺の延伸フィルムおよびその製造方法並びに用途 |
JP2008080674A (ja) | 2006-09-28 | 2008-04-10 | Nippon Zeon Co Ltd | 延伸フィルムの製造方法、位相差フィルム、円偏光板、及び液晶表示装置 |
JP2008107534A (ja) * | 2006-10-25 | 2008-05-08 | Jsr Corp | 光学フィルム、光学フィルムの製造方法、位相差フィルム、偏光板および液晶パネル |
CN101501538B (zh) * | 2006-12-28 | 2011-07-20 | 日东电工株式会社 | 起偏器的制造方法、起偏器、偏振片、光学薄膜、复合偏振片的制造方法、复合偏振片及图像显示装置 |
JP5637924B2 (ja) | 2011-01-18 | 2014-12-10 | 株式会社日本触媒 | 位相差フィルムの製造方法 |
-
2012
- 2012-10-25 KR KR1020157007110A patent/KR101723318B1/ko active IP Right Grant
- 2012-10-25 JP JP2013516884A patent/JP5333699B1/ja active Active
- 2012-10-25 WO PCT/JP2012/006841 patent/WO2014064736A1/ja active Application Filing
- 2012-10-25 CN CN201280076650.3A patent/CN104755251B/zh active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2000009912A (ja) * | 1998-06-25 | 2000-01-14 | Nitto Denko Corp | 延伸フィルムの製造方法及び位相差板 |
JP2006224618A (ja) * | 2005-02-21 | 2006-08-31 | Jsr Corp | フィルム加工方法 |
JP2006255892A (ja) * | 2005-02-21 | 2006-09-28 | Jsr Corp | フィルム加工方法 |
JP2008023775A (ja) * | 2006-07-19 | 2008-02-07 | Toshiba Mach Co Ltd | シート・フィルムの斜め延伸方法およびクリップ式シート・フィルム延伸装置 |
WO2012017639A1 (ja) * | 2010-08-02 | 2012-02-09 | 株式会社日本触媒 | 位相差フィルムの製造方法および位相差フィルムロール |
JP2012025167A (ja) * | 2011-10-07 | 2012-02-09 | Nippon Zeon Co Ltd | 長尺の延伸フィルム、長尺の積層フィルム、偏光板及び液晶表示装置 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107405822A (zh) * | 2015-03-31 | 2017-11-28 | 日本瑞翁株式会社 | 拉伸膜的制造方法及拉伸膜 |
TWI702133B (zh) * | 2015-03-31 | 2020-08-21 | 日商日本瑞翁股份有限公司 | 延伸膜之製造方法以及延伸膜 |
JP2019174636A (ja) * | 2018-03-28 | 2019-10-10 | コニカミノルタ株式会社 | 斜め延伸フィルム、偏光板、異形表示装置および斜め延伸フィルムの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
KR20150046226A (ko) | 2015-04-29 |
JP5333699B1 (ja) | 2013-11-06 |
CN104755251B (zh) | 2017-04-26 |
CN104755251A (zh) | 2015-07-01 |
KR101723318B1 (ko) | 2017-04-04 |
JPWO2014064736A1 (ja) | 2016-09-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5333699B1 (ja) | 長尺延伸フィルムの製造方法 | |
JP5333698B1 (ja) | 長尺斜め延伸フィルム、該長尺斜め延伸フィルムを用いた円偏光板および有機elディスプレイ | |
JP5339017B1 (ja) | 長尺延伸フィルムの製造方法 | |
JP5333697B1 (ja) | 長尺延伸フィルムの製造方法 | |
JP5083483B1 (ja) | 長尺延伸フィルムの製造方法 | |
WO2013161581A1 (ja) | 斜め延伸フィルムの製造方法 | |
JP5088718B1 (ja) | 延伸フィルムの製造方法、延伸フィルムの製造装置および延伸フィルムの製造システム | |
JP5126456B1 (ja) | 長尺斜め延伸フィルムの製造方法および製造装置 | |
JP2013202979A (ja) | 斜め延伸フィルムの製造方法および製造装置 | |
JP5083482B1 (ja) | 長尺延伸フィルムの製造方法 | |
JP5979224B2 (ja) | 長尺延伸フィルムの製造方法及び製造装置 | |
JP5105034B1 (ja) | 延伸フィルムの製造方法、延伸フィルムの製造装置および延伸フィルムの製造システム | |
JP5983732B2 (ja) | 長尺延伸フィルムの製造方法 | |
JP5979217B2 (ja) | 長尺延伸フィルムの製造方法および斜め延伸装置 | |
JP5110234B1 (ja) | 長尺斜め延伸フィルムの製造方法および製造装置 | |
JP5971327B2 (ja) | 長尺延伸フィルムの製造方法 | |
WO2013136725A1 (ja) | 長尺延伸フィルムの製造方法、及び斜め延伸装置 | |
JP2013193226A (ja) | 長尺延伸フィルムの製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2013516884 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12887150 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20157007110 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12887150 Country of ref document: EP Kind code of ref document: A1 |