JP2005300877A - Sheet with alignment film, optical anisotropic sheet, and polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical anisotropic sheet such that the optical anisotropic sheet and a polarizing element can be laminated with good productivity while the slow phase axis of the optical anisotropic sheet and the axis of transmission of the polarizing element are arranged almost in parallel, and to provide a sheet with an alignment film for manufacturing it. <P>SOLUTION: The alignment film 3 of the continuous sheet 1 with the alignment film is rubbed almost at right angles to a length direction Y-Y and liquid crystal is applied over the top surface of the sheet 1 with the alignment film, and dried and cured to form an optical function layer 5 which is aligned in the rubbing direction of the alignment film, thus manufacturing the optical anisotropic sheet 4. The slow phase axis of this optical anisotropic sheet 4 is in a direction B-B perpendicular to the length direction, so this is laminated on a continuous polarizing element merely along the lengths, so that they can be laminated having the slow phase axis and transmission axis arranged almost in parallel to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet with an alignment film, an optically anisotropic sheet, and a polarizing plate used for a liquid crystal display and the like.

  A polarizing plate in which a polarizing element and an optical compensation sheet are laminated is used for a liquid crystal display. Optical compensation sheets are used for correcting image coloring, expanding the viewing angle, and the like, and those having various optical properties have been developed depending on the application and display mode of the liquid crystal display. Conventionally, stretched birefringent polymer films have been frequently used as materials for optical compensation sheets, but in recent years optically anisotropic sheets composed of liquid crystalline molecules having optical anisotropy have been proposed. An optically anisotropic sheet is manufactured by a method in which an alignment film is formed on a support substrate, the surface of the alignment film is rubbed, a liquid crystal material is applied, dried and cured to form an optical functional layer. Often.

In the production of an optically anisotropic sheet or polarizing element used for a polarizing plate, a continuous form wound in a roll is generally used in order to increase productivity. That is, in the production of an optically anisotropic sheet, a continuous base material such as a continuous transparent resin film is used as a supporting base material, and after forming an alignment film on the surface of the continuous base material, the continuous base material is used. A continuous rubbing roll is placed on the alignment film of the continuous base material, and a rubbing roll having an axis parallel to the continuous base material and perpendicular to the running direction of the continuous base material is contacted with the alignment film. A continuous optically anisotropic sheet is produced by a method in which a liquid crystal material is applied, dried and cured to form an optical functional layer. In manufacturing a polarizing element, the polarizing element is manufactured by subjecting a continuous resin film to stretching treatment. In many cases, a polarizing plate used in a liquid crystal display is laminated on a liquid crystal cell member after bonding an optically anisotropic sheet and a polarizing element. At this time, depending on the display mode of the liquid crystal display, the optically anisotropic sheet and the polarizing element have a desired angle (for example, parallel, right angle, etc.) between the transmission axis of the polarizing element and the slow axis of the optically anisotropic sheet. It arranges to become.
JP 2000-98134 A JP-A 61-160720 JP-A-8-160431 JP 2001-255413 A

  In a polarizing element formed by subjecting a resin film to stretching, the direction perpendicular to the stretching direction corresponds to the transmission axis. For this reason, in a continuous polarizing element formed by subjecting a continuous resin film to a stretching process, in many cases, the stretching process is performed in the longitudinal direction, so that the transmission axis is perpendicular to the longitudinal direction, that is, the width direction. ing. On the other hand, the slow axis of the optically anisotropic sheet corresponds to the major axis direction of the rod-like liquid crystalline molecule when the optical functional layer is composed of the rod-like liquid crystalline molecule. In addition, the major axis direction of the rod-like liquid crystalline molecules varies depending on the material of the alignment film, but in many cases, it is the same direction as the rubbing treatment direction (direction in which the alignment film is rubbed with a rubbing cloth or the like). . As described above, in the production of a continuous optically anisotropic sheet, there are many cases where rubbing treatment is generally performed in the longitudinal direction of a continuous base material. The axis is substantially the longitudinal direction of the continuous substrate. From the above, when manufacturing a polarizing plate by laminating a continuous polarizing element wound in a roll and a continuous optical anisotropic sheet wound in a roll, the transmission axis of the polarizing element When laminating so that the slow axis of the optically anisotropic sheet is almost perpendicular, it is only necessary to laminate the polarizing element and the optically anisotropic sheet with their longitudinal directions parallel to each other. Therefore, it can be laminated continuously, so that the productivity can be extremely increased and the bonding error between them can be reduced.

  However, as for the optical characteristics of the polarizing plate, it may be better to arrange the slow axis of the optically anisotropic sheet and the transmission axis of the polarizing element substantially in parallel depending on the display mode. In order to cope with this case, one or both of the optically anisotropic sheet and the polarizing element must be cut to a desired size, and then the two must be aligned and laminated to increase the number of processes. There is a problem that the alignment method becomes complicated.

  The present invention has been made in view of such problems, and is an optical device that can perform the operation of laminating with the slow axis of the optically anisotropic sheet and the transmission axis of the polarizing element arranged substantially in parallel with high productivity. It is an object to provide a mechanically anisotropic sheet. Moreover, this invention also makes it the subject to provide the polarizing plate manufactured using the sheet | seat with the alignment film used for manufacture of the optically anisotropic sheet | seat, and the optically anisotropic sheet | seat.

  The invention according to claim 1 to solve the above-mentioned problems is a sheet with an alignment film in which an alignment film is laminated on the surface of a continuous substrate, and is perpendicular to the longitudinal direction of the continuous substrate on the surface of the alignment film. An alignment film-attached sheet, which is subjected to a rubbing treatment in a direction within a range of 20 °. In the sheet with an alignment film having this configuration, a slow axis of the optically anisotropic sheet obtained by applying a liquid crystal material on the alignment film and forming an optical functional layer formed from rod-like liquid crystalline molecules. Can be substantially perpendicular to the longitudinal direction.

  The invention according to claim 2 facilitates handling as a form in which the alignment film-attached sheet according to claim 1 is rolled up.

  The invention according to claim 3 has an optical functional layer formed by applying a liquid crystal polymer, a liquid crystal oligomer or a polymerizable mesogenic material on the alignment film of the sheet with an alignment film according to claim 1 and crosslinking or polymerizing the material. It is the optically anisotropic sheet | seat made into the structure. Since this optically anisotropic sheet has a slow axis substantially perpendicular to the longitudinal direction, the optically anisotropic sheet is laminated by laminating it on a polarizing element in a continuous form with the longitudinal direction parallel to each other. A polarizing plate in which the slow axis and the transmission axis of the polarizing element are arranged substantially in parallel can be produced with high productivity.

  The invention according to claim 4 facilitates handling as a form in which the optically anisotropic sheet according to claim 3 is rolled up.

  The invention according to claim 5 is a polarizing plate formed by laminating a continuous polarizing element on the optically anisotropic sheet according to claim 3. This polarizing plate has an optical characteristic in which the slow axis of the optically anisotropic sheet and the transmission axis of the polarizing element are arranged substantially in parallel.

  The invention according to claim 6 facilitates handling as a form in which the polarizing plate according to claim 5 is rolled up.

  According to the present invention, in the lamination in which the slow axis of the optically anisotropic sheet and the transmission axis of the polarizing element are arranged substantially in parallel, which is a problem of polarizing plate production, either the optically anisotropic sheet or the polarizing element or The operation of aligning and laminating both of them after cutting them to the desired size is no longer necessary. Simply run the optically anisotropic sheet and the polarizing element in a continuous form while keeping the longitudinal direction of both parallel. What is necessary is just to laminate | stack, and this can manufacture a polarizing plate with sufficient productivity, and can make both bonding errors small.

  The sheet with an alignment film of the present invention has a continuous base material such as a long film as a support and an alignment film formed on the surface thereof, and is usually handled in a roll-up form. For the continuous substrate, a transparent polymer film having small optical anisotropy is preferable. The term “transparent” means that the light transmittance is 80% or more. Examples of the transparent polymer film include a cellulose polymer, a norbornene polymer, a cycloolefin polymer, and polymethyl methacrylate. As the cellulose polymer, a cellulose ester is preferable, and a lower fatty acid ester of cellulose is more preferable. Lower fatty acid means a fatty acid having 6 or less carbon atoms. As the cellulose ester, cellulose acetate is preferable, and examples thereof include diacetyl cellulose and triacetyl cellulose. Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used. When the continuous substrate is a cellulose ester or synthetic polymer film, it is preferably formed by a solvent cast method. The thickness of the continuous base material used as the support is preferably 20 μm to 500 μm, and more preferably 50 μm to 200 μm. Surface treatment (for example, glow discharge treatment, corona discharge treatment, ultraviolet ray (UV) treatment) is applied to the continuous base material in order to improve the adhesion between the continuous base material and the layers (alignment film, optical functional layer, etc.) provided thereon. , Flame treatment, etc.) and a primer layer (adhesive layer) may be formed.

  The alignment film formed on the surface of the continuous substrate has a function of defining the alignment direction of the liquid crystal compound applied thereon. It is known that polymers such as polyimide, polyvinyl alcohol, and gelatin have orientation, and these are used for the alignment film. The thickness of the alignment film is preferably 0.01 μm to 5 μm, and more preferably 0.05 μm to 1 μm.

  The alignment film surface is rubbed by rubbing with a woven fabric, felt, rubber, brush, etc., and the liquid crystal compound applied to the alignment film surface can be easily aligned by the alignment regulating force generated by the rubbing process. . Here, the rubbing treatment direction (direction in which the alignment film surface is rubbed with a rubbing cloth or the like) is determined to be within a range of ± 20 ° perpendicular to the longitudinal direction of the continuous base material supporting the alignment film. This point will be further described with reference to the drawings. Fig.1 (a) is a schematic perspective view which shows the sheet | seat 1 with an oriented film which concerns on embodiment of this invention. The alignment film-attached sheet 1 is in a continuous form wound in a roll shape, and has a continuous base material 2 and an alignment film 3 formed on the surface thereof. When the longitudinal direction of the alignment film-attached sheet 1 is YY and the direction (width direction) perpendicular thereto is XX, the rubbing treatment direction AA is the XX direction perpendicular to the longitudinal direction YY. Alternatively, the angle α formed with respect to the XX direction is set to be within 20 °. In general, when a liquid crystal compound is applied on the alignment film 3 that has been rubbed to align the liquid crystal, the alignment direction of the liquid crystal compound (the direction of the slow axis of the obtained optically anisotropic sheet) is the alignment Although it differs depending on the film material, in many cases, it is almost equal to the rubbing direction AA or slightly deviated from the rubbing direction. Therefore, in order to make the alignment direction of the liquid crystal compound the XX direction perpendicular to the longitudinal direction YY, it may be necessary to slightly shift the rubbing treatment direction with respect to the XX direction. Further, as an optical characteristic required for the polarizing plate, it may be desirable that the slow axis of the optically anisotropic sheet is slightly shifted from the XX direction perpendicular to the longitudinal direction YY. In order to cope with these, in the present invention, the rubbing treatment direction is determined to be within a range of ± 20 ° perpendicular to the longitudinal direction. An apparatus for performing the rubbing process so that the rubbing process direction is in this direction will be described later.

  FIG. 1B shows an optically anisotropic sheet 4 according to an embodiment of the present invention. This optically anisotropic sheet 4 includes an optical functional layer 5 formed by applying a liquid crystal polymer, a liquid crystal oligomer or a polymerizable mesogenic material on the alignment film of the above-mentioned sheet with an alignment film, and crosslinking or polymerizing the material. Usually, it is handled in the form of being wound into a roll. The material of the optical functional layer 5 is not particularly limited as long as it is a liquid crystal material capable of forming a liquid crystal having nematic regularity, smectic regularity, or cholesteric regularity. Either a polymer liquid crystal or a polymerizable liquid crystal compound may be used. Good. The polymerizable liquid crystal compound preferably has a polymerizable functional group at both ends of the molecule in order to obtain an optical element having good heat resistance. Two or more optical function layers may be laminated. As described above, since the alignment film-attached sheet 1 used for the optically anisotropic sheet 4 is rubbed in a direction substantially perpendicular to the longitudinal direction, the optical functional layer 5 formed thereon is delayed. The direction of the phase axis (BB direction) is also almost perpendicular to the longitudinal direction in many cases.

  The polarizing plate of the present invention is formed by laminating a continuous polarizing element on the optically anisotropic sheet 4 having the above-described configuration. That is, as shown in FIG. 2, the optically anisotropic sheet 4 in the form of a roll and the continuous polarizing element 7 in the form of a roll are overlapped and stacked while being continuously drawn out. The polarizing plate 8 thus obtained is usually handled in the form of a roll. Here, as the continuous polarizing element 7, a known one made of a polyvinyl alcohol film or the like can be used. These continuous polarizing elements 7 are polarized by being stretched in the longitudinal direction. Therefore, the direction of the transmission axis (CC direction) of the polarizing element 7 is the film stretching direction, that is, the longitudinal direction Y-. It is perpendicular to Y. Thus, the optically anisotropic sheet 4 in the form of a roll and the continuous polarizing element 7 in the form of a roll are continuously drawn out in the longitudinal direction as indicated by the arrows H and run. By superimposing and laminating, the polarizing plate 8 having optical characteristics in which the slow axis of the optically anisotropic sheet and the transmission axis of the polarizing element are arranged substantially in parallel can be continuously produced with high productivity. . In addition, you may laminate | stack the protective layer comprised with a transparent resin film on the polarizing element surface of the polarizing plate 8 as needed. The lamination of the protective layer may be performed on the same line as the lamination of the optically anisotropic sheet 4 and the polarizing element 7 or may be performed on a separate line.

  The main applications of the optically anisotropic sheet and polarizing plate described above include liquid crystal display element color compensation plates, liquid crystal display element viewing angle compensation plates, optical retardation plates, half-wave plates, / 4 wavelength plate, optical rotatory optical element, laminated sheet for optical elements, and the like.

  Next, an apparatus for performing a rubbing process in a direction substantially perpendicular to the longitudinal direction of the alignment film-attached sheet and an apparatus for manufacturing an optically anisotropic sheet using the apparatus will be described. FIG. 3 shows a schematic configuration of an example of a rubbing treatment facility for performing a rubbing treatment on the alignment film-coated sheet 1 having an alignment film formed on the continuous base material surface. A rubbing treatment facility generally indicated by reference numeral 10 sets a winding of the alignment film-attached sheet 1, and feeds the alignment film-attached sheet 1 (hereinafter referred to as a continuous sheet 1) from the winding, and a continuous sheet EPC device 12 that stabilizes the travel position in the width direction of 1, a rubbing device 13 for performing a rubbing process on continuous sheet 1, an accumulation device 14 for temporarily retaining continuous sheet 1, EPC device 15 that stabilizes the traveling position of the sheet 1 in the width direction, film dust removing device 16 for removing foreign matters such as dust and dust on the surface of the continuous sheet 1, and winding for winding the continuous sheet 1 after the rubbing treatment Take-up device 17 and a number of rolls 18 that run and guide the continuous sheet 1 along a predetermined path (a pair of guide rolls 18a disposed on the rubbing device 13; And a containing 8b) or the like. Here, upstream of the accumulating device 14, the continuous sheet 1 travels intermittently, and when stopped, the continuous sheet 1 between the pair of guide rolls 18a and 18b has an appropriate tension that does not interfere with the rubbing process. In addition, the continuous sheet 1 continuously travels downstream of the accumulator 14.

  The rubbing device 13 rubs the lower surface of the continuous sheet 1 positioned between a pair of guide rolls 18a and 18b arranged so as to run the continuous sheet 1 horizontally in a direction substantially perpendicular to the longitudinal direction thereof. As shown in FIGS. 4 and 5, the rotary table 21 disposed below between the pair of guide rolls 18a and 18b, and the slide held thereon The unit 22, a moving table 23 held so as to be reciprocated by the slide unit 22, a linear motion guide 24 mounted perpendicularly to the moving base 23, and supported by the linear motion guide 24 so as to be movable up and down. Roll support portion 25, drive device 26 for raising and lowering the roll support portion 25, stopper 27 for regulating the upper limit position of the roll support portion 25, and roll support And a rubbing roll 28 or the like which is maintained at 25. The rubbing roll 28 has a structure in which a rubbing cloth made of rayon or the like is uniformly attached to the surface of a metal mirror roll using a double-sided tape or the like, and the rubbing roll 28 is rotated on the continuous sheet 1 while being rotated. A rubbing process can be performed by making it contact. The rubbing roll 28 is connected to a rotational drive device (not shown) for rotationally driving it in both forward and reverse directions. When the stopper 27 is positioned by pressing the roll support portion 25 against the stopper 27, the rubbing roll 28 is positioned in a state where an appropriate tension is applied between the pair of guide rolls 18a and 18b. The height position is determined so as to come into contact with the continuous sheet 1 at a contact pressure necessary to perform a desired rubbing process. The rotary table 21 has a structure that can be swung around a point O in FIG. 5 and fixed at a desired angular position, thereby moving the moving table 23 and the moving direction D of the rubbing roll 28 held by the moving table 23. Can be adjusted. In the drawing, the moving direction D of the rubbing roll 28 is set to be perpendicular to the longitudinal direction YY of the continuous sheet 1.

  In FIG. 3, in the vicinity of the guide rolls 18 a and 18 b located on both sides of the rubbing roll 28, a static eliminator 29 is provided to prevent foreign substances such as dust and dust from adhering to the continuous sheet 1. . In addition, although illustration is abbreviate | omitted, the dustproof provided with the entrance and exit of the continuous sheet 1 so that the continuous sheet 1 which is contacting the rubbing apparatus 13 and the rubbing roll 18 may be covered between a pair of guide rolls 18a and 18b. A cover is provided so that the interior is always evacuated. This prevents foreign matter such as scraps of the continuous sheet 1 generated by the rubbing treatment and falling fibers of the rubbing cloth from being scattered around and deposited on the surroundings or attached to the continuous sheet 1.

  The accumulation device 14 includes a plurality of guide rolls 33 arranged so as to move up and down, and is configured to increase or decrease the amount of the continuous sheet 1 that is retained by the raising and lowering of the guide rolls 33. As described above, the continuous sheet 1 travels intermittently upstream of the accumulation device 14 and continuously travels downstream, but by increasing or decreasing the amount of residence in the accumulation device 14, the upstream and downstream intermittent travels. The area and continuous running area can be connected without hindrance.

  Next, the rubbing operation by the rubbing processing facility 10 having the above-described configuration will be described. The continuous sheet 1 is set so that the surface having the alignment film to be rubbed is on the lower side and passes over the rubbing roll 28. The rubbing roll 28 is waiting at a position where the uppermost portion of the rubbing roll 28 is off the side edge of the continuous sheet 1 and lowered so as not to contact the continuous sheet 1 while rotating at a predetermined rotational speed. Upstream of the accumulator 14, the continuous sheet 1 is intermittently sent at a constant pitch. In addition, the tension of the continuous sheet 1 is adjusted so that an appropriate tension is applied to the continuous sheet 1 extending between the pair of guide rolls 18a and 18b while the continuous sheet 1 is stopped. ing. Now, when the continuous sheet 1 is fed and stopped, the rubbing roll 28 rises to a position regulated by the stopper 27, and then the moving table 23 moves in the direction of arrow D in FIG. Also moves in the direction of arrow D. By this movement, the rubbing roll 28 moves in the direction of arrow D while rubbing the continuous sheet 1, and performs a rubbing process in the direction of arrow D on the continuous sheet 1. When the rubbing roll 28 passes through the full width of the continuous sheet 1 and the rubbing process for the full width of the continuous sheet is completed, the rubbing roll 28 descends at that position to prepare for the next rubbing process. Next, the continuous sheet 1 is stopped by being sent by a certain length not exceeding the length in the longitudinal direction of the previously rubbed region, the rubbing roll 28 is raised again, and the continuous sheet 1 is then moved to the arrow D. The rubbing process is performed by moving in the opposite direction, and then descends to prepare for the next rubbing process. Thereafter, the rubbing process is intermittently performed on the continuous sheet 1 by repeating the same operation. During these rubbing processes, the accumulating device 14 increases or decreases the staying amount of the continuous sheet 1. The continuous sheet 1 is continuously fed downstream and continuously wound by the winding device 17. As described above, the rubbing process for the continuous sheet 1 is performed. Here, as can be seen well from FIG. 5, the rubbing roll 28 is moving in the direction perpendicular to the longitudinal direction YY of the continuous sheet 1, so that the rubbing process in the direction perpendicular to the longitudinal direction YY is performed. Can do. Moreover, the rubbing process to a desired direction can also be performed by adjusting the moving direction D of the rubbing roll 28 by adjusting the position of the turning table 21. As described above, the alignment film-equipped sheet of the present invention that has been rubbed within a range of ± 20 ° perpendicular to the longitudinal direction can be produced.

  In the rubbing process described above, the rubbing process is applied to different regions in the longitudinal direction of the continuous sheet 1 in each reciprocating movement of the rubbing roll 28. The rubbing process is performed only when the rubbing roll 28 moves in one direction. Alternatively, the rubbing roll 28 may be rubbed to the same area of the continuous sheet 1 in one reciprocation.

  Further, the rubbing device 13 shown in FIG. 4 is configured to perform the rubbing process without supporting the upper surface side of the continuous sheet 1 extending between the pair of guide rolls 18a and 18b, but the tension applied to the continuous sheet 1 is increased. In the case where the continuous sheet 1 is likely to be deformed during the rubbing process, as shown in FIG. 6, an adsorption plate 35 is provided on the upper surface side of the continuous sheet 1 so as to be movable up and down by an elevating device 36. When performing the rubbing process after stopping, the suction plate 35 may be lowered to suck and hold the rubbing area of the continuous sheet 1 and the rubbing process by the rubbing roll 28 may be performed in that state. Further, backup support by means other than the suction plate 35 may be used.

  A continuous sheet (sheet with alignment film) 1 that has been rubbed and wound by the rubbing processing facility 10 having the above-described configuration is sent to a step of forming an optical functional layer, and a liquid crystal material is applied onto the alignment film, followed by drying. By curing, an optical functional layer is formed, and an optically anisotropic sheet is produced.

  The rubbing treatment facility 10 described above performs only the rubbing treatment, but it is also possible to carry out the rubbing treatment and the optical functional layer formation in one line by combining this with the optical functional layer forming line. . FIG. 7 shows an optically anisotropic sheet manufacturing apparatus 40 configured as described above, and the same or similar parts as those in the apparatus shown in FIG. Similar to the rubbing treatment facility 10 in FIG. 3, the manufacturing facility 40 includes a supply device 11, an EPC device 12, a rubbing device 13, an accumulating device 14, an EPC device 15, a film dust removing device 16, and the like. A liquid crystal coating device 42, a drying device 43, a UV curing device 44, a winding device 17 and the like are disposed downstream. In the manufacturing equipment 40 having this configuration, the continuous sheet 1 having an alignment film on the surface is pulled out from the supply device 35, and after being rubbed by the rubbing device 13, a liquid crystal is applied to the surface after the rubbing treatment, and a drying step After that, it is wound up by the winding device 17. Thus, an optical functional layer formed of a liquid crystal layer is formed on a rubbing process in a direction substantially perpendicular to the longitudinal direction, so that the slow axis becomes substantially perpendicular to the longitudinal direction. The anisotropic sheet 8 can be manufactured continuously.

  The rubbing treatment facility 10 shown in FIG. 3 is configured to intermittently feed the continuous sheet 1 and perform the rubbing process when the continuous sheet 1 stops, but to perform the rubbing process while continuously feeding the continuous sheet 1. It is also possible. FIG. 8 shows a main part of the rubbing processing facility 50 capable of performing the rubbing process while continuously feeding the continuous sheet 1, and the same or similar parts as the rubbing processing facility 10 shown in FIG. Is attached. The rubbing processing facility 50 shown in FIG. 8 includes a rubbing device 51 that can continuously perform rubbing processing, and does not include an accumulation device. The pair of guide rolls 18a and 18b arranged between the rubbing positions by the rubbing device 51 are held up and down by a linear motion guide (not shown) and are raised and lowered by a driving device 52 and positioned at a desired height. The contact pressure with respect to the rubbing roll of the continuous sheet 1 can be adjusted as desired. As shown in FIGS. 9 and 10, the rubbing device 51 includes a rotary table 21, a plurality of rubbing rolls 53 arranged in multiple rows, and the multiple rows of rubbing rolls 53 along a predetermined endless track. And a rubbing roll train circulating device 54 that travels at a constant speed in a certain direction. The rubbing roll 53 used here also has a structure in which a rubbing cloth is attached to a metal mirror surface roll, and the plurality of rubbing rolls 53 are all made to have the same outer diameter and are connected in parallel and close to each other. Yes. Here, the trajectory through which the plurality of rubbing rolls 53 circulate is determined so that the rubbing roll 53 travels horizontally while being in contact with the continuous sheet 1 at a position in contact with the continuous sheet 1. Further, each rubbing roll 53 itself is driven to rotate from the same drive source (not shown), and all the rubbing rolls 53 are rotated in the same direction at the same speed. The other structure of the rubbing processing facility 50 is the same as that of the rubbing processing facility 10 shown in FIG.

  Next, the rubbing processing operation will be described. Also in this case, as shown in FIG. 10A or 10B, the rotary table 21 is turned around the point O in advance, and the direction E in which the rubbing roll 53 travels is the longitudinal direction Y− of the continuous sheet 1. It is set to be a desired angle perpendicular to Y or in the vicinity thereof. Further, in FIG. 8, the height positions of the pair of guide rolls 18 a and 18 b are positioned at positions where the continuous sheet 1 can be brought into contact with the rubbing roll 53 with a desired contact pressure. In this state, the continuous sheet 1 is continuously conveyed at a constant speed. At the same time, the plurality of rubbing rolls 53 travel at a constant speed along a predetermined circulation path while rotating in the same direction at the same speed. In this traveling, the rubbing process is continuously performed on the continuous sheet 1 by traveling across the continuous sheet 1 while the plurality of rubbing rolls 53 are in contact with the lower surface of the continuous sheet 1.

Here, the rubbing process direction for the continuous sheet 1 is as follows. As shown in FIG. 10A, when the running direction E of the rubbing roll 53 is set to be perpendicular to the longitudinal direction YY of the continuous sheet 1, the rubbing roll 53 is rotated and moved by the rubbing roll 53. The rubbing cloth on the surface of 53 moves in the running direction E of the rubbing roll 53, that is, in a direction perpendicular to the longitudinal direction YY, at a moving speed V _E determined by the peripheral speed and the running speed of the rubbing roll 53. On the other hand, since the continuous sheet 1 is traveling in the longitudinal direction as indicated by the arrow H and in the right direction in the drawing, the rubbing cloth is longitudinal with respect to the continuous sheet 1 and opposite to the traveling direction of the continuous sheet 1. It moves in the direction at a moving speed V _H determined by the traveling speed of the continuous sheet 1. For this reason, the relative moving speed V and moving direction of the rubbing cloth with respect to the continuous sheet 1 are determined by the magnitude and direction of these two moving speeds V _E and V _H , as shown in FIG. In addition, the direction of the moving speed V (this direction becomes an accurate rubbing processing direction) slightly deviates from the traveling direction of the rubbing roll 53 (by an angle θ). However, in practice, since the moving speed V _E determined by the traveling speed and the peripheral speed of the rubbing roll 53 is much larger than the moving speed V _H determined by the traveling speed of the continuous sheet 1, the deviation angle θ is extremely small. For this reason, the rubbing process direction can be approximated to the moving direction of the rubbing roll 53 in many cases. If the rubbing process direction is strictly perpendicular to the longitudinal direction YY, the traveling angle E of the rubbing roll 53 is adjusted by adjusting the arrangement angle of the rotary table 21 as shown in FIG. May be inclined in consideration of the moving speed V _H due to traveling of the continuous sheet 1. Thus, also in this rubbing apparatus 51, it is possible to perform a rubbing process in a direction substantially perpendicular to the longitudinal direction of the continuous sheet 1.

  The rubbing device 51 shown in FIG. 8 is also configured to perform the rubbing process without supporting the upper surface side of the continuous sheet 1 extending between the pair of guide rolls 18a and 18b, but the tension applied to the continuous sheet 1 is small. When there is a possibility that the continuous sheet 1 is deformed during the rubbing process, as shown in FIG. 11, a support conveyor 56 is provided on the upper surface side of the continuous sheet 1 so as to be movable up and down by a driving device 57, and the continuous conveyor 1 It is good also as a structure which supports the upper surface of the sheet | seat 1. FIG. Further, backup support by means other than the conveyor 56 may be used.

  Further, the rubbing treatment facility 50 shown in FIG. 8 can be configured to perform the rubbing treatment and the optical functional layer formation in one line by combining with the formation line of the optical functional layer. FIG. 12 shows an optically anisotropic sheet manufacturing facility 60 configured as described above, and the same or similar parts as those of the manufacturing facility 40 shown in FIG. 12 includes a supply device 11, an EPC device 12, a rubbing device 51, an EPC device 15, a film dust removing device 16, a liquid crystal coating device 42, a drying device 43, a UV curing device 44, a winding device 17, and the like. The rubbing device 51 described in FIGS. 8 to 10 is used. Also in the manufacturing facility 60 having this configuration, after the continuous sheet 1 having the alignment film on the surface is pulled out from the supply device 11 and subjected to the rubbing treatment by the rubbing device 51, the liquid crystal is applied to the surface after the rubbing treatment, and the drying step After that, it is wound up by the winding device 17. Thus, an optical functional layer formed of a liquid crystal layer is formed on a rubbing process in a direction substantially perpendicular to the longitudinal direction, so that the slow axis becomes substantially perpendicular to the longitudinal direction. The anisotropic sheet 8 can be manufactured continuously.

  13 and 14 show another example of an apparatus for rubbing while continuously feeding the continuous sheet 1. Also in FIG. 13, the same or similar parts as those in the rubbing processing facility 50 shown in FIG. In the rubbing device 66 provided in the rubbing processing facility 65 shown in FIGS. 13 and 14, a pair of support columns 67 are provided on the rotary table 21, and a large-diameter rubbing roll 68 is held on the support column 67 so as to rotate at a fixed position. I am letting. The large-diameter rubbing roll 68 also has a configuration in which a rubbing cloth is attached to a metal mirror surface roll, but its outer diameter is set to be considerably larger than the width of the continuous sheet 1. Is arranged so as to be parallel to the longitudinal direction of the continuous sheet 1, the entire width of the continuous sheet 1 is in contact with a part of the circumference of the rubbing roll 68. Further, the rubbing roll 68 is located at a position where the center point C of the rubbing roll 68 coincides with the turning center O of the rotating table 21 when viewed horizontally with respect to the rotating table 21 as shown in FIG. The turntable 21 is disposed so that the turning center O is located on the central axis of the continuous sheet 1. The rubbing roll 68 is connected to a rotation driving device (not shown) for rotating the rubbing roll 68 at a desired speed. The other structure of the rubbing processing facility 65 is the same as that of the rubbing processing facility 50 shown in FIG.

  Next, the rubbing processing operation by the rubbing processing facility 65 shown in FIG. 13 will be described. Also in this apparatus, the turning angle of the rotary table 21 is adjusted in advance so that the central axis of the rubbing roll 68 is substantially parallel to the longitudinal direction of the continuous sheet 1, that is, the circumferential direction of the rubbing roll 68 is continuous sheet 1. It is set so as to be substantially perpendicular to the longitudinal direction. In FIG. 14, the height positions of the pair of guide rolls 18 a and 18 b are positioned at positions where the entire width of the continuous sheet 1 can be brought into contact with the circumferential surface of the rubbing roll 68 with a desired contact pressure. In this state, the continuous sheet 1 is continuously conveyed at a constant speed. At the same time, the large-diameter rubbing roll 68 rotates in a constant direction at a constant speed. 14C and 14D, the circumferential surface of the rubbing roll 68 moves in a direction substantially perpendicular to the longitudinal direction (arrow F direction) while contacting the full width of the continuous sheet 1. Then, the rubbing process is continuously performed, whereby the rubbing process can be performed in a direction substantially perpendicular to the longitudinal direction with respect to the continuous sheet 1. Even in this case, the actual rubbing treatment direction is slightly deviated from the moving direction of the circumferential surface of the rubbing roll 68 due to the running of the continuous sheet 1, so that the installation angle of the rubbing roll 68 ( The turning angle of the rotary table 21) may be adjusted.

  When using the large-diameter rubbing roll 68, it is preferable to bring the entire width of the continuous sheet 1 into contact with the circumferential surface of the rubbing roll 68 with as uniform pressure as possible. For this purpose, the diameter of the rubbing roll 68 is increased as much as possible, It is desirable to reduce the central angle β with respect to the circular arc with which the continuous sheet 1 shown in FIG. As a rough standard of the central angle β, it is preferable to set it to 90 ° or less. Therefore, the radius R of the rubbing roll 68 is such that R> 2W / π when the width of the continuous sheet 1 is W. It is preferable to set to. Further, since the path length of the continuous sheet 1 traveling between the pair of guide rolls 18a and 18b is different in the central region in the width direction of the continuous sheet 1 (region passing through the top of the rubbing roll 68) and both end regions, A tension difference occurs. If this tension difference becomes large, the rubbing treatment effect becomes non-uniform or the running of the continuous sheet becomes unstable, so it is preferable to make this tension difference as small as possible. Therefore, in order to reduce this tension difference as much as possible, it is preferable to increase the distance between the guide rolls 18a, 18b and the rubbing roll 68 (center-to-center distance) as much as possible. As a rough guideline, it should be 10R (mm) or more. Is preferred. Further, in order to reduce the difference in the path length between the central region and both end regions of the continuous sheet 1, a pair of guide rolls 18a and 18b may be replaced by a drum-shaped roll instead of a simple cylindrical roll. good.

  In the rubbing device 66 shown in FIGS. 13 and 14, the rubbing process is performed without supporting the upper surface side of the continuous sheet 1 at a position in contact with the rubbing roll 68, but if necessary, the upper surface of the continuous sheet 1. Backup means for pressing the side against the rubbing roll 68 may be provided. Further, the rubbing device 66 can be used in place of the rubbing device 51 in the optical anisotropic sheet manufacturing facility 60 shown in FIG.

  15 to 17 show still another example of an apparatus for rubbing while continuously feeding the continuous sheet 1. Also in FIG. 15, the same reference numerals are given to the same or similar parts as the rubbing processing facility 50 shown in FIG. 8. The rubbing apparatus 71 provided in the rubbing processing facility 70 shown in FIGS. 15 to 17 is provided with a support column 72 on the rotary table 21, and a pulley 73 is held on the support column 72 and an endless rubbing belt 75 is passed around. . The rubbing belt 75 is configured by attaching a rubbing cloth to an endless belt having a mirror-finished surface such as a steel belt. The rubbing belt 75 is arranged so that the upper running portion is horizontal, and the lower surface of the rubbing belt 75 is a plate-like backup member 77 shown in FIG. 17A or a backup made up of a number of rolls shown in FIG. A member 78 is supported. At least one of the pulleys 73 that support the rubbing belt 75 is connected to a drive device (not shown) for causing the rubbing belt 75 to travel at a constant speed. The other structure of the rubbing processing equipment 70 is the same as that of the rubbing processing equipment 50 shown in FIG.

  Next, the rubbing processing operation by the rubbing processing equipment 71 shown in FIG. 15 will be described. Also in this apparatus, the turning angle of the rotary table 21 is adjusted in advance, and the running direction G of the rubbing belt 75 is set to be substantially perpendicular to the longitudinal direction of the continuous sheet 1. Further, the height positions of the pair of guide rolls 18a and 18b are positioned at positions where the continuous sheet 1 can be brought into contact with the rubbing belt 75 with a desired contact pressure. In this state, the continuous sheet 1 is continuously conveyed at a constant speed. At the same time, the rubbing belt 75 travels in a constant direction (G direction) at a constant speed, and the continuous sheet 1 is rubbed. Thus, the rubbing process can be performed in the direction substantially perpendicular to the longitudinal direction with respect to the continuous sheet 1. Even in this case, the actual rubbing process direction is slightly deviated from the traveling direction of the rubbing belt 75 due to the traveling of the continuous sheet 1, and therefore the installation angle of the rubbing belt 75 (the rotation table 21 of the rotary table 21 is considered). Adjust the turning angle).

  Also in the rubbing device 71 shown in FIGS. 15 to 17, the rubbing process is performed without supporting the upper surface side of the continuous sheet 1 at the position in contact with the rubbing belt 75, but if necessary, the upper surface of the continuous sheet 1. Backup means for pressing the side against the rubbing belt 75 may be provided. FIG. 18 shows an example in which backup means is provided. A roll-shaped backup member 81 and a driving device 82 for raising and lowering the roll-shaped backup member 81 are provided above the continuous sheet 1, and the continuous sheet 1 is rubbed with the backup member 81. It is configured to be pressed against. Further, the rubbing device 71 can be used in place of the rubbing device 51 in the optical anisotropic sheet manufacturing facility 60 shown in FIG.

  As mentioned above, although several examples of the apparatus which manufactures the sheet | seat with an alignment film of this invention by giving the rubbing process to the continuous sheet (sheet | seat with an alignment film) 1 in the substantially perpendicular direction with respect to the longitudinal direction, some examples were demonstrated. The apparatus used for manufacturing the sheet with an alignment film of the invention is not limited to these, and an apparatus having another configuration capable of performing a rubbing process in a direction substantially perpendicular to the longitudinal direction of the sheet with an alignment film is used. Needless to say.

(A) is a schematic perspective view of the sheet | seat with alignment film which concerns on embodiment of this invention, (b) is a schematic perspective view of the optically anisotropic sheet | seat which concerns on embodiment of this invention. Schematic diagram showing the process of manufacturing a polarizing plate by laminating an optically anisotropic sheet and a polarizing element Schematic configuration diagram showing an example of rubbing treatment equipment (A) is a schematic side view of the rubbing apparatus provided in the rubbing treatment facility shown in FIG. 1, and (b) is a schematic front view of the rubbing apparatus. Schematic plan view of the rubbing device shown in FIG. Schematic side view showing a modification of the rubbing device shown in FIG. Schematic configuration diagram showing one example of manufacturing equipment for optically anisotropic sheet Schematic configuration diagram showing the main part of another example of rubbing treatment equipment Schematic which shows the rubbing roll row | line | column of the rubbing apparatus provided in the rubbing processing equipment shown in FIG. (A), (b) is a schematic top view which shows the rubbing apparatus provided in the rubbing processing equipment shown in FIG. 8 in the state which varied the attachment angle. The schematic side view which shows the modification of the rubbing apparatus shown in FIG. Schematic configuration diagram showing another example of manufacturing equipment for optically anisotropic sheet Schematic configuration diagram showing the main part of still another example of rubbing treatment equipment (A) is a schematic side view of the rubbing apparatus provided in the rubbing treatment facility shown in FIG. 13, (b) is a schematic end view showing the rubbing roll shown in (a) in the roll axis direction, and (c) is rubbing. Schematic plan view of the apparatus, (d) is a schematic perspective view of the rubbing apparatus Schematic configuration diagram showing the main part of still another example of rubbing treatment equipment Schematic plan view of the rubbing apparatus provided in the rubbing treatment facility shown in FIG. (A) is a schematic cross-sectional view of a rubbing apparatus provided in the rubbing treatment facility shown in FIG. 15, (b) shows an example of using a large number of support rolls as a backup member, the same part as (a) above Schematic cross section The schematic block diagram which shows the modification of the rubbing apparatus provided in the rubbing processing apparatus shown in FIG.

Explanation of symbols

1 Sheet with orientation film (continuous sheet)
DESCRIPTION OF SYMBOLS 2 Continuous base material 3 Orientation film 4 Optical anisotropic sheet 5 Optical functional layer 7 Polarizing element 8 Polarizing plate 10, 50, 65, 70 Rubbing processing equipment 11 Supply apparatus 12, 15 EPC apparatus 13, 51, 66, 71 Rubbing Device 14 Accumulation device 16 Film dust removal device 17 Winding device 18a, 18b Guide roll 21 Rotary table 28, 53, 68 Rubbing roll 29 Static elimination device 40, 60 Optical anisotropic sheet manufacturing equipment 42 Liquid crystal coating device 43 Drying device 44 UV curing device 77 Rubbing belt

Claims (6)

  A sheet with an alignment film in which an alignment film is laminated on the surface of a continuous substrate, and the alignment film surface is subjected to a rubbing treatment in a direction that is within a range of ± 20 ° perpendicular to the longitudinal direction of the continuous substrate. A sheet with an alignment film characterized by the above.   The sheet with an alignment film according to claim 1, wherein the sheet is rolled up.   An optical functional layer formed by applying a liquid crystal polymer, a liquid crystal oligomer or a polymerizable mesogenic material on the alignment film of the sheet with an alignment film according to claim 1 and crosslinking or polymerizing the optical functional layer. Isotropic sheet.   The optically anisotropic sheet according to claim 3, wherein the optically anisotropic sheet is rolled up.   A polarizing plate formed by laminating a continuous polarizing element on the optically anisotropic sheet according to claim 3.   The polarizing plate according to claim 5, wherein the polarizing plate is rolled up.

Images