TWI690474B - Method for transporting optical film and method for manufacturing polarizing plate - Google Patents

Abstract

An objection of the present invention is to provide a method for transporting optical film which is capable of continuously transporting a film without causing defects such as folding, cracking, bursting and breaking of the optical film.

The method for transporting optical film is a method of transporting the optical film along a transporting path including a nip roll which is composed by a pair of rolls 42. When the optical film passes between the pair of rolls 42, the pressure applied to the end portion in the width direction of the optical film is smaller than the pressure applied to the center portion in the width direction of the optical film.

Description

Optical film conveying method and polarizing plate manufacturing method

The invention relates to a method for conveying an optical film and a method for manufacturing a polarizing plate.

As a film conveying method, a method of continuously feeding a film, passing a predetermined conveying path, and continuously conveying the film while contacting a plurality of rollers. The various rollers used in the above conveying step include guide rollers that support only one side of the film, or rolls that are arranged on both sides of the film and support the film from both sides. Among them, the roll is used for the purpose of adjusting the tension of the film, driving the conveyed film, pressing the film, and bonding the film.

For example, Japanese Patent Laid-Open No. 2008-90271 (Patent Document 1) discloses a method for manufacturing a polarizing plate by applying an aqueous adhesive to both sides of a polarizing plate, superimposing the polarizing plate and a protective film, and using a roll .

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-90271

In recent years, light-weight and thin image display devices (such as liquid crystal display devices) that consume low power and operate at low voltages have been widely used in mobile phones, portable information terminals, computer monitors, televisions, etc. Information display device. Such an information display device is required to be thinner depending on the application, and thinning is also required for various optical films constituting the same.

However, due to the thinning of the optical film, undulations or curls are likely to occur at the ends of the optical film in the width direction. For example, in the manufacturing process of the polarizing plate, although a humidification process is sometimes performed before attaching the protective film to the polarizing film, sometimes it is undulated or curled at the end in the width direction of the optical film. Here, the term “undulation” means that the end in the width direction of the film forms irregularities along the longitudinal direction of the film, and the term “curl” means that the end in the width direction of the film forms a warp on one side of the film along the longitudinal direction of the film By. In addition, even when the protective film is bonded to the polarizing film using an aqueous adhesive, there may be undulations or curling at the widthwise end of the obtained laminate film. When the undulating or curled portion of the film passes between the rollers, pressure is applied to the portion, which may cause creases or breakage, breakage, or cracking (cracking) of the film. Especially on films with low softness and brittleness, it is easy to cause these problems.

When the film is creased, damaged, cracked, or broken, this part becomes a defective part and is discarded, so the yield of the film is reduced, and the manufacturing efficiency is lowered due to the removal operation of the defective part or the preparation for re-operation of the step. In addition, when the film is damaged or broken, it may sometimes be contaminated in the manufacturing process due to the fragments of the splashed film.

The object of the present invention is to provide a A method of conveying an optical film by a conveying path of a roll constituted by a roll, wherein the method of continuously conveying the film without loss such as creases, breakage, cracks, or breakage of the optical film, and without causing the film A method of manufacturing polarizing plates with creases, breakage, cracks, or fractures.

The present invention provides the following optical film transport method.

[1] A method of transporting an optical film, which transports an optical film along a transport path including a roll composed of a pair of rollers, wherein the optical film is applied to the optical film when it passes between the pair of rollers The pressure at the end in the width direction is smaller than the pressure applied to the center in the width direction of the aforementioned optical film.

[2] The method for transporting an optical film as described in [1], wherein at least one of the pair of rollers is a diameter corresponding to the widthwise end of the optical film, which is more suitable for the optical film. The diameter of the central portion in the width direction is small.

[3] The method for transporting an optical film according to [2], wherein at least one of the pair of rollers includes: a first roller portion having a certain diameter; and disposed at both ends of the first roller portion The second roller portion corresponding to the region of the widthwise end of the optical film and having a smaller diameter than the first roller portion.

[4] The method for transporting an optical film according to [1], wherein at least one of the pair of rollers does not exist in a region corresponding to the widthwise end of the optical film.

[5] The transport method of the optical film as described in any one of [1] to [4] In this method, one of the pair of rollers transports the optical film so as to have an angle of 20° or more and 160° or less.

[6] The method for transporting an optical film according to any one of [1] to [5], wherein the optical film is a laminated optical film in which a plurality of films are bonded through an adhesive or an adhesive.

This invention provides the manufacturing method of the polarizing plate shown below.

[7] A method of manufacturing a polarizing plate, comprising: a step of transporting a raw material film along a transport path including rolls composed of a pair of rollers, and a step of manufacturing a polarizing plate using the transported raw material film; However, when the raw material film passes between the pair of rollers, the pressure applied to the widthwise end of the raw material film is smaller than the pressure applied to the widthwise central portion of the raw material film.

This invention provides the manufacturing method of the polarizing plate shown below.

[8] A method of manufacturing a polarizing plate, comprising: a manufacturing step of manufacturing a polarizing plate using a raw material film, and a transporting step of transporting a polarizing plate along a transport path including a roll composed of a pair of rollers; wherein, when When the polarizing plate passes between the pair of rollers, the pressure applied to the end of the polarizing plate in the width direction is smaller than the pressure applied to the central portion of the polarizing plate in the width direction.

According to the method of the present invention, when the optical film is conveyed along the conveying path including the rolls, the optical film can be free from creases, damage, The optical film is continuously transported under the absence of cracks and breaks. Thereby, in the manufacturing method of the polarizing plate including the conveying step, the film does not cause defects such as creases, breakage, cracks, or breakage, and the decrease in the yield of the polarizing plate caused by the foregoing defects can be suppressed.

1‧‧‧ Polarizer

5‧‧‧ Polarizer

10‧‧‧Optical film

15‧‧‧The first adhesive layer

20‧‧‧axis

25‧‧‧ 2nd adhesive layer

40, 40a, 40b

42、44、46‧‧‧‧

50‧‧‧Sending device

60‧‧‧Guide roller

110‧‧‧The first protective film

120‧‧‧Second protective film

A, B‧‧‧Conveying device

FIG. 1 is a schematic diagram showing an example of a conveying device used in the optical film conveying method of the present invention.

FIG. 2 is a diagram showing an example of the configuration of a roller used in the optical film transport method of the present invention.

FIG. 3 is a diagram showing an example of the configuration of a roller used in the optical film transport method of the present invention.

FIG. 4 is a diagram showing an example of the configuration of a roller used in the optical film transport method of the present invention.

FIG. 5 is a diagram showing an example of a cross-sectional view of the optical film in the width direction.

FIG. 6 is a diagram showing an example of a cross-sectional view of the optical film in the width direction.

FIG. 7 is a cross-sectional view showing an example of the layer configuration of the polarizing plate produced by the method for manufacturing a polarizing plate of the present invention.

FIG. 8 is a cross-sectional view showing an example of the layer configuration of the polarizing plate produced by the method for manufacturing a polarizing plate of the present invention.

FIG. 9 is a schematic diagram showing an example of a conveying device used in the optical film conveying method of the present invention.

<Transport method of optical film>

The optical film transport method of the present invention relates to a method of continuously transporting a long film along a transport path (through a transport path) including at least a pair of rolls constructed by a transport device.

In the present invention, in the step of continuously transporting the optical film along the transport path, when the optical film passes between the pair of rollers, the pressure applied to the width-direction end of the optical film is greater than that applied to the optical film The pressure in the central part of the width direction is small.

As described above, the widthwise end of the optical film has some irregularities such as undulations, curls, etc., so when the optical film passes between the rolls, pressure may be applied to the irregularities, which may cause creases or damage to the optical film , Cracks (cracks), fracture. According to the method of the present invention, when the optical film passes between the pair of rolls, the pressure applied to the widthwise end of the optical film is small, so the pressing load is not applied to the uneven portion, or the pressing load on the uneven portion can be reduced , It can effectively prevent the above-mentioned loss.

An embodiment of the film transport method of the present invention will be described using FIGS. 1 and 9. FIGS. 1 and 9 are schematic diagrams each showing an example of a conveying device used in the film conveying method of the present invention.

FIG. 1 shows how the long optical film 10 is continuously transported along the transport path of the transport device A. In the conveying device A shown in FIG. 1, the conveying path includes: a conveying device 50 that continuously feeds out the optical film by the rotation; a guide roller 60 that supports the traveling optical film; and a pair of rollers滚滚40。 40 roller. Although not shown in the figure, at the downstream end of the conveying path, there is usually a take-up device for taking up the optical film Set and wind up the optical film that has passed the transport path in sequence. In FIG. 1, the solid arrows indicate the film transport direction or the rotation direction of the delivery device.

The transport of the optical film can be performed, for example, in the following manner. First, the long optical film 10 is passed through the transport path to start continuous transport. The elongated optical film 10 is usually prepared by a film roll wound into a roll shape. This film roll is installed in a delivery device (a delivery device 50 or a delivery device different from this), and the optical film 10 is continuously delivered from the delivery device, and is continuously transported in the direction of the solid arrow in FIG. 1.

When the optical film passes between the rollers 40 and 40, the pressure applied to the end in the width direction of the optical film is smaller than the pressure applied to the center in the width direction of the optical film. Here, when passing between the rollers 40 and 40, the pressure applied to the optical film is a value measured by sandwiching a pressure-sensitive paper or a pressure sensor between a pair of rollers. For example, the pressure applied to the end in the width direction is preferably 30% or less of the pressure applied to the center in the width direction, and more preferably 10% or less. The pressure applied to the end in the width direction is preferably 0 kPa.

Next, another embodiment of the film transport method of the present invention will be described using FIG. 9. FIG. 9 is a schematic diagram showing an example of the conveying device B used in the film conveying method of the present invention.

FIG. 9 shows how the long optical film 10 is continuously transported along the transport path of the transport device B. FIG. The basic structure of the conveying device B shown in FIG. 9 is the same as the conveying device A shown in FIG. The difference from the transport device A is that the optical film 10 is transported in a state where it is wound around the roller 40a of the pair of rollers 40a and 40b. A pair of rolls 40a, 40b provided in the conveying device B is arranged, for example, The position of the transfer direction of the film transfer, etc. In FIG. 9, the components with the same symbols as in FIG. 1 are the same as those described in FIG. 1, so the description is omitted. The following description is different from the conveying device A shown in FIG. Point.

As shown in FIG. 9, the conveying device B conveys the optical film 10 at an angle θ. Here, the included angle θ refers to the central angle formed by the arc of the outer peripheral surface of the roll contacting the optical film 10 as shown in FIG. 9. Specifically, the included angle θ is expressed by the included angle θ[°]=(optical film 10 is the circumferential length of the roll from the position in contact with the roll to the distant position/the circumferential length of the roll)×360[°] As shown.

In detail, the conveying device B is different from the conveying device A (FIG. 1) in which the included angle of the optical film 10 on the pair of rolls 40 and 40 is substantially the same. In the pair of rolls 40a and 40b, the roll 40a is used. The angle of the optical film 10 in the middle is larger than the angle of the optical film 10 in the roll 40b, and the optical film 10 is conveyed. When the optical film 10 is transported by being wrapped around the roller 40a as in the transport device B, the pressure of the optical film 10 pressed against the radial center of the roller 40a is greater than the pressure of the roller 40 of the transport device A.

In the present embodiment, as described above, when the optical film 10 passes between the rollers 40a and 40b, the pressure applied to the widthwise end of the optical film 10 is smaller than the pressure applied to the widthwise center of the optical film 10 . For example, the pressure applied to the end in the width direction is preferably 30% or less of the pressure applied to the center in the width direction, and more preferably 10% or less. The pressure applied to the end in the width direction is preferably 0 kPa.

Therefore, when the optical film 10 passes through a pair of rollers 40a, 40b In the meantime, even if the optical film 10 is relatively strongly pressed toward the radial center of the roller 40a, the pressure applied to the end in the width direction of the optical film 10 can be reduced. Thereby, even if the optical film 10 has some irregularities such as undulations or curls at the end in the width direction, the pressing load will not be applied to the irregularities at the widthwise end of the optical film 10 or may be reduced to The pressing load can suppress the occurrence of creases, breakage, cracks (cracking) and breakage in the optical film.

In the conveying device B, the distance by which the optical film 10 contacts the outer peripheral surface of the roller 40a and is transported is relatively longer than the distance by which it contacts the outer peripheral surface of the other roller 40b. Therefore, not only the pressing load from the rolling portions of the rolls 40a, 40b, but also the contact of the roll 40a with the optical film 10, the pressing load may be easily applied to the uneven portion at the end in the width direction of the optical film 10. In addition, the distance that the optical film 10 is transported in contact with the outer peripheral surface of the roller 40a is relatively longer than the distance transported in contact with the outer peripheral surface of the roller 40 of the transport device A (Figure 1). Therefore, when the conveying device B is used, compared with the case where the conveying device A is used, the contact of the roller 40 a with the optical film 10 may make it easier for the pressing load to be applied to the uneven portion at the end in the width direction of the optical film 10.

At this time, in this embodiment, since the pressure applied to the end in the width direction is smaller than the pressure applied to the center in the width direction of the optical film 10, the pressing load applied to the end in the width direction of the optical film 10 can be suppressed. This can suppress the occurrence of creases, breakage, cracks (cracking), and breakage of the optical film.

In the method for transporting an optical film of the present invention, when the angle θ of the optical film used on one roll constituting the roll is 20° or more and 160° or less At this time, a further effect can be obtained, and the effect is more remarkable when it is used above 60° and below 120°.

The transport path for transporting the optical film may include two or more roller pairs. At this time, for all the roller pairs, when the optical film passes between the rollers 40, 40 or the rollers 40a, 40b, the pressure applied to the end in the width direction of the optical film is preferably less than that applied to the center in the width direction of the optical film Ministry of pressure is small.

The film transport speed when continuously transporting the optical film along the transport path is, for example, in the range of 2 to 120 m/min, preferably in the range of 10 to 50 m/min.

The method for transporting an optical film of the present invention can be applied to a step of continuously transporting an optical film and all manufacturing steps using an optical film including the transport step. Specific examples of this manufacturing step include the steps of applying a certain treatment (such as coating treatment or stretching treatment) to the optical film, or the step of attaching the optical film to other members (film, etc.). The transport method of the optical film can use the transport of the optical film before and after these manufacturing steps.

<Roller>

The nip rollers 40, 40, 40a, and 40b are a pair of rollers arranged above and below the film to be transported, and can be nipped and pressed from above and below. The rollers 40, 40, 40a, and 40b can take the role of adjusting and controlling the tension of the film to be transported, the driving force for the film transport, the control of the film transport speed, the pressing of the film, and the direction change of the film transport.

The rolls 40, 40, 40a, and 40b will be described using FIGS. 2 to 6. Figures 2 to 4 are diagrams each showing an example of the structure of a roll used for a roll. FIGS. 5 and 6 are diagrams each showing an example of a cross-sectional view of the optical film in the width direction.

As shown in FIG. 2, the roller 42 includes the roller portion 32 and the shaft 20. The shaft 20 is a shaft that is rotatably supported by the rollers and is coupled to both end surfaces of the roller portion 32. The roller portion 32 is composed of a first roller portion 32a and second roller portions 32b disposed at both ends of the first roller portion 32a in the roller axis direction. The first roller portion 32a and the second roller portion 32b each have a cylindrical shape with a constant diameter, and share a rotation axis. The diameter D2 of the second roller portion 32b is smaller than the diameter D1 of the first roller portion 32a.

As shown in FIGS. 5 and 6, the optical film 10 has a flat central portion 10a in the width direction, and has undulations or curls at the end portions 10b in the width direction. When the optical film 10 passes the roller, the central portion 10a in the width direction of the optical film passes through the portion sandwiched by the first roller portion 32a of the roller 42, and the end 10b in the width direction of the optical film passes through the second roller portion 32b. Part. That is, the first roller portion 32a is a region corresponding to the widthwise center portion 10a of the optical film, and the second roller portion 32b is a region corresponding to the widthwise end portion 10b of the optical film.

The length L3 of the first roller portion 32a along the roller axis direction is shorter than the width W3 of the optical film 10 being transported, and preferably shorter than the width W1 of the central portion 10a in the width direction of the optical film. As a result, when the optical film 10 passes between the rollers composed of the pair of rollers 42, the end 10b in the width direction of the optical film 10 is located outside the first roller portion 32a in the roller axis direction, so The pressure from the first roller portion 32a is not applied to the widthwise end portion 10b of the optical film 10, but the pressure from the second roller portion 32b is applied. Since the diameter of the second roller portion 32b is smaller than that of the first roller portion 32a, the pressure applied to the widthwise end portion 10b of the optical film 10 sandwiched by the second roller portion 32b is smaller than that of the first roller portion 32a The pressure of the central portion 10a in the width direction of the sandwiched optical film 10 is small. Therefore, even if there are irregularities such as undulations or curls at the end 10b in the width direction of the optical film 10, the pressure applied to the irregularities when passing through the roller is small, and the folding of the optical film caused by the irregularities being sandwiched by the roller can be suppressed Marks, breakage, cracks (cracks), fractures. The length L3 of the first roller portion 32a along the roller axis direction may be, for example, 300 mm or more and 2300 mm or less.

The length L2 of the second roller portion 32b along the roller axis direction is preferably longer than the width W2 of the width-direction end portion 10b of the optical film 10 to be transported. The width W2 of the end 10b in the width direction of the optical film 10 means the distance along the width direction of the end 10b in the width direction in the presence of irregularities such as undulations or curls. According to this, since the width-direction end 10b of the optical film 10 is accommodated in the gap formed between the pair of second roller portions 32b, the deformation of the optical film 10 in the thickness direction can be suppressed. Therefore, when the optical film 10 passes through the roller, excessive occurrence of undulation or curling can be suppressed, and folds, breakage, cracks (cracking), and breakage of the optical film can be effectively suppressed. The length L2 of the second roller portion 32b along the roller axis direction may be, for example, 30 mm or more and 200 mm or less.

The difference (L1×2) between the diameter D1 of the first roller portion 32a and the diameter D2 of the second roller portion 32b is preferably 20 mm or less, and more preferably 10 mm or less. According to this, it is possible to suppress the undulation or curling of the end 10b in the width direction of the optical film 10 Excessive occurrence of music. On the other hand, the difference between the diameter D1 of the first roller portion 32a and the diameter D2 of the second roller portion 32b is preferably 2 mm or more, and more preferably 5 mm or more. According to this, it is possible to sufficiently reduce the pressure applied to the widthwise end portion 10b of the optical film 10, and to suppress the creases, breakage, and cracks (cracks) of the optical film caused by the unevenness of the widthwise end portion 10b being sandwiched by the roller ),fracture.

Next, another configuration of the roll used for the roll will be described using FIG. 3. The roller 44 shown in FIG. 3 includes the roller portion 34 and the shaft 20. The roller portion 34 is composed of a first roller portion 34a and second roller portions 34b disposed at both ends of the first roller portion 34a in the roller axis direction. The basic configuration of the roller 44 shown in FIG. 3 is the same as the roller 42 shown in FIG. The difference from the roller 42 is that the second roller portion 34b has a tapered shape whose diameter gradually decreases toward the end portion of the roller 44 in the axial direction from the portion in contact with the first roller portion 34a. In FIG. 3, the cross section passing through the roller rotation axis is straight from the portion in contact with the tapered first roller portion 34a to the axial end of the roller 44, but it is not limited to this. For example, from the portion in contact with the first roller portion 34a to the end in the axial direction of the roller 44, the cross section passing through the roller rotation axis may be curved, and the tapered outer shape may be constituted by a curved surface.

The length L3 of the first roller portion 34a along the roller axis direction is shorter than the width W3 of the optical film 10 being transported, and preferably shorter than the width W1 of the central portion 10a in the width direction of the optical film. As a result, when the optical film 10 passes between the rollers composed of the pair of rollers 44, the width-direction end 10 b of the optical film 10 is located outside the first roller portion 34 a in the roller axis direction, so the first roller portion 34a pressure is not applied to the width direction end of the optical film 10 Pressure from the second roller 34b. Since the diameter of the second roller portion 34b is smaller than that of the first roller portion 34a, the pressure applied to the width-direction end 10b of the optical film 10 sandwiched by the second roller portion 34b is smaller than that of the optics sandwiched by the first roller portion 34a. The pressure at the central portion 10a in the width direction of the membrane 10 is small. Therefore, even if there are irregularities such as undulations or curls at the end 10b in the width direction of the optical film 10, the pressure applied to the irregularities when passing through the roller is small, and the creases in the optical film caused by the irregularities being sandwiched by the roller can be suppressed , Damage, cracking (cracking), fracture. The length L3 of the first roller portion 34a along the roller axis direction may be, for example, 300 mm or more and 2300 mm or less.

The length L2 of the second roller portion 34b along the roller axis direction is preferably longer than the width W2 of the width-direction end portion 10b of the optical film 10 to be transported. The width W2 of the end 10b in the width direction of the optical film 10 means the distance along the width direction of the end 10b in the width direction in the presence of irregularities such as undulations or curls. According to this, since the width-direction end portion 10b of the optical film 10 is accommodated in the gap formed between the pair of second roller portions 34b, the deformation of the optical film 10 in the thickness direction can be suppressed. Therefore, when the optical film 10 passes through the roll, excessive generation of undulation or curl can be suppressed, and folds, breakage, cracks (cracking), and breakage of the optical film can be effectively suppressed. The length L2 of the second roller portion 34b along the roller axis direction may be, for example, 30 mm or more and 200 mm or less.

The difference (L1×2) between the diameter D1 of the first roller portion 34a and the axial end portion of the second roller portion 34b is preferably 20 mm or less, and more preferably 10 mm or less. According to this, it is possible to suppress excessive generation of undulation or curling of the end portion 10b in the width direction of the optical film 10. On the other hand, the first roller portion 34a The difference between the diameter D1 and the diameter D2 of the axial end of the second roller portion 34b is preferably 2 mm or more, and more preferably 5 mm or more. According to this, it is possible to sufficiently reduce the pressure applied to the widthwise end portion 10b of the optical film 10, and to suppress the creases, breakage, and cracks (cracks) of the optical film caused by the unevenness of the widthwise end portion 10b being sandwiched by the roller ),fracture.

Next, another configuration of the roll used for the roll will be described using FIG. 4. The roller 46 shown in FIG. 4 includes a roller portion 36 and a shaft 20. The roller portion 36 is composed of a cylindrical first roller portion 36a having a certain diameter. That is, the roller 46 is constituted only by the first roller portion 36a, and does not include the second roller portion having a smaller diameter than the first roller portion 36a.

The length L3 of the first roller portion 36a along the roller axis direction is shorter than the width W3 of the optical film 10 being transported, and preferably shorter than the width W1 of the central portion 10a in the width direction of the optical film. As a result, when the optical film 10 passes between the rollers composed of the pair of rollers 46, the end 10b in the width direction of the optical film 10 is located outside the first roller portion 36a in the roll axis direction, so even the optical film 10 There are irregularities such as undulations or curls at the end 10b in the width direction, and no pressure is applied to the irregularities when passing through the rollers, which can suppress the creases, damages, and cracks (cracks) of the optical film caused by the irregularities being sandwiched by the rollers ),fracture.

In the above, among the rolls composed of a pair of rolls, it is explained that both of the rolls are the rolls shown in FIG. 2 to FIG. 4, but if at least one roll is shown in FIG. 2 to FIG. 4 When the optical film passes between a pair of rollers, the pressure applied to the ends of the optical film in the width direction can be made smaller than the pressure applied to the central portion of the optical film in the width direction. Compare Preferably, the rollers formed by a pair of rollers are the rollers of the shapes shown in Figures 2 to 4. In addition, in a pair of rollers, the rollers of FIGS. 2 to 4 may be used in combination.

As described above in the conveying device B (Figure 9), when the optical film 10 is conveyed in a state where the respective angles of the pair of rolls 40a and 40b are different, the optical film 10 is oriented toward the radial center of the roll 40a toward the side where the angle is relatively large The optical film 10 is conveyed in a state of being pressed tightly. Therefore, in order to reduce the pressure applied to the ends of the optical film 10 in the width direction, it is preferable to use the rollers of the shapes shown in FIGS. .

The material of the rollers 40, 40, 40a, 40b may be metal or rubber. The pair of rollers 40, 40, 40a, 40b may be made of the same material as each other, or may be made of different materials. The diameter of the rolls 40, 40, 40a, and 40b is not particularly limited, but it is usually in the range of 100 to 700 mm φ, preferably in the range of 150 to 400 mm φ.

When the rollers 40, 40, 40a, 40b are rubber rollers, the rubber layer on the surface can be chloroprene rubber (CR), polysiloxane rubber (Si), natural rubber (NR), styrene-butadiene Diene rubber (SBR), nitrile rubber (NBR), ethylene-propylene rubber (EPDM), fluorine rubber (FPM), butyl rubber (IIR), urethane rubber (U), chlorinated polyethylene rubber ( CSM) etc. The surface hardness of the rubber roller is preferably 20 to 95 degrees, and particularly preferably 40 to 90 degrees.

When at least one of the pair of rollers 40, 40, 40a, and 40b is a metal roller or a high-hardness rubber roller, creases, breakage, cracks, and breakage are likely to occur at the end 10b of the optical film 10 in the width direction. Therefore, the method of the present invention is particularly effective under such circumstances.

<Optical Film>

Examples of optical films that can be used in the present invention include: polarizers (polarizing films); protective films; retardation films; optical compensation films in which liquid crystal compounds are coated and oriented on the substrate surface; and certain polarized light can be used Reflective polarizing film that penetrates and shows the light reflection of polarized light of the opposite nature; film with anti-glare function on the surface with uneven shape; film with anti-reflective function on the surface; film with reflective function on the surface Reflective film; semi-transmissive reflective film with both reflective function and penetrating function; viewing angle compensation film, etc.

Examples of the polarizer are those in which the polyvinyl alcohol-based resin layer adsorbs directional iodine.

The protective film is a thermoplastic resin having translucency (preferably optically transparent), and examples thereof include chain polyolefin resins (polypropylene resins, etc.) and cyclic polyolefin resins (norbornene resins, etc.). ) General polyolefin resin; cellulose triacetate, cellulose diacetate-like cellulose ester resin; polyester resin; polycarbonate resin; (meth)acrylic resin; polystyrene resin; Or a film composed of these mixtures, copolymers, etc.

Commercially available products equivalent to retardation films made of cyclic polyolefin resins include "ARTON Film" (manufactured by JSR Corporation), "S-SINA" (manufactured by Sekisui Chemical Industry Co., Ltd.), "ZEONOR" (manufactured by Zeon Japan Co., Ltd.), etc.

Commercial products equivalent to optical compensation films include "WV Film" (manufactured by Fuji Film Co., Ltd.), "NH Film" (manufactured by JX Nippon Oil and Energy Co., Ltd.), and "NR Film" (JX Nippon Oil and Energy Co., Ltd.).

Commercial products equivalent to reflective polarizing films include "DBEF" (manufactured by 3M Company, available from Sumitomo 3M Co., Ltd.) and "APF" (manufactured by 3M Company, available from Sumitomo 3M Co., Ltd.).

Examples of the viewing angle compensation film include an optical compensation film coated with a liquid crystal compound and oriented on the surface of a substrate, a retardation film composed of a polycarbonate resin, and a retardation film composed of a cyclic polyolefin resin, etc. .

The optical film may be a single-layer optical film composed only of any one of the above-mentioned optical films, or a laminated optical film composed of a multi-layer structure of 2, 3 or more layers.

The laminated optical film may be, for example, a film in which a protective film is attached to a polarizing film through an aqueous adhesive. At this time, due to the difference in the expansion ratio of each film due to moisture, undulations or curls are likely to occur at the end in the width direction of the laminated optical film. This deficiency is especially noticeable when different protective films (for example, cellulose triacetate (TAC) film and cyclic polyolefin resin (COP) film) are attached to both sides of the polarizing film through an aqueous adhesive. The present invention is preferably applied to optical films that are prone to such deletion.

In addition, even when a plurality of films are bonded through an adhesive or an adhesive as a laminated optical film, the optical film transport method of the present invention can be preferably used. The laminated optical film is in a state where the adhesive or adhesive is easily deformed before drying, hardening, etc., and the adhesive or adhesive easily penetrates from the end of the laminated optical film due to the pressure applied during transportation Out. The exudation of the adhesive or the adhesive may cause contamination of the transport path or manufacturing path of the laminated optical film, or contamination of the outer surface of the laminated optical film.

Therefore, in the step of continuously transporting the laminated optical film along the transport path, by using the roll of the present invention, the pressure applied to the widthwise end of the laminated optical film can be reduced compared to the widthwise center applied to the laminated optical film The pressure of the department is less. With this, the adhesive or the adhesive can be suppressed from being squeezed out from the end of the laminated optical film toward the outer side in the width direction of the laminated optical film, and the adhesive or the adhesive can be prevented from oozing out from the end of the laminated optical film. As a result, contamination of the transport path or manufacturing path of the laminated optical film due to the bleed of the adhesive or adhesive, or contamination of the outer surface of the laminated optical film can be suppressed.

In the manufacturing method of the polarizing plate described later, the polarizer and the protective film are bonded through the adhesive. Therefore, especially in the conveying step before the curing of the adhesive, by using the optical film conveying method of the present invention, the adhesive can be prevented from oozing out from the end of the laminated optical film, thereby suppressing contamination of the manufacturing path of the polarizing plate or polarizing plate Contamination of external surfaces.

<Manufacturing method of polarizing plate>

The manufacturing method of the polarizing plate of the present invention includes a transporting step of transporting the raw material film along a transporting path including rolls composed of a pair of rollers, and a manufacturing step of manufacturing the polarizing plate using the transported raw material film. In the conveying step, when the raw material film passes between the pair of rollers, the pressure applied to the widthwise end of the raw material film is smaller than the pressure applied to the widthwise central portion of the raw material film.

The roller used in the conveying step can be the same as the roller used in the above-mentioned optical film conveying method. As a result, when the raw material film passes between the pair of rolls, the pressure applied to the widthwise end of the raw material film is small, and the pressing load is not applied to the uneven portion, or the pressing load that can be reduced to the uneven portion is effective. To prevent creases, breakage, cracks (cracking) and breakage of the raw material film due to pressure applied to the uneven portions.

Another method of manufacturing a polarizing plate of the present invention includes: a manufacturing step of manufacturing a polarizing plate using a raw material film, and a transporting step of transporting a polarizing plate along a transport path including a roll composed of a pair of rollers. In the conveying step, when the polarizing plate passes between the pair of rollers, the pressure applied to the end portions of the polarizing plate in the width direction is smaller than the pressure applied to the central portion of the polarizing plate in the width direction.

The roller used in the conveying step can be the same as the roller used in the above-mentioned optical film conveying method. As a result, when the polarizing plate passes between the pair of rolls, the pressure applied to the end portions of the polarizing plate in the width direction is small, and the pressing load is not applied to the uneven portion, or the pressing load on the uneven portion can be reduced, which is effective To prevent creases, breakage, cracks (cracking) and breakage of the polarizing plate due to pressure applied to the uneven portion.

<Polarizer>

(1) Structure of polarizing plate

Fig. 7 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate produced by the method for manufacturing a polarizing plate of the present invention. As shown in FIG. 7, the polarizing plate 1 may include: a polarizer (polarizing film) 5, a first adhesive agent The layer 15 is laminated on both sides of the first protective film 110 of the polarizer and the second protective film 120 laminated on the other side of the second protective film 120 through the second adhesive layer 25. The polarizing plate 1 may further have other optical layers or adhesive layers etc. laminated on the first protective film 110 and/or the second protective film 120.

In addition, the polarizing plate is like the polarizing plate 2 shown in FIG. 8, and may be provided with a polarizer 5 and a single side of the first protective film 110 laminated on one side of the polarizer through the first adhesive layer 15. Polarizer with protective film. The polarizing plate 2 may further have other optical layers (or optical films), adhesive layers, or the like laminated on the first protective film 110 and/or the polarizer 5. Examples of other optical layers include the above-mentioned various optical films.

Hereinafter, the polarizing plate, the protective film of the raw material film of the polarizing plate, and the laminated optical film on which the protective film is attached to one or both sides of the polarizing plate will be described.

(2) Polarizer

The polarizer 5 is used for the polyvinyl alcohol-based resin layer to adsorb and orient iodine. For the polarizing film, for example, a polarizing film manufactured by a method including the steps of: a step of uniaxially stretching a polyvinyl alcohol-based resin film; and iodine adsorption by dyeing the polyvinyl alcohol-based resin film with iodine Steps: a step of treating the polyvinyl alcohol resin film adsorbed with iodine by an aqueous solution of boric acid; and a step of washing with water after the treatment of the aqueous solution of boric acid.

As the polyvinyl alcohol-based resin, those that saponify the polyvinyl acetate-based resin can be used. Polyvinyl acetate-based resins, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, can also be exemplified by vinyl acetate and Copolymer of other monomers for copolymerization. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides with ammonium groups.

The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol%. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl formaldehyde and polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The average degree of polymerization of the polyvinyl alcohol-based resin can be determined in accordance with JIS K 6726.

A film made of such a polyvinyl alcohol-based resin can be used as a base material film of the polarizing film 5 (polarizing film). The method of forming the polyvinyl alcohol-based resin into a film is not particularly limited, and a generally known method can be used. The film thickness of the polyvinyl alcohol-based embryo material film is, for example, about 10 to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before, simultaneously with, or after dyeing with iodine. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before or during boric acid treatment. In addition, it is also possible to perform uniaxial stretching in these plural stages.

In uniaxial stretching, uniaxial stretching can be performed between rollers with different peripheral speeds, or uniaxial stretching using hot rollers. In addition, the uniaxial stretching may be dry stretching performed in the atmosphere, or wet stretching performed in a state in which the polyvinyl alcohol-based resin film is swelled using a solvent. The stretching ratio is usually about 3 to 8 times.

The method of dyeing the polyvinyl alcohol-based resin film with iodine can be, for example, by dipping the polyvinyl alcohol-based resin film in an aqueous solution containing iodine (dyeing) Bath) method. Before the dyeing treatment of the polyvinyl alcohol-based resin film, it is preferably pre-treated by immersion in water.

According to the dyeing treatment performed by iodine, a method of immersing the polyvinyl alcohol-based resin film in a dyeing bath containing iodine and potassium iodide is generally used. The content of iodine in the dyeing bath is 100 parts by weight of water, which may be about 0.01 to 1 part by weight. The content of potassium iodide is per 100 parts by weight of water, which may be about 0.5-20 parts by weight. The temperature of the dyeing bath can be about 20-40°C.

The boric acid treatment after dyeing by iodine is usually a method of immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid (crosslinking bath). The cross-linking bath preferably contains potassium iodide. The amount of boric acid in the crosslinking bath is about 1 to 15 parts by weight per 100 parts by weight of water, and the amount of potassium iodide is about 0.1 to 15 parts by weight per 100 parts by weight of water. The temperature of the cross-linking bath may be about 50°C or higher, for example, 50 to 85°C.

The polyvinyl alcohol resin film after boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing the polyvinyl alcohol-based resin film treated with boric acid in water. The temperature of the water during the washing process is usually about 5 to 40°C. The dipping time is usually about 1 to 120 seconds.

After washing with water and applying a drying treatment, the polarizer 5 can be obtained. The drying process can be performed using a hot air dryer or a far-infrared heater. The thickness of the polarizer 5 is preferably 15 μm or less, and particularly preferably 10 μm or less. By setting the thickness of the polarizer 5 to 15 μm or less, the polarizing plates 1 and 2 can be thinned. The thickness of the polarizer 5 is usually 5 μm or more.

(3) The first and second protective films

The first and second protective films 110 and 120 may be made of a thermoplastic resin having translucency (preferably optically transparent), for example, a chain polyolefin resin (polypropylene resin, etc.), a ring -Like polyolefin resin (norbornene-based resin, etc.)-like polyolefin resin; cellulose triacetate, cellulose diacetate-like cellulose ester resin; polyester resin; polycarbonate resin; (A Base) acrylic resin; polystyrene resin; or a film composed of these mixtures, copolymers, etc. The first protective film 110 and the second protective film 120 may be the same type of protective film, or different types of protective films. However, when the first protective film 110 and the second protective film 120 are different types of protective films, these protective films are attached to the laminated optical film of the polarizer. Due to the expansion ratio of each film due to moisture If it is poor, it will be prone to undulation or curling at the end in the width direction of the laminated optical film. In addition, although the first protective film 110 and the second protective film 120 may be subjected to a humidification process before being bonded to the polarizer, at this time, the end portions of the protective film in the width direction are also prone to undulation or curling. The present invention can be preferably applied to a film that is prone to this deletion.

The first and/or second protective films 110 and 120 may also be protective films with optical functions like phase difference films and brightness enhancement films. For example, a film composed of the above thermoplastic resin can be stretched (uniaxial stretching or biaxial stretching, etc.), or a liquid crystal layer can be formed on the film to form a retardation film with an arbitrary retardation value. .

In addition to the homopolymers of chain olefins such as polyethylene resins and polypropylene resins, the chain polyolefin resins may also include copolymers composed of two or more chain olefins.

Cyclic polyolefin resins use cyclic olefins as polymerized monomers Generic term for resin polymerized by Yuan. Specific examples of cyclic polyolefin resins include: ring-opening (co)polymers of cyclic olefins, addition polymers of cyclic olefins, copolymerization of cyclic olefins with chain olefins such as ethylene and propylene Substances (representatives include random copolymers), graft polymers modified with unsaturated carboxylic acids or the derivatives, and these hydrides. Among them, it can be preferably used as a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as a cyclic olefin.

The cellulose ester resin is an ester of cellulose and fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate (TAC) and cellulose diacetate. In addition, these copolymers may be used, or a part of hydroxyl groups may be modified with other substituents. Among these, the best is TAC.

The polyester-based resin is a resin other than the above-mentioned cellulose ester-based resin having an ester bond, and is generally composed of a polycondensate of a polycarboxylic acid or the derivative and a polyol. As the polycarboxylic acid or the derivative, dicarboxylic acid or the derivative can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalene dicarboxylate. As the polyol, diols can be used, and examples thereof include ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol.

Specific examples of polyester resins include: polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polytriphthalate Methyl ester, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate.

Polycarbonate resins pass through carbonate groups from monomer units Bonded polymer. The polycarbonate-based resin may also be a resin called modified polycarbonate whose polymer skeleton is modified, or a copolymerized polycarbonate.

The (meth)acrylic resin is a resin mainly composed of a compound having a (meth)acryloyl group. Specific examples of (meth)acrylic resins include, for example: poly(meth)acrylate like poly(meth)acrylate; methyl methacrylate-(meth)acrylic acid copolymer; methacrylic acid methyl Ester-(meth)acrylate copolymer; methyl methacrylate-acrylate-(meth)acrylic acid copolymer; methyl methacrylate-styrene copolymer (MS resin, etc.); methyl methacrylate and Copolymers of compounds with alicyclic hydrocarbon groups (eg methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornyl methacrylate copolymer, etc.). Preferably, a polymer containing poly(meth)acrylate C _1-6 alkyl (meth)acrylate as a main component is used, and particularly preferably a methyl methacrylate (50~ 100% by weight, preferably 70 to 100% by weight) methyl methacrylate resin.

Hard coating, anti-glare layer, anti-reflective layer, anti-charge layer, anti-fouling layer, etc. can also be formed on the surface of the first and/or second protective films 110, 120 opposite to the polarizer 5 The surface treatment layer (coating layer).

The thickness of the first and second protective films 110 and 120 is preferably 90 μm or less, particularly preferably 50 μm or less, and more preferably 40 μm or less from the viewpoint of thinning the polarizing plates 1 and 2. The thickness is usually 5 μm or more from the viewpoint of strength and handleability.

(4) Laminated optical film

The laminated optical film is formed by attaching a protective film to one or both sides of the polarizer through the adhesive layer, and then undergoes a drying step and a cutting step as necessary to produce a polarizing plate. As the adhesive for forming the first and second adhesive layers 15, 25, an aqueous adhesive or an active energy ray-curable adhesive can be used. The adhesive forming the first adhesive layer 15 and the adhesive forming the second adhesive layer 25 may be the same type or different types.

Examples of the water-based adhesive agent include an adhesive agent composed of a polyvinyl alcohol-based resin aqueous solution, and an aqueous two-component urethane-based emulsified adhesive agent. Among them, an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin can be preferably used.

Polyvinyl alcohol-based resins can be used in addition to vinyl alcohol homopolymers obtained by saponification of polyvinyl acetate homopolymer polyvinyl acetate, and can be used for vinyl acetate and other monomers copolymerizable with this A polyvinyl alcohol-based copolymer obtained by saponification of the copolymer, or a modified polyvinyl alcohol-based copolymer in which these hydroxyl groups are partially modified. The water-based adhesive may contain additives such as polyaldehydes, water-soluble epoxy compounds, melamine-based compounds, zirconium compounds, and zinc compounds.

When the water-based adhesive is used, after the polarizer 5 and the protective film are bonded, it is preferable to perform a drying step for removing and drying the water contained in the water-based adhesive. After the drying step, for example, it can be set as follows: a aging step for aging at a temperature of about 20 to 45°C.

The above-mentioned activation energy ray-curable adhesive means an adhesive that is hardened by irradiation of activation energy rays like ultraviolet rays, and examples thereof include those containing a polymerizable compound and a photopolymerization initiator, and containing photoreactivity. Resin, those containing binder resin and photoreactive crosslinking agent, etc. Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy monomers, photocurable acrylic monomers, photocurable urethane monomers, or oligomerization derived from photopolymerizable monomers Thing. Examples of the photopolymerization initiator include substances containing activated species such as neutral free radicals, anionic free radicals, and cationic free radicals that are generated by irradiation of activation energy rays such as ultraviolet rays. As the activation energy ray-curable adhesive containing a polymerizable compound and a photopolymerization initiator, those containing a photocurable epoxy monomer and a photocationic polymerization initiator can be preferably used.

When the active energy ray-curable adhesive is used, after the polarizer 5 and the protective film are bonded, a drying step may be performed as necessary, followed by a curing step of curing the active energy ray-curable adhesive by irradiating the active energy ray. The light source of the activation energy ray is not particularly limited, and it is preferably ultraviolet light having a luminous distribution below 400 nm. Specifically, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, Chemical lamps, black lamps, microwave-excited mercury lamps, metal halide lamps, etc.

(5) Adhesive layer

On the first protective film 110 or the second protective film 120 on the polarizing plate 1 shown in FIG. 7, and on the polarizing plate 5 on the polarizing plate 2 shown in FIG. 8, a polarizing plate can be laminated Adhesive layer attached to other members (such as liquid crystal cells when applied to liquid crystal display devices). The adhesive that forms the adhesive layer is usually made of (meth)acrylic resin, styrene resin, polysiloxane resin, etc. as the matrix polymer, and the isocyanate compound, A crosslinking agent such as an epoxy compound and an aziridine compound is added to the adhesive composition. In addition, it may be configured as an adhesive layer that further contains fine particles and exhibits light scattering properties. The thickness of the adhesive layer can be set to 1 to 40 μm. Within a range that does not impair the characteristics of workability and durability, it is preferably formed to be thin, and specifically, it is preferably 3 to 25 μm.

The method of forming the adhesive layer is not particularly limited, and an adhesive composition (adhesive solution) containing each component including the above-mentioned matrix polymer can be applied to the surface of the protective film or the surface of the polarizer, and dried to form the adhesive layer Or, after forming the adhesive layer on the separator (release film), transfer the adhesive layer to the surface of the protective film or the surface of the polarizing film. When the adhesive layer is formed on the surface of the protective film or the polarizer, the protective film, polarizer, or one or both sides of the adhesive layer may be subjected to surface treatment, such as corona treatment, if necessary.

(6) Manufacturing method of polarizing plate

The first protective film 110 can be bonded to the polarizer 5 (polarizing film) through the first adhesive layer 15 according to a general method, whereby a raw material film for a polarizing plate with a protective film on one side can be obtained. Using this raw material film for a polarizing plate with a protective film on one side, the polarizing plate 2 with a protective film on one side shown in FIG. 8 can be obtained. In addition, if the second protective film 120 is bonded to the other surface of the polarizer 5 through the second adhesive layer 25, a raw material film for polarizing plates with a protective film on both sides can be obtained. Using this raw material film for a polarizing plate with a protective film on both sides, a polarizing plate 1 with a protective film on both sides shown in FIG. 7 can be obtained. When obtaining a polarizing plate 1 with a protective film on both sides, the first and second protective films 110 and 120 can be attached simultaneously or successively.

[Example]

In the following, examples are shown to explain the present invention more specifically, but the present invention is not limited to these examples.

<Example 1>

(A) Fabrication of polarizing film

While continuously transporting a long-form polyvinyl alcohol film (average degree of polymerization: about 2400, saponification degree: 99.9 mol% or more, thickness 30 μm), while uniaxially stretching it to about 4 times in a dry manner, and then keep pulling After being immersed in pure water at 40°C for 1 minute in a tight state, it was immersed in an aqueous solution having a weight ratio of iodine/potassium iodide/water of 0.1/5/100 at 28°C for 60 seconds. It was then immersed in an aqueous solution having a weight ratio of potassium iodide/boric acid/water of 10.5/5.5/100 at 68°C for 300 seconds. Next, after washing with pure water at 5°C for 5 seconds and drying at 70°C for 180 seconds, a long polarized film with iodine adsorbed and oriented on the polyvinyl alcohol film after uniaxial stretching was obtained. The thickness of the polarizing film is 11.1 μm, and the width is 1280 mm.

(B) Fabrication of laminated optical film

Continuously transport the polarizing film obtained in (A) above, and continuously transport the long first thermoplastic resin film [a film formed with a hard coat layer on the TAC film "KC2UAW" manufactured by Konica Minolta Opto Co., Ltd., Thickness: 32.4 μm, width: 1330 mm], and a long second thermoplastic resin film [cyclic polyolefin resin film made by JSR Corporation, trade name “FEKB015D3”, thickness: 15.1 μm, width: 1330 mm] ,One Injecting the water-based adhesive between the polarizing film and the first thermoplastic resin film and between the polarizing film and the second thermoplastic resin film, while passing between the bonding rollers, the first thermoplastic resin film/water-based adhesive is obtained Multilayer optical film composed of layer/polarizing film/water-based adhesive layer/second thermoplastic resin film. The above-mentioned water-based adhesive agent is used: a crosslinking agent [sodium glyoxylate manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] is mixed with the polyvinyl alcohol powder at a ratio of 1 part by weight relative to 10 parts by weight of the polyvinyl alcohol powder. [Trade name "Gohsefimer" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., average degree of polymerization 1100] An aqueous solution obtained by dissolving in a 3% by weight aqueous polyvinyl alcohol solution dissolved in hot water at 95°C. The width-direction end of the obtained laminated optical film was undulated in a range of about 30 mm in width.

(C) Transportation of laminated optical film

The obtained laminated optical film was continuously conveyed at a conveying speed of 1 to 40 m/min through a conveying path including rollers composed of rubber rollers. A pair of rolls constituting the roll, either of which has the shape shown in FIG. 2 (the length of the first roll part L3: 1260 mm, the length of the second roll part L2: 700 mm, the diameter of the first roll part D1: 150 mm, The diameter D2 of the second roller part: 145 mm). When the laminated optical film passes through the roller, the positional relationship between the laminated optical film and the roller is adjusted so that the widthwise end of the polarizing plate passes through the gap between the second roller portions, so that the laminated optical film does not cause creases, damage, It is cracked and broken, and the laminated optical film is continuously transported without problems. In addition, the exudation system of the water-based adhesive from the end of the laminated optical film after passing through the roll was not observed.

<Example 2>

Use the shape shown in Figure 3 (L3 of the first roller part: 1260 mm, L2 of the second roller part: 700 mm, D1 of the first roller part: 150 mm, D2 of the second roller part: 140 mm) As for the roll used in Example 1 (C), the rest is the same as in Example 1 and continuous transport of the laminated optical film is performed. When the laminated optical film passes through the roller, the positional relationship between the laminated optical film and the roller is adjusted so that the widthwise end of the laminated optical film passes through the gap between the second roller portions, so that the laminated optical film does not cause creases or damage , Crack, break, and transport the laminated optical film continuously without problems. In addition, the exudation system of the water-based adhesive from the end of the laminated optical film after passing through the roll was not observed.

<Example 3>

In addition to the shape shown in FIG. 4 (the length L1 of the first roller portion: 1260 mm, the diameter D1 of the first roller portion: 150 mm), as the roller used in (C) of Example 1, in addition, The rest is the same as in Example 1, and the continuous transport of the laminated optical film is performed. When the laminated optical film passes through the roller, the positional relationship between the laminated optical film and the roller is adjusted so that the widthwise end of the laminated optical film passes outside the first roller portion, so that the laminated optical film does not cause creases, damage, It is cracked and broken, and the laminated optical film is continuously transported without problems. In addition, the exudation system of the water-based adhesive from the end of the laminated optical film after passing through the roll was not observed.

<Comparative Example 1>

In addition to the shape shown in FIG. 4 (the length L1 of the first roller portion: 1400 mm, the diameter D1 of the first roller portion: 150 mm), as the roller used in (C) of Example 1, in addition, The rest is the same as in Example 1, and the continuous transport of the laminated optical film is performed. When the laminated optical film passes through the rollers, the end in the width direction of the laminated optical film passes between the first roller portions, causing folds, damage, cracks, and breakage of the laminated optical film. In addition, the water-based adhesive oozes out from the end of the laminated optical film after passing through the roll.

20‧‧‧axis

32‧‧‧Roll

32a‧‧‧1st roll part

32b‧‧‧The second roller

42‧‧‧Roll

D1‧‧‧Diameter of the first roller

D2‧‧‧Diameter of the second roller

L1‧‧‧Difference of diameter D1 and diameter D2

L2‧‧‧Length of the second roller part along the roller axis

L3‧‧‧Length of the first roller along the roller axis

Claims (9)

A method for transporting an optical film, which transports an optical film along a transport path including rolls composed of a pair of rollers, wherein at least one of the pair of rollers is longer in the direction of the roller axis than the optical film The width of the central portion in the width direction is short, and when the optical film passes between the pair of rollers, the pressure applied to the end portions in the width direction of the optical film is smaller than the pressure applied to the central portion in the width direction of the optical film. The method for conveying an optical film as described in item 1 of the patent application scope, wherein at least one of the pair of rollers is a diameter corresponding to the widthwise end of the optical film, which is more suitable for the optical film The diameter of the central portion in the width direction is small. The method for conveying an optical film as described in item 2 of the patent application scope, wherein at least one of the pair of rollers includes: a first roller portion having a certain diameter; and, disposed at both ends of the first roller portion The portion corresponds to the area of the end portion in the width direction of the optical film and has a second roller portion having a smaller diameter than the first roller portion. The method for transporting an optical film as described in item 1 of the patent application range, wherein at least one of the pair of rollers does not exist in a region corresponding to the widthwise end of the optical film. The method for transporting an optical film as described in any one of claims 1 to 4, wherein one of the pair of rollers transports the optical film so as to have an included angle of 20° or more and 160° or less. Removal of optical film as described in any of items 1 to 4 of patent application In the delivery method, the aforementioned optical film is a laminated optical film laminated with a plurality of films through an adhesive or an adhesive. The method for transporting an optical film as described in item 5 of the patent application range, wherein the optical film is a laminated optical film in which a plurality of films are bonded through an adhesive or an adhesive. A method of manufacturing a polarizing plate, comprising: a transporting step of transporting a raw material film along a transport path including rolls composed of a pair of rollers, and a manufacturing step of manufacturing a polarizing plate using the transported raw material film; wherein, the aforementioned At least one of the pair of rollers is: the length along the roller axis direction is shorter than the width of the central portion of the width direction of the optical film, and when the raw material film passes between the pair of rollers, it is applied to the width direction of the raw material film The pressure at the end is smaller than the pressure applied to the widthwise center of the raw material film. A method of manufacturing a polarizing plate includes: a manufacturing step of manufacturing a polarizing plate using a raw material film, and a transporting step of transporting a polarizing plate along a transport path including a roll composed of a pair of rollers; wherein the pair of rollers At least one of: the length along the roller axis direction is shorter than the width of the central portion of the optical film in the width direction, and when the polarizing plate passes between the pair of rollers, it is applied to the end of the polarizing plate in the width direction The pressure is smaller than the pressure applied to the central part in the width direction of the polarizing plate.

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