JP2009149388A - Conveying method and conveying device for optical film, and its conveyor belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying method of an optical film capable of properly conveying the optical film with which a conveyor belt and a roll have contact in a large nip area in order to convey the optical film and to perform a predetermined processing through a processing part. <P>SOLUTION: In the conveying method of an optical film for performing the predetermined processing to the optical film 2 by the processing part 3, the optical film is conveyed by pushing a peripheral surface of the endless conveyor belt 5 to the roll 6 and rotating the conveyor belt and the roll in a state of sandwiching the optical film between the peripheral surface of the conveyor belt and the roll. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical film transport method, a transport device, and a transport belt for transporting an optical film and performing predetermined processing in a processing unit.

Examples of the optical film include an alignment film, a polarizing film, and a retardation film, and the alignment film is used as a polarizing film and a retardation film. There are a dry stretching method and a wet stretching method as methods for producing this oriented film. The oriented film is transported and subjected to a predetermined treatment in the processing section.
FIG. 12 is a perspective view showing a conventional transport state of an optical film. As shown in FIG. 12, the optical film 2 is transported by the transport device 101 and predetermined processing is performed by the processing unit 3. The transport apparatus 101 includes a pair of rolls 102 and 103. With the optical film 2 sandwiched between the rolls 102 and 103, the rolls 102 and 103 are rotated to convey the optical film 2.
Since the optical film 2 is wound around one roll 102 and its traveling direction is changed, the optical film 2 and the one roll 102 are in contact with each other with a relatively wide contact area.

However, the other roll 103 and the optical film 2 are in contact with each other with a narrow contact area at a contact position 104 extending in a direction parallel to the central axis CL of the roll 103.
Here, the rolls 102 and 103 are slightly crushed and elastically deformed at the contact position 104 by pressurization. Therefore, paying attention to the contact position 104, the contact surface between the roll 103 and the optical film 2 at the contact position 104 has a nip (Nip) area represented by the following equation. The nip width is a contact dimension in the traveling direction of the optical film 2.

Nip area = (nip width) × (length in the direction parallel to the central axis CL (surface length))

Although the nip width relating to the roll 103 and the optical film 2 is narrow, strictly speaking, the roll 103 is in contact with a certain area. In other words, the contact surface between the roll 103 and the optical film 2 has a small nip area with a small but constant area.

  Even in the method for producing an oriented film described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-333521) and the method for producing a polarizing film described in Patent Document 2 (Japanese Patent Laid-Open No. 10-153709), optical The film is sandwiched and transported between a pair of rolls.

JP 2002-333521 A JP-A-10-153709

12, the rolls 102 and 103 are in direct contact with the optical film 2, and the roll 103 is in contact with the optical film 2 with a narrow nip width.
As described above, since the contact with the narrow nip width is caused, the optical film 2 slips with respect to the rolls 102 and 103 due to external factors such as changes in rubber hardness of the rolls 102 and 103, vibration, and fluctuations in moisture brought in. As a result, the optical film 2 may be broken.

  Also in the techniques described in Patent Document 1 and Patent Document 2, the optical film is conveyed with a pair of rolls. Since one or both of the rolls and the optical film are in direct contact with each other with a narrow nip area, the optical film may slip and break due to the same external factors as described above.

  The present invention has been made to solve such a problem. In order to convey an optical film and perform a predetermined process in a processing unit, a conveying belt and a roll are in contact with the optical film with a wide nip area. It is an object of the present invention to provide an optical film transport method, a transport device, and a transport belt for transporting the optical film.

In order to achieve the above-mentioned object, a method for transporting an optical film according to the present invention is a method for transporting an optical film in order to perform a predetermined process on the optical film in a processing unit, and includes an endless belt-shaped transport belt. The outer peripheral surface is pressed against a roll, and the optical film is transported by rotating the transport belt and the roll while sandwiching the optical film between the outer peripheral surface of the transport belt and the roll.
An optical film transport device according to the present invention is a transport device for transporting the optical film having at least one belt mechanism in order to perform predetermined processing on the optical film in a processing section, the belt The mechanism includes a roll that is driven to rotate, and a belt unit that has an endless belt-like conveyance belt that can rotate by pressing the outer circumferential surface against the roll, and the optical unit is disposed between the outer circumferential surface of the conveyance belt and the roll. The optical belt is conveyed by rotating the conveying belt and the roll while sandwiching the film.
It is preferable that the belt mechanism is disposed at one or both of an inlet portion and an outlet portion of the processing portion.
As a preferred embodiment, the belt unit is disposed at an upper part or a lower part of the roll, and the conveying belt rotates while maintaining a predetermined annular shape by a plurality of belt unit guide rollers.
In this case, the position of at least one belt unit guide roller close to the roll among the belt unit guide rollers can be adjusted, and the nip area between the optical film and the roll can be changed. preferable.
As another embodiment, the belt unit is disposed at an upper portion or a lower portion of the roll, and the conveying belt is pressed against the roll by a pressing member disposed on an inner peripheral side of the belt and capable of movement control. Rotate.
Note that a part or all of the belt mechanism may be disposed in the liquid of the processing unit, and the conveying belt may move in the liquid to convey the optical film.
The transport belt according to the present invention is an endless belt-shaped transport belt used in a transport device that transports an optical film, and the transport belt includes an inner base layer and an inner base layer from the base layer. An inner peripheral layer formed on the peripheral side, and a film side layer formed on the outer peripheral side from the base material layer and in contact with the optical film are provided.
The base material layer is preferably formed of a single layer or a multi-layered woven fabric or non-woven fabric, and the inner peripheral side layer and the film side layer are preferably formed of elastic members, respectively.
It is preferable that a large number of grooves having a predetermined cross-sectional shape are formed on the outer peripheral surface or inner peripheral surface of the conveying belt.
The conveyor belt according to an embodiment includes a first groove arrangement state in which the plurality of grooves are formed in parallel to each other in a direction parallel to a traveling direction of the conveyor belt, and the plurality of grooves. A second groove arrangement state in which the conveying belt is oriented in a direction perpendicular to the traveling direction and parallel to each other, and the plurality of grooves are parallel to the traveling direction of the conveying belt. This is one groove arrangement state selected from the third groove arrangement state having a lattice shape facing the direction perpendicular to the direction.
In the conveyor belt, the plurality of grooves are formed obliquely rearward in the direction opposite to the traveling direction of the conveyor belt as it goes from the substantially central portion of the conveyor belt to both end edges. The plurality of grooves are preferably formed in parallel to each other.
The conveyor belt is pressed against the roll on the outer peripheral surface, and the optical film is rotated by rotating the conveyor belt and the roll with the optical film sandwiched between the outer peripheral surface of the conveyor belt and the roll. Used to carry.
The transport device has at least one belt mechanism for performing predetermined processing on the optical film in the processing unit, and the belt mechanism can press the outer peripheral surface against a roll that is driven to rotate. A belt unit having the conveyance belt rotating at a position, and rotating the conveyance belt and the roll in a state where the optical film is sandwiched between an outer peripheral surface of the conveyance belt and the roll. To be transported.
Note that a part or all of the belt mechanism may be disposed in the liquid of the processing unit, and the transport belt may move in the liquid to transport the optical film.

The transport method and transport apparatus for an optical film according to the present invention having the above-described configuration are configured so that a transport belt and a roll have a wide nip area and a transport belt and a roll in order to transport the optical film and perform predetermined processing in the processing unit. It can contact and can convey this satisfactorily.
In addition, the conveyor belt according to the present invention presses the outer peripheral surface against the roll, and rotates the conveyor belt and the roll in a state where the optical film is sandwiched between the outer peripheral surface of the conveyor belt and the roll. If it conveys, a conveyance belt and a roll can contact this with a wide nip area with respect to an optical film, and this can be conveyed favorably.
Furthermore, since the conveyor belt has a three-layer structure, bending stress is improved and bending deformation is suppressed, crack resistance is improved and cracking can be prevented, and the durability of the conveyor belt is improved. improves.

  The optical film is a film intended to transmit or absorb light and give various effects. In addition to the above-mentioned oriented film, polarizing film, and retardation film, the optical film includes an antireflection film, a polarizing film. There are layer protective films, viewing angle enhancement films, brightness enhancement films, electromagnetic wave shielding films, light shielding films, and the like. The present invention is applicable to the conveyance of such various optical films.

FIG. 1 to FIG. 11 are diagrams showing an embodiment of the present invention, FIG. 1 is a process diagram for processing an optical film, FIG. 2 is a perspective view showing a conveyance state of the optical film, and FIG. 3 is a polarizing film as an optical film. It is process drawing which manufactures.
4 and 5 are various process diagrams for processing the optical film, FIG. 6 is a sectional view showing various structures of the conveying belt, and FIG. 7 is various sectional shapes of grooves formed in the conveying belt. FIG. 8 to 11 are explanatory views showing the outer peripheral surface or the inner peripheral surface of the conveyor belt, respectively.

As shown in FIGS. 1 to 5, the optical film 2 is transported by the transport device 1 and subjected to predetermined processing by the processing unit 3. 1 to 5 is a method of transporting the optical film 2 in order to perform a predetermined process on the optical film 2 in the processing unit 3, and for that purpose, the transport belt 5 is used. , 5c are used.
In this conveying method, the belt mechanism 4, 4 b, 4 c presses the outer peripheral surface of the endless belt-shaped conveying belts 5, 5 c against the roll 6, and the optical film is interposed between the outer peripheral surface of the conveying belts 5, 5 c and the roll 6. In a state where 2 is sandwiched, the conveying belts 5 and 5 c and the roll 6 are rotated to convey the optical film 2.

The transport device 1 has at least one belt mechanism 4, 4 b, 4 c for performing predetermined processing on the optical film 2 by the processing unit 3. Since the transport object of the transport device 1 is the optical film 2, the belt mechanisms 4, 4 b and 4 c exhibit a function of transporting the optical film 2.
The belt mechanisms 4, 4 b, 4 c include a roll 6 that is rotationally driven, and belt units 7, 7 c that have endless belt-like transport belts 5, 5 c that can press the outer peripheral surface of the roll 6 and rotate. . Then, the optical film 2 is conveyed by rotating the conveying belts 5, 5 c and the roll 6 with the optical film 2 being sandwiched between the outer peripheral surface of the conveying belts 5, 5 c and the roll 6.

In such a transport method and transport apparatus 1, the outer peripheral surface of the transport belts 5, 5 c is pressed against the roll 6, and the optical film 2 is sandwiched between the outer peripheral surface of the transport belts 5, 5 c and the roll 6. It has become.
Then, the conveying belts 5 and 5 c and the roll 6 are all in direct contact with the optical film 2, but since the nip width is increased, they are in contact with the optical film 2 with a wide nip area. Therefore, if the conveyor belts 5, 5 c and the roll 6 are rotated, the optical film 2 is conveyed without slipping with respect to the conveyor belts 5, 5 c and the roll 6.
Thus, since the optical film 2 is in contact with the transport belts 5 and 5c and the roll 6 with a wide nip area, the slip of the optical film 2 during transport (running) is eliminated, and the optical film 2 is broken. The phenomenon can be prevented and the yield of the optical film 2 can be improved.
Since the optical film 2 does not slip even when the conveyance speed is increased, the breaking phenomenon of the optical film 2 is eliminated as a result, and the productivity is improved, and the accuracy of the stretching control of the optical film 2 is improved.
Moreover, since it becomes possible to give a uniform tensile force in the width direction of the optical film 2, the optical film 2 is widened in the width direction.

In the process shown in FIG. 1, the optical film 2 unwound from the unwinding unit 8 is wound up by the winding unit 9 after predetermined processing is performed in the processing unit 3. At this time, the optical film 2 is transported by the transport device 1 having one or a plurality of belt mechanisms 4.
The processing unit 3 includes a single processing step, a plurality of processing steps, a wet processing, and a dry processing. Various processing is performed on the optical film 2.

In the processing step 20 shown in FIG. 2, the belt mechanism 4 is disposed at the outlet of the processing unit 3. The processing unit 3 includes a wet processing tank 21, and a predetermined process is performed on the optical film 2 in the processing tank 21. An inlet guide roller 22 is provided at the inlet of the processing tank 21, and a pair of submerged guide rollers 23 are provided inside the processing tank 21.
The belt mechanism 4 is disposed at the outlet of the processing tank 21. The belt unit 7 is disposed on the top of the roll 6. The conveying belt 5 rotates while maintaining a predetermined annular shape by a plurality of (here, a total of four) belt unit guide rollers 24 and 25.
Since the belt unit 7 is disposed above the roll 6, the roll 6 can be disposed immediately above the wet processing tank 21. Further, since the conveyor belt 5 is wound around the plurality of belt unit guide rollers 24 and 25, the conveyor belt 5 is rotated while pressing the outer peripheral surface of the conveyor belt 5 against the roll 6 while maintaining a predetermined annular shape.

The roll 6 is rotationally driven by a driving device (not shown). One guide roller among the plurality of belt unit guide rollers 24 and 25 is rotationally driven by another driving device (not shown). As a result, the conveying belt 5 is wound around the plurality of belt unit guide rollers 24 and 25 and rotates while maintaining a predetermined annular shape.
Of the four belt unit guide rollers 24 and 25, at least one (here, two) belt unit guide rollers 25 near the roll 6 can be adjusted in the direction indicated by the arrow B. I have to.
Thereby, the nip area of the optical film 2 and the roll 6 can be changed freely. If the nip area is adjusted in this way, the optical film 2 will not slip and will not break, and the operating conditions for increasing the transport speed as much as possible can be adjusted to an optimum state.

In the processing step 20 shown in FIG. 2, the optical film 2 is guided by the inlet guide roller 22 and conveyed into the processing tank 21 where predetermined processing is performed while being guided by the plurality of submerged guide rollers 23.
Thereafter, the optical film 2 leaves the processing tank 21 and is conveyed in the direction indicated by the arrow D by the belt mechanism 4. In the belt mechanism 4, the outer peripheral surface of the conveying belt 5 is pressed against the roll 6.
By rotating the conveying belt 5 and the roll 6, the optical film 2 is sandwiched between the outer peripheral surface of the conveying belt 5 and the roll 6, and the conveying belt 5 and the roll 6 have a wide nip area. Run while touching. Thereafter, the optical film 2 is transported away from the transport belt 5 as indicated by an arrow D.

In the processing step 30 of the optical film (here, polarizing film) 2 shown in FIG. 3, the optical film 2 unwound from the unwinding unit 8 is processed by the plurality of processing units 31 to 36 and then the winding unit 9. It is designed to wind up.
That is, the transparent polyvinyl alcohol (PVA) resin film (optical film 2) that is the base material of the polarizing film is unwound from the unwinding coil of the unwinding section 8, and the swelling tank 31, the dyeing tank 32, and the stretching tank 33. , Fixed tank 34, water washing tank 35, and drying furnace 36 are passed through in order, and each is subjected to a predetermined treatment, and then wound around a winding coil of winding section 9. Each tank from the swelling tank 31 to the washing tank 35 and the drying furnace 36 correspond to the processing unit 3 in the present invention.
A belt mechanism 4 is disposed at each outlet of the stretching tank 33, the fixed tank 34, and the water washing tank 35.

In the swelling tank 31, the PVA resin film (optical film 2) is immersed in water and swollen. In the next dyeing tank 32, the swollen PVA resin film is dyed with an iodine solution.
In the next drawing tank 33, the iodine-dyed PVA resin film is drawn in the production line direction. The speed at which the PVA resin film passes between the nip rollers 37 and 38 on the inlet side of the stretching tank 33 (slow speed) and the speed at which the PVA resin film passes through the belt mechanism 4 disposed at the outlet of the stretching tank 33 ( Tension is applied to the PVA resin film due to the difference (speed difference) from the high speed, and the PVA resin film is stretched.
In the next fixing tank 34, the polyiodine in the dye-stretched PVA resin film is fixed. In the next water washing tank 35, shower water is sprayed on the film surface, whereby chemicals such as boric acid adhering to the film surface are washed away. In the drying furnace 36 in the final step, hot air is blown onto the PVA resin film surface to dry the film.
Thus, since the belt mechanism 4 is provided in the exit part of the extending | stretching tank 33, the fixed tank 34, and the washing tank 35, respectively, there exists the same effect as each embodiment shown in FIG. 1 and FIG.

In the processing steps shown in FIG. 1 to FIG. 3, the belt mechanism 4 is disposed on the outlet side of the processing unit. As a modified example, as shown in FIG. Alternatively, it may be disposed at the entrance of the processing unit 3.
As another modified example, as shown in FIG. 4 (B), if the belt mechanism 4 is disposed at both the inlet and outlet of the processing unit 3, the optical film 2 can be satisfactorily stabilized. Can be transported.
For example, if the transport apparatus having the configuration shown in FIG. 4B is applied to the stretching tank 33 in the processing step 30 shown in FIG. 3, the optical film 2 is transported satisfactorily, and the optical film 2 is favorable in the stretching tank 33. Can be stretched.

A liquid 26 such as water or an iodine solution is stored in the treatment tank 21 of the treatment unit 3 illustrated in FIG. In the modification shown in FIG. 4C, part or all of the belt mechanism 4 is disposed in the liquid 26 of the processing unit 3, and the transport belt 5 moves through the liquid 26 to transport the optical film 2. Yes.
In this modification, a case where a part of the belt unit 7 and the entire roll 6 are arranged in the liquid 26 is shown. That is, by disposing the roll 6, the belt unit guide roller 25, and a part of the transport belt 5 below the liquid surface 27 of the liquid 26, the transport belt 5 is in the liquid 26 when rotating. To move the optical film 2.

Various polymer materials can be used for the production of the optical film 2. Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, or binary, ternary copolymers, graft copolymers, blends, etc. can give.
These polymer materials are stretched to form an optical film, which is used as an alignment film, a polarizing film, a retardation film, or the like.

In the processing step 40 shown in FIG. 5A, the optical film 2 is processed in a dry manner and conveyed by the belt mechanism 4. For example, in the processing unit 3, processing for drying the optical film 2 in the drying furnace 41 is performed. The configuration and operational effects of the belt mechanism 4 are the same as those in the above-described embodiment.
In the processing step 50 shown in FIG. 5B, the belt unit 7 and the roll 6 in the belt mechanism 4b are turned upside down. That is, in the belt mechanism 4 b, the belt unit 7 is disposed below the roll 6.
The conveyor belt 5 is rotated while maintaining a predetermined annular shape by a plurality of (here, four) belt unit guide rollers 24 and 25 as described above. This belt mechanism 4b has the same effect as the belt mechanism 4 described above.
When the space for installing the belt mechanism cannot be secured at the outlet of the processing tank 21 in the processing unit 3, the belt mechanism 4b can be installed.

In the processing step 60 shown in FIG. 5C, a belt mechanism 4c having a pressing member 61 is used. The belt unit 7c of the belt mechanism 4c is disposed at the upper part or the lower part (here, the lower part) of the roll 6.
The pressing member 61 is disposed on the inner peripheral side of the conveying belt 5 c and can be controlled to move as indicated by an arrow G. The conveyor belt 5c rotates while being pressed against the roll 6 by the pressing member 61.
According to the belt mechanism 4c, since it is not necessary to provide the belt unit 7c with a belt unit guide roller, the belt unit 7c can be made compact, and the belt unit 7c does not need to be provided with a driving device. That is, if the roll 6 is rotationally driven, the conveying belt 5c also rotates following the optical film 2 (arrow E). The optical film 2 sandwiched between the roll 6 and the conveyor belt 5c is satisfactorily conveyed without breaking.
By controlling the position of the pressing member 61 (position in the arrow G direction), the pressing force of the conveying belt 5c against the roll 6 can be easily adjusted. As a result, the optical film 2 can be conveyed by rotating the conveyance belt 5c and the roll 6 in a state where the optical film 2 is sandwiched between the outer peripheral surface of the conveyance belt 5c and the roll 6 with an appropriate pressure. it can.
The conveying belt 5c and the roll 6 are in direct contact with the optical film 2, but are in contact with the optical film 2 with a wide nip area. As a result, since the optical film 2 does not slip, it does not break and is widened in the width direction.

  Note that the belt mechanism 4b shown in FIG. 4C is applied to the belt mechanism 4b shown in FIG. 5B or the belt mechanism 4c shown in FIG. 5C, and part or all of the belt mechanisms 4b and 4c are applied. It may be arranged in the liquid 26 of the processing unit 3, and the conveying belts 5 and 5 c may move in the liquid 26 to convey the optical film 2.

Next, the conveying belt 5 will be described.
6A to 6F show cross sections of the conveyor belt 5 having various structures. The outer peripheral surface 70 of each conveyor belt 5 is in direct contact with the optical film 2, and the inner peripheral surface 71 is in contact with the belt unit guide rollers 24, 25 or the pressing member 61.
The conveyor belt 5 is formed on the inner peripheral side layer 73 formed on the inner peripheral side of the base material layer 72, the outer peripheral side of the base material layer 72, and contacts the optical film 2. And a film side layer 74 to be provided.
Thus, the conveying belt 5 has a three-layer structure. Therefore, the bending stress of the conveying belt 5 is improved and bending deformation is suppressed. In addition, the crack resistance is improved and the occurrence of cracks can be prevented, and the durability of the transport belt 5 is improved.

In the conveying belt 5 shown in FIGS. 6A to 6C, a case where a plain woven fabric (woven fabric) is used for the base material layer 72 is shown. 6D to 6F show the case where a nonwoven fabric is used for the base material layer 72. FIG.
If a nonwoven fabric is used for the base material layer 72, the base material layer can be formed in a short time by shortening the weaving time. In addition, the yarn entanglement points (the warp yarn of the woven fabric and the knuckle of the weft yarn) that may stick to the optical film 2 when the conveying belt 5 presses the optical film 2 are eliminated or reduced. Moreover, since the nonwoven fabric can comprise a thread | yarn material linearly, the dimension of the base material layer 72 is stabilized.
Although the case where the woven fabric or the nonwoven fabric of the base material layer 72 is a single layer is illustrated, the rigidity of the conveying belt 5 is improved by forming a multilayer in which a plurality of woven fabrics or nonwoven fabrics are overlapped.

The inner peripheral side layer 73 and the film side layer 74 are each formed of an elastic member. The material of the elastic member is generally an elastomer (for example, rubber), but preferably a polyurethane resin is used.
Among these polyurethane resins, a thermosetting urethane resin is preferable from the viewpoint of physical properties. A polyurethane is produced | generated by reaction of the polyurethane prepolymer which has an isocyanate group, and the hardening | curing agent which has an active hydrogen group.

The outer peripheral surface 70 and the inner peripheral surface 71 of the conveying belt 5 shown in FIGS. 6 (A) and 6 (D) are formed in a flat state. As a result, the outer peripheral surface 70 comes into contact with the optical film 2 with a wide contact area and applies a uniform pressure to the optical film 2 as a whole, so that the conveyance speed can be improved.
If the conveying speed is increased too much, the optical film 2 may slip and break, and the tensile force in the width direction on the optical film 2 may be nonuniform.
In contrast, a large number of grooves 78 having a predetermined cross-sectional shape are formed on the outer peripheral surface 70 of the conveying belt 5 shown in FIGS. 6 (B) and 6 (E). A large number of grooves 75 having a predetermined cross-sectional shape are formed on the inner peripheral surface 71 of the conveying belt 5 shown in FIGS. 6 (C) and 6 (F).
If a large number of grooves 78 are formed on the outer peripheral surface 70 of the conveying belt 5, slippage between the optical film 2 and the outer peripheral surface 70 can be more effectively prevented, and the breaking phenomenon of the optical film 2 can be further effectively prevented. be able to.

As shown in FIGS. 6B and 6E, if a groove 78 is formed on the outer peripheral surface 70 of the conveying belt 5, a uniform tensile force is applied to the optical film 2 in the width direction. As a result, the optical film 2 can be widened in the width direction, and the optical film 2 can be transported satisfactorily.
As shown in FIGS. 6C and 6F, it is preferable to form a groove 75 on the inner peripheral surface 71 of the conveying belt 5. In this way, when the conveying belt 5 is pressed against the roll 6 and elastically deformed, the outer peripheral surface 70 also has a slight wave shape corresponding to the groove 75 on the inner peripheral surface side, and the unevenness 79 is slightly formed. .
The unevenness 79 gives the optical film 2 a uniform tensile force in the width direction. As a result, since the optical film 2 can be widened in the width direction, the optical film 2 can be transported satisfactorily.
Although the outer peripheral surface 70 that contacts the optical film 2 with a wide contact area is formed with faint irregularities 79, the outer peripheral surface 70 is almost flat as a whole, and therefore the traces of the irregularities 79 are not attached to the optical film 2.

The cross-sectional shapes of the grooves 78 and 75 are generally rectangular as shown in FIG. 6, but as shown in FIG. 7, they are V-shaped (FIG. 7A), U-shaped (FIG. 7B )), And various cross-sectional shapes such as a land having a curved shape (FIG. 7C).
Alternatively, the outer peripheral surface 70 or the inner peripheral surface 71 between adjacent grooves may form a convex curved cross section, and the grooves 78 and 75 may have a rectangular shape (FIG. 7D).

The conveying belt 5 shown in FIG. 8 is in a first groove arrangement state in which a large number of grooves 78 and 75 are formed in a direction parallel to the traveling direction D of the conveying belt 5 and parallel to each other.
In the transport belt 5 shown in FIG. 9, a plurality of grooves 78 and 75 are formed in a direction that is perpendicular to the traveling direction D of the transport belt 5 (that is, the width direction) and parallel to each other. This is a groove arrangement state.
The conveying belt 5 shown in FIG. 10 is in a third groove arrangement state in which a large number of grooves 78 and 75 form a lattice shape that faces a direction parallel to the traveling direction D of the conveying belt 5 and a direction perpendicular thereto. is there.

In the conveying belt 5 shown in FIG. 11, the numerous grooves 78 and 75 are directed obliquely rearward in the direction opposite to the belt traveling direction D as they go from the substantially central portion C 0 of the conveying belt 5 to both end edges 76 and 77. Is formed. Note that the plurality of grooves 78 and 75 are preferably formed in parallel to each other.
According to the configuration of the grooves 78 and 75 shown in FIG. 11, the optical film 2 that is in contact with the conveying belt 5 and the roll 6 with a wide nip area is guided by the numerous grooves 78 and 75 in the oblique direction. Thus, the width of the optical film 2 is effectively widened in the both-ends edge direction (width direction).

  As shown in FIGS. 8 to 11, slipping of the optical film 2 can be more effectively prevented by forming a large number of grooves 78 and 75 in the conveying belt 5. Thereby, the fracture | rupture phenomenon of the optical film 2 at the time of conveyance (at the time of driving | running | working) can be prevented effectively, and the yield of the optical film 2 improves. Since the optical film 2 does not slip even if the conveyance speed is increased, the optical film 2 is not broken and the productivity is further improved.

The thickness of the conveyor belt 5 is 1 mm to 6 mm, preferably 1 mm to 4.5 mm. The base material layer 72 has a thickness of 1 mm to 3 mm.
As the thickness of each of the transport belt 5 and the base material layer 72 is smaller, the flexibility and the grip property are better. As a result, the transport belt 5 freely deforms following the shape of the roll 6 and is used for transport. The optical film 2 is conveyed without slipping with respect to the belt 5, and the meandering prevention control is facilitated.
The hardness of the outer peripheral surface 70 of the conveying belt 5 is 60 to 95 ° (JIS-A, JIS K 7312), preferably 70 to 85 ° (JIS-A, JIS K 7312).
If the outer peripheral surface 70 is too hard, pressure spots may be formed on the optical film 2 when the optical film 2 is pressed by the film outer peripheral surface 70. On the contrary, if the outer peripheral surface 70 is too soft, the conveying belt 5 may be worn or scratched due to a decrease in strength.
Therefore, if the hardness of the outer peripheral surface 70 is set as described above, the conveying belt 5 is reasonably flexible and deforms well following the shape of the roll 6, increasing the nip area with the optical film 2 and increasing the grip. And the meandering prevention control becomes easy.
The hardness of the inner peripheral surface 71 of the conveying belt 5 is also the same as the hardness of the outer peripheral surface 70 described above. In this case, if the inner peripheral surface 71 is made harder than the outer peripheral surface 70, wear of the inner peripheral surface 71 by the roll 6 and the pressing member 61 is reduced. On the contrary, when the inner peripheral surface 71 is made softer than the outer peripheral surface 70, cracks and cracks are less likely to occur in the conveying belt 5.

The surface roughness of the outer peripheral surface 70 and the inner peripheral surface 71 is Ra (arithmetic mean roughness: JIS B 0601) 1 to 6 μm, preferably Ra 1 to 3 μm. As the outer peripheral surface 70 is smoother, the contact area with the optical film 2 becomes larger and the frictional force (grip force) increases to prevent the optical film 2 from slipping. Further, the smoothness of the surface of the optical film 2 can be prevented. The degree (surface property) is improved.
As for the inner peripheral surface 71, the smoother one has a larger contact area with the roll 6 and the pressing member 61, and the frictional force (grip force) increases.

As described above, as compared with the conventional technique in which the optical film is conveyed in contact with the roll with a narrow contact area, the belt mechanism 4, 4b, 4c is used in the present invention, and the optical film 2 is composed of the conveying belt 5, Since it contacts 5c and the roll 6 with a wide nip area, there is no possibility of occurrence of a slip phenomenon.
Therefore, the unevenness of the contact state between the transport belts 5 and 5c and the roll 6 with respect to the optical film 2 is averaged and uniformly contacted as a whole. Further, the conveyor belts 5 and 5c and the roll 6 have less wear on each surface and extend the life, and the surfaces of the optical film 2 are also smooth because each surface is always kept in a smooth state. Will improve.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and additions are possible within the scope of the gist of the present invention.
In the drawings, the same reference numerals denote the same or corresponding parts.

  The present invention is applied to an optical film manufacturing apparatus, a transport apparatus for transporting an optical film with the manufacturing apparatus, a belt mechanism constituting the transport apparatus, and a transport belt used therefor.

1 to 11 are views showing an embodiment of the present invention, and FIG. 1 is a process diagram for processing an optical film. It is a perspective view which shows the conveyance state of an optical film. It is process drawing which manufactures a polarizing film. It is various process drawings for processing an optical film. It is various process drawings for processing an optical film. It is sectional drawing which shows the various structures of a belt for conveyance. It is a figure which shows the various cross-sectional shapes of the groove | channel formed in the belt for conveyance. It is explanatory drawing which shows the outer peripheral surface or inner peripheral surface of a conveyance belt. It is explanatory drawing which shows the outer peripheral surface or inner peripheral surface of a conveyance belt. It is explanatory drawing which shows the outer peripheral surface or inner peripheral surface of a conveyance belt. It is explanatory drawing which shows the outer peripheral surface or inner peripheral surface of a conveyance belt. It is a perspective view which shows the conveyance state of the optical film in the past, and is a figure equivalent to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conveyance apparatus 2 Optical film 3 Processing part 4, 4b, 4c Belt mechanism 5, 5c Conveyance belt 6 Roll 7, 7c Belt unit 24, 25 Guide roller for belt unit 26 Liquid 61 Press member 70 Outer peripheral surface 71 Inner peripheral surface 72 Base material layer 73 Inner circumferential side layer 74 Film side layer 75, 78 Groove 76, 77 Edge C0 center D Belt running direction

Claims (15)

A method of transporting the optical film in order to perform a predetermined process on the optical film in the processing unit,
The outer peripheral surface of the endless belt-shaped transport belt is pressed against a roll, and the optical film is rotated by rotating the transport belt and the roll with the optical film sandwiched between the transport belt outer peripheral surface and the roll. An optical film transport method comprising transporting the optical film. A transport device for transporting the optical film having at least one belt mechanism in order to perform a predetermined process on the optical film in the processing unit,
The belt mechanism includes a roll that is driven to rotate, and a belt unit that has an endless belt-like transport belt that rotates by pressing an outer peripheral surface of the roll.
An apparatus for transporting an optical film, wherein the optical film is transported by rotating the transport belt and the roll in a state where the optical film is sandwiched between an outer peripheral surface of the transport belt and the roll.   The said belt mechanism is arrange | positioned in the one or both of the entrance part and exit part of the said process part, The conveying apparatus of the optical film of Claim 2 characterized by the above-mentioned.   The said belt unit is arrange | positioned at the upper part or the lower part of the said roll, The said belt for conveyance rotates by maintaining the predetermined | prescribed cyclic | annular form with the several guide roller for belt units. Optical film transport device.   Of the belt unit guide rollers, at least one belt unit guide roller at a position close to the roll can be adjusted to change a nip area between the optical film and the roll. The optical film conveying apparatus according to claim 4.   The belt unit is disposed at an upper portion or a lower portion of the roll, and the transport belt is pressed against the roll and rotated by a pressing member disposed on an inner peripheral side of the belt and capable of movement control. The optical film conveying apparatus according to claim 2 or 3.   5. The belt mechanism according to claim 2, wherein a part or all of the belt mechanism is disposed in a liquid of the processing unit, and the conveying belt moves in the liquid to convey the optical film. , 5 or 6 for conveying an optical film. An endless belt-shaped transport belt used in a transport device that transports an optical film,
The conveyor belt includes an inner base layer, an inner peripheral layer formed on the inner peripheral side of the base layer, and a film that is formed on the outer peripheral side of the base layer and contacts the optical film. A transport belt for an optical film transport device, comprising: a side layer.   The said base material layer is formed by the woven fabric or the nonwoven fabric of a single layer or a multilayer, The said inner peripheral side layer and the said film side layer are respectively formed by the elastic member. The belt for conveyance of the optical film conveyance device.   The conveyance belt of the optical film conveyance device according to claim 8 or 9, wherein a plurality of grooves having a predetermined cross-sectional shape are formed on an outer circumferential surface or an inner circumferential surface of the conveyance belt. .   The conveying belt includes a first groove arrangement state in which the plurality of grooves are formed in parallel with each other in a direction parallel to a traveling direction of the conveying belt, and the plurality of grooves are formed on the conveying belt. A second groove arrangement state in which the direction is perpendicular to the running direction and parallel to each other, and a direction in which the plurality of grooves are perpendicular to the direction parallel to the running direction of the conveying belt The conveying belt of the optical film conveying device according to claim 10, wherein the groove is in a single groove arrangement state selected from a third groove arrangement state in a lattice shape facing the direction.   The plurality of grooves are formed obliquely rearward in the direction opposite to the traveling direction of the conveyor belt as they extend from the substantially central portion of the conveyor belt to both end edges, and the plurality of grooves are parallel to each other. The transport belt of the transport device for an optical film according to claim 10, wherein the transport belt is formed as described above.   The conveyor belt is pressed against the roll on the outer peripheral surface, and the optical film is rotated by rotating the conveyor belt and the roll with the optical film sandwiched between the outer peripheral surface of the conveyor belt and the roll. The belt for conveyance of the conveyance apparatus of the optical film of any one of Claims 8 thru | or 12 used for conveyance. The transport device has at least one belt mechanism for performing predetermined processing on the optical film in a processing unit;
The belt mechanism includes a roll that is driven to rotate, and a belt unit that includes the transport belt that rotates by pressing an outer peripheral surface of the roll.
9. The optical film is conveyed by rotating the conveying belt and the roll in a state where the optical film is sandwiched between an outer peripheral surface of the conveying belt and the roll. A conveyor belt for an optical film conveyor apparatus according to any one of items 12 to 12.   15. The belt mechanism according to claim 14, wherein a part or all of the belt mechanism is disposed in the liquid of the processing unit, and the transport belt moves in the liquid to transport the optical film. The belt for conveyance of the optical film conveyance device.

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