JP4077010B2 - Polarizing film continuous manufacturing equipment - Google Patents

Description

  The present invention relates to a polarizing film by placing a polyvinyl alcohol (PVA) film used for a polarizing film or the like between rotating rollers, uniaxially stretching in a certain direction while heating, and orienting a polymer of the PVA film. The present invention relates to a polarizing film continuous manufacturing apparatus for continuously manufacturing a polarizing film.

Polarizing plates, for which demand is rapidly increasing with the spread of liquid crystal display devices, are generally polarizing substrates (such as PVA) containing polarizing elements (iodine and dichroic dyes) and protection for protecting polarizing substrates. It consists of a film.
Conventionally, as a method for producing a polyvinyl alcohol polarizing film, a method in which iodine or a dye is adsorbed on an unoriented polyvinyl alcohol film and then stretched several times (for example, refer to Patent Document 1), and a stretched orientation in advance. There is a method of adsorbing iodine or a dye on a polyvinyl alcohol film subjected to (for example, see Patent Document 2).
Moreover, the orientation method of a polyvinyl alcohol film has the extending | stretching by a wet method (for example, refer patent document 1) and the extending | stretching by a dry method (for example, refer patent document 3).

When the plastic film is pulled in one direction by utilizing the flexibility that is the property of a plastic film such as a polyvinyl alcohol film, the molecules constituting the plastic film are aligned in the tensile direction, and the strength is increased in the tensile direction. Become. In contrast, the lateral strength decreases. This tendency is noticeably generated by pulling quickly. Therefore, a polarizing film with good quality can be obtained if the molecules can be arranged in a certain direction without decreasing the strength both vertically and horizontally.
JP-A-63-311203 JP-A-01-237601 JP-A-63-261201

  The present invention is a first-stage stretching and transfer in which a polyvinyl alcohol film or the like (also referred to as “plastic film original fabric” in this specification) is stretched at a stage where the plastic film original moving speed is low. By constructing so that the second stage stretching, which is stretched at a high speed stage, can be performed in a continuous work process, a polarizing film with uniform properties can be continuously produced without reducing the strength in both length and width. It is an object of the present invention to provide a device that performs the above-described process.

In order to achieve the above object, the inventor has conducted various experiments, and as a result, the moving speed of the plastic film original fabric in the stretching process is small at the initial speed and needs to be increased compared to the initial speed, Moreover, the initial speed is 1.5 to 5 cm / min, preferably 2 to 4 cm / min, and the final speed is 6 to 20 cm / min, preferably 8 to 16 cm / min. As a result of earnestly researching how to do this continuously, the present invention has been created.
The apparatus for continuously producing a polarizing film according to the present invention produces a polarizing film by uniaxially stretching a plastic film raw material in a fixed direction by a plurality of driving rolls having the same diameter in the process of continuously supplying the plastic film from the unwinding roll to the winding roll. The apparatus is characterized in that a second-stage stretching section is provided on the downstream side of the first-stage stretching section that stretches in a state where the moving speed of the plastic film raw material is low, and is stretched in a state where the moving speed is high.
In the polarizing film continuous production apparatus of the present invention, the movement speed of the raw plastic film is 2 to 4 cm / min in the first stage stretching section and 8 to 16 cm / min in the second stage stretching section. It is a feature.
Further, in the polarizing film continuous production apparatus of the present invention, in the first stage stretching section, when the rotational speed of the driving roll at the entrance is 1, the rotational speed of the driving roll at the exit is about 1.25 times. The stretching section is characterized in that when the rotational speed of the driving roll at the entrance of the first stage stretching section is 1, the rotational speed of the driving roll at the exit is about 5 times.
Further, the polarizing film continuous production apparatus of the present invention is provided with a softening processing section between the first-stage stretching section and the second-stage stretching section, and the second-stage stretching section is provided with a fixing tank following the adsorption processing tank. In addition, a drying processing section is provided following the second stage stretching section.
In the polarizing film continuous production apparatus of the present invention, the driving roll of the first stage stretching unit is driven by the first motor, and the driving roll of the second stage stretching unit and the driving roll on the downstream side of the drying processing unit are connected to the first roll. A power transmission mechanism is provided so as to be driven by two motors, each drive roll is provided with a speed reducer, and the number of rotations of each drive roll is controlled by a control device.
Further, the polarizing film continuous production apparatus of the present invention is provided with a nip roll having rubber on the surface for pressing the plastic film original against the drive roll and preventing slippage between the plastic film original and the drive roll above the drive roll. And the nip roll is movable up and down by a fluid cylinder.

The present invention has the following excellent effects.
(1) By providing a second-stage stretched portion that stretches in a state where the moving speed is large on the downstream side of the first-stage stretched portion that stretches in a state where the moving speed is low, without reducing the strength in both length and width, and A polarizing film having uniform properties in which molecules are arranged in a certain direction can be continuously produced.
(2) A softening processing section is provided between the first-stage stretching section and the second-stage stretching section, the second-stage stretching section is provided with a fixing tank following the adsorption processing tank, and the second-stage stretching section is provided with a second-stage stretching section. Subsequently, stretching can be efficiently performed by providing a drying processing section.
(3) Each drive roll is provided with a speed reducer, and the number of rotations of each drive roll is controlled by a control device, whereby the plastic roll can be stretched without exerting an excessive force.
(4) Since the nip roll can be moved up and down by the fluid cylinder, the plastic film can be easily attached and the number of workers can be reduced.

  The best mode for carrying out the polarizing film continuous production apparatus according to the present invention will be described below with reference to the drawings based on the embodiments.

  FIG. 1 is a schematic side view for explaining the entire polarizing film continuous manufacturing apparatus according to the embodiment of the present invention, and FIG. 2 illustrates a drive system of the polarizing film continuous manufacturing apparatus according to the embodiment of the present invention. FIG. 3 is a plan view of the main part of FIG. 2 as viewed from above, and FIG. 4 is a front view of the drive roll and nip roll as viewed from the front.

  In FIG. 1, an original plastic film 100 is supplied from an unwinding roll 1 on the left side of the drawing, processed as it goes to the right side of the drawing, becomes a stretched polarizing film, and is wound by a winding roll 56 on the right side of the drawing. As a material of the raw fabric 100, a polyvinyl alcohol film is typically used.

   While the raw plastic film 100 supplied from the unwinding roll 1 passes through the first-stage stretching section 110, the softening processing section 120, the second-stage stretching section 130, and the drying processing section 140 sequentially toward the downstream side. It is processed and wound on a winding roll 56.

  After the plastic film original fabric 100 is wound around the unwinding roll 1 at another location, the plastic film original fabric 100 is transported in that state and mounted at a predetermined location. Is desorbed. When the unwinding roll 1 is a free roll, it is excessively unwound, so that a brake is attached, a constant braking force is applied, and excessive unwinding is prevented. The material of the unwinding roll 1 is preferably made of, for example, stainless steel for rust prevention. Moreover, as a brake provision means, well-known means, such as a form which presses a friction member to the axis | shaft which supports the unwinding roll 1, is used.

  In FIG. 1, rolls 3, 7, 11, 13, 17, 21, 25, 29 and 53 painted black are drive rolls to which drive force is transmitted from a motor, and all have the same diameter. However, it has a length larger than the width of the original plastic film 100. These drive rolls 3, 7, 11, 13, 17, 21, 25, 29, and 53 are made of stainless steel and have a roll surface on the roll surface in order to obtain rust prevention and adhesion to the plastic film original fabric 100. Polished. Further, in order to prevent the meandering of the plastic film original fabric 100, the drive roll is required to have a high processing accuracy for the parallelism of the roll.

Further, above the drive rolls 3, 7, 11, 13, 17, 21, 25, 29 and 53, as shown in FIGS. 1 and 4, nip rolls 60, 61, 62, 63 having the same diameter as the drive rolls are provided. , 64, 65, 66, 67 and 68 are arranged. The nip rolls 60 to 68 also require roll parallelism for the same reason as the drive roll. Further, rubber having an appropriate hardness and a considerable thickness is attached to the surface in order to press the original plastic film 100 against the driving roll and prevent slippage between the original plastic film 100 and the driving roll. ing.
Since these nip rolls 60 to 68 need to secure a corresponding gap between the drive rolls 3, 7, 11, 13, 17, 21, 25, 29 and 53 when the plastic film original fabric 100 is first attached, It must be lifted upward together with the bearings 70, 70 at both ends, and when the plastic film original 100 is pressed, the drive rolls 3, 7, 11, 13, 17, 21, 25, 29, and 53 Since pressure must be applied uniformly, cylinders 71 and 71 are attached to bearings 70 and 70 at both ends, respectively, so that they can be moved up and down using air pressure or hydraulic pressure.

  Driving rolls 3, 7, 11, nip rolls 60, 61, 62 are arranged in the first stage stretching section 110, and a first water tank 72 is provided between the driving rolls 3, 7, and the driving rolls 7, 11, A second water tank 73 is provided between the two. The first water tank 72 and the second water tank 73 are subjected to a peeling process in order to facilitate the prevention of adhesion at the time of winding and peeling at the time of rewinding during the production of the raw plastic film 100, and are used at that time. The guide rolls 4 to 6 and 8 to 10 are placed at positions as shown in FIG. 1 in order to move the plastic film 100 while meandering in each water tank. Each is arranged. The guide rolls 4 to 6 and 8 to 10 can be moved up and down manually. The guide rolls 4 to 6 and 8 to 10 are lifted when the film is mounted and submerged in the liquid after the film is mounted. By causing the plastic film original 100 to meander with the guide rolls 4 to 6 and 8 to 10, the plastic film original 100 can be submerged in the liquid for a considerable time. The liquid in the 1st water tank 72 and the 2nd water tank 73 is maintained in a clean state by the system replaced | exchanged for a new liquid suitably, or the circulation filtration system.

The speed of the raw plastic film 100 in the first stage stretching section 110 is set to 1.5 to 5 cm / min in the liquid. Moreover, it is preferably 2-4 cm / min.
At this time, the rotational speed of the driving roll is about 1.25 times (about 1.25 times in this specification) when the rotational speed of the first driving roll 3 is 1. Means 1.2 to 1.3 times), and the rotation speed of the second drive roll 7 is set to about the middle between the two drive rolls 3 and 11. This is because an excessive force is not applied to the original plastic film 100.
In this way, the speed of the original plastic film 100 is increased up to about 1.25 times while performing water washing from the first drive roll 3 to the second drive roll 7 and the third drive roll 11. At that time, if the original plastic film 100 slips, the stretching effect cannot be obtained. Therefore, the nip rolls 60 to 62 are pressed against the drive rolls 3, 7, and 11 at a constant pressure, respectively.
By changing the rotation speeds of the first drive roll 3 to the second drive roll 7 and the third drive roll 11, the impurities attached to the plastic film original fabric 100 can be easily removed.

  The softening processing unit 120 is provided with a hot water tank 74, and the plastic film raw material 100 passes through the hot water tank 74 in a meandering manner by the guide roll 12 provided below the hot water tank 74. ing. The original plastic film 100 is softened by passing through the hot water tank 74, and the subsequent stretching process is smoothly performed. The water temperature in the hot water tank 74 is set to about 60 ° C. or less. The guide roll 12 can be moved up and down manually. The guide roll 12 is lifted when the film is mounted, and is submerged in the liquid after the film is mounted. By causing the plastic film original fabric 100 to meander with the guide roll 12, the plastic film original fabric 100 can be submerged in the liquid for a considerable time. The hot water tank 74 is appropriately supplemented with new water and heated to a certain temperature.

  Driving rolls 13, 17, 21, 25, and 29 and nip rolls 60 to 67 are arranged in the second-stage stretching section 130, and an adsorption treatment tank 75 is provided between the driving rolls 13 and 17, and the driving roll A fixing tank 76 is provided between 17 and 29. In the adsorption treatment tank 75, a polarizing element such as iodine or a dye is adsorbed on the original plastic film 100 to be colored and improved in physical properties. In the fixing tank 76, the polarizing elements such as iodine and dye adsorbed on the original plastic film 100 are fixed. As shown in FIG. 1, guide rolls 14 to 16 and 18 to 28 are arranged in the adsorption treatment tank 75 and the fixing tank 76 so that the plastic film raw material 100 meanders in each tank. It has become. The guide rolls 14 to 16 and 18 to 28 can be moved up and down manually, and are lifted when the film is mounted and submerged in the liquid after the film is mounted. By causing the plastic film original fabric 100 to meander with the guide rolls 14 to 16 and 18 to 28, the plastic film original fabric 100 can be submerged in the liquid for a considerable time. A new processing solution is appropriately replenished in the adsorption processing tank 75 and the fixing tank 76.

The speed of the plastic film original fabric 100 in the second stage stretching section 130 is set to be 6 to 20 cm / min in the liquid. Moreover, Preferably it is 8-16 cm / min.
At this time, the rotation speed of the drive roll 29 is set to about 5 times the rotation speed of the eighth drive roll 29 when the rotation speed of the first drive roll 3 is 1. Further, the rotational speed of the fourth drive roll 13 to the seventh drive roll 25 is also increased in a stepwise manner so that an excessive force is not applied to the original plastic film 100.
As described above, the stretching ratio in the second-stage stretching section 130 is set to be larger than the stretching ratio in the first-stage stretching section 110, but after the plastic film original fabric 100 is softened in the softening processing section 120. As a result, smooth stretching is performed.
Moreover, since the stretching effect cannot be obtained when the plastic film original fabric 100 slips, the nip rolls 63 to 67 are pressed against the drive rolls 13, 17, 21, 25, and 29 with a constant pressure.

The drying processing unit 140 is provided with a plurality of drying chambers 77, and hot air is sent from the blower 78 to each drying chamber 77.
A plurality of guide rollers 31 to 51 are provided in the drying chamber 77, and a plurality of guide rollers are arranged in each drying chamber, and the plastic film raw material 100 alternately contacts the upper and lower surfaces of each guide roller. While being guided, uniform drying is performed. In FIG. 1, a guide roll at the upper part of the plastic film original 100 is attached to the upper member of the drying chamber, and a guide roll at the lower part of the plastic film 100 is attached to the lower member of the drying chamber. The member may be lifted to a required height and lowered to a predetermined position after mounting.

The raw plastic film 100 that has been dried and dried in the drying processing unit 140 is pulled by a ninth drive roll 53 installed on the downstream side of the drying processing unit 140. The ninth drive roll 53 needs to be set higher than the rotation speed of the eighth drive roll 29 in order to remove the slack of the plastic film original fabric 100 in the middle of the drying processing unit 140 from the eighth drive roll 29. Since the weight varies depending on the plastic film original 100, it is necessary to set the weight according to the plastic film original 100.
Further, in order to protect both surfaces of the stretched plastic film original fabric 100, a laminate film (not shown) is supplied along the upper and lower surfaces of the plastic film original fabric 100 and moved to the take-up roll 56 through the ninth drive roll 53. I will let you.

  The winding roll 56 cannot be rotated at the same speed because the outer diameter of the winding roll 56 increases as the plastic film original fabric 100 protected on both sides with a laminate film is wound. For this reason, the take-up roll 56 requires a torque motor that operates at a constant pressure. In addition, a tension roll 54 is disposed between the drive roll 53 and the take-up roll 56 to prevent the plastic film original 100 from meandering, and a cutter (not shown) is disposed after the tension roll 54 to dispose the plastic film original 100. After both ends are cut off by the take-up roll 56. Since the winding roll 56 must be removed after the winding is completed, the winding roll 56 is formed in a structure that is easy to attach and detach and that does not slip.

Next, a drive mechanism such as a drive roll will be described with reference to FIGS.
As shown in FIG. 2, the driving rolls 3, 7, 11, 13, 17, 21, 25, 29, 53 are supported at both ends at the upper part of the frame 95 and are provided at the same height above the apparatus. As shown in FIG. 3, gears 82 are respectively provided at one end of the one side. The first motor 83 and the second motor 84 that drive the drive roll are located on one side of the drive roll and are installed on the frame 96.
The driving force of the first motor 83 is transmitted from the gear mechanisms 85 and 86 to the speed reducer 89 via the transmission shaft 87 and the gear mechanism 88, decelerated by the speed reducer 89 and transmitted to the gear 90, and from the gear 90 to the chain 91. Then, it is transmitted to the drive rolls 3, 7, 11 via the gear 82.
The rotational force of the second motor 84 is transmitted from the gear mechanisms 85 and 86 to the speed reducer 89 via the transmission shaft 92 and the gear mechanism 88, decelerated by the speed reducer 89 and transmitted to the gear 90, and from the gear 90 to the chain 91. Via the gear 82, the drive rolls 13, 17, 21, 25, 29, 53
Is transmitted to.

As described above, the drive rolls 3, 7, and 11 of the first stage stretching unit 110 are driven by the first motor 83, and the drive rolls 13, 17, 21, 25, and 29 of the second stage stretching unit 120 and the drying process. The ninth drive roll 53 on the downstream side of the section 140 is driven by the second motor 84.
Since the quality of the original plastic film 100 differs slightly depending on the manufacturer, it is necessary to control the rotational speed of the driving roll accordingly, and the moving speed of the original plastic film 100 is 1.5 cm / min. Therefore, the speed reducer 89 has a structure in which a continuously variable transmission is incorporated into a geared motor.
Since each drive roll has a different rotational speed, a speed reducer 89 is installed corresponding to each drive roll, and each speed reducer 89 has a rotational speed required for the drive roll. It is controlled by a control device (not shown) so as to be obtained.

  The take-up roll 56 is provided with a torque motor 93 that operates at a constant pressure, and is driven at a constant pressure. For this reason, even if a winding diameter changes in the winding roll 56, the plastic film original fabric 100 is wound by fixed tension.

Next, the process until the polarizing film is manufactured by stretching the original plastic film 100 will be described.
(1) First, the unwinding roll 1 on which the plastic film original fabric 100 is wound is mounted on the support member.
(2) A cleaning liquid is supplied into the 1st water tank 72 and the 2nd water tank 73, a process liquid is also supplied into the warm water tank 74, and it heats to fixed temperature. Further, an adsorption liquid made of iodine or dye is supplied into the adsorption treatment tank 75, and the fixing liquid is also supplied into the fixing tank 76.
(3) The nip rolls 60 to 69 are retracted upward by operating the fluid cylinder 71. Further, the upper member of the drying chamber 77 and the guide roll attached thereto are lifted to a required height.
(4) The plastic film original fabric 100 is unwound from the unwinding roll 1 and sequentially pulled out so as to be in contact with the upper surfaces of the drive roll and the guide roll, and the first stage stretching section 110, the softening processing section 120, and the second stage stretching section 130. After passing through the drying processing unit 140, the leading end is mounted on the winding roll 56 via the drive roll 53 and the tension roll 54.
(5) The nip rolls 60 to 68 are moved downward by operating the fluid cylinder 71, and the original plastic film 100 is pressed against the upper surface of the drive roll. Further, the guide rolls 4 to 6, 8 to 10, 12, 14 to 16, 18 to 20, and 26 to 28 are submerged in the liquid. Further, the upper member of the drying chamber and the guide roll attached thereto are lowered.
(6) The warm air is sent from the blower 78 and the first motor 83, the second motor 84, and the torque motor 93 are driven.
(7) The raw plastic film 100 passes through the first-stage stretching unit 110, the softening processing unit 120, the second-stage stretching unit 130, and the drying processing unit 140, and passes through the driving roll 53 and the tension roll 54, and the winding roll 56. In the meantime, the driving rolls of the first-stage stretching section 110 and the second-stage stretching section 130 are stretched without difficulty, and a high-quality polarizing film is obtained.
(8) When the stretching process of the plastic film original fabric 100 wound on one unwinding roll is completed, the next unwinding roll is set and the procedures (1) to (7) are repeated.

It is a schematic side view for demonstrating the whole polarizing film continuous manufacturing apparatus which concerns on embodiment of this invention. It is a schematic side view for demonstrating the drive system of the polarizing film continuous manufacturing apparatus which concerns on embodiment of this invention. It is the top view which looked at the principal part of FIG. 2 from upper direction. It is the front view which looked at the drive roll and the nip roll from the front.

Explanation of symbols

1 Unwinding roll 3, 7, 11, 13, 17, 21, 25, 29, 53 Drive roll
2, 4-6, 8-10, 12, 14-16, 18-20, 22-24, 26-28,
30 to 52, 55 Guide roll 54 Tension roll
56 Winding roll
60-68 nip roll
70 Bearing
71 Fluid cylinder
72 1st water tank 73 2nd water tank 74 Warm water tank 75 Adsorption processing tank 76 Fixing tank 77 Drying room 78 Blower 82 Gear 83 First motor 84 Second motor 85, 86 Gear mechanism 87 Transmission shaft 88 Gear mechanism 89 Reduction gear 90 Gear 91 Chain 92 Transmission shaft 93 Torque motor 95 Frame 96 Underframe 100 Plastic film original fabric 110 First stage stretching section 120 Softening processing section 130 Second stage stretching section 140 Drying processing section

Claims (3)

In an apparatus for producing a polarizing film by uniaxially stretching a peeled plastic film raw material in a fixed direction by a plurality of driving rolls having the same diameter in the process of continuously supplying the raw film from the unwinding roll to the winding roll, the second stage drawing unit for drawing at a moving speed 8～16Cm / min to the downstream side of the first stage drawing unit for drawing in a counter moving speed 2 to 4 cm / min is provided in the first-stage drawing unit, the inlet of the drive roll The rotational speed of the driving roll at the outlet is about 1.25 times when the rotational speed of the first roll is 1, and the rotational speed of the driving roll at the entrance of the first stretched section is 1 in the second-stage stretched section. The number of rotations of the drive roll is about 5 times, a water tank is provided in the first stage extending portion, a guide roll for moving the plastic film raw material in a meandering manner in the water tank is provided in the water tank, Step stretching section The softening treatment unit between the second-stage drawing unit is provided, in the second step stretching unit the fixing tank provided subsequent to the adsorption treatment tank, also providing a drying section following the second step stretching unit A polarizing film continuous manufacturing apparatus.   A power transmission mechanism is provided so that the driving roll of the first stage extending section is driven by the first motor, and the driving roll of the second stage extending section and the driving roll downstream of the drying processing section are driven by the second motor. 2. A polarizing film continuous manufacturing apparatus according to claim 1, wherein each drive roll is provided with a speed reducer, and the number of rotations of each drive roll is controlled by a control device.   A nip roll with rubber on the surface is provided above the drive roll to press the plastic film original against the drive roll and prevent slippage between the plastic film and the drive roll, and the nip roll can be moved up and down by a fluid cylinder. The polarizing film continuous production apparatus according to claim 1 or 2, wherein

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