WO2012120943A1

WO2012120943A1 - Apparatus for manufacturing polarization plate, method for manufacturing polarization plate, polarization plate, and liquid crystal display device using polarization plate

Info

Publication number: WO2012120943A1
Application number: PCT/JP2012/052097
Authority: WO
Inventors: 篤史郡; 伸知高島; 中嶋　浩
Original assignee: 株式会社サンリッツ
Priority date: 2011-03-09
Filing date: 2012-01-31
Publication date: 2012-09-13
Also published as: JP5665622B2; CN103502851B; JP2012189968A; TW201243405A; KR20140053864A; CN103502851A; TWI554792B; KR101854873B1

Abstract

[Problem] To uniformly adhere protection films on both the surfaces of a polarization element using an adhesive, and to prevent the protection films from peeling and generating wrinkles, even if the direction is converted at the time of guiding the polarization element to a subsequent adhesive drying or hardening step. [Solution] A strip-like film of a polarization element is moved downward from above in the vertical direction, and a laminated film is formed by adhering first and second protection films at the same time to the polarization element from both the sides in the horizontal direction using an adhesive. Then, the moving direction of the laminated film is converted from the vertical direction to the horizontal direction by two or more steps, and the laminated film is dried or hardened.

Description

Polarizing plate manufacturing apparatus, polarizing plate manufacturing method, polarizing plate, and liquid crystal display device using the same

The present invention relates to a polarizing plate manufacturing apparatus and a polarizing plate manufacturing method. Moreover, this invention relates to the polarizing plate obtained by the said manufacturing method, and the liquid crystal display device using the said polarizing plate.

Since liquid crystal display devices are thin and consume low power, they are widely used as display devices for televisions, computers, mobile phones, car navigation systems, and the like. Such a liquid crystal display device mainly includes a backlight system and a liquid crystal panel. The liquid crystal panel further includes a liquid crystal cell and polarizing plates provided on the front surface (surface on the viewing side) and the back surface (surface on the backlight system side) via an adhesive layer.

A polarizing plate used in such a liquid crystal display device is composed of a polarizing element having polarization performance and a protective film that is provided on both surfaces of the polarizing element via an adhesive layer to protect the polarizing element. The polarizing element is generally formed of a polyvinyl alcohol (hereinafter sometimes referred to as PVA) resin that is dyed with iodine and uniaxially stretched. The protective film is formed of, for example, a triacetyl cellulose (hereinafter sometimes referred to as TAC) resin.

In the production of such a polarizing plate, it is generally formed continuously in a strip-like long film shape. In this continuous production, the step of adhering the polarizing element and the protective film is, for example, a strip-like long film-shaped polarizing plate that moves in the horizontal direction as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2008-90271). From the top and bottom of the element, supply a strip-like long film-like protective film to make them approach each other, apply an adhesive between the polarizing element and the protective film before superimposing them, and then apply an adhesive on the top and bottom of the polarizing element The protective film is overlapped through the layers, and pressure is applied by passing through a pinch roll to bond them together. Next, the bonding process is completed by drying the bonded layered film and drying the adhesive layer. Depending on the type of the adhesive, the adhesive layer may be cured by applying an active energy pretreatment such as UV treatment instead of the drying treatment.

In addition, the step of bonding such a polarizing element and a protective film is performed in the vertical direction, that is, in the vertical direction, as disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 11-179971). In some cases, the protective film is guided from the top to the bottom, and the protective film is simultaneously approached and bonded from the left and right sides while applying the adhesive. By doing in this way, compared with the case where the protective films on both sides shown in Patent Document 1 are bonded to the upper and lower sides of the polarizing element, the adhesive is applied symmetrically to the polarizing element on the left and right sides. The uniformity of film adhesion is improved.

In this way, when the polarizing element is guided in the vertical direction and the protective film is bonded from the left and right, the work space in the vertical direction is limited, so the next adhesive layer is dried after the protective film is bonded. Or in the process of hardening, it is necessary to change the direction of the laminated | multilayer film bonded together from the movement of a perpendicular direction to the movement of a horizontal direction.

An example will be described with reference to the drawings. FIG. 6 shows an example of a conventional polarizing plate manufacturing apparatus. As shown in FIG. 6, a strip-shaped long film-shaped polarizing element 111 made of a PVA-based resin already dyed with iodine and uniaxially stretched is guided in a vertical direction from top to bottom by a guide roll 155. The first protective film 114 from the left side and the second protective film 115 from the right side simultaneously approach each other, and between the polarizing element 111 and the first protective film 114 immediately before bonding, the polarizing element 111 and the second protective film 114 A first adhesive 112a and a second adhesive 113a are applied between the film 115 and the first nozzle 151 and the second nozzle 152, respectively, and the polarizing element 111 is applied with a pair of pinch rolls 158a and 158b. In addition, the first protective film 114 and the second protective film 115 are bonded to the left and right simultaneously.

The laminated film 110a bonded together is moved 90 degrees (right angle) at a time by one guide roll 161 in the direction from the top to the bottom in the vertical direction, from the right to the left, that is, in the horizontal direction. The direction is changed. Thereafter, the laminated film 110a is passed through the drying chamber 171 in the horizontal direction to dry the laminated film 110a, and the first adhesive formed by the first adhesive 112a and the second adhesive 113a. The layer and the second adhesive layer are subjected to a drying process, and the bonding process of the polarizing element 111 and the first and second

protective films

114 and 115 is completed, whereby the polarizing plate which is the film configuration of the laminated film 110a is obtained. can get. In FIG. 6, illustration of the film configuration of the laminated film 110a is omitted.

As an example of this, for example, in Patent Document 3 (Japanese Patent Laid-Open No. 2008-276136), a polarizing film is guided in the vertical direction, a protective film is bonded from the left and right sides thereof, and then the laminated film is bonded to one It is disclosed that the direction is changed by 90 degrees with a guide roll, and the adhesive is cured by guiding in the horizontal direction.

JP 2008-90271 A Japanese Patent Laid-Open No. 11-179871 JP 2008-276136 A

As described above, after the protective film is bonded to the polarizing element, and before the step of drying or curing the adhesive layer, the laminated film is turned 90 degrees with one guide roll. The inventors have found a phenomenon of peeling from the surface and causing wrinkles. In particular, the protective film on the inner side in the direction of bending by changing direction, that is, the first protective film 114 in the example of FIG. In particular, this phenomenon is more likely to occur when the film conveyance speed is increased to increase production efficiency. This is because immediately after the protective film is bonded to the polarizing element, the adhesive layer is not dried or cured, so that the adhesiveness is insufficient. The inventors speculated that this was because the laminated film was bent at a steep angle such as 90 degrees (right angle).

From the process of attaching the protective film to the polarizing element to the process of drying or curing the adhesive layer, if all are guided in the horizontal direction, such a problem will not occur. However, as in Patent Document 1, when the step of attaching the protective film to the polarizing element is performed by a method in which the polarizing element is guided in the horizontal direction and the protective film is approached from above and below, the adhesive is applied to the polarizing element. Since the upper and lower sides cannot be made symmetrically and evenly due to the influence of gravity, the uniformity of adhesion of the protective films on both sides of the polarizing element is deteriorated. Therefore, in the step of attaching the protective film to the polarizing element, it is desirable to guide the polarizing element from top to bottom in the vertical direction and attach the protective film from the left and right.

However, the polarizing element is guided in the vertical direction from top to bottom, the protective film is bonded from the left and right, and the laminated film is turned 90 degrees with one guide roll to change the next adhesive layer. When guided to the drying or curing process, the protective film is peeled off or wrinkled from the polarizing element as described above, and the polarizing plate becomes defective.

The present invention has been made to solve such a problem, and guides the adhesion between the polarizing element and the protective film from top to bottom in the vertical direction, and bonds the protective film from the left and right. In order to guide to the next drying or curing process of the adhesive layer, the object is to change the direction so that peeling or wrinkling of the protective film does not occur even if the direction is changed in the horizontal direction.

The apparatus for producing a polarizing plate of the present invention moves a strip-like film of a polarizing element made of polyvinyl alcohol resin from the top to the bottom in the vertical direction, and supplies the first protective film and the second protective film supplied from the left and right respectively. From the top to the bottom in the vertical direction, the laminating portion that is simultaneously pasted to the polarizing element by the adhesive and the movement of the laminated film on which the first protective film, the polarizing element, and the second protective film are pasted A direction changing unit that changes the direction from movement to horizontal movement, and a drying unit that subjects the laminated film to direction change to horizontal movement and then dries or cures the adhesive of the laminated film The polarizing plate has at least a plurality of guide rolls, and the direction changing section is provided with the plurality of guide rolls. Characterized by being configured so that the direction conversion of the laminated film is applied in two or more stages.

Moreover, the manufacturing method of the polarizing plate of this invention moves and supplies the strip | belt-shaped film of the polarizing element which consists of polyvinyl alcohol-type resin to the down direction from the perpendicular direction, and the 1st protective film and the 2nd protective film from the right and left , Respectively, and a bonding step in which the first protective film and the second protective film are simultaneously bonded to the polarizing element by an adhesive, the first protective film, the polarizing element, and the second A direction changing step of changing the movement of the laminated film on which the protective film is bonded from the movement from the top to the bottom in the vertical direction to the movement in the horizontal direction, and the direction changing from the movement in the horizontal direction to the lamination film. And a drying step of drying or curing the adhesive of the laminated film, wherein the method comprises the steps of: Converting step is characterized by performing dividing the direction conversion of the laminated film in two or more stages.

The polarizing plate of the present invention is a polarizing plate manufactured by the above-described manufacturing method.

The liquid crystal display device of the present invention is a liquid crystal display device using the above-mentioned polarizing plate.

According to the present invention, when the protective film is bonded to the polarizing element, the polarizing element is guided from top to bottom in the vertical direction, and the protective film is bonded from the left and right. Even if the direction of the laminated film is changed in the horizontal direction to guide it to the next drying or curing process of the adhesive, it is divided into two or more stages by a plurality of guide rolls. Since the direction is changed, peeling of the protective film and wrinkles are prevented, and the polarizing plate can be stably produced even when the film conveyance speed is increased to increase production efficiency.

It is sectional drawing of an example of the polarizing plate manufactured by the manufacturing method of this invention. It is sectional drawing of an example of the manufacturing apparatus of the polarizing plate of this invention. It is sectional drawing of an example of the direction change part of the manufacturing apparatus of the polarizing plate of this invention. It is sectional drawing of the other example of the direction change part of the manufacturing apparatus of the polarizing plate of this invention. It is sectional drawing of an example of the liquid crystal display device with which the polarizing plate of this invention was used. It is sectional drawing of an example of the manufacturing apparatus of the conventional polarizing plate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an example of a polarizing plate manufactured by the polarizing plate manufacturing apparatus and the polarizing plate manufacturing method of the present invention. The polarizing plate 10 is provided on each surface of the polarizing element 11 having polarizing performance and the polarizing element 11 via the first adhesive layer 12 and the second adhesive layer 13, respectively. It comprises a first protective film 14 and a second protective film 15 to be protected. The polarizing element 11 is formed of a PVA resin that is dyed with iodine and uniaxially stretched. The first and second

protective films

14 and 15 are formed of a TAC resin. In addition, a PVA adhesive is used as the first adhesive and the second adhesive for forming the first adhesive layer 12 and the second adhesive layer 13. The film thickness of the polarizing element 11 is, for example, 10 μm to 40 μm, and the film thicknesses of the first and second

protective films

14 and 15 are, for example, 20 μm to 120 μm, respectively.

FIG. 2 is a schematic cross-sectional view of an example of a polarizing plate manufacturing apparatus of the present invention. FIG. 2 is a part of a polarizing plate manufacturing apparatus, in which the polarizing element 11, the first protective film 14, and the second protective film 15 are bonded together by the first adhesive 12a and the second adhesive 13a. For the first adhesive layer 12 formed between the polarizing element 11 and the first protective film 14 and the second protective film 15 in the bonding portion 50, A drying unit 70 used in the process of drying the adhesive layer 13, and a polarizing plate provided between the bonding unit 50 and the drying unit 70, and the polarizing element 11 and the first and second

protective films

14 and 15 are bonded to each other. The direction change part 60 which guides the laminated | multilayer film 10a used as the structure of 10 and changes the moving direction of the laminated | multilayer film 10a is comprised. Further, in the following description, “right”, “right”, “left”, and “left” indicate “right”, “right”, “left”, and “left”.

As shown in FIG. 2, the bonding unit 50 that bonds the polarizing element 11 and the first and second

protective films

14 and 15 guides the polarizing element 11 to be supplied vertically from top to bottom. A first guide roll 55 and a second guide roll 56 that supplies the first protective film 14 from the left side of the polarizing element 11 and the second protective film 15 from the right side to guide the polarizing element 11 so as to approach it, Provided between the third guide roll 57 and each of the polarizing element 11 and the first protective film 14 and the second protective film 15 that are close to each other, the first adhesive 12a and the second adhesive The first nozzle 51 for supplying the agent 13a, the second nozzle 52, the first adhesive 12a, the polarizing element 11 to which the second adhesive 13a is applied, and the first and second

protective films

14, 15; Pressure from the left and right At the same time Te be bonded pair of pinch rolls 58a, consisting of 58b. The first and

second nozzles

51 and 52 are provided at symmetrical positions with respect to the polarizing element 11 guided from above to below, respectively, and the polarizing element 11 and the first and second supplied respectively to the left and right thereof. The ejection port is arranged substantially downward in the vertical direction so that the first and

second adhesives

12a and 13a are applied between the

protective films

14 and 15. Further, it is desirable that a predrying device 59 is provided between the pair of pinch rolls 58 a and 58 b and the direction changing unit 60 in the bonding unit 50. The preliminary drying device 59 is only schematically shown in FIG. 2, but for example, a heating heater, a far infrared heater, or a drying device that blows high-temperature air is exemplified.

The polarizing element 11 supplied to the bonding unit 50 is made of a belt-like PVA-based resin film, and is uniaxially stretched by being dyed with a dichroic dye such as iodine in the previous step of the bonding. The stretched PVA resin film has a film thickness of, for example, 10 μm to 40 μm, and a width of, for example, 500 mm to 2000 mm. About this pre-process, it can produce using a known apparatus and a manufacturing method, Although illustration and detailed description are abbreviate | omitted, the example is demonstrated easily below.

A PVA-based resin film is drawn out from a strip-like long PVA-based resin film roll wound in a roll shape, and swollen in pure water. Subsequently, it is immersed in an aqueous solution of iodine in potassium iodide, and the PVA resin film is dyed with iodine. Next, the PVA resin film dyed with iodine is immersed in an aqueous solution containing boric acid to perform a crosslinking treatment. Next, the PVA resin film is uniaxially stretched at a predetermined magnification. The draw ratio is, for example, 4 to 7 times. Stretching may be performed in two or more stages, may be performed before or simultaneously with dyeing, or may be performed in a crosslinking treatment step. At this time, the crosslinking treatment may be performed simultaneously with the dyeing or after the dyeing. Thereafter, the PVA-based resin film is dried to obtain the polarizing element 11 having polarization performance, and supplied to the bonding unit 50.

The polarizing element 11 in the form of a strip-like long film supplied to the bonding unit 50 is guided downward in the vertical direction by the first guide roll 55. The moving speed of the polarizing element 11 is, for example, 10 m / min to 50 m / min. The first and second

protective films

14 and 15 supplied from the left and right are both made of a TAC-based resin, and each is supplied as a strip-like long film, the width of which corresponds to the width of the polarizing element 11. The film thickness is, for example, 20 μm to 120 μm, and the moving speed is matched to the moving speed of the polarizing element 11. In order to improve adhesiveness, the surface of each TAC resin bonded to the PVA resin may be subjected to saponification treatment or corona discharge treatment.

In the step of bonding the polarizing element 11 and the first and second

protective films

14 and 15 on the left and right sides thereof at the bonding portion 50, the left oblique upper direction with respect to the polarizing element 11 moving from the vertical direction to the lower direction. The first protective film 14 and the second protective film 15 from the diagonally upper right direction are supplied in such a manner that they gradually move closer to the polarizing element 11 symmetrically. And just before the bonding, between the polarizing element 11 and the first protective film 14, and between the polarizing element 11 and the second protective film 15, respectively, from the first and

second nozzles

51 and 52, respectively. The first and

second adhesives

12a and 13a are supplied and applied. The first and

second adhesives

12a and 13a are dropped from the first and

second nozzles

51 and 52 substantially downward in the vertical direction, and the surface of the polarizing element 11 or the first and second protective films. It is applied between the polarizing element 11 and each of the first and second

protective films

14 and 15 at the time when they are in close contact with each other. The first and

second adhesives

12a and 13a are applied to the polarizing element 11 with the polarizing element 11 and the first protective film 14 on the left side, and the polarizing element 11 and the second protective film 15 on the right side. Since it is applied symmetrically, the uniformity on the left and right of the coating is good.

The first and

second adhesives

12a and 13a are both PVA resin adhesives. Since the PVA resin has high hydrophilicity, water is mainly used as the solvent. That is, an adhesive made of an aqueous solution of PVA resin is dropped from the first and

second nozzles

51 and 52. With the first and

second adhesives

12a and 13a, the first adhesive layer 12 and the second adhesive are bonded between the polarizing element 11 and each of the first protective film 14 and the second protective film 15. The agent layer 13 is formed. That is, by this bonding step, the first protective film 14 and the second protective film 15 are provided via the polarizing element 11 and the first adhesive layer 12 and the second adhesive layer 13 on the respective surfaces thereof. A laminated film 10a having a film configuration of the polarizing plate 10 is formed. In addition, illustration of the film | membrane structure of the laminated | multilayer film 10a is abbreviate | omitted in FIG. It is desirable that the bonding process includes a preliminary drying process by the preliminary drying device 59. The preliminary drying step is performed after the laminated film 10a is formed by the pair of pinch rolls 58a and 58b and before the direction change by the direction changing unit 60, and the first adhesive layer 12 and the second adhesive layer 13 are applied. A part of the drying is preliminarily performed prior to the drying process of the drying unit 70. The preliminary drying step is performed by allowing the laminated film 10a to pass through the preliminary drying device 59 in the vertical direction, and the drying method includes a thermal drying method, a far infrared drying method, or a high temperature air drying method. Illustrated.

After the bonding step, the first adhesive layer 12 and the second adhesive layer 13 in the laminated film 10a are dried to volatilize the solvent. This is a drying process and is performed by the drying unit 70 of FIG. Although only schematically illustrated in FIG. 2, the drying unit 70 includes a drying chamber 71 for vaporizing and drying the solvent in the first adhesive layer 12 and the second adhesive layer 13. Although not shown in the figure, a thermal heater, a far infrared heater, or a drying device that blows high-temperature air is arranged, and the laminated film 10a is configured to pass through the drying chamber 71 in the horizontal direction. The Examples of the drying method include a thermal drying method, a far infrared ray drying method, and a high temperature air drying method. The drying unit 70 volatilizes and removes the water that is the solvent in the first adhesive layer 12 and the second adhesive layer 13 from the PVA-based resin, and completes the bonding. That is, the bonding process between the polarizing element 11 and the first and second

protective films

14 and 15 is achieved by the above-described bonding process and the drying process, and the laminated film 10 a that is the polarizing plate 10 is obtained. Thereafter, although not shown, the strip-shaped laminated film 10 a is cut into a predetermined shape as the polarizing plate 10. 2 illustrates the case where the laminated film 10a moves in the horizontal direction in the drying chamber 71. However, in order to increase the drying efficiency, the movement direction such as repeated movement in the drying chamber 71 up and down, diagonally up and down, etc. May be changed.

As described above, the bonding unit 50 moves the polarizing element 11 from the upper side to the lower side in the vertical direction so that the first and

second adhesives

12a and 13a are uniformly applied to both surfaces of the polarizing element 11. It is preferable. Moreover, the installation area of the horizontal direction of the manufacturing apparatus of a polarizing plate can be saved by doing in this way. However, since the distance that can be installed in the vertical direction is also limited, in the next drying unit 70, the laminated film 10a is moved in the horizontal direction. In the drying unit 70, it is desirable to move in the horizontal direction in order to prevent non-uniformity of the solvent component liquid due to gravity and to prevent appearance defects such as wrinkles. Moreover, since the height of the building is usually limited, it is preferable to move the laminated film 10a in the horizontal direction in the drying unit 70.

Therefore, it is necessary to change the moving direction of the laminated film 10a from the vertical direction to the horizontal direction by the direction changing unit 60 after the bonding step and before the drying step. This is a direction changing process. In the direction changing section 60 of the polarizing plate manufacturing apparatus according to the present invention, at least two direction changing guide rolls for changing the direction of the laminated film 10a are arranged.

2 shows an example of the arrangement of the direction change guide rolls of the present invention. In FIG. 2, the drying unit 70 shows a case where the drying unit 70 is arranged on the left side of the bonding unit 50, so the direction changing unit 60 of the present invention will be described with an example in which the direction of the laminated film 10 a is changed to the left side. Even when the drying unit 70 is disposed on the right side and the direction of the laminated film 10a is changed to the right side, the explanation is exactly the same by interpreting the left and right symmetrically.

FIG. 2 shows an example in which two direction change guide rolls are arranged in the direction change unit 60. This is referred to as a first direction change guide roll 61 and a second direction change guide roll 62. The 1st direction change guide roll 61 is arrange | positioned on the left surface along the moving direction of the perpendicular direction of the laminated | multilayer film 10a under the bonding part 50. As shown in FIG. The second direction change guide roll 62 is disposed on the upper surface of the laminated film 10a whose direction is changed in the horizontal direction, obliquely below the left side of the first direction change guide roll 61. The laminated film 10a is sequentially changed in direction and guided by the two direction changing guide rolls, but in total, the direction is changed from the vertical direction to the horizontal direction, that is, substantially 90 degrees. However, since the direction change is performed in two stages in this way, the bending angle of the laminated film 10a in each direction change guide roll can be made larger than 90 degrees (right angle), that is, one direction The bending of the laminated film 10a at the conversion guide roll can be eased. Therefore, peeling of the protective film from the polarizing element, which occurs when the laminated film is bent 90 degrees at a time as in the prior art, can be prevented. Here, the bending angle is an angle on the direction conversion guide roll side formed by a straight line in the moving direction of the laminated film 10a before passing through the corresponding direction changing guide roll and a straight line in the moving direction of the laminated film 10a after passing through. And

Here, as the first direction change guide roll 61 and the second direction change guide roll 62, normal guide rolls can be used, and the surface material may be made of resin or metal. Its cross section is circular and its diameter is, for example, 100 mm to 450 mm, more preferably 200 mm to 300 mm, and its width is larger than the width of the laminated film 10a. Further, the first direction change guide roll 61 and the second direction change guide roll 62 preferably have a rotation drive mechanism, and preferably have a temperature control mechanism. For example, the temperatures of the first direction change guide roll 61 and the second direction change guide roll 62 are each preferably controlled to a temperature in the range of 35 ° C. to 45 ° C., more preferably 40 ° C. Yes. The first direction change guide roll 61 and the second direction change guide roll 62 may have the same diameter, material, and mechanism, or may have different diameters, materials, and mechanisms.

The inventors further studied a more preferable arrangement of these two direction change guide rolls. This will be described with reference to FIG. FIG. 3 shows only the direction changing unit 60 of FIG. The present inventors have found that the bending angle θ by the first direction change guide roll 61 is particularly important in order to prevent the protective film from peeling off. In order to make the preferable range easy to understand, the complementary angle θ ′ (θ + θ ′ = 180 °) of the bending angle θ is shown. That is, θ ′ represents an angle from the vertical direction in which the laminated film 10 a is changed in direction by the first direction changing guide roll 61. In order to prevent the protective film from being peeled off by the first direction change guide roll 61, θ ′ should be as close as possible to 0 °. In that case, the bending angle at the second direction change guide roll 62 Then, the protective film peels off. As a result of the research conducted by the present inventors in view of such factors, θ ′ that does not cause peeling of the protective film is 35 ° <θ ′ <70 °, and more preferably 40 ° <θ ′ <65 °. It is. For example, peeling occurred when θ ′ = 30 °, and no peeling or wrinkle occurred when θ ′ = 45 ° and θ ′ = 60 °. Further, the distance between the centers of the first direction changing guide roll 61 and the second direction changing guide roll 62 is preferably in the range of 250 mm to 1000 mm, more preferably 300 mm to 500 mm, when expressed in the vertical direction.

In the above-described embodiment, the case where two direction change guide rolls are arranged in the direction change unit 60 has been described. However, in the present invention, three or more direction change guide rolls may be arranged. FIG. 4 shows an example of the direction changing section 60 in which three direction changing guide rolls are arranged by adding the third direction changing guide roll 63 to the example of FIG. 3 described above. FIG. 4 shows another example in which only the direction changing unit 60 is extracted. Similar to the example of FIG. 3, the first direction change guide roll 61 is arranged on the left surface along the vertical movement direction of the laminated film 10a, and the second direction change guide roll 62 is the first direction change guide roll. 61 is arranged on the upper surface of the laminated film 10a that has been changed in the horizontal direction, diagonally below the left side. The third direction change guide roll 63 is disposed between the first direction change guide roll 61 and the second direction change guide roll 62. Each of the turn angles of the three direction changing guide rolls is larger than 90 degrees and smaller than 180 degrees. The moving direction of the laminated film 10a is converted into the horizontal direction by the second direction conversion guide roll 62. Thus, by arranging three direction changing guide rolls, the bending of the laminated film 10a by each direction changing guide roll can be further eased compared to the case where two direction changing guide rolls in FIG. 3 are arranged. It is possible to further prevent peeling of the protective film.

In the present invention, four or more direction changing guide rolls may be further arranged in the direction changing unit 60. Even in the case where three or more are arranged in this manner, the bending angle θ of the laminated film 10a by the first direction changing guide roll, that is, the first direction changing guide roll 61 is important, and as described above, the complementary angle θ ′ (θ + θ ′) of θ. = 180 °), preferably 35 ° <θ ′ <70 °, and more preferably 40 ° <θ ′ <65 °. Even when three or more direction change guide rolls are arranged, any of the direction change guide rolls similar to the first and second guide rolls 61 and 62 described above can be used. The diameter, material, and mechanism of each guide roll may be the same or different. 3 and 4 also omit the illustration of the film configuration of the laminated film 10a.

Although the 1st protective film 14 and the 2nd protective film 15 demonstrated the case where it was a TAC resin, this invention is not limited to this, The 1st protective film 14 and the 2nd protective film 15 On one or both sides, in addition to the TAC resin, a cycloolefin resin such as norbornene, a polyethylene terephthalate (PET) resin, an acrylic resin, or a laminated film of these may be used. The first protective film 14 and the second protective film 15 may be made of the same material or different materials. Further, one or both of the first and second

protective films

14 and 15 may be retardation films. Further, one or both of the first and second

protective films

14 and 15 may be provided with an AG (anti-glare) layer on the surface thereof in order to reduce glare resistance, antireflection function and optical unevenness. Well, AG treatment may be performed, and haze may be given to the inside of the film. One or both of the first and second

protective films

14 and 15 may be subjected to antistatic treatment.

Moreover, although the 1st adhesive agent 12a and the 2nd adhesive agent 13a demonstrated the case of hydrophilic PVA-type resin, it is not limited to this, The 1st protective film 14 and the 2nd protective film 15 of An arbitrary solvent such as an acrylic adhesive or a urethane adhesive can be used depending on the material, and an appropriate solvent such as an organic solvent can be used depending on each adhesive. Further, the first adhesive 12a and the second adhesive 13a may be the same or different.

Furthermore, an active energy ray curable adhesive such as ultraviolet rays can be used as the first adhesive 12a and the second adhesive 13a. In this case, although not shown in the drawing, an active energy ray curing device that cures the adhesive with active energy rays such as ultraviolet rays is arranged in place of the drying chamber 71 of the drying unit 70 in the polarizing plate manufacturing apparatus of FIG. The adhesive is subjected to a curing process instead of the drying process. That is, the drying unit 70 may be configured by a curing device that cures the adhesive, and the drying process of the adhesive may be a process of curing the adhesive. An example of the active energy ray curable adhesive is an ultraviolet (UV) curable epoxy adhesive, and an example of the active energy ray curable device is an ultraviolet curing device. Since the ultraviolet ray (UV) curable adhesive is fast to be bonded, the protective film is not easily peeled off due to the direction change. However, the application of the present invention can further suppress the peeling of the protective film. When the active energy ray-curable adhesive is used as described above, the preliminary drying device 59 can be omitted.

Next, the liquid crystal display device of the present invention using the polarizing plate 10 of the present invention manufactured using the polarizing plate manufacturing apparatus and the polarizing plate manufacturing method of the present invention will be described. FIG. 5 shows a liquid crystal panel 20 constituting the liquid crystal display device of the present invention. In addition, the liquid crystal display device includes a backlight system disposed on the back side of the liquid crystal panel 20, but since a known configuration can be adopted, illustration and description thereof are omitted.

The liquid crystal panel 20 includes a liquid crystal cell 21 and a first polarized light bonded to the front surface side of the liquid crystal cell 21 (viewing side, that is, opposite to the backlight system) via a first adhesive layer 22f. The plate 10f is composed of the second polarizing plate 10r bonded to the back surface side (that is, the backlight system side) of the liquid crystal cell 21 via the second pressure-sensitive adhesive layer 22r.

The polarization axes of the first polarizing plate 10f and the second polarizing plate 10r are arranged in crossed Nicols. The liquid crystal cell 21 may be any of TN type, STN type, VA type, and IPS type, and a known one can be used, and the description and illustration of the internal structure are omitted. In the liquid crystal panel 20 of the liquid crystal display device of the present invention, the polarizing plate 10 according to the present invention may be used for one or both of the first polarizing plate 10f and the second polarizing plate 10r. In FIG. 5, the film configurations of the first polarizing plate 10f and the second polarizing plate 10r are omitted. The first pressure-sensitive adhesive layer 22f and the second pressure-sensitive adhesive layer 22r (hereinafter, the first pressure-sensitive adhesive layer 22f and the second pressure-sensitive adhesive layer 22r are not distinguished from each other and will be described as pressure-sensitive adhesive layers). A well-known thing can be used also about an adhesive. For example, an acrylic adhesive, a urethane adhesive, a silicone adhesive, and the like can be given. Moreover, you may use the adhesive which has an ultraviolet-ray (UV) cut function.

In general, the pressure-sensitive adhesive layer is often formed in advance by a polarizing plate manufacturer. That is, after the bonding of the polarizing element 11 and the first and second

protective films

14 and 15 is completed to obtain a strip-like long laminated film 10a having a film configuration of the polarizing plate 10, this lamination is performed before cutting. A pressure-sensitive adhesive layer is formed on the surface of the film 10a to be bonded to the liquid crystal cell 21 by coating, a release film (not shown) is bonded to the surface of the pressure-sensitive adhesive layer, and then the liquid crystal cell to be bonded. According to the shape of 21, the pressure-sensitive adhesive layer and the release film are cut together to obtain a sheet-like polarizing plate product in which the pressure-sensitive adhesive layer and the release film are formed on one surface of the polarizing plate 10. This is delivered to a liquid crystal panel production line, where the polarizing plate 10 and the liquid crystal cell 21 are bonded together by an adhesive layer formed on the surface of the polarizing plate 10. Here, the release film is provided to protect the surface of the pressure-sensitive adhesive layer, and is peeled and removed immediately before the polarizing plate 10 is bonded to the liquid crystal cell 21. Moreover, after forming an adhesive layer and a peeling film in the surface which should be bonded to the liquid crystal cell 21 of the strip | belt-shaped long laminated | multilayer film 10a, without completely cut | disconnecting, for example, the part of a peeling film and an adhesive layer A cut surface is formed according to the shape of the liquid crystal cell 21 to be bonded only (half cut), and supplied to the liquid crystal panel production line as a polarizing plate product in a roll shape with a strip-like long film, In this case, the release film may be removed by pulling out from the roll immediately before being bonded to the liquid crystal cell 21, and may be completely cut and bonded according to the shape of the liquid crystal cell 21.

The embodiment of the present invention has been described above, but the present invention is not limited to this, and can be modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Polarizing plate 10a Laminated film 10f First polarizing plate 10r Second polarizing plate 11 Polarizing element 12 First adhesive layer 12a First adhesive layer 13 Second adhesive layer 13a Second adhesive layer 14 First Protective film 15 second protective film 20 liquid crystal panel 21 liquid crystal cell 22f first pressure-sensitive adhesive layer 22r second pressure-sensitive adhesive layer 50 bonding portion 51 first nozzle 52 second nozzle 55 first guide roll 56 Second guide roll 57 Third guide roll

58a Pinch roll

58b Pinch roll 59 Predrying device 60 Direction changing section 61 First direction changing guide roll
62 2nd direction change guide roll 63 3rd direction change guide roll 70 Drying part 71 Drying chamber 110a Laminated film 111 Polarizing element 112a 1st adhesive agent 113a 2nd adhesive agent 114 1st protective film 115 2nd Protective film 151 First nozzle 152 Second nozzle 155 Guide roll 158a Pinch roll 158b Pinch roll 161 Guide roll 171 Drying chamber

Claims

A strip film of a polarizing element made of polyvinyl alcohol resin is moved from the top to the bottom in the vertical direction, and the first protective film and the second protective film respectively supplied from the left and right sides thereof are simultaneously bonded to the polarizing element with an adhesive. A bonding section;
A direction changing unit that changes the movement of the laminated film on which the first protective film, the polarizing element, and the second protective film are bonded from the vertical movement to the horizontal movement. When,
A polarizing plate manufacturing apparatus comprising at least a drying unit that performs drying or curing on the adhesive of the laminated film after performing a direction change to the horizontal movement of the laminated film,
The said direction change part is provided with the some guide roll, The direction change of the said laminated | multilayer film is divided into two steps or more by the said some guide roll, It was comprised, The manufacturing apparatus of the polarizing plate characterized by the above-mentioned.
The polarizing plate manufacturing apparatus according to claim 1, wherein each of the plurality of guide rolls is provided with a rotation drive mechanism.
3. The polarizing plate manufacturing apparatus according to claim 1, wherein each of the plurality of guide rolls is provided with a temperature control mechanism.
The plurality of guide rolls are a first guide roll for changing the direction of the laminated film moving from the upper side to the lower side in the oblique direction, and the laminated film whose direction is changed in an oblique direction by the first guide roll. The polarizing plate according to any one of claims 1 to 3, wherein the polarizing plate is configured with a second guide roll that changes direction in the horizontal direction, and the direction change of the laminated film is performed in two stages. Manufacturing equipment.
The plurality of guide rolls include a first guide roll for changing the direction of the laminated film moving from the upper side to the lower side in the oblique direction, and a second guide roll for changing the direction of the laminated film in the horizontal direction. And one or more guide rolls provided between the first guide roll and the second guide roll, and the direction change of the laminated film is performed in three or more stages. The polarizing plate manufacturing apparatus according to claim 1, configured as described above.
The polarizing plate manufacturing apparatus according to claim 4 or 5, wherein an angle from the vertical direction in which the direction of the laminated film is changed by the first guide roll is 35 ° to 70 °.
A strip film of a polarizing element made of a polyvinyl alcohol resin is supplied by moving from the top to the bottom in the vertical direction, and the first protective film and the second protective film are supplied from the left and right, respectively. And a bonding step in which the second protective film is simultaneously bonded to the polarizing element with an adhesive,
A direction changing step of changing the movement of the laminated film on which the first protective film, the polarizing element, and the second protective film are bonded from the movement in the vertical direction to the movement in the horizontal direction. When,
A method of producing a polarizing plate comprising at least a drying step of performing drying or curing on the adhesive of the laminated film after performing a direction change to the horizontal movement of the laminated film,
The said direction change process divides and performs direction change of the said laminated | multilayer film in two steps or more, The manufacturing method of the polarizing plate characterized by the above-mentioned.
The direction changing step is a step in which the direction change of the laminated film is performed in two stages, the first direction changing the direction of the laminated film moving from the vertical direction downward to the oblique direction, The manufacturing method of the polarizing plate of Claim 7 which consists of the 2nd direction change which changes the direction of the said laminated | multilayer film changed into the diagonal direction by the 1st direction change to the said horizontal direction.
The direction changing step is a step in which the direction change of the laminated film is performed in three or more stages, and the first direction change for changing the direction of the laminated film moving from the top to the bottom in an oblique direction; Further one or more directions applied to the laminated film between the second direction change for changing the direction of the laminated film in the horizontal direction, and the first direction change and the second direction change. The manufacturing method of the polarizing plate of Claim 7 which consists of conversion.
The method for producing a polarizing plate according to claim 8 or 9, wherein an angle from the vertical direction in which the direction of the laminated film is changed by the first direction change is 35 ° to 70 °.
A polarizing plate produced by the method for producing a polarizing plate according to claim 7.
A liquid crystal display device using the polarizing plate according to claim 11.