KR20220107915A - Method for producing polarizer and device for manufacturing the same - Google Patents

Abstract

Provided is a method for producing a polarizer capable of suppressing stretching and cutting of a disk film in a treatment tank, and the like. The present invention relates to the method for manufacturing the polarizer (F1) by treating a disk film in the treatment tank, while disposing a nip roller (2) in the treatment tank (L) and conveying the disk film (FO) with the nip roller, wherein the nip roller is composed of a driving roller (21), and a driven roller (22) that conveys the disk film by sandwiching the same between the driving roller, and the surface hardness of the driving roller and the surface hardness of the driven roller are different.

Description

The manufacturing method and manufacturing apparatus of a polarizer TECHNICAL FIELD

This invention relates to the manufacturing method and manufacturing apparatus of a polarizer. In particular, the present invention relates to a method and apparatus for manufacturing a polarizer by subjecting a raw film to a treatment in a treatment bath while disposing a nip roller in the treatment bath and conveying the raw film to the nip roller, in the raw film in the treatment bath It is related with the manufacturing method and manufacturing apparatus of the polarizer which can suppress the extending|stretching cutting|disconnection of.

DESCRIPTION OF RELATED ART Conventionally, the polarizing film containing a polarizer is used as constituent materials, such as a liquid crystal display device and an organic electroluminescent display. A polarizing film is comprised, for example from the polarizer dyed with dichroic substances, such as iodine, and the protective film which protects this polarizer. A long strip|belt-shaped polarizing film is manufactured by bonding an elongate strip|belt-shaped protective film to at least single side|surface of a long strip|belt-shaped polarizer normally by a roll-to-roll system. The manufactured elongate strip-shaped polarizing film is cut into a size or shape according to a use, and is used for a liquid crystal display device or the like.

A polarizer is manufactured by making a long strip|belt-shaped polymer film into a raw film, conveying this raw film in a longitudinal direction, immersing it in various treatment baths, and performing various processes. As a treatment tank for storing the treatment bath, for example, a swelling treatment tank for performing a swelling treatment on the raw film in order from the upstream side in the conveying direction of the raw film, and a dichroic substance such as iodine for the raw film subjected to the swelling treatment. A dyeing treatment tank for performing a dyeing treatment, a crosslinking treatment tank for performing a crosslinking treatment on the raw film subjected to the dyeing treatment, a stretching treatment tank for performing a stretching treatment on the raw film subjected to the crosslinking treatment, and the raw material to which the stretching treatment has been performed A washing treatment tank that performs a washing (washing) treatment on a film is used (see, for example, Patent Document 1).

Generally, in order to convey a raw film in a process bath, the guide roller arrange|positioned in a process bath is used, However, The nip roller arrange|positioned in a process bath may be used (for example, refer patent document 2). A guide roller is a roller with which the single side|surface of a raw film contacts. A nip roller is a roller comprised by the drive roller which rotates by drive sources, such as a motor, and the driven roller which rotates according to rotation of a drive roller, and pinches|interposes a raw film between a drive roller and conveys.

However, when a raw film is conveyed using the nip roller arrange|positioned in a process bath, it turns out that what is called a stretch cut|disconnection which a raw film fractures|ruptures at the time of extending|stretching of a raw film may occur.

Japanese Patent Laid-Open No. 2004-341515 Japanese Laid-Open Patent Publication No. 2014-142392

The present invention has been made to solve the problems of the prior art, and in a method and apparatus for manufacturing a polarizer by placing a nip roller in the treatment bath and performing a treatment on the raw film in the treatment bath while conveying the raw film to the nip roller, It makes it a subject to provide the manufacturing method and manufacturing apparatus of the polarizer which can suppress the extending|stretching cut|disconnection of the raw film in a process bath.

In order to solve the above problems, the present inventors have studied diligently, and as a result, stretching and cutting of the raw film occurs when the surface hardness (outer surface hardness) of the driving roller and driven roller constituting the nip roller is high, when the raw film is nipped (When the raw film is sandwiched in a pressurized state between the driving roller and the driven roller), it has been discovered that one factor is that the linear pressure acting on the raw film from the nip roller becomes large.

In order to reduce the linear pressure which acts on a raw film from a nip roller, it is also considered to make both the surface hardness of a drive roller and a driven roller low. However, when surface hardness is made low, since durability of a nip roller falls by immersion in a bath liquid, it is unpreferable. Therefore, when only the surface hardness of one roller among the driving roller and the driven roller is reduced, the linear pressure acting on the raw film from the nip roller is lowered to suppress the stretching and cutting of the raw film, and the durability of the nip roller is also not affected. found to be able to maintain.

The present invention has been completed based on the above findings of the present inventors.

That is, in order to solve the above problems, the present invention is a method of manufacturing a polarizer by placing a nip roller in a treatment bath and performing a treatment on the raw film in the treatment bath while conveying the raw film to the nip roller, the nip The roller is composed of a driving roller and a driven roller which sandwiches the raw film between the driving roller and conveys, and provides a method for manufacturing a polarizer in which the surface hardness of the driving roller and the surface hardness of the driven roller are different.

In the present invention, “arranging the nip roller in the treatment bath” means disposing the nip roller in a state in which at least a part of the nip roller is immersed in the treatment bath.

According to the present invention, the surface hardness of the driving roller and the driven roller constituting the nip roller disposed in the treatment bath are different. In other words, among the driving roller and the driven roller, the surface hardness of one roller is high and the surface hardness of the other roller is low. Therefore, as the present inventors found, the linear pressure acting on the raw film from the nip roller is lowered, and while the stretch cut of the raw film is suppressed, it can be maintained to such an extent that the durability of the nip roller is also not impaired.

Preferably, a part of the drive roller is located above the liquid level of the treatment bath, the nip roller is disposed so that the driven roller is immersed in the treatment bath, and the surface hardness of the drive roller is the surface hardness of the driven roller lower than

According to the above preferred configuration, a part of the drive roller is positioned above the liquid level of the treatment bath (in other words, the remaining part of the drive roller is immersed in the treatment bath), and the driven roller (all of the driven rollers) is immersed in the treatment bath. The nip roller is arranged so as to Accordingly, it is not necessary to immerse a driving source such as a motor required to rotate the driving roller in the treatment bath (a waterproof treatment facility for the driving source is unnecessary), and it is possible to manufacture a polarizer with few facility restrictions.

Moreover, according to the said preferable structure, the surface hardness of the drive roller whose part is located above the liquid level of a process bath is lower than the surface hardness of the driven roller immersed in a process bath. In other words, since the entire drive roller, which is less durable than the driven roller due to its low surface hardness, is not immersed in the treatment bath all the time, but is only partially and intermittently immersed in accordance with the rotation, it is possible to suppress the deterioration of the driving roller .

The surface hardness of the roller having the lower surface hardness among the driving roller and the driven roller is, for example, less than 50 in Shore A hardness or less than 80 in Asuka C hardness, and the surface hardness of the roller having the higher surface hardness is Shore A hardness is 50 or more.

Preferably, the driving roller and/or the driven roller includes a core material and a plurality of layers of elastic members wound around the core, and the plurality of layers of elastic members are on the surface hardness side of the elastic member of the inner layer. This is higher than the surface hardness of the elastic member of the layer located on the outside.

In the above preferred method, "the surface hardness of the elastic member in the inner layer is higher than the surface hardness of the elastic member in the outer layer" in the above preferred method means the diameter of the core material when three or more layers of elastic members are wound around the core material. When comparing the elastic members of any two layers adjacent to each other in the direction (diameter direction of the driving roller and the driven roller), the surface hardness of the elastic member of the inner layer is higher than that of the elastic member of the outer layer. It means higher than the surface hardness. For example, when there are three layers of elastic members wound around the core, the innermost layer has the highest surface hardness, and the middle layer has the next highest surface hardness of the elastic member, and the outermost layer means that the surface hardness of the elastic member is the lowest value.

Further, in the above preferred method, the surface hardness of the elastic member of each layer means the surface hardness in a state in which the elastic member is wound around the core material in order from the inside, and the elastic member of each layer is located at the outermost side. For example, when there are three layers of elastic members wound around the core, the surface hardness of the elastic member of the innermost layer is in a state where only the elastic member is wound around the core and the elastic member is positioned at the outermost (out of the three layers of elastic members). It means the surface hardness measured in a state in which the elastic member of the outermost layer and the elastic member of the intermediate layer are not wound). In addition, the surface hardness of the elastic member of the intermediate layer is that the elastic member of the innermost layer is wound around the core material, and the elastic member of the layer located in the middle is wound around the core material, and the elastic member is located on the outermost side. It means the surface hardness measured in a state (a state in which the elastic member of the outermost layer among the three layers of elastic members is not wound). In addition, the surface hardness of the elastic member of the outermost layer is determined by winding the elastic member of the innermost layer and the elastic member of the intermediate layer around the core material, and the elastic member of the outermost layer is the core material. It means the surface hardness measured in the state wound on.

According to the above preferred method, the core material is sufficiently protected by the elastic member (the elastic member with the highest surface hardness) of the innermost layer, and the adhesive force when the core material and the elastic member are bonded can be increased. In addition, since the elastic member (elastic member with the lowest surface hardness) of the layer located on the outermost side contacts the raw film, the linear pressure acting on the raw film is lowered, thereby suppressing stretching and cutting of the raw film.

In the above preferred method, more preferably, the multi-layered elastic member is a three-layered elastic member.

According to the above more preferable method, the core material is sufficiently protected by the elastic member of the innermost layer (the elastic member with the highest surface hardness) among the three layers of elastic members, and when the core material and the elastic member are adhered can increase the adhesion of In addition, since the elastic member (elastic member with the lowest surface hardness) of the layer located on the outermost side contacts the raw film, the linear pressure acting on the raw film is lowered, thereby suppressing stretching and cutting of the raw film. Further, it is possible to adjust the surface hardness of the elastic member of the outermost layer according to the surface hardness of the elastic member of the intermediately located layer (the elastic member whose surface hardness exhibits an intermediate value).

Preferably, among the driving roller and the driven roller, the outer diameter of the roller having the lower surface hardness is larger than the outer diameter of the roller having the higher surface hardness.

According to the above preferred method, for example, when the nip roller is disposed such that a part of the roller having the lower surface hardness is located above the liquid level of the treatment bath and the roller having the higher surface hardness is immersed in the treatment bath, the surface hardness Since the outer diameter of the roller on the lower side is large, it is easy to position a part of the roller above the liquid level of the treatment bath. Thereby, it is possible to suppress deterioration of the said roller.

Since the method which concerns on this invention can suppress the extending|stretching cut|disconnection of a raw film, when the said process bath is a process bath which performs an extending|stretching process on the said raw film, it is used suitably.

In addition, in order to solve the above problems, the present invention is provided with a treatment tank for storing a treatment bath, and a nip roller disposed in the treatment bath, while conveying the raw film to the nip roller, the raw film is treated in the treatment bath As an apparatus for manufacturing a polarizer by carrying out It is provided also as a manufacturing apparatus of the polarizer from which surface hardness differs.

According to the present invention, in a method and apparatus for manufacturing a polarizer by arranging a nip roller in a treatment bath and subjecting the raw film to a treatment in the treatment bath while conveying the raw film to the nip roller, the linear pressure acting on the raw film from the nip roller This is reduced, and while the stretching cut of the raw film is suppressed, it can be maintained to such an extent that the durability of the nip roller is not impaired.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the schematic structure of the manufacturing apparatus of the polarizer which concerns on one Embodiment of this invention.
It is a figure which shows typically the schematic structure of the drive roller of one Embodiment of this invention.
It is a figure which shows typically the schematic structure of the driven roller of one Embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, the manufacturing method and manufacturing apparatus of the polarizer which concern on one Embodiment of this invention are demonstrated, referring an accompanying drawing suitably. In addition, please note that each figure is shown for reference, and the dimension, scale, and shape of a member etc. shown in each figure may differ from an actual thing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the schematic structure of the manufacturing apparatus of the polarizer which concerns on this embodiment. Fig. 1 (a) is a side view (a view seen from the horizontal direction orthogonal to the conveyance direction of the raw film F0 and the polarizer F1) which shows the schematic structure of the manufacturing apparatus 100 whole, Fig.1 (b) It is an enlarged view of the extending|stretching processing tank 14 shown to Fig.1 (a). The thick line arrow shown in FIG. 1 means the conveyance direction of the raw film F0 and the polarizer F1.

As shown in FIG. 1, the manufacturing apparatus 100 of this embodiment includes the some processing tank 1 which stores the processing bath L (the part which performed dot-shaped hatching in FIG. 1), respectively, and a predetermined process. The treatment bath L ( It is an apparatus which manufactures the polarizer F1 by giving a process to the raw film F0 by L1-L5).

The manufacturing apparatus 100 conveys the raw film F0 fed out from the feeding roller FR and the feeding roller FR on which the elongate raw film F0 was wound other than the processing tank 1 and the nip roller 2 The oven 3 for drying the nip roller NR and guide roller GR for carrying out, and the raw film F0 is provided.

In addition, a polarizing film is manufactured by bonding a protective film to the polarizer F1 manufactured by the manufacturing apparatus 100 after that, for example at least on the single side through an ultraviolet curable adhesive, and hardening an adhesive agent with an ultraviolet irradiation apparatus. do. Moreover, a polarizing plate is manufactured, for example by bonding a surface protection film together on the single side|surface of a polarizing film.

As the raw film F0, a long band-shaped polymer film is used.

It does not specifically limit as a polymer film which forms the raw film F0, A various thing can be used. For example, hydrophilic polymer films such as polyvinyl alcohol (PVA) films, polyethylene terephthalate (PET) films, ethylene/vinyl acetate copolymer films, partially saponified films thereof, cellulose films, etc. Polyene-type oriented films, such as a dehydrochloric acid process material of vinyl chloride, etc. are mentioned. Among these, it is preferable to use the PVA-type film excellent in dyeability by iodine.

The polymerization degree of the polymer which is the material of the said polymer film is generally 500-10000, It is preferable that it is the range of 1000-6000, It is more preferable that it exists in the range of 1400-4000. Further, when the polymer film is a saponification film, the degree of saponification thereof is, for example, preferably 75 mol% or more, more preferably 98 mol% or more, from the viewpoint of solubility in water, and is in the range of 98.3 to 99.8 mol%. more preferably.

When using a PVA-based film as the polymer film, as a method for producing the PVA-based film, any method such as a casting method, a casting method, and an extrusion method of casting a film of a stock solution dissolved in water or an organic solvent can be used. As for the retardation value of a PVA-type film, it is used preferably that they are 5 nm - 100 nm. In addition, in order to obtain an in-plane uniform polarizer F1, the in-plane retardation deviation of the PVA-based film is preferably as small as possible, and the in-plane retardation deviation of the PVA-based film as the raw film F0 is 10 nm or less at a measurement wavelength of 1000 nm. It is preferable, and it is more preferable that it is 5 nm or less.

The raw film F0 demonstrated above is wound around the feeding roller FR, and is arrange|positioned at the most upstream side (the conveyance direction upstream side of the raw film F0) of the manufacturing apparatus 100. As shown in FIG. And the raw film F0 is immersed in the processing bath L (L1-L5) in the processing tank 1, conveying the raw film F0 fed out from the feeding roller FR, and it processes.

The manufacturing apparatus 100 which concerns on this embodiment is the processing tank 1, The swelling processing tank 11 for performing a swelling process sequentially from the conveyance direction upstream of the raw film F0, and dyeing. A dyeing treatment tank 12 for performing a crosslinking treatment, a crosslinking treatment tank 13 for performing a crosslinking treatment, a drawing treatment tank 14 for performing a drawing treatment, and a cleaning treatment tank 15 for performing a cleaning treatment. are being prepared

In addition, the order, frequency, and presence or absence of each process of swelling, dyeing|staining, crosslinking, extending|stretching, and washing|cleaning in each treatment tank 1 are not specifically limited, Some treatments are performed in a single treatment tank 1 It may be performed simultaneously, and it is not necessary to perform several processes. For example, an extending|stretching process may be performed immediately after a dyeing process, and may be performed simultaneously with a swelling process or a dyeing process. Moreover, you may perform a dyeing|staining process after an extending|stretching process.

In the swelling treatment tank 11, for example, water is used as the treatment bath L (swelling treatment bath L1). By immersing the raw film F0 in this swelling treatment bath L1, the raw film F0 is washed with water, and the contamination and blocking agent on the raw film F0 surface can be wash|cleaned. Moreover, by swelling the raw film F0, the effect of preventing nonuniformity, such as dyeing unevenness, is expectable. In the swelling treatment bath L1, glycerin, potassium iodide, or the like may be appropriately added, and the concentration to be added is preferably 5% by weight or less for glycerin and 10% by weight or less for potassium iodide. It is preferable that it is the range of 20-45 degreeC, and, as for the temperature of the swelling treatment bath L1, it is more preferable that it is 25-40 degreeC. It is preferable that it is 2-180 second, as for the immersion time of the raw film F0 to the swelling treatment bath L1, it is more preferable that it is 10-150 second, It is especially preferable that it is 60-120 second. In addition, the raw film F0 may be extended|stretched in this swelling treatment bath L1, and the draw ratio at this time is about 1.1 to 3.5 times including extension by swelling.

In the dyeing treatment tank 12, a treatment bath containing, for example, a dichroic substance such as iodine is used as the treatment bath L (dyeing treatment bath L2), and the raw film F0 is applied to the dyeing treatment bath L2. ), the dichroic substance is adsorbed to the raw film F0.

As said dichroic substance, a conventionally well-known substance can be used, For example, iodine, an organic dye, etc. are mentioned. Examples of the organic dye include Red BR, Red LR, Red R, Pink LB, Rubin BL, Bordeaux GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, Green LG, Violet LB, Violet B, Black H. , Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Splar Blue G, Splar Blue GL, Splar Orange GL, Direct Sky Blue , Direct First Orange S, Fast Black, etc. can be used.

One type may be sufficient as these dichroic substances, and it may use them in combination of two or more types. In the case of using the organic dye, for example, it is preferable to combine two or more kinds of organic dyes from the viewpoint of neutralizing the visible light region. Specific examples include a combination of Congo Red and Splat Blue G, a combination of Splash Orange GL and Direct Sky Blue, or a combination of Direct Sky Blue and Fast Black.

As the dyeing treatment bath (L2), a solution obtained by dissolving the dichroic substance in a solvent can be used. As the solvent, water is generally used, but an organic solvent compatible with water may be further added. The concentration of the dichroic substance is preferably in the range of 0.010 to 10% by weight, more preferably in the range of 0.020 to 7% by weight, and particularly preferably 0.025 to 5% by weight.

Moreover, when using an iodine as said dichroic substance, it is preferable to add iodide further from the point which can improve dyeing efficiency further. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, and the like. It is preferable that it is 0.010 to 10 weight% in the dyeing process bath (L2), and, as for the addition ratio of these iodides, it is more preferable that it is 0.10 to 5 weight%. Among these, potassium iodide is preferably added, and the ratio (weight ratio) of iodine to potassium iodide is preferably in the range of 1:5 to 1:100, and more preferably in the range of 1:6 to 1:80. It is preferably in the range of 1:7 to 1:70, particularly preferably.

Although the immersion time of the raw film F0 to the dyeing process bath L2 is not specifically limited to this, It is preferable that it is the range of 1 to 20 minutes, and it is more preferable that it is 2 to 10 minutes. Moreover, it is preferable to exist in the range of 5-42 degreeC, and, as for the temperature of the dyeing process bath L2, it is more preferable to exist in the range of 10-35 degreeC. In addition, you may extend|stretch the raw film F0 in this dyeing process bath L2, and the accumulated total draw ratio at this time is about 1.1 to 4.0 times.

In addition, as a dyeing process, other than the method of immersing in the dyeing treatment bath L2 as described above, for example, the method of apply|coating or spraying the aqueous solution containing a dichroic substance to the raw film F0 may be sufficient, and the raw film F0 A dichroic substance may be mixed in advance at the time of film forming.

In the crosslinking treatment tank 13, the raw film F0 is bridge|crosslinked by immersing the raw film F0 in the process bath L (crosslinking process bath L3) containing a crosslinking agent. As said crosslinking agent, a conventionally well-known substance can be used, For example, boron compounds, such as boric acid and borax, glyoxal, glutaraldehyde, etc. are mentioned. One type may be sufficient as these, and they may use two or more types together. When two or more types are used in combination, for example, a combination of boric acid and borax is preferable, and the addition ratio (molar ratio) thereof is preferably in the range of 4:6 to 9:1, and 5.5:4.5 to 7:3. The range of is more preferably, and most preferably, 6:4.

As the crosslinking treatment bath L3, a solution obtained by dissolving the crosslinking agent in a solvent can be used. As said solvent, although water can be used, for example, you may contain the organic solvent compatible with water further. Although the concentration of the crosslinking agent in the solution is not limited thereto, it is preferably in the range of 1 to 10% by weight, more preferably 2 to 6% by weight.

In the crosslinking treatment bath L3, since the in-plane uniform characteristic of the polarizer F1 is acquired, you may add an iodide. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide, and the content thereof is 0.05 to 15 % by weight, more preferably 0.5 to 8% by weight. Among these, a combination of boric acid and potassium iodide is preferable, and the ratio (weight ratio) of boric acid and potassium iodide is preferably in the range of 1:0.1 to 1:3.5, and in the range of 1:0.5 to 1:2.5. more preferably.

The temperature of the crosslinking treatment bath L3 is usually in the range of 20 to 70°C, and the immersion time of the raw film F0 is usually in the range of 1 second to 15 minutes, and preferably 5 seconds to 10 minutes. In addition, you may use the method of apply|coating or spraying a crosslinking agent containing solution similarly to a dyeing process for crosslinking treatment. In addition, the raw film F0 may be extended|stretched in the crosslinking treatment bath L3, and the accumulated total draw ratio at this time is about 1.1 to 4.0 times.

In the stretching treatment tank 14, the raw film F0 is formed so that the total draw ratio accumulated in the state in which the raw film F0 is immersed in the treatment bath L (the stretching treatment bath L4) is about 2 to 7 times. stretch

Although it does not specifically limit as extending|stretching process bath L4, For example, various metal salts and the solution which added the compound of iodine, boron, or zinc can be used. As a solvent of this solution, water, ethanol, or various organic solvents are used suitably. Among these, it is preferable to use the solution which added about 2 to 18 weight% of boric acid and/or potassium iodide, respectively. When using this boric acid and potassium iodide simultaneously, the content ratio (weight ratio) is about 1:0.1-1:4, More preferably, it is preferable to use it in the ratio of about 1:0.5-1:3.

It is preferable that it is the range of 40-67 degreeC, and, as for the temperature of the extending|stretching process bath L4, it is more preferable that it is 50-62 degreeC, for example.

In the washing treatment tank 15, for example, by immersing the raw film F0 in the treatment bath L (washing treatment bath L5), which is an aqueous solution, boric acid adhering to the raw film F0 in the previous treatment is unnecessary. Residues can be washed away. An iodide may be added to the aqueous solution, for example, sodium iodide or potassium iodide is preferably used as the iodide. When potassium iodide is added to the washing treatment bath L5, the concentration thereof is usually 0.1 to 10% by weight, preferably 3 to 8% by weight. Moreover, it is preferable that it is 10-60 degreeC, and, as for the temperature of the washing process bath L5, it is more preferable that it is 15-40 degreeC. In addition, the frequency|count of washing|cleaning process is not specifically limited, You may carry out multiple times, and in this case, you may change the kind and density|concentration of the additive in each washing process bath L5.

Moreover, in this embodiment, since the nip roller NR is arrange|positioned on the exit side of each processing tank 1, when pulling up the raw film F0 from each processing tank 1, generation|occurrence|production of a liquid drip is prevented. .

A drying process is given to the raw film F0 to which the process was performed by the process bath L of each processing tank 1 demonstrated above. Although suitable methods, such as natural drying, wind drying, and heat drying, can be used as a drying process, Usually, heat drying is used preferably. In the manufacturing apparatus 100 of this embodiment, heat-drying by the oven 3 is performed. In the oven 3, for example, it is preferable that the heating temperature is about 20 to 80°C, and the drying time is about 1 to 10 minutes. Furthermore, it is preferable to make the drying temperature as low as possible from a viewpoint of preventing deterioration of the polarizer F1 regardless of the said method. More preferably, it is 60 degrees C or less, and it is especially preferable that it is 45 degrees C or less.

It is preferable that it is 3.0-7.0 times with respect to the raw film F0 before a process, and, as for the final total draw ratio of the polarizer F1 manufactured as mentioned above, it is more preferable to exist in the range of 5.5-6.2 times. If final total draw ratio is less than 3.0 times, it will be difficult to obtain the polarizer F1 of high polarization degree, and when it exceeds 7.0 times, the raw film F0 will become easy to fracture|rupture.

The manufacturing apparatus 100 which concerns on this embodiment is equipped with the nip roller 2 arrange|positioned in the processing bath L. In this embodiment, the nip roller 2 is arrange|positioned in the extending|stretching treatment bath L4 stored in the extending|stretching treatment tank 14 among the treatment tanks 1 . In addition, in this embodiment, two sets of nip rollers 2 (2a, 2b) are arrange|positioned along the conveyance direction of the raw film F0. As shown in FIG.1(b), the nip roller 2 is comprised from the driven roller 22 which pinches|interposes the raw film F0 between the drive roller 21 and the drive roller 21. . Hereinafter, the structure of the nip roller 2 of this embodiment is demonstrated more concretely.

The nip roller 2 of this embodiment has the characteristics in the point from which the surface hardness of the drive roller 21 and the surface hardness of the driven roller 22 differ. In the present embodiment, the surface hardness of the drive roller 21 is lower than the surface hardness of the driven roller 22 .

And as shown in FIG.1(b), in this embodiment, the drive roller 21 and the driven roller 22 may oppose up and down, so that the drive roller 21 may be located above the driven roller 22. A nip roller 2 is arranged. And the nip roller 2 is arrange|positioned so that a part of drive roller 21 may be located above the liquid level of the extending|stretching bath L4, and the driven roller 22 may be immersed in the extending|stretching bath L4. Specifically, it is arrange|positioned so that the shaft part 211a of the drive roller 21 may be located above the liquid level of the extending|stretching process bath L4.

As described above, since the surface hardness of the driving roller 21 and the surface hardness of the driven roller 22 are different (specifically, the surface hardness of the driving roller 21 is lower than the surface hardness of the driven roller 22) , the linear pressure acting on the raw film F0 from the nip roller 2 is reduced, and while the stretch cut of the raw film F0 is suppressed, it is maintainable to such an extent that the durability of the nip roller 2 does not interfere either. In addition, since a part of the driving roller 21 is located above the liquid level of the stretching bath L4, a driving source (not shown) such as a motor necessary to rotate the driving roller 21 is connected to the stretching bath ( It is not necessary to be immersed in L4), and manufacture of the polarizer F1 with few facility restrictions is possible. In addition, since a part of the drive roller 21 having a lower surface hardness than the driven roller 22 is located above the liquid level of the stretching bath L4, the entire driving roller 21 is always in the stretching bath L4. Since it is not immersed, but only partially and intermittently immersed in accordance with rotation, it is possible to suppress deterioration of the drive roller 21 .

2 : is a figure which shows typically the schematic structure of the drive roller 21 of this embodiment. Fig. 2(a) is a side view (as viewed from the horizontal direction orthogonal to the conveyance directions of the raw film F0 and the polarizer F1 shown in Fig. 1), and Fig. 2(b) is a front view sectional view (Fig. 1). It is sectional drawing which passes the center of the drive roller 21 seen from the conveyance direction of the raw film F0 and the polarizer F1 shown to).

As shown in FIG. 2 , the driving roller 21 of the present embodiment includes a core 211 and a plurality of layers of elastic members 212 wound around the core 211 .

The core material 211 of the present embodiment has a shaft portion 211a having a circular cross-section and a tubular portion 211b having a circular cross-section. A driving source (not shown) is connected to the shaft portion 211a, and the shaft portion 211a rotates by a rotational driving force supplied from the driving source. The central axis of the shaft portion 211a becomes the rotational central axis of the driving roller 21 . The tubular portion 211b is coupled to the shaft portion 211a by having a hollow portion provided in its center, and the shaft portion 211a is fitted to the hollow portion. When the shaft portion 211a rotates, the tubular portion 211b also rotates integrally with the shaft portion 211a. The material of the shaft portion 211a and the tubular portion 211b is not particularly limited, but, for example, the shaft portion 211a is made of stainless steel (eg, SUS316), and the tubular portion 211b is made of resin (eg, CFRP). is formed The outer diameter of the core 211 (the outer diameter of the tubular portion 211b) is, for example, 400 to 600 mm.

In this embodiment, as the elastic member 212, three layers of elastic members 212a, 212b, and 212c are wound around the surface (outer surface) of the tubular portion 211b of the core 211 . The elastic member 212a of the innermost layer is adhered to the surface of the tubular portion 211b via an appropriate adhesive. The elastic member 212b of the intermediate layer is adhered to the surface (outer surface) of the elastic member 212a via an appropriate adhesive. The elastic member 212c of the outermost layer is adhered to the surface (outer surface) of the elastic member 212b via an appropriate adhesive.

Although the material of the elastic member 212a is not particularly limited, for example, the elastic member 212a is preferably made of styrene-butadiene rubber (SBR). In addition, it is also possible to form the elastic member 212a of acrylonitrile-butadiene rubber (NBR) or ethylene-propylene-diene rubber (EPDM). Although the thickness of the elastic member 212a is not specifically limited, Preferably it is 0.5-5 mm, More preferably, it is 1.5-2 mm.

Although the material of the elastic member 212b is not particularly limited, for example, the elastic member 212b is preferably formed of EPDM. In addition, it is also possible to form the elastic member (212b) of NBR or SBR. Although the thickness of the elastic member 212b is not specifically limited, Preferably it is 1-10 mm, More preferably, it is 6-6.5 mm.

Although the material of the elastic member 212c is not particularly limited, for example, the elastic member 212c is preferably made of EPDM like the elastic member 212b. However, in order to lower the surface hardness of the elastic member 212c, the elastic member 212c is preferably formed of EPDM foam. The EPDM foam can be produced by, for example, foaming EPDM with a foaming agent and crosslinking with a crosslinking agent. Although the thickness of the elastic member 212c is not specifically limited, Preferably it is 0.5-10 mm, More preferably, it is 1-5 mm, Especially preferably, it is 1.5-2.5 mm.

In the three-layer elastic member 212 , the surface hardness of the elastic member 212 of the inner layer is higher than the surface hardness of the elastic member 212 of the outer layer. That is, the surface hardness of the elastic member 212a of the innermost layer is the highest, the surface hardness of the elastic member 212b of the intermediate layer is the next highest, and the elastic member of the outermost layer ( 212c) has the lowest surface hardness.

Specifically, the surface hardness (outer surface hardness) of the elastic member 212a is preferably 70 to 100 in terms of Shore A hardness, more preferably 80 to 100, and particularly preferably 90 to 100. Shore A hardness can be measured using a commercially available durometer (type A) based on JIS K6253 (1997). As the durometer (type A), for example, "ASKER-TYPE A (Asuka A-type durometer)" manufactured by Polymer Instruments Co., Ltd. can be used.

The surface hardness (outer surface hardness) of the elastic member 212b is preferably 60 to 99 in terms of Shore A hardness, more preferably 70 to 90, and particularly preferably 75 to 85.

The surface hardness (outer surface hardness) of the elastic member 212c is preferably less than 50 in terms of Shore A hardness, or less than 80 in terms of Asuka C hardness, more preferably 10 to 40 in terms of Shore A hardness, or Asuka C hardness. 60 to 79, particularly preferably 20 to 30 in terms of Shore A hardness, and 65 to 75 in Asuka C hardness. Asuka C hardness can be measured using a commercially available durometer (type C) based on JIS K7312 (1996). As the durometer (type C), for example, 'ASKER-TYPE C (Asuka C-type durometer)' manufactured by Polymer Instruments Co., Ltd. can be used.

The surface hardness (outer surface hardness) of the drive roller 21 is expressed by the surface hardness of the elastic member 212c of the layer located at the outermost side. Therefore, the surface hardness of the driving roller 21 is preferably less than 50 in Shore A hardness, or less than 80 in Asuka C hardness.

As described above, in the drive roller 21 of the present embodiment, the surface hardness of the elastic member 212 of the inner layer is higher than the surface hardness of the elastic member 212 of the outer layer. An elastic member 212 is provided. Accordingly, the core material 211 is sufficiently protected by the elastic member 212a having a high surface hardness of the innermost layer, and the adhesive force between the core material 211 and the elastic member 212a can be increased. In addition, since the elastic member 212c having a low surface hardness of the outermost layer contacts the raw film F0, the linear pressure acting on the raw film F0 is lowered, so that stretching and cutting of the raw film F0 is reduced. is suppressed Further, it is possible to adjust the surface hardness of the elastic member 212c of the outermost layer according to the surface hardness of the elastic member 212b of the intermediate layer.

3 : is a figure which shows typically the schematic structure of the driven roller 22 of this embodiment. Fig. 3(a) is a side view (as viewed from the horizontal direction orthogonal to the conveyance direction of the raw film F0 and the polarizer F1 shown in Fig. 1), and Fig. 3(b) is a front view sectional view (Fig. 1). It is sectional drawing which passes the center of the driven roller 22 seen from the conveyance direction of the raw film F0 and the polarizer F1 shown to).

As shown in FIG. 3 , the driven roller 22 of this embodiment is provided with the core material 221 and the one-layer elastic member 222 wound around the core material 221 .

The core member 221 has the same configuration as the core member 211 of the driving roller 21 . That is, the core 221 includes a shaft portion 221a having a circular cross-section and a tubular portion 221b having a circular cross-section. The central axis of the shaft portion 221a becomes the rotational central axis of the driven roller 22 . The tubular part 221b is coupled to the shaft part 221a by providing a hollow part in the center thereof, and fitting the shaft part 221a to the hollow part. When the shaft part 221a rotates, the tubular part 221b also rotates integrally with the shaft part 221a. The material of the shaft portion 221a and the tubular portion 221b is not particularly limited, but for example, the shaft portion 221a is made of stainless steel (eg, SUS316), and the tubular portion 221b is made of resin (eg, CFRP). is formed The outer diameter of the core 221 (the outer diameter of the tubular portion 221b) is, for example, 400 to 500 mm.

The elastic member 222 is adhered to the surface of the tubular portion 221b via an appropriate adhesive.

The material of the elastic member 222 is not particularly limited, but, for example, the elastic member 222 is preferably made of styrene-butadiene rubber (SBR). In addition, it is also possible to form the elastic member 222 of NBR or EPDM. Although the thickness of the elastic member 222 is not specifically limited, Preferably it is 5-20 mm, More preferably, it is 5-15 mm, Especially preferably, it is 10 mm.

Further, the preferred thickness of the elastic member 222 is the thickness at the central portion of the driven roller 22 in the axial direction, and the thickness at this central portion is maximum, and the thickness is decreased toward the axial end of the driven roller 22 ), it is desirable to provide a crown. By providing the crown on the driven roller 22, when the driving roller 21 is pushed toward the driven roller 22, a gap equal to or greater than the thickness of the original film F0 between the driving roller 21 and the driven roller 22 It is hard to produce, and it is possible to pinch and convey the raw film F0 reliably.

The surface hardness (outer surface hardness) of the driven roller 22 is represented by the surface hardness (outer surface hardness) of the elastic member 222 , and as described above, the surface hardness of the driven roller 22 is the surface hardness of the driving roller 21 . (the surface hardness of the elastic member 212c) is higher. Accordingly, the surface hardness of the elastic member 222 is preferably 50 or more in terms of Shore A hardness.

In addition, in this embodiment, the outer diameter of the drive roller 21 is larger than the outer diameter of the driven roller 22. As shown in FIG. For example, the outer diameter of the driving roller 21 is 500 mm (the outer diameter of the core 211 480 mm + the thickness of the elastic member 212a 1.5 mm × 2 + the thickness of the elastic member 212b 6.5 mm × 2 + the elastic member 212c) The thickness is 2 mm x 2 = 500 mm), and the outer diameter of the driven roller 22 is 460 mm (the outer diameter of the core 221 440 mm + the thickness of the elastic member 222 10 mm x 2 = 460 mm).

In this way, since the outer diameter of the drive roller 21 is large, it is easy to position a part of the drive roller 21 above the liquid level of the stretching treatment bath L4, and it is possible to suppress deterioration of the drive roller 21 .

In this embodiment described above, a part of the drive roller 21 is located above the liquid level of the stretching bath L4, and the nip roller 2 is immersed in the stretching bath L4 so that the driven roller 22 is immersed in the stretching bath L4. Although the case where it is arranged has been described, the present invention is not limited thereto. It is also possible to employ|adopt the aspect by which the nip roller 2 was arrange|positioned so that both the drive roller 21 and the driven roller 22 may be immersed in the extending|stretching process bath L4. Moreover, it is also possible to employ|adopt the aspect in which the up-and-down positional relationship of the drive roller 21 and the driven roller 22 was reversed. The aspect in which the nip roller 2 is arrange|positioned so that a part of driven roller 22 may be specifically, located above the liquid level of the extending|stretching bath L4, and the drive roller 21 may be immersed in the extending|stretching bath L4. However, it is also possible to employ the aspect in which the nip roller 2 is arrange|positioned so that both the driven roller 22 located above and the drive roller 21 located below may be immersed in the extending|stretching process bath L4.

In addition, although this embodiment demonstrated the case where the surface hardness of the drive roller 21 is lower than the surface hardness of the driven roller 22, this invention is not limited to this, The surface hardness of the driven roller 22 drives It is also possible to employ an aspect lower than the surface hardness of the roller 21 .

In addition, in this embodiment, although the case where the drive roller 21 is provided with the elastic member 212 of 3 layers is demonstrated, this invention is not limited to this, The some elastic member 212 of 2 or 4 or more layers is not limited. ) It is also possible to employ an aspect having a. Further, the driven roller 22 is provided with a plurality of layers of elastic members 222 similarly to the driving roller 21 (that is, both of the driving roller 21 and driven roller 22 are each provided with a plurality of layers of elastic members). It is also possible to employ the aspect provided with (212, 222). Moreover, it is also possible to employ|adopt the aspect in which the driven roller 22 is provided with the elastic member 222 of multiple layers, and the drive roller 21 is provided with the elastic member 212 of one layer. Moreover, it is also possible to employ|adopt the aspect in which both of the drive roller 21 and the driven roller 22 are provided with one layer of elastic members 212 and 222, respectively.

In addition, in this embodiment, although the case where the nip roller 2 is arrange|positioned in the extending|stretching bath L4 of the extending|stretching tank 14 was demonstrated, this invention is not limited to this, The arbitrary treatment tank 1 ), it is also possible to arrange in an arbitrary treatment bath L. For example, as described above, the swelling treatment bath L1 of the swelling treatment tank 11, the dyeing treatment bath L2 of the dyeing treatment tank 12, and the crosslinking treatment bath L3 of the crosslinking treatment tank 13 Since you may also perform the extending|stretching process of the raw film F0, when extending|stretching in these process baths L, the nip roller 2 of this embodiment is arrange|positioned in these process baths L, also be Thereby, the extending|stretching cut|disconnection of the raw film F0 in each process bath L can be suppressed.

1: treatment tank
2: nip roller
14: stretching treatment tank
21: drive roller
22: driven roller
F0: raw film
F1: Polarizer
L: treatment bath
L4: stretching treatment bath
100: manufacturing device

Claims (8)

A method of manufacturing a polarizer by arranging a nip roller in a treatment bath and treating the raw film in the treatment bath while conveying the raw film to the nip roller,
The nip roller is composed of a driven roller and a driven roller for transporting the raw film between the driving roller and the driving roller,
The manufacturing method of the polarizer from which the surface hardness of the said drive roller differs from the surface hardness of the said driven roller. According to claim 1,
A part of the driving roller is positioned above the liquid level of the treatment bath, and the nip roller is disposed so that the driven roller is immersed in the treatment bath,
The surface hardness of the driving roller is lower than the surface hardness of the driven roller,
A method for manufacturing a polarizer. 3. The method of claim 1 or 2,
The surface hardness of the roller having the lower surface hardness among the driving roller and the driven roller is less than 50 in terms of Shore A hardness, or less than 80 in terms of Asuka C hardness, and the surface hardness of the roller having the higher surface hardness is Shore A hardness 50 or more,
A method for manufacturing a polarizer. 3. The method of claim 1 or 2,
The driving roller and/or the driven roller includes a core material and a plurality of layers of elastic members wound around the core material,
In the plurality of layers of the elastic member, the surface hardness of the elastic member of the inner layer is higher than the surface hardness of the elastic member of the outer layer,
A method for manufacturing a polarizer. 5. The method of claim 4,
The elastic member of the plurality of layers is a three-layer elastic member,
A method for manufacturing a polarizer. 3. The method of claim 1 or 2,
Among the driving roller and the driven roller, the outer diameter of the roller having the lower surface hardness is larger than the outer diameter of the roller having the higher surface hardness,
A method for manufacturing a polarizer. 3. The method of claim 1 or 2,
The treatment bath is a treatment bath for applying a stretching treatment to the raw film,
A method for manufacturing a polarizer. An apparatus for manufacturing a polarizer by providing a treatment tank for storing a treatment bath, and a nip roller disposed in the treatment bath, and performing a treatment on the raw film in the treatment bath while conveying the raw film to the nip roller,
The nip roller is composed of a driven roller and a driven roller for transporting the raw film between the driving roller and the driving roller,
The manufacturing apparatus of the polarizer from which the surface hardness of the said drive roller differs from the surface hardness of the said driven roller.

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