WO2016072359A1

WO2016072359A1 - Method for manufacturing polarization plate sheet

Info

Publication number: WO2016072359A1
Application number: PCT/JP2015/080677
Authority: WO
Inventors: 宙孝石川; 泰礼加藤
Original assignee: 住友化学株式会社
Priority date: 2014-11-05
Filing date: 2015-10-30
Publication date: 2016-05-12
Also published as: CN107003459B; KR20170082542A; CN107003459A; TWI666475B; KR102256908B1; TW201621365A

Abstract

Provided is a method for manufacturing a polarization plate sheet, the polarization plate sheet being of rectangular shape having long sides and short sides, and including a polarization element and a protective film laminated onto at least one surface thereof, the method including a step for preparing a first polarization plate sheet having one or more ruffle defects situated in at least one of the long sides, and a step for slit removal of an end of the first polarization plate sheet, the end including the long side having the ruffle defects, to obtain a second polarization plate sheet.

Description

Manufacturing method of polarizing plate sheet

The present invention relates to a method for producing a polarizing plate sheet with reduced undulation defects, which is preferably used in an image display device such as a liquid crystal display device.

A polarizing plate used in an image display device such as a liquid crystal display device generally has a laminated structure in which a protective film is bonded to one or both sides of a polarizer via an adhesive layer, and a long polarizer and Using a long protective film, it is produced as a long product (polarizing plate roll) by a roll-to-roll method [for example, JP 2009-134190 A (Patent Document 1)]. The obtained long polarizing plate is cut into a sheet of a predetermined size according to the screen size of the image display device, and is laminated to an image display element such as a liquid crystal cell using an adhesive layer or the like. Embedded in an image display device.

In Patent Document 1, as a method for suppressing a problem called reverse curling and wave curling that occurs in a polarizing plate, a long polarizer and a long protective film are laminated with an adhesive interposed therebetween. It is described that an adhesive is polymerized and cured while the laminate is in close contact with a convex curved surface formed in an arc shape along the longitudinal direction of the laminate.

JP 2009-134190 A

According to the method described in Patent Document 1, it is possible to suppress the occurrence of the above problems at least immediately after manufacturing a long polarizing plate or immediately after cutting it into a sheet. However, even if the polarizing plate (polarizing plate sheet) cut into a single sheet does not have the above-mentioned problems in the initial stage, depending on the storage environment, the wavy defect may occur during storage due to moisture absorption. May occur. “Wavy defect” refers to a deformation defect in which at least one side of a polarizing plate sheet and an end region including the same are wavy. When a wavy defect occurs in the polarizing plate sheet, for example, when applied to a liquid crystal display device, for example, when the polarizing plate sheet and the liquid crystal cell are bonded via an adhesive layer, Air bubbles are likely to be mixed into the bonding interface between the pressure-sensitive adhesive layer and the liquid crystal cell, particularly the end region of the bonding interface and the vicinity thereof. When the bubbles are generated in the image display area of the liquid crystal panel, the visibility of the liquid crystal display device can be lowered when the bubbles are turned on and become bright spots.

Therefore, an object of the present invention is to provide a method for producing a polarizing plate sheet having a reduced number or height of undulating defects.

This invention provides the manufacturing method of the polarizing plate sheet shown below.
[1] A rectangular polarizing plate sheet including a polarizer and a protective film laminated on at least one surface thereof, and having a long side and a short side, wherein at least one of the long sides is 1 Preparing a first polarizing plate sheet having one or more wavy defects;
Slit removing the end including the long side having the undulation defect in the first polarizing plate sheet to obtain a second polarizing plate sheet;
A method for producing a polarizing plate sheet comprising:

[2] The manufacturing method according to [1], wherein in the step of preparing the first polarizing plate sheet, there are four or more wavy defects in the at least one long side.

[3] The manufacturing method according to [1] or [2], wherein, in the step of preparing the first polarizing plate sheet, a height of a wavy defect in at least one of the long sides exceeds 2 mm.

[4] In the step of obtaining the second polarizing plate sheet, slits are removed from the first polarizing plate sheet including the long side having the wavy defect with a width of 65 mm or more. [3] The production method according to any one of [3].

[5] The first polarizing plate sheet includes the polarizer, a first protective film laminated on one surface of the polarizer through a first adhesive layer, and a second adhesive on the other surface. A production method according to any one of [1] to [4], comprising a second protective film laminated via a layer.

[6] The manufacturing method according to [5], wherein the first protective film and the second protective film differ in moisture permeability at a temperature of 40 ° C. and a relative humidity of 90% by 30 g / (m ² · 24 hr) or more.

[7] The manufacturing method according to [5] or [6], wherein at least one of the first adhesive layer and the second adhesive layer is made of a cured product of an active energy ray-curable adhesive.

[8] The first polarizing plate sheet has the following (a) and (b):
(A) a protective film laminated on the protective film;
(B) The adhesive layer according to any one of [1] to [7], further comprising at least one of an adhesive layer laminated on the polarizer or the protective film and a separate film laminated on the outer surface thereof. Manufacturing method.

According to the present invention, it is possible to provide a polarizing plate sheet having a reduced number or height of undulating defects. In particular, the present invention is capable of reducing wavy defects to a sufficient extent even for polarizing plate sheets having four or more or wavy defects whose height exceeds 2 mm. Can provide a method.

It is a schematic sectional drawing which shows an example of the layer structure of a 1st polarizing plate sheet.

The manufacturing method of the polarizing plate sheet according to the present invention includes the following steps:
(1) A rectangular polarizing plate sheet including a polarizer and a protective film laminated on at least one surface thereof and having a long side and a short side, wherein at least one of the long sides is 1 A step of preparing a first polarizing plate sheet having at least one wavy defect, and (2) slit removing an end portion including the long side having the wavy defect in the first polarizing plate sheet; A step of obtaining a polarizing plate sheet,
including. Hereinafter, each step will be described.

(1) Step of preparing first polarizing plate sheet The first polarizing plate sheet has a undulating defect, and is likely to be accompanied by the above-described problem of bubble mixing and accompanying visibility deterioration. Specifically, it is a polarizing plate sheet that has one or more undulation defects on at least one of the long sides. As a result of further occurrence of undulation defects, the first polarizing plate sheet has undulation defects whose height exceeds 2 mm on at least any one long side, or at least four on at least any one long side. It may be a polarizing plate sheet having undulating defects, and the first polarizing plate sheet has four or more undulating defects on at least one of the long sides, and these undulating defects. Any one or more of the above may be a waving defect whose height exceeds 2 mm.

The height of the undulating defect is the height from the flat table to the top of the undulating defect when the first polarizing plate sheet is placed on the flat table. At this time, the first polarizing plate sheet is displayed as an image. The surface to be bonded to the element (for example, a liquid crystal cell) is placed on a flat table with the surface facing up. The height of the undulation defect is measured at the side (end) of the first polarizing plate sheet. The number of undulating defects is substantially the number of undulating defects. Specifically, when the first polarizing plate sheet is placed on a flat table, the height is 0 from the flat table. It is the number of undulating defects that are 5 mm or more. The number of wavy defects is also measured at the side (edge) of the first polarizing plate sheet.

The first polarizing plate sheet has a rectangular shape having a long side and a short side, and is typically a rectangle. The lengths of the long side and the short side are not particularly limited, but the long side of the first polarizing plate sheet is usually 700 mm or more and the short side is 400 mm or more. As the size of the first polarizing plate sheet is larger, the waviness defect is more prominent in the height and number of waviness. If the size (long side and / or short side) is too small, the problem of undulation defects itself is less likely to occur. The first polarizing plate sheet is a polarizing plate in which the above-described wavy defects are generated in the process of storing and transporting under some conditions after cutting the polarizing plate manufactured as a long product. it can.

In general, the first polarizing plate having a wavy defect whose height exceeds 2 mm or four or more wavy defects on any one long side has the same degree of wavy defect on the long side facing the long side. Often has Further, the first polarizing plate sheet having a wavy defect with a height exceeding 2 mm or four or more wavy defects on any one long side may have a wavy defect also on two short sides. Many. However, the wavy defects that occur on the two short sides tend to be smaller in height and / or number than the wavy defects that occur on the long sides, and the wavy defects on the short sides are Compared to this, there is a tendency that the problem of air bubbles is less likely to occur. Therefore, in order to suppress the problem of mixing of bubbles and the accompanying deterioration in visibility, it is important to reduce the undulation defect that occurs on the long side.

The layer configuration of the first polarizing plate sheet is not particularly limited as long as it includes a polarizer and a protective film laminated and bonded on at least one surface thereof, and the protective film is laminated and bonded on both surfaces of the polarizer. May be. The protective film is usually laminated and bonded onto the polarizer via an adhesive layer.

The first polarizing plate sheet may have a layer (or film) other than the polarizer and the protective film. For example, in general, a polarizing plate produced as a long product and a polarizing plate sheet obtained by cutting the polarizing plate have a pressure-sensitive adhesive layer for bonding to an image display element (for example, a liquid crystal cell) on the outer surface of the polarizing plate in advance. Although often marketed as a laminated polarizing plate with an adhesive layer, the first polarizing plate sheet can also include such an adhesive layer. When an adhesive layer is included, a separate film (separator) for protecting the surface (outer surface) is usually laminated on the outer surface of the adhesive layer.

In addition, a polarizing plate produced as a long product is usually stored or distributed as a polarizing plate roll formed by winding the polarizing plate. In order to protect the outer protective film surface during winding, the protective film is used. In general, a protective film (surface protective film) is provided on the polarizing plate, and in this case, a polarizing plate sheet obtained by cutting the polarizing plate generally has a protective film. As in such a case, the first polarizing plate sheet may include a protective film laminated on the protective film.

Further, the protective film of the first polarizing plate sheet has a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, an antifouling layer on the outer surface (the surface opposite to the polarizer). A surface treatment layer (coating layer) may be provided. Moreover, the 1st polarizing plate sheet can contain the layer or film which has optical functions other than a polarizer. One example is a retardation film.

An example of the layer structure of the first polarizing plate sheet is shown in FIG. A first polarizing plate sheet 1 shown in FIG. 1 includes a polarizer 10; a first protective film 20 that is bonded to one surface of the polarizer 10; a first film that is bonded to the other surface of the polarizer 10. 2 protective film 30; adhesive layer 40 laminated on the outer surface of the second protective film 30; separate film 50 laminated on the outer surface of the adhesive layer 40; a protective film 60 laminated on the outer surface of the first protective film 20 Including. In addition to the polarizer 10 and the protective film (the first protective film 20 and the second protective film 30), the layer configuration having the pressure-sensitive adhesive layer 40 and the separate film 50, the layer configuration having the protective film 60, or the pressure-sensitive adhesive layer 40, The layer structure having the separate film 50 and the protect film 60 is an example of a preferable layer structure of the first polarizing plate sheet. As will be described later, the pressure-sensitive adhesive layer 40 may be directly laminated on the polarizer 10 by omitting one of the first protective film 20 and the second protective film 30.

The polarizer 10 is an optical film having a property of absorbing linearly polarized light having a vibration plane parallel to the optical axis and transmitting linearly polarized light having a vibration plane perpendicular to the optical axis. For example, the polarizer 10 is uniaxially stretched and has two colors. It can be a polyvinyl alcohol-based resin film in which a functional dye is adsorbed and oriented. As the dichroic dye, iodine or a dichroic organic dye is used. The polyvinyl alcohol-based resin constituting the polarizer 10 includes polyvinyl alcohol, which is a saponified product of polyvinyl acetate, and a copolymer of vinyl acetate and other monomers copolymerizable therewith (for example, ethylene and unsaturated carboxylic acid). It may be a vinyl alcohol copolymer which is a saponified product. The thickness of the polarizer 10 is usually about 5 to 40 μm.

The polarizer 10 includes a step of uniaxially stretching a polyvinyl alcohol-based resin film, a step of dyeing the polyvinyl alcohol-based resin film with a dichroic dye and adsorbing the dichroic dye, and polyvinyl alcohol on which the dichroic dye is adsorbed. It can manufacture by the method of including the process of wash | cleaning a system resin film with the boric-acid aqueous solution, and the process of washing with water after the process by boric-acid aqueous solution. The dichroic dye can be dyed by immersing the film in an aqueous solution containing the dichroic dye, and the treatment with the boric acid aqueous solution can be performed by immersing the film in the boric acid aqueous solution.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing of the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.

The first and second

protective films

20 and 30 can be a thermoplastic resin film having translucency (preferably optically transparent). Specific examples of thermoplastic resins include polyolefin resins such as chain polyolefin resins (polypropylene resins, etc.) and cyclic polyolefin resins (norbornene resins, etc.); polyester resins (polyethylene terephthalate resins, etc.); ) Acrylic resin (methyl methacrylate resin etc.); Cellulosic resin (cellulose acetate resin such as triacetyl cellulose [TAC], diacetyl cellulose etc.); Polycarbonate resin; Polyvinyl alcohol resin; Polyvinyl acetate resin Polyarylate resins; polystyrene resins; polyethersulfone resins; polysulfone resins; polyamide resins; polyimide resins; and mixtures and copolymers thereof. The thickness of the first and second

protective films

20 and 30 is, for example, about 5 to 200 μm, preferably 10 to 150 μm, and more preferably 15 to 100 μm. In the present specification, “(meth) acryl” means at least one selected from acryl and methacryl.

In the case where the first protective film 20 is provided on one surface of the polarizer 10 and the second protective film 30 is provided on the other surface like the first polarizing plate sheet 1 shown in FIG. The 1st protective film 20 and the 2nd protective film 30 may be comprised with the same kind of thermoplastic resin, and may be comprised with a different kind of thermoplastic resin, but are comprised with a different kind of thermoplastic resin. When the moisture permeability of the protective films bonded to both surfaces is different from each other, such as in the case where the moisture film absorbs moisture, the undulation defect is particularly likely to occur due to the difference in hygroscopicity. Therefore, the present invention is particularly advantageous in such a case. According to the present invention, the difference in moisture permeability of the protective films bonded on both sides is 30 g / (m ² · 24 hr) or more, further 50 g / (m ² · 24 hr) or more, and even more 100 g / (m ² Even if it is 24 hr) or more, and more particularly 300 g / (m ² · 24 hr) or more, it is possible to obtain a polarizing plate sheet that is less likely to cause undulation defects and is less likely to cause problems of air bubbles and associated visibility degradation. it can. Usually, the difference in the water vapor transmission rate of the protective film bonded to both surfaces is 900 g / (m ² · 24 hr) or less.

The moisture permeability is a moisture permeability at a temperature of 40 ° C. and a relative humidity of 90%, and is measured by a cup method defined in JIS Z 0208. Examples of combinations of protective films having a difference in moisture permeability of 30 g / (m ² · 24 hr) at a temperature of 40 ° C. and a relative humidity of 90% include, for example, a cellulose resin film (TAC film, etc.) and a cyclic polyolefin resin , A combination of a cellulose resin film (TAC film or the like) and a (meth) acrylic resin film, a combination of a cyclic polyolefin resin and a (meth) acrylic resin film, or the like. In addition, even if the thermoplastic resin which comprises the protective film bonded on both surfaces is the same kind, a difference may arise in a water vapor transmission rate by the presence or absence of a surface treatment layer laminated | stacked on it, or a kind difference.

The polarizer 10, the first protective film 20, and the second protective film 30 can be bonded via an adhesive layer. As the adhesive forming the adhesive layer, a water-based adhesive, that is, an adhesive component dissolved or dispersed in water, or an active energy ray-curable adhesive can be used.

The adhesive component of the water-based adhesive can be, for example, a polyvinyl alcohol resin or a urethane resin. The active energy ray-curable adhesive can be, for example, a curable composition containing an active energy ray-curable compound such as an epoxy compound or a (meth) acrylic compound and a polymerization initiator. The active energy ray-curable adhesive can be a solventless adhesive, but can also contain an organic solvent. If a solventless type adhesive is used, a drying process for removing the solvent becomes unnecessary. When an active energy ray-curable adhesive is used, after bonding a protective film through an adhesive layer, the active energy rays such as visible light, ultraviolet rays, X-rays, electron beams, etc., preferably ultraviolet rays are irradiated and bonded. The agent layer is cured. Therefore, in this case, the adhesive layer in the first polarizing plate sheet is made of a cured product of an active energy ray-curable adhesive.

In the case where the first protective film 20 is provided on one surface of the polarizer 10 and the second protective film 30 is provided on the other surface like the first polarizing plate sheet 1 shown in FIG. The 1st adhesive layer which bonds 1 protective film 20, and the 2nd adhesive layer which bonds 2nd protective film 30 may be formed from the same kind of adhesives, and are formed from a different kind of adhesives. However, it is preferably formed from the same kind of adhesive from the viewpoint of production efficiency.

When at least one (preferably both) of the first adhesive layer and the second adhesive layer is made of a cured product of an active energy ray-curable adhesive, undulation defects due to moisture absorption are particularly likely to occur. In such a case, the present invention is particularly advantageous.

As an adhesive which comprises the adhesive layer 40 for bonding to an image display element (for example, liquid crystal cell), for example, a (meth) acrylic adhesive, a urethane adhesive, a silicone adhesive, a polyester adhesive, Examples thereof include a polyamide-based adhesive, a polyether-based adhesive, a fluorine-based adhesive, and a rubber-based adhesive. Among these, a (meth) acrylic pressure-sensitive adhesive is preferably used from the viewpoints of transparency, adhesive strength, reliability, reworkability, and the like. The thickness of the pressure-sensitive adhesive layer 40 is usually 2 to 40 μm.

The separate film 50 and the protect film 60 are provided for the purpose of temporarily protecting the adhesive layer 40 and the first protective film 20 when the polarizing plate is stored, transported, or inspected. The separate film 50 that protects the pressure-sensitive adhesive layer 40 is peeled and removed immediately before the second polarizing plate sheet described below is put to practical use (for example, bonded to an image display element such as a liquid crystal cell). The protective film 60 is usually peeled and removed together with the pressure-sensitive adhesive layer after the second polarizing plate sheet is put into practical use (for example, bonded to an image display element such as a liquid crystal cell).

The separate film 50 is usually composed of a thermoplastic resin film having a release treatment on one side, and the release treatment surface is bonded to the pressure-sensitive adhesive layer 40. The protect film 60 is usually configured by providing an adhesive layer on one side of a thermoplastic resin film. The thermoplastic resin constituting the separate film 50 and the protect film 60 may be, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or a polyester resin such as polyethylene terephthalate or polyethylene naphthalate. it can. Regarding the pressure-sensitive adhesive layer that the protective film 60 has, the description of the pressure-sensitive adhesive layer 40 described above is cited.

The layer configuration of the first polarizing plate sheet is not limited to the example shown in FIG. 1, and may be the following layer configuration, for example.

[A] Configuration in which any one or more of the pressure-sensitive adhesive layer 40, the separate film 50, and the protect film 60 are omitted;
[B] a configuration in which one of the first protective film 20 and the second protective film 30 is omitted;
[C] a configuration using an optical compensation film such as a retardation film as the second protective film 30;
[D] A configuration having an optical compensation film such as a retardation film in addition to the first protective film 20 and the second protective film 30.

An example of the above [b] is a configuration in which the second protective film 30 is omitted, and a preferred specific example thereof is that the pressure-sensitive adhesive layer 40 is directly laminated on the surface of the polarizer 10 opposite to the first protective film 20. Thus, the protective film 60 / first protective film 20 / polarizer 10 / adhesive layer 40 / separate film 50 are layered.

A preferred specific example of the above [c] is a protective film 60 / first protective film 20 / polarizer 10 / retardation film (second protective film 30) / adhesive layer 40 / separate film 50 layer structure. It is. A preferred specific example of the above [d] is a protective film 60 / first protective film 20 / polarizer 10 / second protective film 30 / retardation film / adhesive layer 40 / separate film 50 layer structure. is there. In this case, the 2nd protective film 30 and retardation film can be bonded through an adhesive layer, for example.

The retardation film is an optical film having optical anisotropy such as uniaxial or biaxial, and can be, for example, a stretched film of a thermoplastic resin. The thermoplastic resin can be the one exemplified above for the first and second

protective films

20 and 30, as well as polyvinylidene fluoride / polymethyl methacrylate copolymer, liquid crystal polyester, acetyl cellulose, ethylene-vinyl acetate. A saponified copolymer, polyvinyl chloride, or the like can also be used. The draw ratio is usually about 1.01 to 6 times.

(2) Step of obtaining a second polarizing plate sheet This step is a process of obtaining a long side end portion of the first polarizing plate sheet having one or more wavy defects on at least one of the long sides (the wavy defect is removed). This is a step of obtaining a second polarizing plate sheet with reduced waviness defects by slit-removing the end portion including the long side. Conventionally known cutting (cutting) means such as a shear cutter can be used for the slit.

The first polarizing plate sheet has a protective film 60 laminated on the protective film, and / or a pressure-sensitive adhesive layer 40 laminated on the polarizer 10 or the protective film, and a separate film 50 laminated on the outer surface thereof. In some cases, the first polarizing plate sheet having a wavy defect at the end (particularly, the long side end) may be accompanied by an appearance defect in which the color of the end becomes dark. This poor appearance is caused by a shift in the interface between the thermoplastic resin film constituting the protective film 60 and the pressure-sensitive adhesive layer or the interface between the separate film 50 and the pressure-sensitive adhesive layer 40 due to the stress at the time when the wavy defect occurs. This is thought to be due to the rough surface of the layer. In particular, when the surface of the pressure-sensitive adhesive layer 40 is rough, there is a possibility that an appearance defect may remain even after being bonded to an image display element such as a liquid crystal cell.

If a slit is removed by this step so as to remove the defective appearance portion, a polarizing plate sheet having good appearance quality can be obtained even in terms of color.

¡Slit removal is performed on the long side end portion having the undulation defect. In particular, the first polarizing plate sheet having a wavy defect with a height exceeding 2 mm or four or more wavy defects on any one long side has the same degree of wavy defect on the long side facing the long side. Therefore, typically, slit removal is performed on both long side end portions.

The width W1 at the end of the long side to be slit-removed is reduced in the case of a polarizing plate sheet having a wavy defect having a height exceeding 2 mm or four or more wavy defects in at least one of the long sides. From the viewpoint of effect, it is preferably 65 mm or more per one end. It should be noted that as long as the first polarizing plate sheet is the above-described normal size (long side 700 mm or more and short side 400 mm or more), the long side end portion is preferably 65 mm or more regardless of the size. By removing with the slit width W1, it is possible to obtain a good undulating defect reduction effect. From the viewpoint of more effectively reducing undulation defects, the slit width W1 is more preferably 70 mm or more, more preferably 80 mm or more, still more preferably 100 mm or more, and particularly preferably 140 mm, per one end. That's it.

As described above, the wavy defects that can occur in the two short sides tend to be smaller in height and / or number than the wavy defects that occur in the long side, and the wavy defects in the short side However, it is not always necessary to remove the slits at the end of the short side. However, in order to reduce the undulation defect on the short side, the undulation defect has occurred. In addition to the side edge part, the short side edge part (one end part or both end parts) where the undulation defect has occurred may be slit removed. The slit width W2 at the short side end can be, for example, 35 mm or more, preferably 40 mm or more, more preferably 45 mm or more, per one end.

In addition, regardless of whether or not a wavy defect occurs at the short side end, the second polarizing plate is reduced in size from the first polarizing plate sheet by removing one or both of the short side ends. Leaf bodies may be obtained. As a specific example of the size reduction, the long side edge and the short side edge of the 46-inch size (long side 1031 mm × short side 585 mm) first polarizing plate sheet are slit to remove a 39 inch size (long side). 860 mm × short side 490 mm) to obtain a second polarizing plate sheet, or 39 inch size (long side 860 mm × short side 490 mm) first polarizing plate sheet For example, the slit may be removed to obtain a second polarizing plate sheet having a size of 32 inches (long side 700 mm × short side 400 mm).

In slit removal for size reduction, in the case of a polarizing plate sheet having a wavy defect with a height exceeding 2 mm or having four or more wavy defects, the long side end is 65 mm or more per one end. As long as the slit width W1 is removed, only one of the two long side ends may be removed by slit, or both of the long side ends may be removed by slit. Similarly, only one of the two short side ends may be slit removed, or both short side ends may be slit removed.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the following examples, the number and height of undulating defects were in accordance with the following measuring method.

(Number and height of undulating defects)
The polarizing plate sheet is placed on a flat table with the separate film 50 side facing upward, and the number of wavy defects on the two long sides of the polarizing plate sheet (the height is 0 from the flat table as described above). , And the height of the undulating defect from the plane table was measured. Table 1 shows the number and height of undulating defects on the long side having more undulating defects among the two long sides. The height of the undulating defect shown in Table 1 is the highest height of the undulating defect when having a plurality of undulating defects.

<Experimental example 1>
[1] Production of first polarizing plate sheet A long polarizing plate having the layer structure shown in FIG. 1 was prepared. This polarizing plate is composed of a protective film 60 having a thickness of 53 μm (consisting of a (meth) acrylic pressure-sensitive adhesive layer and a polyethylene terephthalate film) / first protective film 20 having a thickness of 60 μm (TAC film) / a polarizer having a thickness of 25 μm. 10 (uniaxially stretched polyvinyl alcohol film in which iodine is adsorbed and oriented) / 52 μm thick second protective film 30 (retardation film made of cyclic polyolefin resin) / 20 μm thick adhesive layer 40 ((meth) acrylic adhesive) Agent layer) / separate film 50 having a thickness of 38 μm (polyethylene terephthalate film having a release treatment on one surface). Both the first protective film 20 and the second protective film 30 are an active energy ray-curable adhesive (a UV curable adhesive containing a curable compound that is a cationic polymerizable epoxy compound and a photocationic polymerization initiator). It is bonded to the polarizer 10 through an adhesive layer made of a cured product of “KR-70T” manufactured by ADEKA Corporation. Further, the moisture permeability of the first protective film 20 and the second protective film 30 at 40 ° C. and 90% relative humidity was 560 g / (m ² · 24 hr) and 5 g / (m ² · 24 hr), respectively.

After cutting out a rectangular polarizing plate sheet having a size of 46 inches (long side: 1031 mm × short side: 585 mm) from the long polarizing plate, it was stored for 3 days in an environment of 30 ° C. and 80% relative humidity, A first polarizing plate sheet having a long side with a corrugated height of 3.5 mm and a number of corrugated defects of 5 according to the measurement method was obtained.

[2] Fabrication of second polarizing plate sheet (removal of slits at end of long side)
In the first polarizing plate sheet obtained above, the long edge of the corrugated height of 3.5 mm and the number of corrugated defects of 5 is removed with a shear cutter to a width of 10 mm. Then, the height and number of undulation defects on the long side of the second polarizing plate sheet after the slit were measured. This operation was repeated until the total slit width (slit width W1) reached 170 mm, and the relationship between the slit width W1 and the wavy defect reduction effect was examined. The results are shown in Table 1.

<Experimental example 2>
The first polarized light of 46 inch size (long side: 1031 mm × short side: 585 mm) having a long side of 3.5 mm and a number of wavy defects of 4 mm obtained in the same manner as in Experimental Example 1 above. Use a shear cutter to slit the two long side edges of the plate sheet body by 85.5 mm per one end, and slit the two short side edges by 47.5 mm per one end. Thus, a second polarizing plate sheet reduced in size to 39 inches (long side 860 mm × short side 490 mm) was obtained. About this 2nd polarizing plate sheet, the height of the undulation defect in the long side corresponding to the long side of the 1st polarizing plate sheet whose wave height is 3.5mm and the number of undulation defects is four. And the number was measured. The results are shown in Table 2.

Next, the two long side ends of the 39-inch size second polarizing plate obtained above were slit by 80.0 mm per one end using a shear cutter, and two short sides A second polarizing plate sheet having a size reduced to 32 inches (long side: 700 mm × short side: 400 mm) was obtained by slitting the end part by 45.0 mm per one end part. For the second polarizing plate sheet, the height and number of wavy defects on the long side corresponding to the long side of the 39-inch size second polarizing plate sheet, the height and number of which were measured above, were measured. It was measured. The results are shown in Table 2.

1 first polarizing plate sheet, 10 polarizer, 20 first protective film, 30 second protective film, 40 adhesive layer, 50 separate film, 60 protective film.

Claims

A polarizing plate sheet including a polarizer and a protective film laminated on at least one surface thereof and having a long side and a short side, wherein at least one of the long sides has at least one Preparing a first polarizing plate sheet having undulation defects;
Slit removing the end including the long side having the undulation defect in the first polarizing plate sheet to obtain a second polarizing plate sheet;
A method for producing a polarizing plate sheet comprising:
The manufacturing method according to claim 1, wherein, in the step of preparing the first polarizing plate sheet, there are four or more undulating defects on at least one of the long sides.
The manufacturing method according to claim 1 or 2, wherein, in the step of preparing the first polarizing plate sheet, a height of a wavy defect on at least one of the long sides exceeds 2 mm.
4. The step of obtaining the second polarizing plate sheet includes slit-removing an end including a long side having the wavy defect in the first polarizing plate sheet with a width of 65 mm or more. The production method according to claim 1.
The first polarizing plate sheet includes the polarizer, a first protective film laminated on one surface of the polarizer through a first adhesive layer, and a second adhesive layer on the other surface. The manufacturing method according to any one of claims 1 to 4, further comprising a second protective film laminated in a stacked manner.
The manufacturing method according to claim 5, wherein the first protective film and the second protective film differ in moisture permeability at a temperature of 40 ° C. and a relative humidity of 90% by 30 g / (m 2 · 24 hr) or more.
The manufacturing method according to claim 5 or 6, wherein at least one of the first adhesive layer and the second adhesive layer is made of a cured product of an active energy ray-curable adhesive.
The first polarizing plate sheet has the following (a) and (b):
(A) a protective film laminated on the protective film;
(B) The adhesive layer according to any one of claims 1 to 7, further comprising at least one of an adhesive layer laminated on the polarizer or the protective film and a separate film laminated on an outer surface thereof. Manufacturing method.