KR102256908B1 - Method for manufacturing polarization plate sheet - Google Patents

Abstract

In the present invention, a polarizer and a protective film laminated on at least one side thereof, and a rectangular polarizing plate sheet having a long side and a short side, wherein the first having one or more waveform defects on at least one long side Provided is a method of manufacturing a polarizing plate sheet including a step of preparing a polarizing plate sheet member, and a step of removing a slit end portion including a long side having a waveform defect in the first polarizing plate sheet member to obtain a second polarizing plate sheet member do.

Description

Manufacturing method of a polarizing plate sheet blade {METHOD FOR MANUFACTURING POLARIZATION PLATE SHEET}

The present invention relates to a method of manufacturing a polarizing plate sheet with reduced waveform defects, which is suitably used for an image display device such as a liquid crystal display device.

Polarizing plates used in image display devices such as liquid crystal displays generally have a laminated structure in which a protective film is bonded to one or both sides of a polarizer through an adhesive layer, and a long polarizer and a long protective film are used. , Manufactured as a long piece (polarizing plate roll) by a roll-to-roll method [for example, Japanese Patent Laid-Open No. 2009-134190 (Patent Document 1)]. The obtained elongated polarizing plate is cut into a sheet of a predetermined size according to the screen size of the image display device, laminated and laminated to an image display element such as a liquid crystal cell using a pressure-sensitive adhesive layer or the like, and inserted into the image display device.

In Patent Document 1, as a method for suppressing a problem called inverse curl and wave curl occurring in a polarizing plate, a long polarizer and a long protective film are polymerized through an adhesive to obtain a laminate, and then the length of the laminate It is described that the adhesive is polymerized and cured while the laminate is in close contact with a convex curved surface formed in an arc shape along the direction.

Japanese Patent Publication No. 2009-134190

According to the method described in Patent Document 1, it is possible to suppress the occurrence of the above problem at least immediately after manufacturing a long polarizing plate or immediately after cutting it into a sheet. However, even when a polarizing plate cut into a sheet member (polarizing plate sheet member) does not have the above-described problem at an initial stage, depending on the storage environment, a waveform defect may be generated during storage due to moisture absorption. The "waveform defect" refers to a deformation defect in which at least one side of a sheet of a polarizing plate and an end region including the same are wave-like. When waveform defects occur in the polarizing plate sheet body, for example, when applied to a liquid crystal display device, when bonding the polarizing plate sheet body and the liquid crystal cell through the pressure-sensitive adhesive layer, the bonding interface between the pressure-sensitive adhesive layer and the liquid crystal cell, especially the bonding interface. Air bubbles are easily mixed in the end region and the vicinity thereof. If these bubbles are generated in the image display area of the liquid crystal panel, they become bright spots when lit, which can reduce the visibility of the liquid crystal display.

Accordingly, an object of the present invention is to provide a method for manufacturing a polarizing plate sheet having a reduced number or height of corrugated defects.

The present invention provides a method for producing a sheet of a polarizing plate shown below.

[1] a rectangular polarizing plate sheet having a long side and a short side, comprising a polarizer and a protective film laminated on at least one side thereof, the first polarizing plate having one or more waveform defects on at least one long side The process of preparing the sheet frond,

A step of slit-removing an end portion of the first polarizing plate sheet member including the long side having the waveform defect to obtain a second polarizing plate sheet member,

Containing, the manufacturing method of the polarizing plate sheetfed body.

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

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

[4] In the step of obtaining the second polarizing plate sheet member, [1] to [3], wherein an end portion of the first polarizing plate sheet member including the long side having the corrugation defect is slit-removed to a width of 65 mm or more. ] The production method according to any one of.

[5] The first polarizing plate sheet includes the polarizer, a first protective film laminated on one side of the polarizer through a first adhesive layer, and a first protective film laminated on the other side through a second adhesive layer. 2 The production method according to any one of [1] to [4] including a protective film.

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

[8] The first polarizing plate sheet body, the following (a) and (b):

(a) a protective film laminated on the protective film,

(b) a pressure-sensitive adhesive layer laminated on the polarizer or on the protective film, and a separate film laminated on the outer surface thereof

The production method according to any one of [1] to [7], further including at least any one of them.

According to the present invention, a polarizing plate sheet having a reduced number or height of waveform defects can be provided. Particularly, the present invention can provide a manufacturing method capable of reducing waveform defects to a sufficient degree even for a polarizing plate sheet having four or more waveform defects, or having waveform defects having a height of more than 2 mm.

1 is a schematic cross-sectional view showing an example of a layer structure of a first polarizing plate sheet body.

The manufacturing method of the polarizing plate sheet according to the present invention, the following steps:

(1) A first polarizing plate comprising a polarizer and a protective film laminated on at least one side thereof and having a long side and a short side of a rectangular polarizing plate sheet having one or more waveform defects on at least one long side The process of preparing the sheet frond,

(2) a step of slit-removing an end portion of the first polarizing plate sheet member including the long side having the corrugated defect to obtain a second polarizing plate sheet member,

Includes. Hereinafter, each process is demonstrated.

(1) Process of preparing the first polarizing plate sheet body

The first polarizing plate sheet member is an inexpensive polarizing plate sheet member that is prone to waveform defects and is likely to be accompanied by the problem of mixing of bubbles as described above or the resulting decrease in visibility, and specifically, one in at least one long side. It is a polarizing plate sheetfed body having the above waveform defects. As a result of the occurrence of more waveform defects, the first polarizing plate sheet has a waveform defect having a height of more than 2 mm on at least one long side, or a polarizing plate sheet having four or more waveform defects on at least one long side. A blade may be sufficient, and the 1st polarizing plate sheet blade may have four or more corrugated defects in at least any one of the long sides, and any one or more of these corrugated defects may be a corrugated defect having a height of more than 2 mm.

The height of the corrugated defect is the height from the flat surface to the top of the corrugated defect in the case where the first polarizing plate sheet member is placed on the flat surface, and at this time, the first polarizing plate sheet member is an image display element (e.g., a liquid crystal cell) It is placed on a flat surface with the side to be joined to the side facing up. The height of the corrugated defect is measured at the side (end) of the sheet of the first polarizing plate. In addition, the number of corrugated defects is the number substantially recognized as corrugated defects, and specifically, is the number of corrugated defects whose height is 0.5 mm or more from the flat surface when the 1st polarizing plate sheet metal is placed on a flat surface. The number of waveform defects is also measured at the side (end) of the sheet of the first polarizing plate.

The first polarizing plate sheet member 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. Usually, the long side of the first polarizing plate sheeting body is 700 mm or more, and the short side is 400 mm or more. Waveform defects tend to become more pronounced as the size of the sheet of the first polarizing plate increases, in terms of the height and number of waveforms. When the size (long side and/or short side) is too small, the problem of waveform defect itself is unlikely to occur. The first polarizing plate sheetfed body may be a polarizing plate in which the above-described waveform defects occur during a process of cutting a polarizing plate manufactured as an elongated material and then storing and transporting it under certain conditions.

In general, a first polarizing plate sheet having a waveform defect of more than 2 mm in height or four or more waveform defects on any one long side often has the same degree of waveform defects on the long side opposite the long side. In addition, the first polarizing plate sheetfed body having a corrugated defect of more than 2 mm in height or four or more corrugated defects on any one long side often has corrugated defects on two short sides. However, waveform defects occurring on the two short sides tend to be smaller in height and/or number compared to the waveform defects occurring on the long side, and the waveform defects on the short side tend to contain bubbles compared to the waveform defects on the long side. It tends to be difficult to cause problems. Therefore, in order to suppress the problem of mixing of air bubbles and the resulting decrease in visibility, it is essential to reduce the waveform defects occurring in the long side in particular.

The layer configuration of the first polarizing plate sheet body 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 a protective film may be laminated and bonded to both surfaces of the polarizer. The protective film is usually laminated and bonded on a polarizer through an adhesive layer.

The first polarizing plate sheet body may have a layer (or film) other than a polarizer and a protective film. For example, generally, a polarizing plate manufactured as an elongated material and a polarizing plate sheet formed by cutting the same are distributed in the market as a polarizing plate having a pressure-sensitive adhesive layer pre-laminated on the outer surface of the polarizing plate with a pressure-sensitive adhesive layer for bonding to an image display element (e.g., a liquid crystal cell). In many cases, the first polarizing plate sheet may also contain such a pressure-sensitive adhesive layer. When the pressure-sensitive adhesive layer is included, a separate film (separator) for protecting the surface (outer surface) is usually laminated on the outer surface of the pressure-sensitive adhesive layer.

In addition, the polarizing plate manufactured as a long product is usually stored or distributed as a polarizing plate roll formed by winding it up, but in order to protect the outer protective film surface during winding, a protective film (surface protective film) is provided on the protective film. It is common to put it, and in this case, it is common that the polarizing plate sheet|leaf body formed by cutting the polarizing plate also has a protective film. As in this case, the first polarizing plate sheet may include a protective film laminated on the protective film.

In addition, the protective film that the first polarizing plate sheet has a surface treatment layer (coating layer) such as a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, and an antifouling layer is provided on the outer surface (the surface opposite to the polarizer). It may be a thing. Further, the first polarizing plate sheet member may include a layer or film having an optical function other than a polarizer. One example is a retardation film.

Fig. 1 shows an example of the layer structure of the first polarizing plate sheet body. The first polarizing plate sheet 1 shown in FIG. 1 includes a polarizer 10; A first protective film 20 bonded to one surface of the polarizer 10; A second protective film 30 bonded to the other side of the polarizer 10; A pressure-sensitive adhesive layer 40 laminated on the outer surface of the second protective film 30; A separate film 50 laminated on the outer surface of the pressure-sensitive adhesive layer 40; It includes a protective film 60 laminated on the outer surface of the first protective film 20. In addition to the polarizer 10 and the protective film [the first protective film 20, the second protective film 30], a layer configuration having an adhesive layer 40 and a separate film 50, having a protective film 60 The layer configuration or the layer configuration including the pressure-sensitive adhesive layer 40, the separate film 50, and the protect film 60 is an example of a preferred layer configuration of the first polarizing plate sheet body. As will be described later, the pressure-sensitive adhesive layer 40 may be directly laminated on the polarizer 10 by omitting either 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 vibrating surface parallel to the optical axis and transmitting linearly polarized light having a vibrating surface orthogonal to the optical axis. It may be an adsorption-oriented polyvinyl alcohol-based resin film. As the dichroic dye, iodine or a dichroic organic dye is used. The polyvinyl alcohol-based resin constituting the polarizer 10 is a saponified product of a copolymer of vinyl acetate and other monomers copolymerizable therewith (eg, ethylene or unsaturated carboxylic acid) in addition to polyvinyl alcohol, which is a saponified product of polyvinyl acetate. It may be a phosphorus vinyl alcohol-based copolymer. The thickness of the polarizer 10 is usually about 5 µm to 40 µm.

The polarizer 10 is a process of uniaxially stretching a polyvinyl alcohol-based resin film, a process of dyeing a polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye, and a polyvinyl alcohol-based with a dichroic dye adsorbed thereto. It can be produced according to a method including a step of treating a resin film with an aqueous boric acid solution and a step of washing with water after treatment with an aqueous boric acid solution. The dyeing of the dichroic dye can be performed by immersing the film in an aqueous solution containing the dichroic dye, and the treatment with the aqueous boric acid solution can be performed by immersing the film in the aqueous boric acid solution.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after 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. Further, uniaxial stretching may be performed in a plurality of these steps.

The first and second protective films 20 and 30 may be a thermoplastic resin film having light transmission properties (preferably optically transparent). Specific examples of the thermoplastic resin include polyolefin-based resins such as chain-type polyolefin-based resins (polypropylene-based resins, etc.) and cyclic polyolefin-based resins (norbornene-based resins, etc.); Polyester resin (polyethylene terephthalate resin, etc.); (Meth)acrylic resin (methyl methacrylate resin, etc.); Cellulose resin (triacetyl cellulose [TAC], cellulose acetate resin such as diacetyl cellulose, etc.); Polycarbonate resin; Polyvinyl alcohol-based resin; Polyvinyl acetate-based resin; Polyarylate resin; Polystyrene resin; Polyethersulfone resin; Polysulfone resin; Polyamide resin; Polyimide resin; And mixtures and copolymers thereof. The thickness of the first and second protective films 20 and 30 is, for example, about 5 µm to 200 µm, preferably 10 µm to 150 µm, and more preferably 15 µm to 100 µm. In this specification, "(meth)acryl" means at least one selected from acrylic and methacrylic.

Like the first polarizing plate sheet 1 shown in FIG. 1, a first protective film 20 is provided on one side of the polarizer 10, and a second protective film 30 is provided on the other side. In the case of having, the first protective film 20 and the second protective film 30 may be composed of the same type of thermoplastic resin, may be composed of a different type of thermoplastic resin, but different types of thermoplastic resin In the case where the moisture permeability of the protective films bonded to both sides is different from each other, such as when composed of a resin, since a wave defect is particularly likely to occur due to a difference in hygroscopicity, the present invention is particularly advantageous in such a case. According to the present invention, the difference in moisture permeability of the protective film bonded to both sides is 30 g/(m 2 ·24 hr) or more, further 50 g/(m 2 ·24 hr) or more, and further 100 g/(m 2 ·24 hr) or more. , In particular, even if it is more than 300 g/(m 2 ·24 hr), the corrugation defect is reduced, and a polarizing plate sheeting body can be obtained which is less likely to cause the problem of mixing of air bubbles or the resulting decrease in visibility. Usually, the difference in moisture permeability of the protective film bonded to both sides 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 according to the cup method specified in JIS Z 0208. As a combination of a protective film having a moisture permeability difference of 30 g/(m 2 ·24 hr) or more at a temperature of 40°C and a relative humidity of 90%, for example, a combination of a cellulose-based resin film (TAC film, etc.) and a cyclic polyolefin-based resin, cellulose-based A combination of a resin film (TAC film, etc.) and a (meth)acrylic resin film, a combination of a cyclic polyolefin resin and a (meth)acrylic resin film, and the like may be mentioned. In addition, even if the thermoplastic resin constituting the protective film to be bonded to both sides is the same type, there may be a difference in moisture permeability due to the presence or absence of a surface treatment layer laminated thereon and differences in types.

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

The adhesive component of the water-based adhesive may be, for example, a polyvinyl alcohol-based resin or a urethane resin. The active energy ray-curable adhesive may be, for example, a curable composition comprising 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 may be a solvent-free adhesive, but may contain an organic solvent. When a solvent-free adhesive is used, drying treatment for removing the solvent becomes unnecessary. In the case of using an active energy ray-curable adhesive, after bonding the protective film through the adhesive layer, the adhesive layer is cured by irradiating active energy rays such as visible light, ultraviolet rays, X-rays, and electron rays, preferably ultraviolet rays. Accordingly, 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.

Like the first polarizing plate sheet 1 shown in FIG. 1, a first protective film 20 is provided on one surface of the polarizer 10, and a second protective film 30 is provided on the other surface. When provided, the first adhesive layer bonding the first protective film 20 and the second adhesive layer bonding the second protective film 30 may be formed of the same type of adhesive, or a different type of adhesive. Although it may be formed, it is preferably formed of the same type of adhesive from the viewpoint of manufacturing efficiency.

In the case where 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, wave defects due to moisture absorption are particularly prone to occur. The invention is particularly advantageous.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 40 for bonding to an image display device (e.g., a liquid crystal cell), for example, a (meth)acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a polyamide-based pressure-sensitive adhesive, and a polyether-based pressure-sensitive adhesive , A fluorine-based adhesive, and a rubber-based adhesive. Among them, from the viewpoints of transparency, adhesive force, reliability, rework property, and the like, a (meth)acrylic pressure-sensitive adhesive is preferably used. The thickness of the pressure-sensitive adhesive layer 40 is usually 2 µm to 40 µm.

The separate film 50 and the protective film 60 are each provided for the purpose of temporarily protecting the pressure-sensitive adhesive layer 40 and the first protective film 20 when storing, transporting, or inspecting a polarizing plate. The separate film 50 that protects the pressure-sensitive adhesive layer 40 is peeled off immediately before the second polarizing plate sheet to be described later is provided for practical use (eg, bonded to an image display element such as a liquid crystal cell). In addition, the protective film 60 is usually peeled off for each of the pressure-sensitive adhesive layers after the second polarizing plate sheet is provided for 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 subjected to a release treatment on one side, and the release treatment side is bonded to the pressure-sensitive adhesive layer 40. In addition, the protective film 60 is usually constituted by providing a pressure-sensitive adhesive layer on one side of a thermoplastic resin film. The thermoplastic resin constituting the separate film 50 and the protect film 60 is, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, and a polyester resin such as polyethylene terephthalate or polyethylene naphthalate. Etc. As for the pressure-sensitive adhesive layer of the protective film 60, the above-described description of the pressure-sensitive adhesive layer 40 is cited.

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

[A] a configuration in which at least one of the pressure-sensitive adhesive layer 40, the separate film 50, and the protective film 60 is omitted,

[B] a configuration in which either 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] In addition to the first protective film 20 and the second protective film 30, a configuration having an optical compensation film such as a retardation film.

An example of the above [b] is a configuration in which the second protective film 30 is omitted, and a suitable specific example is the pressure-sensitive adhesive layer 40 on the side opposite to the first protective film 20 in the polarizer 10. ) Is directly laminated to obtain a layer configuration of the protective film 60/first protective film 20/polarizer 10/adhesive layer 40/separate film 50.

A suitable specific example of the above [c] is a protective film 60 / a first protective film 20 / a polarizer 10 / a phase difference film [the second protective film 30] / an adhesive layer 40 / a separate film ( 50). Suitable specific examples of (d) are the protective film 60 / first protective film 20 / polarizer 10 / second protective film 30 / phase difference film / adhesive layer 40 / separate film 50 ). In this case, the second protective film 30 and the retardation film may be bonded, for example, through an adhesive layer.

The retardation film is an optical film having optical anisotropy such as uniaxial or biaxial, and may be, for example, a stretched film of a thermoplastic resin. The thermoplastic resin is polyvinylidene fluoride/polymethyl methacrylate copolymer, liquid crystal polyester, acetyl cellulose, ethylene- A saponified product of a vinyl acetate 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 the second polarizing plate sheet body

In this step, the long-side end (end including the long side having the waveform defect) of the first polarizing plate sheet having one or more waveform defects on at least one long side is slit-removed, and the waveform defect is reduced. 2 This is a step of obtaining a sheet of a polarizing plate. For the slit, a conventionally known cutting (cutting) means such as a shear cutter can be used.

The first polarizing plate sheet having a protective film 60 laminated on the protective film, and/or the polarizer 10 or the pressure-sensitive adhesive layer 40 laminated on the protective film and a separate film 50 laminated on the outer surface thereof In the case of including, the first polarizing plate sheet having a waveform defect in the end portion (especially the long-side end portion) may be accompanied by an appearance defect in which the color tone of the end portion becomes dark. This appearance defect 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 when a corrugated defect occurs. It is thought that the cause is that the surface of the pressure-sensitive adhesive layer becomes rough. In particular, when roughness occurs on the surface of the pressure-sensitive adhesive layer 40, there is a fear that an appearance defect remains even after bonding to an image display element such as a liquid crystal cell.

By performing the slit removal so that the above-described defective part of the appearance is removed by this step, a polarizing plate sheet having good appearance quality can be obtained even in terms of color tone.

Slit removal is performed with respect to the long-side end portion having the corrugated defect. In particular, the first polarizing plate sheet having a waveform defect of more than 2 mm in height or four or more waveform defects on any one long side often has the same degree of waveform defects on the long side opposite the long side. Typically, slit removal is performed on both long-side ends.

The width W1 of the end of the long side to be slit removed is from the viewpoint of the effect of reducing waveform defects in the case of a polarizing plate sheet having a height of more than 2 mm or four or more waveform defects in at least one of the long sides, It is preferably 65 mm or more per one end. It should be noted that, as long as the first polarizing plate sheetfed body is the above-described normal size (long side 700 mm or more, and short side 400 mm or more), regardless of the size, the slit width W1 at the long side end is preferably 65 mm or more. By removing it, it is said that a favorable effect of reducing waveform defects can be obtained. From the viewpoint of more effectively reducing corrugated defects, the slit width W1 is per one end, more preferably 70 mm or more, still more preferably 80 mm or more, still more preferably 100 mm or more, in particular Preferably it is 140 mm or more.

As described above, waveform defects that may occur on the two short sides tend to be smaller in height and/or number than the waveform defects on the long side, and waveform defects on the short side are the waveform defects on the long side. Since there is a tendency that it is less likely to cause the problem of bubble mixing compared to defects, it is not necessary to remove the slit at the short side end, but in order to reduce the wave shape defects at the short side, in addition to the long side end where the wave shape defect is occurring, the wave shape defect The resulting short-side ends (one end or both ends) may be slit removed. The slit width W2 of the short side end may be, for example, 35 mm or more per one end, preferably 40 mm or more, and more preferably 45 mm or more.

Further, irrespective of whether or not a corrugated defect has occurred at the short-side end, one or both of the short-side end portions may be slit-removed to obtain a second polarizing plate sheet-fed body sized down from the first polarizing plate sheet-fed body. As a specific example of the size down, the long-side and short-side ends of the first polarizing plate sheetfed body having a size of 46 inches (long side 1031 mm x short side 585 mm) were slit-removed, and a second size of 39 inches (long side 860 mm×short side 490 mm) In the case of obtaining a sheet of a polarizing plate, or by sliting the long and short end of the first polarizing plate sheet having a size of 39 inches (long side 860 mm x short side 490 mm), a 32-inch size (long side 700 mm x short side 400 mm) The case of obtaining a second polarizing plate sheet body, etc. are mentioned.

In the case of removing the slit for downsizing, in the case of a polarizing plate sheet having a height of more than 2 mm, or a polarizing plate sheet having four or more wave defects, the long side end, and the slit width of 65 mm or more per one end (W1) As long as it is removed by slit removal, only one of the two long-side ends may be slit-removed, and both long-side ends may be slit-removed. Similarly, only one of the two short-side end portions may be slit-removed, or both short-side end portions may be slit-removed.

Example

Hereinafter, the present invention will be described in more detail by showing examples, but the present invention is not limited by these examples. In the following examples, the number and height of waveform defects followed the following measurement method.

(Number and height of waveform defects)

With the side of the separate film 50 facing upward, the polarizing plate sheet body is placed on a flat surface, and the number of corrugated defects on the two long sides of the polarizing plate sheet body (as described above, a waveform having a height of 0.5 mm or more from the flat surface) Defects only) and the height of the corrugated defect from the flat surface were measured, respectively. Table 1 shows the number and height of waveform defects on the long side having more waveform defects among the two long sides. The height of the waveform defect shown in Table 1 is the height of the highest waveform defect in the case of having a plurality of waveform defects.

<Experimental Example 1>

[1] Preparation of the first polarizing plate sheetfed body

A long polarizing plate having a layer structure shown in FIG. 1 was prepared. The layer configuration of this polarizing plate is a protective film 60 having a thickness of 53 μm (consisting of a (meth)acrylic pressure-sensitive adhesive layer and a polyethylene terephthalate film)/the first protective film 20 (TAC film) having a thickness of 60 μm/thickness 25 Μm polarizer 10 (uniaxially stretched polyvinyl alcohol film in which iodine is adsorbed and oriented) / second protective film 30 having a thickness of 52 µm (phase difference film made of cyclic polyolefin resin) / pressure-sensitive adhesive layer having a thickness of 20 µm ( 40) ((meth)acrylic pressure-sensitive adhesive layer)/38 µm-thick separate film 50 (polyethylene terephthalate film subjected to a release treatment on one side). Both the first protective film 20 and the second protective film 30 are made of an active energy ray-curable adhesive (made by ADEKA Co., Ltd., which is an ultraviolet curable adhesive containing a curable compound that is a cationic polymerizable epoxy-based compound and a photo-cationic polymerization initiator). It is bonded to the polarizer 10 through an adhesive layer made of a cured product of "KR-70T"). In addition, 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. hr).

From the long polarizing plate, a 46-inch-sized (long side 1031 mm x short side 585 mm) rectangular polarizing plate sheeting was cut out, and then stored for 3 days in an environment of 80% relative humidity at 30°C, and the waveform according to the measurement method A first polarizing plate sheet having a long side having a height of 3.5 mm and a number of corrugated defects of 5 was obtained.

[2] Fabrication of the second polarizing plate sheet (remove the slit at the end of the long side)

In the first polarizing plate sheet leaf body obtained above, the long-side end portion having a corrugated height of 3.5 mm and the number of corrugated defects was 5, slit-removed to a width of 10 mm using a shear cutter, and the second polarizing plate sheet leaf body after the slit was removed. The height and number of corrugated defects on the long side were measured. This operation was repeated until the total slit width (slit width W1) became 170 mm, and the relationship between the slit width W1 and the waveform defect reduction effect was investigated. Table 1 shows the results.

<Experimental Example 2>

Two long-side ends of the first polarizing plate sheet leaf body of a 46-inch size (long side 1031 mm x short side 585 mm) having a long side with a waveform height of 3.5 mm and a number of waveform defects obtained in the same manner as in Experimental Example 1 Using a shear cutter, the slit was removed by 85.5 mm per one end, and the two short-side ends were slit-removed by 47.5 mm per one end, so that the size was down to a size of 39 inches (long side 860 mm x short side 490 mm). A second polarizing plate sheet was obtained. With respect to this second polarizing plate sheet member, the height and the number of waveform defects on the long side corresponding to the long side of the first polarizing plate sheet member having a waveform height of 3.5 mm and four number of waveform defects were measured. Table 2 shows the results.

Next, the two long-side ends of the 39-inch-sized second polarizing plate sheet obtained above were slit-removed by 80.0 mm per one end using a shear cutter, and the two short-side ends were 45.0 mm per one end. By removing the slits each time, a second polarizing plate sheet blade sized down to a size of 32 inches (long side 700 mm x short side 400 mm) was obtained. With respect to this second polarizing plate sheet member, the height and number of waveform defects on the long side corresponding to the long side of the 39-inch-sized second polarizing plate sheet member having the height and number of the waveform defects measured from above were measured. Table 2 shows the results.

1 1st polarizing plate sheet|leaf body, 10 polarizers, 20 1st protective film, 30 2nd protective film, 40 adhesive layer, 50 separate film, 60 protective film.

Claims (8)

A rectangular polarizing plate sheet having a long side and a short side, comprising a polarizer and a protective film laminated on at least one side thereof, wherein a first polarizing plate sheet having one or more waveform defects on at least one long side is provided. The preparation process,
Step of obtaining a second polarizing plate sheet by slit-removing an end portion of the first polarizing plate sheet including the long side having the waveform defect
Including,
The method of manufacturing a sheet of a polarizing plate, wherein the height of the corrugated defect exceeds 2 mm. The manufacturing method according to claim 1, wherein in the step of preparing the first polarizing plate sheet member, four or more corrugated defects are present in the at least one long side. delete The process according to claim 1 or 2, wherein in the step of obtaining the second polarizing plate sheet member, slit-removing an end portion including the long side having the wave shape defect in the first polarizing plate sheet member to a width of 65 mm or more. It is a manufacturing method. The method according to claim 1 or 2, wherein the first polarizing plate sheet includes the polarizer, a first protective film laminated on one side of the polarizer through a first adhesive layer, and a second protective film on the other side. The manufacturing method comprising a second protective film laminated through an adhesive layer. The manufacturing method according to claim 5, wherein the first protective film and the second protective film have different 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, 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 method according to claim 1 or 2, wherein the first polarizing plate sheet body is the following (a) and (b):
(a) a protective film laminated on the protective film,
(b) a pressure-sensitive adhesive layer laminated on the polarizer or on the protective film, and a separate film laminated on the outer surface thereof
The manufacturing method further comprises at least any one of.

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