KR20170072922A - Polarizing plate roll - Google Patents

Abstract

A core having a first convex portion and a second convex portion extending in the circumferential direction on an outer peripheral surface thereof and a polarizer wound around the core, wherein the polarizer comprises a polarizer and a protective film laminated on at least one surface thereof A polarizing plate roll is provided in which the one end region in the width direction of the protective film is positioned on the first convex portion and the other end region is wound on the core so as to be located on the second convex portion.

Description

Polarizing plate roll {POLARIZING PLATE ROLL}

The present invention relates to a polarizing plate roll obtained by winding a long polarizing plate on a core.

BACKGROUND ART [0002] Polarizing plates are widely used in display devices such as liquid crystal display devices, and particularly in various mobile devices such as smart phones. As a polarizing plate, a protective film is bonded to one surface or both surfaces of a polarizer. However, as polarizing plates are developed in mobile devices, the polarizers and protective films constituting the polarizing plates are increasingly required to be thinned.

The production of the polarizing plate is carried out by using a long (band-like) raw material film and processing the raw material film while loosening the raw film from the roll in which the raw film is wound around the core (winding core) ), And the resultant polarizing plate is wound on a core to form a roll, which is generally called a roll-to-roll method. Therefore, the polarizing plate is usually obtained as a polarizing plate roll in which a long polarizing plate is wound on a core (for example, JP-A-2013-029754 (Patent Document 1)).

Patent Document 1: JP-A-2013-029754

As described above, the polarizing plate is generally produced in the form of a polarizing plate roll. For example, assuming that the film length of the polarizing plate is 2000 m and the diameter of the winding core is 150 mm ?, for example, the number of turns of the polarizing plate is about 4000 times.

The polarizing plate produced as a polarizing plate roll is held in a roll state in a continuous period such as during a period until the polarizing plate is provided to a subsequent process such as joining another film or forming a coating layer, .

However, there has been a problem that the polarizer that has been released after being held in a roll state for a continuous period tends to be accompanied by a problem called " winding streak defect ". This problem becomes more remarkable as the polarizer or protective film constituting the polarizing plate becomes thinner. Referring to Fig. 7, the term " wound wire defect " refers to a streak extending in the width direction of the polarizing plate, which is generated by pressing a polarizing plate being wound on a high level difference, that is, a step portion, between a starting end of the polarizing plate It is a depression defect of the shape. In particular, when the polarizing plate is wound after fixing the winding start end of the polarizing plate to the winding core by using a fixing member such as a double-sided tape, the winding streak defect becomes remarkable. As shown in Figure 7, the winding stem defects, caused by being edge portion pressed against the edge portion of the winding starting end of the _first (polarizing plate defect K derived from (short-side edge of the end portion) of the winding starting end of the polarizer Defect), and when the fixing member is used, the defect K ₂ (defect caused by pressing on the corner of the fixing member) derived from the corner of the fixing member is also included.

The winding streak defect is generated strongly on the polarizing plate (polarizing plate at the beginning of winding start) inside the polarizing plate roll and becomes weaker toward the outside of the polarizing plate roll, but can occur over several tens of meters in the longitudinal direction from the beginning of winding of the polarizing plate. When a polarizing plate including a wound stem defect is applied to an image display apparatus such as a liquid crystal display apparatus, visibility may be lowered. If the polarizing plate portion having such a defect is removed as a defective product, the product yield of the polarizing plate is significantly lowered.

The object of the present invention is to provide a polarizing plate roll comprising a polarizing plate wound around a core and capable of suppressing "winding streak defect" which can be confirmed when the polarizing plate is unwound from the roll.

The present invention provides the following polarizing plate roll.

[1] A light source comprising: a core having a first convex portion and a second convex portion extending in the circumferential direction on an outer peripheral surface; and a polarizer wound on the core,

Wherein the polarizing plate comprises a polarizer and a protective film laminated on at least one surface thereof,

Wherein the polarizing plate is wound on the core so that one end region in the width direction of the protective film is positioned on the first convex portion and the other end region is positioned on the second convex portion.

[2] The polarizing plate according to any one of [1] to [4], wherein the polarizer is arranged such that one end in the width direction of the polarizer is positioned inside of the inner end of the first convex portion and the other end is located inward of the inner end of the second convex portion Polarizer roll described in [1].

[3] The polarizing plate roll according to [1] or [2], wherein the starting end of the polarizing plate is fixed to the outer circumferential surface using a fixing member.

[4] The polarizing plate roll described in any one of [1] to [3], wherein the height of the first convex portion and the second convex portion is 50 μm or more, respectively.

[5] The polarizing plate roll described in any one of [1] to [4], wherein the first convex portion and the second convex portion are made of a resin film adhered to the outer circumferential surface.

According to the present invention, it is possible to provide a polarizing plate roll capable of suppressing a winding streak defect. By suppressing the winding streak defect, the product quality and product yield of the polarizing plate can be improved.

1 is a schematic view showing an example of a winding core having a convex portion used in a polarizing plate roll according to the present invention.
Fig. 2 is a cross-sectional view of a portion of the winding core having the convex portion shown in Fig. 1 at a portion having the first convex portion. Fig.
3 is a cross-sectional view schematically showing an example of the positional relationship in the width direction between the convex portion of the winding core having the convex portion and the polarizing plate to be wound.
4 is a cross-sectional view schematically showing another example of the positional relationship in the width direction between the convex portion of the winding core having the convex portion and the polarizing plate to be wound.
5 is a cross-sectional view showing another example of a winding core having a convex portion.
6 is a schematic view showing a state in which a winding start end of a polarizing plate is fixed to a winding having a convex portion using a fixing member.
Fig. 7 is a schematic view for explaining a winding streak defect. Fig.

1 and 2, the polarizing plate roll according to the present invention includes a first convex portion 10a and a second convex portion 10b extending in the circumferential direction on the outer peripheral surface as a winding core Is a roll-shaped polarizing plate formed by winding a long polarizing plate on a core 10 having a convex portion. In the present invention, in order to suppress the occurrence of the " winding streak defect " described above, one end region in the width direction of the protective film constituting the polarizing plate is positioned on the first convex portion 10a, And the end region is wound on the winding core 10 having the convex portion so as to be positioned on the second convex portion 10b. The positional relationship in the width direction between the convex portions 10a and 10b of the winding core 10 having convex portions and the polarizing plate to be wound will be described in detail in the following section (3).

(1) Ream with convex

The core 10 having a convex portion may have the same shape as a conventionally known core except for having the first convex portion 10a and the second convex portion 10b and the main portion of the core, For example, columnar or cylindrical. The material is not particularly limited, and metals, alloys, resins (thermoplastic resins, etc.) can be used. The length in the width direction (rotation axis direction) of the core 10 having convex portions is equal to or longer than the width of the polarizing plate being wound. In the case where the core 10 having a convex portion is a columnar or cylindrical shape, its diameter may be a general diameter of the winding core, for example, about 100 to 200 mmφ.

The mounting positions of the first convex portion 10a and the second convex portion 10b formed on the outer circumferential surface of the core 10 having the convex portion depend on the width of the polarizer being wound. More specifically, the first convex portion 10a and the second convex portion 10b are arranged such that one end region in the width direction of the protective film constituting the polarizing plate, And the other end region is located on the second convex portion 10b. As shown in Fig. 1, the first convex portion 10a and the second convex portion 10b usually have an end region (including an end portion) in the width direction (rotation axis direction) of the core 10 having convex portions or As shown in Fig.

The first convex portion 10a and the second convex portion 10b are formed so as to extend in the circumferential direction of the core 10 having the convex portion on the outer peripheral surface of the core 10 having the convex portion, (In the direction perpendicular to the direction of the rotation axis of the core 10 having the convex portion) with respect to the circumferential direction of the core 10 having the convex portion. As shown in Fig. 2, the first convex portion 10a and the second convex portion 10b are preferably strip-shaped. Also, the first convex portion 10a and the second convex portion 10b are preferably formed in a strip- It is preferable that they are formed in an annular shape.

The first convex portion 10a and the second convex portion 10b may be formed integrally with the body portion of the core 10 having the convex portion and may be formed using a separate member different from the body portion There may be. As a method of forming the convex portion by using a separate member, the first convex portion 10a and the second convex portion 10b are formed on the outer circumferential surface of the columnar or cylindrical winding core as the body portion of the winding core 10 having the convex portion And a resin film (for example, a film tape made of a thermoplastic resin) to be formed thereon is adhered. The resin film may have a pressure-sensitive adhesive layer on one side thereof for adhesion to the outer peripheral surface of the winding core. According to the method in which the resin film is adhered by using an adhesive, since it can be stuck and fixed, the position of the convex portion can be adjusted or the position can be easily changed. The method of forming the convex portion by the adhesion of the resin film is advantageous in terms of manufacturing cost and simplicity of production of the winding core 10 having the convex portion and also the winding core 10 having the convex portion having sufficient strength can be obtained have. The resin film may be adhered to the outer peripheral surface of the winding core by using an adhesive.

(2) Polarizer

The polarizing plate wound on the winding core 10 having a convex portion includes a polarizer and a protective film laminated on at least one surface thereof. A protective film may be laminated on both sides of the polarizer. The protective film is usually bonded to the polarizer through an adhesive layer. As the adhesive, an active energy ray-curable adhesive such as an ultraviolet ray-curable adhesive or an aqueous adhesive such as a polyvinyl alcohol-based resin aqueous solution can be used. The overall thickness of the polarizing plate is generally about 30 to 300 mu m.

As the polarizer, those having a dichroic dye adsorbed on a uniaxially stretched polyvinyl alcohol-based resin can be suitably used. As the dichroic dye, iodine or a dichroic dye can be used. As the polyvinyl alcohol-based resin constituting the polarizer, a saponified polyvinyl acetate-based resin can be used. As the polyvinyl acetate resin, a copolymer of vinyl acetate and other monomers copolymerizable therewith may be mentioned in addition to polyvinyl acetate as a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include (meth) acrylamides having unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids and ammonium groups. In the present specification, "(meth) acryl" means at least one selected from acrylic and methacrylic. The same applies to "(meth) acryloyl".

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl formal and polyvinyl acetal modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

The polarizer is a step of uniaxially stretching the original film made of the polyvinyl alcohol-based resin (typically, longitudinal uniaxial stretching in the longitudinal direction of the film), staining the polyvinyl alcohol-based resin film with a dichroic dye, A step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film adsorbed with a dichroic dye with an aqueous solution of boric acid, and a step of washing after treatment with an aqueous solution of boric acid. A swelling step may be performed in which a treatment for immersion in water is performed before the dyeing treatment.

The uniaxial stretching of the polyvinyl alcohol based resin film can be performed before, simultaneously with, or after dyeing the dichroic dye. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. In addition, uniaxial stretching may be performed at a plurality of these steps.

The thickness of the polarizer (average thickness in the entire width) is, for example, not more than 40 占 퐉, preferably not more than 25 占 퐉 and more preferably not more than 20 占 퐉. Particularly in polarizers for mobile devices, And more preferably 10 m or less. The thickness of the polarizer is usually 2 占 퐉 or more. Even when such a thin film polarizer is used, according to the present invention, it is possible to effectively suppress the winding streak defect.

The protective film to be bonded to the polarizer is preferably a thermoplastic resin having translucency (preferably optically transparent) such as a polyolefin such as a chain polyolefin resin (polypropylene resin), a cyclic polyolefin resin (norbornene resin, etc.) Based resin; Cellulose ester-based resins such as cellulose triacetate and cellulose diacetate; Polyester-based resin; Polycarbonate resin; (Meth) acrylic resins; Polystyrene type resin; Or a mixture or copolymer thereof, or the like. When a protective film is bonded to both surfaces of the polarizer, they may be protective films made of the same kind of resin or protective films made of different kinds of resins.

The protective film may be a protective film having optical functions such as a retardation film and a brightness enhancement film. For example, a retardation film having an arbitrary retardation value can be obtained by stretching (uniaxially stretching or biaxially stretching) a film made of the thermoplastic resin, or forming a liquid crystal layer or the like on the film.

Examples of the chain polyolefin resin include a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, and a copolymer composed of two or more chain olefins.

The cyclic polyolefin-based resin is a generic name of a resin that is polymerized using a cyclic olefin as a polymerization unit. Specific examples of the cyclic polyolefin-based resin include ring-opened (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers (typically, random copolymers) of cyclic olefins and chain olefins such as ethylene and propylene, Graft polymers modified with carboxylic acids or their derivatives, and hydrides thereof. Among them, a norbornene resin using a norbornene monomer such as norbornene or a polycyclic norbornene monomer as the cyclic olefin is preferably used.

The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. These copolymers and those obtained by modifying a part of hydroxyl groups with other substituents may also be used. Of these, cellulose triacetate (triacetylcellulose: TAC) is particularly preferable.

The polyester-based resin is a resin other than the cellulose ester-based resin having an ester bond, and is generally composed of a polycondensation product of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. As the polycarboxylic acid or its derivative, a dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethylterephthalate, and dimethyl naphthalenedicarboxylate. Examples of polyhydric alcohols include diols such as ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol.

Specific examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, polycyclohexane Dimethyl naphthalate.

The polycarbonate resin is composed of a polymer having a monomer unit bonded through a carbonate group. The polycarbonate resin may be a modified polycarbonate such as modified polymer skeleton, or a copolymerized polycarbonate.

The (meth) acrylic resin is a resin mainly composed of a compound having a (meth) acryloyl group. Specific examples of the (meth) acrylic resin include poly (meth) acrylic acid esters such as polymethyl methacrylate; Methyl methacrylate- (meth) acrylic acid copolymer; Methyl methacrylate- (meth) acrylic acid ester copolymer; Methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer; (Meth) acrylate-styrene copolymer (MS resin and the like); A copolymer of methyl methacrylate and a compound having an alicyclic hydrocarbon group (e.g., methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.) . Preferably, a polymer consisting essentially of a poly (meth) acrylate C _{1 -6} alkyl ester such as poly (meth) acrylate is used, more preferably methyl methacrylate as a main component (50 to 100 wt% Is 70 to 100% by weight).

The thickness of the protective film is preferably 90 占 퐉 or less, more preferably 50 占 퐉 or less, further preferably 30 占 퐉 or less, from the viewpoint of thinning of the polarizing plate. The thickness of the protective film is usually 5 占 퐉 or more from the viewpoints of strength and handleability. Even in the case of using such a thin film protective film, according to the present invention, it is possible to effectively suppress the winding streak defect.

The polarizing plate may include a film or a layer other than the protective film. Specific examples of the film or layer other than the protective film include a pressure-sensitive adhesive layer; A separate film (release film) for protecting the outer surface of the pressure-sensitive adhesive layer; A protective film (surface protective film) for protecting the surface of the protective film; A surface treatment layer (coating layer) for imparting various functions to the polarizing plate; And various optical functional films.

As the pressure-sensitive adhesive to be used for the pressure-sensitive adhesive layer, conventionally known pressure-sensitive adhesives can be used. Examples of the pressure-sensitive adhesives include pressure-sensitive adhesives such as (meth) acrylic adhesives, urethane adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, polyether adhesives, An adhesive, and the like. Among them, 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 may generally be 1 to 40 占 퐉 (for example, 3 to 25 占 퐉).

The constituent material of the separate film may be a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, or a polyester-based resin such as polyethylene terephthalate. Among them, a stretched film of polyethylene terephthalate is preferable.

As a constituent material of the protective film, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, etc. Among them, from the viewpoint of moisture permeability and mechanical strength, polyethylene terephthalate Is preferred.

Examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer and an antifouling layer.

Examples of the optical function film include a reflection type polarizing film that transmits polarized light of any kind and reflects polarized light exhibiting properties opposite to that of the polarized light; A film having an antireflection function on the surface and having an antiglare function; A film having a surface antireflection function; A reflecting film having a reflecting function on the surface; A transflective film having a reflection function and a transmission function; And a viewing angle compensation film.

The width of the polarizer wound around the winding core 10 having convex portions is not particularly limited, but is usually about 300 to 2500 mm, and more typically about 500 to 2000 mm. The length of the polarizing plate is not particularly limited, but is usually several hundred meters to 3000 meters (for example, about 2000 meters), and more typically about 1500 to 2500 meters. The width of the polarizer and the width of the protective film to be bonded to the polarizer may be the same or may be different. However, the width of the protective film may be made larger so that both end portions in the width direction (both end surfaces) It is common to join the protective film.

(3) positional relation with respect to the width direction between the convex portion of the winding core having the convex portion and the polarizing plate to be wound

3 is a cross-sectional view schematically showing an example of the positional relationship in the width direction between the convex portion of the winding core 10 having the convex portion and the polarizing plate 20 to be wound. In Fig. 3, as an example, a polarizing plate 20 composed of a polarizer 21, a first protective film 22 bonded to one surface thereof and a second protective film 23 bonded to the other surface is used However, the layer structure of the polarizing plate is not limited to this, as described above. Further, although Fig. 3 employs only the first convex portion 10a of the core 10 having the convex portion, the following description is also applied to the positional relationship with the second convex portion 10b.

In the polarizing plate 20 of the polarizing plate roll of the present invention, one end region in the width direction of the protective film is located on the first convex portion 10a and is not shown in Fig. 3, Is wound on the winding core 10 having the convex portion so that the region is located on the second convex portion 10b. When the protective films (first and second protective films 22 and 23) are provided on both sides of the polarizer 21 as in the example of Fig. 3, it is preferable that both protective films are wound so as to satisfy the above- desirable.

The fact that one end region of the protective film is positioned on the first convex portion 10a means that the end portion (the end face, T ₁ in FIG. 3) of the protective film is located on the first convex portion 10a as in the example shown in FIG. The end portion T ₁ of the protective film is located outside the outer end T ₂ of the first convex portion 10a but the end region near the end T ₁ of the protective film is located outside the first convex portion 10a, And is placed on the portion 10a. The end region near the end portion T ₁ of the protective film is an area up to 15% of the width of the polarizing plate with respect to each of the end portions. As a result, the effect of suppressing the winding streak defect can be obtained. The fact that the end T ₁ of the protective film is located on the first convex portion 10a means that the end T ₁ is located between the outside end T ₂ and the inside end T ₃ of the first convex portion 10a _{1 corresponds} to T ₂ or T ₃ ). When the end portion T ₁ of the protective film is located on the inner side than the inner end portion (end face) T ₃ of the first convex portion 10 a, it is difficult to obtain a winding string defect restraining effect.

In obtaining the winding stem defect suppression effect polarizing plate 20, as illustrated in Figure 3, than the end portion T ₄ in the width direction of the polarizer 21, the inner end T ₃ of the first projections (10a) 4, the end T ₄ of the polarizer 21 is positioned on the first convex portion 10a, that is, the polarizer 21 (not shown) is disposed on the first convex portion 10a, ) end T ₄ is includes a case that matches the first convex portion (10a) outer end arranged between the T ₂ and the inner end T ₃ (T ₁ is T ₂ or T ₃ in.) convex with portions cores of (Not shown). It is preferably an electron.

3 and 4, the first projections (10a) of the end region of the (burning) a protective film which is located on the width W ₂ (the protective film and the overlapping width between the first convex portion (10a)) is, More preferably 5 mm or more, and more preferably 10 mm or more. If the overlap width W ₂ is too small, it is difficult to obtain sufficient effect of suppressing the pulling-back streak defect. The upper limit of the overlap width W ₂ is not particularly limited, but may be, for example, about 30 mm. The width W ₁ of the first convex portion 10a is preferably 5 mm or more so as to obtain the preferable overlap width W ₂ . The upper limit of the width W ₁ is not particularly limited, and is, for example, 100 mm.

The height H of the first convex portion 10a is preferably not less than 50 占 퐉 in order to more effectively obtain the effect of suppressing the winding streak defect. The upper limit of the height H may be 1500 [mu] m (e.g., 1000 [mu] m). For example, when the convex portion is formed by adhesion of the resin film, as shown in Fig. 5, a plurality of layers of the resin film may be superposed so as to increase the height H. 5 is an example in which the first convex portion (10a) by winding overlaps the second resin film, t ₂ t ₁ on the first resin film. When a plurality of layers of the resin film are rolled up, it is preferable that these joints are displaced without being matched as shown in Fig. If they are matched, the joints that are connected can become a factor of the winding stem defect.

As shown in Figure 4, to the end portion T ₄ of the polarizer 21, the first gain when positioned on the convex portions (10a), the winding stem defect suppressing effect more effectively, portions the end portion T _4, the first projections as compared with the case of an inner end located on an inner side than the T ₃ in (10a), the first is preferred to be lower than the height H of the convex portion (10a). That is, since the thickness of the polarizer 21 located on the first convex portion 10a increases the height difference (stepped portion) generated between the winding start end of the polarizing plate causing the winding streak defect and the outer circumferential surface of the core, The height H of the first convex portion 10a is preferably set to, for example, not more than 400 占 퐉, and furthermore, not more than 200 占 퐉.

On the other hand, an end of the polarizer (21) T ₄ of the first projections (10a) an inner end thereof is positioned on the inner side than T _3, the winding stem defects suppressed to achieve the effect more effectively, the first convex portion (10a) of It is preferable to set the height H relatively high, for example, 150 mu m or more, and more preferably 300 mu m or more.

As described above, it is general to increase the width of the protective film and to bond the protective film so that both end portions in the width direction of the protective film are positioned outside the widthwise opposite ends of the polarizer. As shown in Fig. 3, 1, protective film 22 and the second projecting width W ₃ distance end to T ₄ from the end T _1, the polarizer (21 of the protective film (22, 23) of the protective film 23)) is 1 ~ 100 mm (For example, about 5 to 60 mm).

(4) Polarizing plate Fixing to the core with the convex part of the beginning

The polarizing plate 20 is wound by rotating the core 10 having the convex portion about its rotation axis. 6 (a)), the winding start (longitudinal direction leading end) of the polarizing plate 20 is rotated by the fixing member 30 before the winding is started, as shown in Fig. 6, And is preferably fixed to the outer peripheral surface of the core 10 (Fig. 6 (b)). Since the polarizing plate 20 can be easily fixed, a double-sided tape can be preferably used as the fixing member 30. [ For example, the fixing member 30, which is a double-sided tape, is adhered to the outer peripheral surface of the winding core 10 having the convex portion in parallel with the rotation axis of the winding core 10 having the convex portion, 20 are parallel to the rotation axis of the winding core 10 having the convex portion. By fixing the winding start end of the polarizing plate 20 to the winding core 10 having the convex portion, the polarizing plate 20 can be smoothly wound particularly at the initial stage. When the winding start end of the polarizing plate 20 is fixed to the winding core 10 having the convex portion by using the fixing member, a difference in level between the winding start end of the polarizing plate 20 and the outer circumferential surface of the winding core 10 having the convex portion, So that it is easy for the occurrence of faulty winding streaks. According to the present invention, even in such a case, the faulty winding streak can be effectively suppressed.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

≪ Comparative Example 1 &

(Thickness: 28 占 퐉) / adhesive layer / second layer formed by adsorbing and orienting a dichroic dye onto a first protective film (thickness: 40 占 퐉) / adhesive layer / polyvinyl alcohol-based resin film stretched in the longitudinal direction uniaxially stretched with triacetyl cellulose (TAC) A long polarizing plate having a layer structure of a second protective film (thickness: 40 占 퐉) made of TAC / a protective film made of stretched polyethylene phthalate (thickness: 62 占 퐉) was continuously manufactured in a roll-to-roll manner, ) To obtain a polarizing plate roll. Specific conditions in the production of the polarizing plate roll are as follows. The polarizing plate was fixed on the outer peripheral surface of the winding core using a double-sided tape having a thickness of 176 占 퐉.

[1] Cylindrical core (without convex)

· Material: FRP (fiber reinforced plastic),

Width direction (rotation axis direction) length: 1480 mm,

Diameter: 167 mmφ,

[2] Polarizing plate

· Width of protective film: 1330 mm,

Polarizer width: 1270 mm,

W ₃ : 30 mm (both ends) in Fig. 3,

Polarizer plate length: about 2000 m,

Tension at polarizing plate winding: 60 N.

≪ Comparative Examples 2 to 4 >

A polarizing plate roll was produced in the same manner as in Comparative Example 1 except that the tension at the time of polarizing plate winding was 100 N (Comparative Example 2), 150 N (Comparative Example 3) and 250 N (Comparative Example 4), respectively.

≪ Example 1 >

A polarizing plate roll was produced in the same manner as in Comparative Example 1 except that the winding core having the convex portion as shown in Fig. 1 was used and the specific conditions in the production of the polarizing plate roll were as follows. The polarizing plate was wound so that one end region in the width direction of the protective film bonded to both surfaces of the polarizer was positioned on the first convex portion and the other end region was positioned on the second convex portion. 3, the end T ₄ of the polarizer 21 is positioned so as to be located further inside than the inner end T ₃ of the first convex portion 10a and the second convex portion 10b (the polarizer ₂₁ and the convex portion overlap each other ). As shown in Fig. 5, the first and second convex portions of the winding core having convex portions are formed by adhering a resin film tape having a constant width having a pressure-sensitive adhesive layer on one surface to the outer circumferential surface of the winding body portion over substantially the entire circumference, A resin film tape of the same width having a pressure-sensitive adhesive layer on one side thereof was displaced by about 15 mm and adhered to almost the entire circumference.

[1] Core with convex (main part: cylindrical)

· Material: FRP (fiber reinforced plastic),

Width direction (rotation axis direction) length: 1480 mm,

· Diameter of body part: 167 mmφ,

The width of the first and second convex portions (W ₁ in FIG. 3): 10 mm,

Heights of the first and second convex portions (H in Fig. 3): 360 mu m,

[2] Polarizing plate

· Width of protective film: 1330 mm,

Polarizer width: 1270 mm,

Protrusion width of the protective film (W ₃ in FIG. ₃ ): 30 mm (both ends),

Polarizer plate length: about 2000 m,

Tension at polarizing plate winding: 60 N,

[3] The positional relationship between the polarizing plate and the core having the convex portion

(W ₂ in FIG. 3) between the protective films on both sides and the first and second convex portions: 10 mm,

Overlapping width of the polarizer and the first and second convex portions: 0 mm.

≪ Examples 2 to 3 >

A polarizing plate roll was produced in the same manner as in Example 1 except that the tension at the time of winding the polarizing plate was 150 N (Example 2) and 250 N (Example 3), respectively.

<Example 4>

Except that the tension at the time of polarizing plate winding was set to 150 N, the resin film tape was wound in three layers and the height of the first and second convex portions (H in Fig. 3) was 540 탆, To prepare a polarizing plate roll.

&Lt; Example 5 >

A polarizing plate roll was produced in the same manner as in Comparative Example 1 except that the winding core having the convex portion as shown in Fig. 1 was used and the specific conditions in the production of the polarizing plate roll were as follows. The polarizing plate was wound so that one end region in the width direction of the protective film bonded to both surfaces of the polarizer was positioned on the first convex portion and the other end region was positioned on the second convex portion. In this embodiment, as shown in Figure 4, the end portion T ₄ on one side in the width direction of the polarizer 21 is located on the first convex portion (10a), the other end T ₄ second projections So as to be positioned on the portion 10b. The first and second convex portions of the winding core having the convex portions were formed by adhering a resin film tape having a certain width having a pressure-sensitive adhesive layer on one surface thereof to the outer circumferential surface of the winding core body portion over substantially the entire circumference as shown in Fig.

[1] Core with convex (main part: cylindrical)

· Material: FRP (fiber reinforced plastic),

Width direction (rotation axis direction) length: 1480 mm,

· Diameter of body part: 167 mmφ,

Width of the first and second convex portions (W ₁ in FIG. 4): 10 mm,

Heights of the first and second convex portions (H in Fig. 4): 360 mu m,

[2] Polarizing plate

· Width of protective film: 1330 mm,

Polarizer width: 1270 mm,

Protrusion width of the protective film (W ₃ in FIG. ₃ ): 30 mm (both ends),

Polarizer plate length: about 2000 m,

Tension at the time of polarizing plate winding: 250 N,

[3] The positional relationship between the polarizing plate and the core having the convex portion

The overlap width (W ₂ in FIG. 4) between the protective film on both sides and the first and second convex portions: 10 mm,

, The polarizer and the first and second (the distance from the end 4 T ₄ at the inner end to the convex portion T ₃₎ and the overlapping width of the projections: 10 mm.

&Lt; Example 6 >

A polarizing plate roll was produced in the same manner as in Example 5 except that the height of the first and second convex portions (H in Fig. 4) was 180 탆.

Major production conditions of the polarizing plate rolls in Examples 1 to 6 and Comparative Examples 1 to 4 are summarized in Table 1. The produced polarizing plate roll was stored for 15 days under an environment of 25 캜 and 50% RH, and then the polarizing plate roll was loosened to measure the occurrence length of the winding streak defect from the start of winding of the polarizing plate. The results are shown in Table 1.

10: a first convex portion, 10b: a second convex portion, 20: a polarizer, 21: a polarizer, 22: a first protective film, 23: a second protective film, 30: a fixing member.

Claims (5)

A core having a first convex portion and a second convex portion which extend in the circumferential direction on the outer peripheral surface, and a polarizer wound on the core,
Wherein the polarizing plate comprises a polarizer and a protective film laminated on at least one surface thereof,
Wherein the polarizing plate is wound on the core so that one end region in the width direction of the protective film is positioned on the first convex portion and the other end region is positioned on the second convex portion. The polarizing plate according to claim 1, wherein the polarizing plate has one end in the width direction of the polarizer positioned inside of the inner end of the first convex portion and the other end inward of the inner end of the second convex portion The polarizer roll being wound around the core. The polarizing plate roll according to claim 1 or 2, wherein the winding start end of the polarizing plate is fixed to the outer circumferential surface using a fixing member. The polarizing plate roll according to any one of claims 1 to 3, wherein the height of the first convex portion and the second convex portion is 50 占 퐉 or more, respectively. The polarizing plate roll according to any one of claims 1 to 4, wherein the first convex portion and the second convex portion are made of a resin film adhered to the outer circumferential surface.

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