TW201617649A - Polarizing plate roll - Google Patents

Abstract

The present invention provides a polarizing plate roll containing a rolling core having a first convex part and a second convex part extending in a circumferential direction on the outer surface thereof, and a polarizing plate rolled on the rolling core. The polarizing plate contains a polarizer and a protective film laminated on at least one surface of the polarizer, and rolled on the core roll such that one end part in a width direction of the protective film rests on the first convex part, and the other end part rests on the second convex part.

Description

Polarizer reel

The present invention relates to a polarizing plate roll in which a long polarizing plate is wound around a winding core.

Polarizers are widely used in display devices such as liquid crystal display devices, and in particular, various mobile devices such as smart phones in recent years. The polarizing plate is generally formed by laminating a protective film on one surface or both surfaces of a polarizing plate. However, as the mobile device progresses, the polarizing plate or the protective film constituting the polarizing plate is gradually required to be thinned.

In the production of a polarizing plate, a raw material film of a long strip (belt shape) is used, and a raw material film is wound up from a roll in which a raw material film is wound around a winding core (a core), and the raw material film which is wound up is processed. The strip (belt) polarizing plate is wound around the core to form a reel, that is, generally in the form of a so-called reel to reel. For this reason, a polarizing plate is generally obtained by winding a long polarizing plate around a core of a polarizing plate (for example, JP-A-2013-029754 (Patent Document 1)).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-029754

As described above, the polarizing plate is generally manufactured in the form of a polarizing plate roll. For example, if the polarizing plate has a film length of 2000 m and the core diameter is 150 mm. For example, the number of windings of the polarizing plate is about 4,000 times.

The polarizing plate which is used to form the polarizing plate reel is often held in a reel state during some continuous periods between the supply of further films or subsequent steps of forming a coating layer, or between the supply objects.

However, in some continuous periods, the polarizing plate which is wound up after being held in a roll state is liable to be accompanied by an unsuitable problem called "winding defect". The thinner the polarizer or the protective film constituting the polarizing plate, the more remarkable the problem. Referring to Fig. 7, the "cricket defect" is caused by the difference in height between the winding start end of the polarizing plate and the outer peripheral surface of the core, that is, the width of the polarizing plate is caused by the drop portion being pressed against the wound polarizing plate. A stripe-shaped recess defect extending in the direction. The use of a fixing member such as a double-sided tape fixes the winding start end of the polarizing plate to the winding core and winds up the polarizing plate, and the curl defect is particularly remarkable. As shown in Fig. 7, the defect of the winding includes the defect K ₁ derived from the corner portion (the short corner of the end portion) at the winding start end of the polarizing plate (because the corner portion of the winding start end of the polarizing plate is pressed Further, when the fixing member is used, the defect K ₂ derived from the corner portion of the fixing member (the defect generated by pressing the corner portion of the fixing member) is further included.

The curl defect is a polarizing plate on the inside of the polarizing plate reel (open The polarizing plate at the beginning of the initial winding is strongly generated, and the weaker the outer side of the polarizing plate is, but it may occur at a position of several tens of meters from the start of winding of the polarizing plate to the length direction. When the polarizing plate containing the curl defect is suitable for an image display device such as a liquid crystal display device, there is a concern that the visibility is lowered. When the polarizing plate portion having the defect is removed as a defective product, the product yield of the polarizing plate is greatly lowered.

Therefore, an object of the present invention is to provide a polarizing plate roll in which a polarizing plate is wound around a winding core, and a polarizing plate roll capable of confirming a "winding defect" can be suppressed when the polarizing plate is taken out from the winding.

The present invention provides a polarizing plate reel shown below.

[1] A polarizing plate roll comprising: a winding core having a first convex portion and a second convex portion extending in a circumferential direction on an outer peripheral surface; and a polarizing plate wound around the winding core, wherein the polarizing plate is provided with a polarizing plate And a protective film laminated on at least one of the surfaces of the polarizing plate, wherein one end region of one of the width directions of the protective film is located on the first convex portion, and the other end region is located at the second convex portion The above method is wound around the aforementioned core.

[2] The polarizing plate roll according to the above aspect, wherein the polarizing plate is located at an inner side of one of the width direction of the polarizer, and is located further inward than an inner end of the first convex portion, and One end portion is wound around the winding core so as to be located further inside than the inner end portion of the second convex portion.

[3] The polarizing plate reel according to [1], wherein the winding start end of the polarizing plate is fixed to the foregoing by using a fixing member. The outer perimeter.

[4] The polarizing plate reel according to any one of [1], wherein the height of each of the first convex portion and the second convex portion is 50 μm or more.

[5] The polarizing plate roll according to any one of [1], wherein the first convex portion and the second convex portion are formed of a resin film adhered to the outer peripheral surface.

According to the present invention, it is possible to provide a polarizing plate reel capable of suppressing curl defects. By suppressing the curl defect, the product quality or product yield of the polarizing plate can be improved.

10‧‧‧With the core of the convex part

10a‧‧‧1st convex

10b‧‧‧2nd convex

20‧‧‧Polar plate

21‧‧‧ polarizer

22‧‧‧1st protective film

23‧‧‧2nd protective film

30‧‧‧Fixed components

Fig. 1 is a schematic view showing an example of a winding core used in a convex portion of a polarizing plate roll of the present invention.

Fig. 2 is a cross-sectional view showing a portion of a first convex portion of a winding core having a convex portion shown in Fig. 1.

Fig. 3 is a cross-sectional view schematically showing an example of a positional relationship between a convex portion of a winding core of a convex portion and a width direction of a wound polarizing plate.

Fig. 4 is a cross-sectional view schematically showing another example of the positional relationship between the convex portion of the winding core of the convex portion and the width direction of the wound polarizing plate.

Fig. 5 is a cross-sectional view showing another example of the core of the convex portion.

Fig. 6 is a schematic view showing a state in which the winding start end portion of the polarizing plate is fixed to the winding core of the convex portion by using a fixing member.

Figure 7 is a schematic diagram for explaining the defects of the curl.

An example of the polarizing plate roll of the present invention is shown in Figs. 1 and 2, and is a winding core 10 having a convex portion for the first convex portion 10a and the second convex portion 10b extending in the circumferential direction on the outer peripheral surface. As a winding core, a long polarizing plate is wound around a winding core to form a polarizing plate in the form of a roll. In the present invention, in order to suppress the occurrence of the above-mentioned "winding defect", the polarizing plate is located on the first convex portion 10a and the other end portion in the end portion of one of the width directions of the protective film. The manner of the convex portion 10b is wound around the winding core 10 of the convex portion. The positional relationship between the convex portions 10a and 10b of the core 10 with the convex portion and the width direction of the wound polarizing plate will be described in detail in the following item (3).

(1) The core of the convex part

The winding core 10 having the convex portion may have the same shape as the conventional winding core except for the first convex portion 10a and the second convex portion 10b. The body portion of the winding core may be cylindrical, for example, in addition to the convex portions. Or cylindrical. The material is not particularly limited, and metals, alloys, and resins (thermoplastic resins, etc.) can be used. The length of the winding core 10 with the convex portion in the width direction (the direction of the rotation axis) is equal to or longer than the width of the wound polarizing plate. When the core 10 of the convex portion is cylindrical or cylindrical, the diameter thereof may be a general diameter of the core, for example, 100 to 200 mm. about.

The position where the first convex portion 10a and the second convex portion 10b provided on the outer circumferential surface of the winding core 10 having the convex portion are disposed depends on the width of the wound polarizing plate. Specifically, the first convex portion 10a and the second convex portion 10b are on The outer peripheral surface is at a position different from each other, and the end portion of one of the width directions of the protective film constituting the polarizing plate is located on the first convex portion 10a, and the other end portion is located on the second convex portion 10b. . As shown in Fig. 1, the first convex portion 10a and the second convex portion 10b are generally provided at an end portion (including an end portion) in the width direction (rotational axis direction) of the winding core 10 of the convex portion or near the end portion. .

The first convex portion 10a and the second convex portion 10b are provided on the outer circumferential surface of the winding core 10 of the convex portion, and are provided to extend in the circumferential direction of the winding core 10 of the convex portion, preferably with respect to the convex portion. The circumferential direction of the core 10 extends in parallel (in a direction perpendicular to the direction of the rotation axis of the winding core 10 of the convex portion). As shown in Fig. 2, the first convex portion 10a and the second convex portion 10b are preferably belt-shaped, and are preferably provided in a ring shape over the entire circumference or about the entire circumference of the outer circumferential surface of the winding core 10 covering the convex portion. .

The first convex portion 10a and the second convex portion 10b may be integrally formed with the main body portion of the winding core 10 of the convex portion, or may be formed of another member different from the main body portion. In the method of forming the convex portion by using another member, for example, the first convex portion 10a and the second convex portion are adhered to each other on the outer circumferential surface of the cylindrical or cylindrical core of the main body portion of the winding core 10 as the convex portion. A method of a resin film of the portion 10b (for example, a film tape composed of a thermoplastic resin). The resin film may be an adhesive layer on one side in order to adhere to the outer surface of the core. The method of using an adhesive to stick a resin film is reproducible, so that the positional adjustment or positional change of the convex portion becomes easy. The method of forming the convex portion by the adhesion of the resin film is advantageous in terms of the manufacturing cost of the core 10 with the convex portion and the simplicity of manufacture, and can be obtained by charging. The core 10 of the convex portion with a partial intensity. The resin film may also be adhered to the outer surface of the core by using an adhesive.

(2) Polarizer

The polarizing plate wound around the winding core 10 of the convex portion is provided with a polarizer and a protective film laminated on at least one of the faces. The film can also be protected on the two layers of the polarizer. The protective film is usually attached to the polarizer through the adhesive layer. As the subsequent agent, an active energy ray-curable adhesive such as an ultraviolet curable adhesive or an aqueous adhesive such as an aqueous solution of a polyvinyl alcohol-based resin can be used. The total thickness of the polarizing plate is generally about 30 to 300 μm.

The polarizer can be suitably used to align a dichroic dye to a polyvinyl alcohol-based resin which is stretched by one axis. As the dichroic dye, iodine or a dichroic dye can be used. As the polyvinyl alcohol-based resin constituting the polarizer, those obtained by saponifying a polyvinyl acetate-based resin can be used. Polyvinyl acetate-based resin In addition to polyvinyl acetate of a vinyl acetate homopolymer, a copolymer of vinyl acetate and another monomer copolymerizable therewith can be exemplified. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group. In the present specification, "(meth)acrylic group" means at least one selected from the group consisting of an acryl group and a methacryl group. The same applies to "(meth)acrylonitrile".

The degree of saponification of the polyvinyl alcohol-based resin is generally from about 85 to 100 mol%, preferably from 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyethylene formaldehyde modified with an aldehyde and polyvinyl acetaldehyde may be used. The degree of polymerization of the polyvinyl alcohol-based resin is generally from 1,000 to 10,000. Around 1500 to 5000 is preferred.

The polarizer can be produced by a method comprising the steps of: stretching a matrix film composed of the above polyvinyl alcohol-based resin on one axis (typically extending toward a longitudinal axis of the film length direction); and using a polyvinyl alcohol-based resin film as two The step of adsorbing the dichroic dye by the dyeing of the coloring matter; the step of treating the polyvinyl alcohol resin film adsorbing the dichroic dye with a boric acid aqueous solution; and the step of washing with a boric acid aqueous solution and then washing with water. A swelling step of subjecting the water to an immersion treatment may also be provided before the dyeing treatment.

One of the polyvinyl alcohol-based resin films is axially stretched, and can be carried out before dyeing of the dichroic dye, simultaneously with dyeing, or after dyeing. When a shaft extension is performed after dyeing, the one-axis extension can also be carried out before boric acid treatment or boric acid treatment. Moreover, one-axis extension can also be performed in the plural steps of the order.

The thickness of the polarizer (the average thickness of the full width) is, for example, 40 μm or less, preferably 25 μm or less, more preferably 20 μm or less, and particularly in a polarizing plate for a mobile device, from the viewpoint of reducing the thickness of the polarizing plate to 10 μm or less. good. The thickness of the polarizer is generally 2 μm or more. When such a film polarizer is used, the present invention can effectively suppress curl defects.

The protective film to be bonded to the polarizer may be a translucent (preferably optically transparent) thermoplastic resin such as a chain polyolefin resin (such as a polypropylene resin) or a cyclic polyolefin resin. A polyolefin resin such as a benzylene resin; a cellulose ester resin such as cellulose triacetate or cellulose diacetate; a polyester resin; a polycarbonate resin; A olefinic resin; a polystyrene resin; or a film composed of a mixture such as a copolymer or the like. When the protective film is bonded to both surfaces of the polarizer, these may be a protective film made of the same kind of resin, or may be a protective film made of a different kind of resin.

The protective film may also be a protective film having an optical function such as a phase difference film or a brightness enhancement film. For example, a film made of the above thermoplastic resin may be stretched (one-axis stretching or biaxial stretching or the like), or a liquid crystal layer or the like may be formed on the film, whereby a phase difference film imparting an arbitrary phase difference value may be formed.

In addition to a homopolymer of a chain olefin such as a polyethylene resin or a polypropylene resin, the chain polyolefin resin may, for example, be a copolymer composed of two or more kinds of chain olefins.

The cyclic polyolefin resin is a general term for a resin obtained by polymerizing a cyclic olefin as a polymerization unit. Specific examples of the cyclic polyolefin-based resin include a ring-opened (co)polymer of a cyclic olefin, an addition polymer of a cyclic olefin, a copolymer of a cyclic olefin and a chain olefin such as ethylene or propylene (representative The same is a random copolymer), a graft polymer which is modified with an unsaturated carboxylic acid or a derivative thereof, and a hydride or the like. Among them, a decylene-based resin having a nordene-based monomer such as a norbornene or a polycyclic nordzene-based monomer as a cyclic olefin is preferred.

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. Further, it is also possible to use one of these copolymers or a part of a hydroxyl group to be modified with other substituents. Among these, cellulose triacetate (triethyl fluorenyl cellulose: TAC) is special. good.

The polyester-based resin is a resin other than the cellulose ester-based resin having an ester bond, and is generally composed of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. As the polyvalent carboxylic acid or a derivative thereof, a dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalene dicarboxylate. As the polyhydric alcohol, a glycol may be used, and examples thereof include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, and cyclohexane dimethanol.

Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polytrimethylene terephthalate. , propylene naphthalate, dimethyl dimethyl terephthalate, cyclohexane dimethyl phthalate.

The polycarbonate resin is composed of a polymer that transmits a monomer unit through a carbonate group. The polycarbonate resin may be a resin modified with a polymer skeleton called modified polycarbonate, or a copolymerized polycarbonate.

The (meth)acrylic resin is a resin having a compound having a (meth)acryl fluorenyl group as a main constituent monomer. Specific examples of the (meth)acrylic resin include, for example, poly(meth)acrylate such as polymethyl methacrylate; methyl methacrylate-(meth)acrylic acid copolymer; methyl methacrylate-( Methyl) acrylate copolymer; methyl methacrylate-acrylate-(meth)acrylic acid copolymer; methyl (meth) acrylate-styrene copolymer (MS resin, etc.); methyl methacrylate Copolymer with a compound having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-(meth)acrylic acid reduced alkyl ester copolymer, etc.). It is preferable to use a polymer having a poly(meth)acrylic acid C _1-6 alkyl ester such as poly(methyl) acrylate as a main component, and it is more preferable to use methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100% by weight, based on the methyl methacrylate resin.

The thickness of the protective film is preferably 90 μm or less, more preferably 50 μm or less, and still more preferably 30 μm or less from the viewpoint of reducing the thickness of the polarizing plate. The thickness of the protective film is usually 5 μm or more from the viewpoint of strength and handleability. Even when a protective film of such a film is used, according to the present invention, curl defects can be effectively suppressed.

The polarizing plate may also be a film or layer other than the protective film. Specific examples of the film or layer other than the protective film include: an adhesive layer; a separation film (peeling film) protecting the outer surface of the adhesive layer; a protective film (surface protective film) for protecting the surface of the protective film; A surface treatment layer (coating layer) imparting various functions; various optical functional films.

As the adhesive for the adhesive layer, a conventionally known suitable adhesive can be used, and examples thereof include a (meth)acrylic adhesive, an urethane adhesive, a polyoxygen adhesive, and a polyester. An adhesive, a polyamide-based adhesive, a polyether adhesive, a fluorine-based adhesive, a rubber-based adhesive, or the like. Among them, a (meth)acrylic adhesive is preferably used from the viewpoints of transparency, adhesion, letterability, and reworkability. The thickness of the adhesive layer may generally be from 1 to 40 μm (for example, from 3 to 25 μm).

The constituent material of the separation film may be a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or polyethylene terephthalate. Polyester resin, etc. Among them, an extended film of polyethylene terephthalate is preferred.

The constituent material of the protective film may, for example, be a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or a polyester resin such as polyethylene terephthalate. From the viewpoint of moisture permeability or mechanical strength, An extended film of polyethylene terephthalate is preferred.

The surface treatment layer may, for example, be a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, or an antifouling layer.

The optical functional film may be, for example, a reflective polarizing film that transmits light of a certain polarized light and reflects polarized light having opposite properties; a film with an anti-glare function having a concave-convex shape on the surface; and a film with a surface anti-reflective function; a reflective film having a reflective function on the surface; a semi-transmissive reflective film having a reflective function and a transmissive function; and a viewing angle compensation film.

The width of the polarizing plate wound around the winding core 10 of the convex portion is not particularly limited, but is usually about 300 to 2,500 mm, more typically about 500 to 2,000 mm. Further, the length of the polarizing plate is not particularly limited, but is usually about several hundred m to about 3,000 m (for example, about 2000 m), and more typically about 1,500 to 2,500 m. The width of the polarizer and the width of the protective film attached thereto may be the same or different, but generally, the width of the protective film is further increased, and both ends (both ends) of the protective film are located at the opposite ends. The protective film is bonded to the outer side of both ends (both ends) of the polarizer in the width direction.

(3) Positional relationship between the convex portion of the core of the convex portion and the width direction of the wound polarizing plate

Fig. 3 is a cross-sectional view showing an example of a positional relationship between the convex portion of the winding core 10 and the wound polarizing plate 20 in the convex portion. 3 is a view showing a case where the polarizing plate 20 including the polarizing film 21 and the first protective film 22 bonded to one surface and the second protective film 23 bonded to the other surface is used as an example, but As described above, the layer configuration of the polarizing plate is not limited thereto. In addition, in the third drawing, only the first convex portion 10a of the winding core 10 having the convex portion is used. However, the positional relationship with the second convex portion 10b will be similarly applied to the following description.

In the polarizing plate 20 of the polarizing plate roll of the present invention, one end region of the protective film in the width direction is located on the first convex portion 10a, and in the third drawing, although not shown, the other end is used. The portion of the portion is located on the second convex portion 10b so as to be wound around the winding core 10 of the convex portion. In the case of the protective film (the first and second protective films 22 and 23) provided on both surfaces of the polarizer 21, it is preferable to wind the protective film on both sides so as to satisfy the above-described positional relationship.

The end portion of one of the protective films is located on the first convex portion 10a, as in the example shown in Fig. 3, except that the end portion (end surface, T ₁ in Fig. 3) of the protective film is located on the first convex portion 10a. In addition, the end portion T ₁ including the protective film is located outside the outer end portion T _{2 of the} first convex portion 10a, but the end portion near the end portion T _{1 of the} protective film is placed in the first convex portion 10a. The situation on the top. The end region near the end portion T _{1 of the} protective film refers to a region where each end portion is 15% of the width of the polarizing plate. Thereby, the curl defect suppressing effect can be obtained. The end portion T ₁ of the protective film is located on the first convex portion 10a, and the end portion T ₁ is located between the outer end portion T ₂ and the inner end portion T ₃ of the first convex portion 10a (including T ₁ and T ₂ or T). ₃ consistent situation). When the end portion T ₁ of the protective film is located further inside than the inner end portion (end surface) T _{3 of the} first convex portion 10a, it is difficult to obtain the curl defect suppressing effect.

The polarizing plate 20 which can obtain the effect of suppressing the curling defect can be such that the end portion T ₄ in the width direction of the polarizing plate 21 is located further inside than the inner end portion T _{3 of the} first convex portion 10a as shown in Fig. ₃ The winding core 10 wound around the convex portion may have the end portion T ₄ of the polarizing plate 21 positioned on the first convex portion 10a as shown in Fig. ₄ , that is, the end of the polarizing plate 21 The portion T ₄ is located between the outer end portion T ₂ of the first convex portion 10a and the inner end portion T ₃ (including the case where T ₁ coincides with T ₂ or T ₃ ). The winding core 10 is wound around the convex portion 10 . . It is better to be the former.

With reference to Fig. 3 and Fig. 4, the width W ₂ (the overlapping width of the protective film and the first convex portion 10a) of the end portion of the protective film (mounted on the first convex portion 10a) is preferably 5 mm or more. More preferably 10mm or more. If the overlap width W _{2 is} too small, it is difficult to obtain a sufficient curl defect suppressing effect. The upper limit of the overlapping 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 in order to obtain the above-described preferable overlapping width W ₂ . The upper limit of the width W ₁ is not particularly limited and is, for example, 100 mm.

In order to obtain the curl defect suppressing effect more effectively, the height H of the first convex portion 10a is preferably 50 μm or more. The upper limit of the height H may be 1500 μm (for example, 1000 μm). For example, when the convex portion is formed by the adhesion of the resin film, as shown in Fig. 5, in order to increase the height H, the resin film may be wound and wound in a plurality of layers. Fig. 5 shows an example in which the first convex portion 10a is formed by superposing and winding the second resin film t ₂ on the first resin film t ₁ . When the resin film is wound around a plurality of layers, the connection points thereof are preferably shifted from each other without being uniform as shown in Fig. 5. If they are consistent, the connection point of the connection can be the cause of the defect of the wound.

As shown in Fig. 4, when the end portion T ₄ of the polarizer 21 is positioned on the first convex portion 10a, the curl portion defect suppressing effect is more effectively obtained, and the end portion T ₄ is located on the inner side of the first convex portion 10a. It is preferable that the end portion T _{3 is} further inside so that the height H of the first convex portion 10a is lower. In other words, the thickness of the polarizer 21 located on the first convex portion 10a increases the height difference (falling portion) between the winding start end of the polarizing plate which is a factor of the curl defect and the outer peripheral surface of the core, so that the thickness is increased. When the height H of the first convex portion 10a is, for example, 400 μm or less, and further 200 μm or less, the lower one is advantageous in suppressing the curl defect.

On the other hand, when the end portion T ₄ of the polarizer 21 is located inside the inner end portion T _{3 of} the first convex portion 10a, the height H of the first convex portion 10a is improved in order to more effectively obtain the curl defect suppressing effect. Preferably, it is preferably 150 μm or more, and more preferably 300 μm or more.

As described above, the protective film is bonded so as to increase the width of the protective film so that both end portions in the width direction of the protective film are located outside the both end portions in the width direction of the polarizer. Referring to FIG. 3, the protective film (No. The excess width W ₃ (the distance from the end portion T _{1 of the} protective films 22 and 23 to the end portion T ₄ of the polarizing film 21) of the protective film 22 and the second protective film 23) can be set to about 1 to 100 mm (for example, 5) Up to 60mm).

(4) The winding end of the polarizing plate is fixed to the core of the convex portion

The polarizing plate 20 can be wound up by rotating the winding core 10 of the convex portion around the rotation axis thereof. At this time, as shown in Fig. 6, before the start of winding, the winding start end (length direction start end) of the polarizing plate 20 is fixed to the core of the convex portion by using the fixing member 30 [Fig. 6 (a)]. The outer peripheral surface of 10 is preferable (Fig. 6(b)). Since the polarizing plate 20 can be easily fixed, it is preferable to use the double-sided tape for the fixing member 30. For example, the double-sided tape as the fixing member 30 is parallel to the rotation axis of the core 10 of the convex portion, and is adhered to the outer circumferential surface of the core 10 of the convex portion, and the winding start end of the polarizing plate 20 is made thereon. The short side direction of the polarizing plate 20 is adhered in parallel with the rotation axis of the winding core 10 of the convex portion. By fixing the winding start end of the polarizing plate 20 to the winding core 10 of the convex portion, the winding of the polarizing plate 20, particularly in the initial stage, can be smoothly performed. When the winding start end of the polarizing plate 20 is fixed to the winding core 10 of the convex portion by using the fixing member, a height difference (fall) is generated between the winding start end of the polarizing plate 20 and the outer peripheral surface of the winding core 10 of the convex portion. However, it is easy to cause a curl defect, and according to the present invention, even in such a case, the curl defect can be effectively suppressed.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited by these examples.

<Comparative Example 1>

A polarizing film (thickness: 28 μm) obtained by adsorbing a dichroic dye to a first protective film (thickness: 40 μm)/adhesive layer/longitudinal axis-extending polyvinyl alcohol-based resin film made of triethylenesulfonyl cellulose (TAC) /then Coating layer / second protective film (thickness 40 μm) composed of TAC / long polarizing plate composed of a layer structure of a protective film (thickness 62 μm) composed of extended polyethylene terephthalate, from reel to reel The method is continuously produced, and is wound around a cylindrical core (without a convex portion) to obtain a polarizing plate roll. The specific conditions for the production of the polarizing plate reel are as follows. Further, the winding start end (starting end in the longitudinal direction) of the polarizing plate was fixed to the outer peripheral surface of the core by using a double-sided tape having a thickness of 176 μm.

[1] cylindrical core (no convex). Material: FRP (fiber reinforced plastic),. Width direction (rotation axis direction) length: 1480mm,. Diameter: 167mm , [2] polarizing plate. The width of the protective film: 1330mm, The width of the polarizer: 1270mm,. In the third figure, W ₃ : 30mm (both ends are). Polarizer length: about 2000m. Tension when the polarizing plate is taken up: 60N.

<Comparative Examples 2 to 4>

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

<Example 1>

A polarizing plate reel was produced in the same manner as in Comparative Example 1, except that the specific conditions for the production of the polarizing plate reel were as follows, using the same winding core as in the first embodiment. The polarizing plate is wound such that one end region of one of the width directions of the protective film bonded to both surfaces of the polarizer is positioned on the first convex portion and the other end portion is located on the second convex portion. However, as shown in Fig. 3, the end portion T ₄ of the polarizer 21 is located further inside than the inner end portion T _{3 of the} first convex portion 10a and the second convex portion 10b (the polarizer and the convex portion are not Repeatedly) winding. The first and second convex portions of the core of the convex portion are as shown in Fig. 5, and the resin film tape having a certain width of the adhesive layer on one side substantially covers the periphery of the core portion of the core. The surface of the resin film tape having the same width of the adhesive layer on one side of the outer peripheral surface is formed by sticking approximately 15 mm from the joint point to cover the entire circumference.

[1] The core of the convex part (body part: cylindrical). Material: FRP (fiber reinforced plastic),. Width direction (rotation axis direction) length: 1480mm,. The diameter of the body part: 167mm , The width of the first and second convex portions (W _{1 in} Fig. 3): 10 mm, The height of the first and second convex portions (H in Fig. 3): 360 μm, [2] polarizing plate. The width of the protective film: 1330mm, The width of the polarizer: 1270mm,. The excess width of the protective film (W _{3 in} Fig. ₃ ): 30mm (both ends are). Polarizer length: about 2000m. The tension when the polarizing plate is taken up: 60N, [3] the positional relationship between the polarizing plate and the core of the convex portion. The overlapping width of the protective film on both sides and the first and second convex portions (W _{2 in} Fig. 3): 10 mm. The overlap width between the polarizer and the first and second convex portions is 0 mm.

<Examples 2 to 3>

A polarizing plate reel was produced in the same manner as in Example 1 except that the tension when the polarizing plate was taken up was 150 N (Example 2) and 250 N (Example 3).

<Example 4>

In addition to the tension when the polarizing plate was taken up, the tension was 150 N, and the resin film tape was wound and wound in three layers, and the heights of the first and second convex portions (H in FIG. 3) were set to 540 μm. In Example 1, a polarizing plate reel was also produced.

<Example 5>

A core of a polarizing plate was produced in the same manner as in Comparative Example 1, except that the specific conditions for producing the polarizing plate were the same as in the first embodiment. The polarizing plate is wound such that one end region of one of the width directions of the protective film bonded to both surfaces of the polarizer is positioned on the first convex portion and the other end portion is located on the second convex portion. In the present embodiment, as shown in Fig. 4, the end portion T ₄ in which one of the width directions of the polarizing plate 21 is located on the first convex portion 10a, and the other end portion T ₄ is located in the second convex portion 10b. Winding on the way. The first and second convex portions of the core of the convex portion are resin film tapes having a certain width of the adhesive layer on one side, and as shown in FIG. 2, the periphery of the core portion is substantially covered for the entire circumference. Formed in the face.

[1] The core of the convex part (body part: cylindrical). Material: FRP (fiber reinforced plastic), . Width direction (rotation axis direction) length: 1480mm,. The diameter of the body part: 167mm , The width of the first and second convex portions (W1 in Fig. 4): 10 mm, The height of the first and second convex portions (H in Fig. 4): 360 μm, [2] polarizing plate. The width of the protective film: 1330mm, The width of the polarizer: 1270mm,. The excess width of the protective film (W3 in Fig. 3): 30mm (both ends are). Polarizer length: about 2000m. The tension when the polarizing plate is taken up: 250N, [3] the positional relationship between the polarizing plate and the core of the convex portion. The overlapping width of the protective film on both sides and the first and second convex portions (W2 in Fig. 4): 10 mm. The overlapping width of the polarizer and the first and second convex portions (the distance from the end portion T4 in Fig. 4 to the inner end portion T3 of the convex portion): 10 mm.

<Example 6>

A polarizing plate reel was produced in the same manner as in Example 5 except that the heights of the first and second convex portions (H in Fig. 4) were 180 μm.

The main manufacturing conditions of the polarizing plate reels of Examples 1 to 6 and Comparative Examples 1 to 4 are summarized in Table 1. The prepared polarizing plate roll was stored in an environment of 25 ° C and 50% RH for 15 days, and then the polarizing plate roll was taken up, and the length of occurrence of the curl defect at the winding from the start of the polarizing plate was measured. The results are shown in the first table.

10‧‧‧With the core of the convex part

10a‧‧‧1st convex

20‧‧‧Polar plate

21‧‧‧ polarizer

22‧‧‧1st protective film

23‧‧‧2nd protective film

Claims (5)

A polarizing plate roll includes: a winding core having a first convex portion and a second convex portion extending in a circumferential direction on an outer circumferential surface; and a polarizing plate wound around the winding core, wherein the polarizing plate includes a polarizing plate and a laminate The protective film on the surface of at least one of the polarizing plates is such that one end region of the protective film in the width direction is located on the first convex portion and the other end region is located on the second convex portion. Winding on the aforementioned core. The polarizing plate roll according to the first aspect of the invention, wherein the polarizing plate has one end portion in a width direction of the polarizing plate located further inward than an inner end portion of the first convex portion, and the other side The end portion is wound around the winding core so as to be located further inside than the inner end portion of the second convex portion. The polarizing plate reel according to claim 1 or 2, wherein the winding start end of the polarizing plate is fixed to the outer peripheral surface by using a fixing member. The polarizing plate roll according to any one of claims 1 to 3, wherein the height of each of the first convex portion and the second convex portion is 50 μm or more. The polarizing plate roll according to any one of claims 1 to 4, wherein the first convex portion and the second convex portion are formed of a resin film adhered to the outer peripheral surface.