KR102530378B1 - Manufacturing method of polarizing plate and manufacturing method of display device - Google Patents

Abstract

As a method for producing a polarizing plate, a raw film containing a material for a polarizer is stretched in one or more directions at a draw ratio X to obtain a polarizer material film (a), a base film is provided on the polarizer material film, and a laminate [A] ], step (b) of obtaining, step (c) of stretching the layered product [A] in one or more directions at a draw ratio Z, in this order, X is 1.5 or more and 5.5 or less, Z is 1.2 or more and 5.0 or less, X*Z is 5.1 or more and 9.0 or less, The manufacturing method of the polarizing plate whose thickness T of the polarizer material film after passing through a process (c) is 20 micrometers or less.

Description

Manufacturing method of polarizing plate and manufacturing method of display device

The present invention relates to a manufacturing method of a polarizing plate and a manufacturing method of a display device.

BACKGROUND ART Display devices such as liquid crystal display devices and organic electroluminescence (EL) display devices have conventionally been required to have a large display area, light weight, and thin thickness. Therefore, conventionally, thin panels constituting display devices have also been required.

In a display device, a polarizing plate provided with a polarizer and a protective film that protects the polarizer is generally used. In order to construct a display device having a thin thickness, a polarizing plate is also required to be thinner. In particular, since a material such as polyvinyl alcohol commonly used as a polarizer may shrink in the use environment of a display device, warpage due to such shrinkage may be a problem in a thin display device having a large area. . Therefore, by adopting a thin polarizer having a thickness of 10 μm or less, in addition to the reduction in the thickness of the display device due to the reduction in the thickness of the polarizer itself, reduction in the occurrence of warpage as described above can be expected.

By the way, when it is going to manufacture the light polarizer of polyvinyl alcohol with such a thin thickness by the conventional manufacturing method, melting of the light polarizer occurs frequently. Several methods have been proposed as a method for preventing the melting of such a polarizer and manufacturing a polarizing plate containing a thin polarizer. For example, in Patent Literature 1, an unstretched polyvinyl alcohol-based film is attached to a base film made of unstretched high-density polyethylene to form a laminate, and the laminate is stretched, and then the base film is peeled off to form a polyvinyl alcohol-based film. A method of obtaining the film has been proposed.

Further, in Patent Document 2, a polyvinyl alcohol-based resin layer is formed into a film by applying an aqueous solution containing a polyvinyl alcohol-based resin to an amorphous ester-based thermoplastic resin base material to form a laminate, and after stretching the laminate, A method of obtaining an optical film by orienting a sexual material to obtain a colored laminate and subjecting the colored laminate to a stretching treatment has been proposed.

Japanese Published Patent Publication No. 2016 - 505404 (corresponding publication: US Patent Application Publication No. 2016/084990 specification) Japanese Patent No. 4691205 (corresponding publication: US Patent Application Publication No. 2012/057232 specification)

When a thin polarizing plate is manufactured by the method described in Patent Documents 1 and 2, a phase difference may occur in the base film after the stretching treatment due to stretching the laminate at a high draw ratio. In such a case, it is difficult to use the base film as a polarizing plate protective film as it is, and since it is peeled off and discarded, waste material is generated. In addition, an operation of separately preparing a protective film for protecting the polarizing plate and attaching it to the polarizing plate may occur.

In addition, in order to obtain a thin polarizing plate of sufficient width, preparing a base film having a very wide width dimension and applying or sticking a polarizer material (eg polyvinyl alcohol material) may be considered, but the width dimension of the base film When is too large, there is a problem that production is difficult.

Therefore, an object of this invention is to provide the manufacturing method of the polarizing plate which can use a base film also as a protective film, and can manufacture efficiently even if it is thin, and the manufacturing method of the display apparatus provided with the said polarizing plate .

As a result of examining to solve the above problems, the present inventors found that the above problems can be solved by stretching a laminate comprising a polarizer material film stretched at a predetermined stretching ratio at a predetermined stretching ratio, completed the present invention.

Therefore, according to the present invention, the following [1] to [22] are provided.

[1] As a method for producing a polarizing plate,

Step (a) of obtaining a polarizer material film by stretching a raw film containing the material of the polarizer at a draw ratio X in one or more directions;

Step (b) of providing a base film on the polarizer material film to obtain a layered product [A];

A step (c) of stretching the layered product [A] in one or more directions at a stretching ratio Z is included in this order,

X and Z satisfy the relationship of the following formulas (1) to (3),

The manufacturing method of the polarizing plate whose thickness T of the polarizer material film after passing through a process (c) is 20 micrometers or less.

1.5 ≤ X ≤ 5.5 . (One)

1.2 ≤ Z ≤ 5.0 . (2)

5.1 ≤ X * Z ≤ 9.0 . (3)

[2] The method for producing a polarizing plate according to [1], including a step (d) of dyeing the polarizer material film with a dichroic substance after the step (b).

[3] The method for producing a polarizing plate according to [1] or [2], wherein the step (c) is performed under a temperature condition of 50°C to 160°C.

[4] The method for producing a polarizing plate according to any one of [1] to [3], wherein the polarizer material film is made of polyvinyl alcohol resin.

[5] The method for producing a polarizing plate according to any one of [1] to [4], wherein the retardation in the in-plane direction of the base film after passing through the step (c) is 20 nm or less.

[6] After the step (c), a step (e1) of attaching a protective film to the polarizer material film of the laminate [A] directly or through an adhesive, or forming an adhesive layer on the polarizer material film The manufacturing method of the polarizing plate as described in any one of [1]-[5] including a process (e2).

[7] The method for producing a polarizing plate according to any one of [1] to [6], wherein the base film is a film made of at least one selected from cycloolefin resins, amorphous polyester resins, polyolefin resins, and acrylic resins. .

[8] The base film is a film made of a cycloolefin resin,

The cycloolefin resin includes a cycloolefin-based polymer,

[1] to [7], wherein the cycloolefin-based polymer is composed of at least one selected from hydrides of ring-opening polymers of norbornene-based monomers, addition copolymers of norbornene-based monomers and α-olefins, and hydrides thereof. The manufacturing method of the polarizing plate of any one of the above.

[9] The base film is a film made of a cycloolefin resin,

The cycloolefin resin includes a cycloolefin-based polymer,

The cycloolefin-based polymer comprises a polymer block [A] containing, as a main component, a repeating unit [I] derived from an aromatic vinyl compound;

A polymer block [B] mainly composed of a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or

Polymer block [C] containing a repeating unit [II] derived from a chain-like conjugated diene compound as a main component

A block copolymer [D] consisting of

The manufacturing method of the polarizing plate in any one of [1]-[7] which consists of a hydrogenated block copolymer hydride.

[10] The method for producing a polarizing plate according to any one of [1] to [9], wherein the base film contains a plasticizer and/or a softener.

[11] The method for producing a polarizing plate according to [10], wherein the plasticizer and/or softener is an ester plasticizer, an aliphatic hydrocarbon polymer, or a mixture thereof.

[12] The angle θ1 formed by the stretching direction in the step (a) and the width direction of the polarizer material film is 90°, and the angle θ2 formed by the stretching direction in the step (c) and the width direction of the laminate [A] is 90°. The method for producing a polarizing plate according to any one of [1] to [11], which is °.

[13] The angle θ1 formed between the stretching direction in the step (a) and the width direction of the polarizer material film is 0°, and the angle θ2 formed between the stretching direction in the step (c) and the width direction of the laminate [A] is 0 The method for producing a polarizing plate according to any one of [1] to [11], which is °.

[14] Any one of the angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film and the angle θ2 formed by the stretching direction and the width direction of the laminate [A] in the step (c) It is 90 degrees, and the manufacturing method of the polarizing plate in any one of [1]-[11] whose other side is 0 degrees.

[15] The angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film is 90°, and the angle θ2 (°) formed by the stretching direction of the step (c) and the width direction of the laminate [A] ) The manufacturing method of the polarizing plate as described in any one of [1]-[11] which satisfy|fills following formula (4).

θ2 ≠ 90 … (4)

[16] The angle θ1 (°) formed between the stretching direction of the step (a) and the width direction of the polarizer material film satisfies the following formula (5),

The method for producing a polarizing plate according to any one of [1] to [11], wherein the angle θ2 formed by the stretching direction in the step (c) and the width direction of the layered product [A] is 90°.

θ1 ≠ 90 … (5)

[17] An angle θ1 (°) formed between the stretching direction of the step (a) and the width direction of the polarizer material film, and an angle θ2 (°) formed between the stretching direction and the width direction of the laminate [A] in the step (c) ), the manufacturing method of the polarizing plate according to any one of [1] to [11], which satisfies the following formula (6) and the following formula (7).

θ1 ≠ 90 … (6)

θ2 ≠ 90 … (7)

[18] The method for producing a polarizing plate according to any one of [15] to [17], wherein the absolute value of the difference between θ1 and θ2 is 50 or less.

[19] The method for producing a polarizing plate according to any one of [2] to [18], wherein the dichroic substance is an organic dye.

[20] A method for manufacturing a display device in which a polarizing plate obtained by the method for manufacturing a polarizing plate according to any one of [12] to [14] is laminated on a liquid crystal panel.

[21] A method for manufacturing a display device in which a polarizing plate obtained by the method for manufacturing a polarizing plate according to any one of [15] to [17] is laminated on an organic EL panel or an inorganic EL panel.

[22] A method for manufacturing a display device in which a polarizing plate obtained by the method for manufacturing a polarizing plate described in [19] is laminated on a vehicle-mounted display panel.

According to the present invention, since the phase difference expressed in the base film can be reduced even after passing through the step of stretching the laminate, the base film can also be used as a protective film, and the manufacturing method of a polarizing plate that can be efficiently produced even when the thickness is thin , and a method of manufacturing a display device having the above polarizing plate.

1 is a cross-sectional view schematically showing a polarizing plate obtained by a manufacturing method according to Embodiment 1 of the present invention.
Fig. 2 is a diagram schematically showing an example of a manufacturing process of the layered product [A].
FIG. 3 is a cross-sectional view schematically showing a laminate [A] obtained through the manufacturing process shown in FIG. 2 .
FIG. 4 is a diagram schematically illustrating an example of a manufacturing step of manufacturing a polarizing plate from a layered product [A] in the manufacturing method of Embodiments 1 to 3. FIG.
5 is a cross-sectional view schematically showing a polarizing plate obtained by a manufacturing method according to Embodiment 2 of the present invention.
6 is a cross-sectional view schematically showing a polarizing plate obtained by a manufacturing method according to Embodiment 3 of the present invention.
7 is a cross-sectional view schematically showing a display device obtained by a manufacturing method according to Embodiment 4 of the present invention.
8 is a cross-sectional view schematically showing a display device obtained by a manufacturing method according to Embodiment 5 of the present invention.
9 is a cross-sectional view schematically showing a display device obtained by a manufacturing method according to Embodiment 6 of the present invention.
10 is a cross-sectional view schematically showing a display device obtained by a manufacturing method according to Embodiment 7 of the present invention.

Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be implemented with arbitrary changes within a range not departing from the scope of the claims of the present invention and their equivalents.

In the present application, a "long" film refers to a film having a length of 5 times or more of the width of the film, and preferably having a length of 10 times or more, specifically, the degree to which it is wound up in a roll shape and stored or transported. means having a length of The upper limit of the ratio of the length to the width of the film is not particularly limited, but is, for example, 100,000 times or less.

In the present application, the retardation Re in the in-plane direction and the retardation Rth in the thickness direction of the film are according to the formula Re = (nx - ny) × d, and Rth = [{(nx + ny) / 2} - nz] × d yield The Nz coefficient of the film is a value expressed by [(nx - nz)/(nx - ny)], which can also be expressed by [(Rth/Re) + 0.5]. Here, nx is the refractive index in the in-plane slow axis direction of the film (maximum in-plane refractive index), ny is the refractive index in the direction perpendicular to the in-plane slow axis of the film, nz is the refractive index in the thickness direction of the film, d is the thickness (nm) of the film. The measurement wavelength is 590 nm, which is a typical wavelength in the visible light region, unless otherwise specified.

[Embodiment 1: Manufacturing method of polarizing plate]

[One. Outline of manufacturing method of polarizing plate]

The manufacturing method of the polarizing plate concerning Embodiment 1 of this invention is demonstrated, referring FIGS. 1-4.

1 is a cross-sectional view schematically showing a polarizing plate 100 obtained by the manufacturing method of the present embodiment. In the polarizing plate 100, as shown in FIG. 1, the base film 112 is laminated|stacked on one surface (upper side in illustration) of the polarizer material film 111. As shown in FIG. In Fig. 1, 113 denotes an adhesive layer. Although the polarizing plate 100 obtained by the manufacturing method of this embodiment contains the adhesive layer 113, the structure which does not contain the adhesive layer may be sufficient as the polarizing plate obtained by the manufacturing method of this invention.

The manufacturing method of the polarizing plate of this embodiment stretches the raw film containing the material of a polarizer at the draw ratio X in one or more directions, and the step (a) of obtaining a polarizer material film, the base film is provided and laminated|stacked on a polarizer material film The step (b) of obtaining the body [A], and the step (c) of stretching the layered product [A] at the draw ratio Z in one or more directions are included in this order. The manufacturing method of the polarizing plate of this embodiment includes the process (d) of dyeing a polarizer material film with a dichroic substance after process (b).

Fig. 2 is a schematic diagram schematically showing an example of a manufacturing apparatus 200 for manufacturing the layered product [A] obtained through steps (a) and (b). The manufacturing device 200 includes unwinding devices 201 and 202 , a stretching device 204 , a bonding device 205 , and a take-up device 203 .

As shown in FIG. 2, the raw film 1 unwound from the unwinding device 201 is conveyed to the stretching device 204, and the polarizer material film 11 is obtained by carrying out a stretching process in the stretching device 204 (step (a)). A laminate ( 10) is obtained (step (b)). The manufactured layered product 10 is wound up by the winding device 203 and can be used in an additional step as a roll shape.

4 is a schematic diagram schematically showing an example of a manufacturing apparatus 300 for manufacturing the polarizing plate 100 of the present embodiment through steps (c) and (d). The manufacturing device 300 includes unwinding devices 301 and 307 , processing devices 302 to 305 , drying devices 306 and 309 , bonding devices 308 , and winding device 310 .

As shown in Fig. 4, the layered product 10 unwound from the unwinding device 301 is conveyed to processing devices 302 to 305, dyeing treatment (step (d)) of dyeing with a dichroic substance, and the layered product A process such as a stretching process (step (c)) of stretching is performed. If the layered product after performing these processes is dried with the drying apparatus 306, the polarizing plate 100 will be obtained.

Hereinafter, each process is demonstrated in detail.

[2. Process (a)]

A process (a) is a process of extending|stretching the raw film containing the material of a polarizer at the draw ratio X in one or more directions, and obtaining a polarizer material film.

[2.1. fabric film]

In this invention, a raw film is a film for obtaining a polarizer material film, and refers to what is not used for the extending|stretching process (unstretched film containing the material of a polarizer).

In this invention, although a raw film is not necessarily limited if it can achieve the objective of this invention, The film of polyvinyl alcohol resin is preferable at a point with high cost performance.

In the present invention, the polyvinyl alcohol resin (hereinafter sometimes abbreviated as PVA) is not necessarily limited, but from availability and the like, those produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate are used. it is desirable PVA preferably has a degree of polymerization in the range of 500 to 8000, and a degree of saponification of 90 mol% or more, from the viewpoint of excellent stretchability and polarization performance of the obtained film. Here, the degree of polymerization is an average degree of polymerization measured according to the description of JIS K6726-1994, and the degree of saponification is a value measured according to the description of JIS K6726-1994. A more preferred range of the polymerization degree is 1000 to 6000, more preferably 1500 to 4000. A more preferable range of the degree of saponification is 95 mol% or more, more preferably 99 mol% or more. PVA may be a copolymer of vinyl acetate and another monomer copolymerizable with vinyl acetate, or a graft polymer, as long as the effect of the present invention is not adversely affected.

In the present invention, the production method of the raw film of PVA is not particularly limited, and can be produced by a known method. For example, a PVA solution in which PVA is dissolved in a solvent is used as a film forming stock solution, a film casting method, Wet film forming method (discharge into poor solvent), dry/wet film forming method, gel film forming method (method of obtaining a raw PVA film by once cooling and gelling the PVA aqueous solution and then removing the solvent by extraction), and combinations thereof Any method can be employed, such as a method or a melt extrusion film forming method in which a melted PVA containing a solvent is used as a film forming undiluted solution. Among these, the cast film forming method and the melt extrusion film forming method are preferable in terms of obtaining a raw PVA film having high transparency and little coloration, and the melt extrusion film forming method is more preferable.

In the present invention, the raw film of PVA preferably contains 0.01 to 1% by mass of a plasticizer such as a polyhydric alcohol such as glycerin, based on PVA, in order to improve mechanical properties and process passability during secondary processing. In addition, in order to improve handleability and film appearance, etc., it is preferable to contain 0.01 to 30% by mass of a surfactant such as an anionic surfactant or a nonionic surfactant based on PVA.

The fabric film of PVA is an antioxidant, an ultraviolet absorber, a lubricant, a pH adjuster, inorganic fine particles, a colorant, a preservative, an antifungal agent, other polymer compounds other than the above components, as needed within the range that does not impair the effect of the present invention. You may further contain other components, such as water|moisture content. The raw PVA film may contain one or two or more of these other components.

The thickness of the raw film is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, preferably 5 μm or more, more preferably 10 μm or more, still more preferably 15 μm or less. more than μm. When the thickness of the raw film is equal to or greater than the lower limit of the above range, a polarizing plate having a sufficiently high degree of polarization can be obtained, and resistance to bending of the polarizing plate can be effectively increased when it is equal to or less than the upper limit of the above range.

[2.2. Polarizer Material Film]

A polarizer material film is a film (film for polarizers) for manufacturing a polarizer. A polarizer material film is obtained by extending|stretching a raw film by the draw ratio X in one or more directions. The polarizer material film is a (stretched) film containing the material of the polarizer.

Dry stretching, wet stretching, etc. are mentioned as a method of extending|stretching a raw film. Since dry stretching requires simpler equipment and processes than wet stretching, dry stretching is preferable as a method of stretching treatment of a raw film. As dry stretching, stretching methods such as tenter stretching, float stretching, and hot roll stretching can be used. Dry stretching refers to a stretching treatment method in which the film is stretched in a gas atmosphere at a high temperature (for example, 100° C. or higher). Air is exemplified as a gas used in dry stretching.

The conditions of the stretching at the time of extending|stretching a raw film and setting it as a polarizer material film can select suitably so that a desired polarizer material film may be obtained. For example, the aspect of extending|stretching at the time of extending|stretching a raw film and setting it as a polarizer material film can be set as arbitrary aspects, such as uniaxial stretching and biaxial stretching. In addition, when the raw film is a long film, the direction of stretching is the longitudinal direction (direction parallel to the longitudinal direction of the long film), the transverse direction (direction parallel to the width direction of the long film), and the oblique direction ( Any direction that is neither vertical nor horizontal) may be used. The relationship between the stretching direction in the step (a) and the stretching direction in the step (c) will be described in the description of the step (c).

The draw ratio X at the time of extending|stretching a raw film and using it as a polarizer material film is 1.5 or more and 5.5 or less, and satisfy Formula (1) (1.5<=X<=5.5) mentioned above. The draw ratio X is preferably 2.0 or more, more preferably 2.5 or more, while preferably 4.5 or less, more preferably 3.5 or less. That is, the polarizer material film is preferably a film stretched at a draw ratio X of 2.0 or more and 4.5 or less, and more preferably a film stretched at a draw ratio X of 2.5 or more and 3.5 or less. If the draw ratio X is equal to or less than the upper limit of the above range, occurrence of breakage can be prevented when a raw film is stretched to obtain a polarizer material film. Moreover, when the draw ratio X is made more than the lower limit of the said range, the draw ratio at the time of extending|stretching a laminated body and obtaining a polarizing plate can be made low. When extending|stretching of a raw film is performed by extending|stretching in two or more directions, such as biaxial stretching, the draw ratio X is the product of the magnification of each stretch.

The stretching temperature when dry-stretching a raw film to make a polarizer material film is preferably 100°C or higher, more preferably 110°C or higher, and preferably 150°C or lower, more preferably 140°C or lower. When the temperature of dry stretching is within the above range, a polarizer material film having a uniform film thickness is obtained.

The thickness T1 of the polarizer material film is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and is preferably 3 μm or more, more preferably 5 μm or more. A polarizing plate having a sufficiently high degree of polarization can be obtained when the thickness T1 of the polarizer material film is equal to or more than the lower limit of the above range, and resistance to bending of the polarizer can be effectively increased when it is equal to or less than the upper limit of the above range.

The retardation Re1 of the polarizer material film in the in-plane direction is preferably 10 nm or more, more preferably 50 nm or more, still more preferably 100 nm or more, preferably 500 nm or less, more preferably 400 nm or less. When the retardation Re1 in the in-plane direction of the polarizer material film is equal to or greater than the lower limit of the above range, the stretching ratio when the laminate is stretched to obtain a polarizing plate is suppressed low, and the retardation of the base material after the stretching process can be kept low. When the retardation Re1 in the in-plane direction of the polarizer material film is equal to or less than the upper limit of the above range, the draw ratio at the time of stretching the raw film to obtain the polarizer material film can be lowered, and generation of wrinkles when the raw film is stretched alone. problems can be avoided.

The Nz coefficient of the polarizer material film is preferably 0.95 or more, more preferably 0.99 or more, preferably 1.5 or less, and more preferably 1.4 or less. When the Nz coefficient is within the above range, a polarizer having a sufficient degree of polarization can be obtained.

The shape and dimensions of the polarizer material film can be appropriately adjusted according to the desired use. In terms of manufacturing efficiency, it is preferable that the polarizer material film is a long film.

[3. Process (b)]

A process (b) is a process of providing a base film on a polarizer material film and obtaining a layered product [A]. In the step (b), the polarizer material film and the base film can be bonded together with an adhesive, and the layer of the base film can be formed on the polarizer material film. In the manufacturing method of the present embodiment, an adhesive is used in step (b), but in the manufacturing method of the present invention, the adhesive is an optional component. Applying an adhesive between the polarizer material film and the base film is preferable in that problems such as peeling between both films can be prevented, but when sufficient adhesive strength is obtained between the polarizer material film and the base film without using an adhesive, No need to use adhesive.

[3.1. glue]

The adhesive for bonding the polarizer material film and the base film is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, polyester adhesives, polyvinyl alcohol adhesives, polyolefin adhesives, modified polyolefin adhesives, and polyvinyl adhesives. Alkyl ether adhesives, rubber adhesives, vinyl chloride-vinyl acetate adhesives, SEBS (styrene-ethylene-butylene-styrene copolymer) adhesives, ethylene-based adhesives such as ethylene-styrene copolymers, ethylene-methyl(meth)acrylate Acrylic acid ester type adhesives, such as a copolymer and an ethylene-ethyl (meth)acrylate copolymer, etc. can be used.

Adhesion-facilitating treatments, such as corona treatment, saponification treatment, priming treatment, and anchor coating treatment, may be given to the surface of the base film to be affixed to the polarizer material film.

[3.2. base film]

The base film is formed of resin. There is no limitation in particular as resin which forms a base film. The base film is preferably a film made of at least one selected from cycloolefin resins, amorphous polyester resins, polyolefin resins, and acrylic resins, and more preferably a film made of cycloolefin resins.

The cycloolefin resin forming the base film includes a cycloolefin-based polymer, and the cycloolefin-based polymer is a hydride of a ring-opening polymer of a norbornene-based monomer, an addition copolymer of a norbornene-based monomer and an α-olefin, and It is preferable that it is the hydride. Among these, as the cycloolefin-based polymer, an addition copolymer of a norbornene-based monomer and an α-olefin, and a hydride thereof are preferable from the viewpoint that phase difference is difficult to develop even when stretched. As a hydride of a ring-opening polymer of a norbornene-based monomer, an addition copolymer of a norbornene-based monomer and an α-olefin, and/or a hydride thereof, Japanese Unexamined Patent Publication No. 2-180976 and Japanese Unexamined Patent Publication No. 3-109418 , Japanese Unexamined Patent Publication No. Hei 3-223328, Japanese Unexamined Patent Publication No. Hei 4-301415, Japanese Unexamined Patent Publication No. Hei 5-212828, Japanese Unexamined Patent Publication No. Hei 7-145213, and the like.

Further, the cycloolefin resin forming the base film includes a cycloolefin-based polymer, and the cycloolefin-based polymer comprises a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, and an aromatic vinyl Polymer block [B] containing as main components the repeating unit [I] derived from the compound and the repeating unit [II] derived from the chain-like conjugated diene compound, or a polymer containing the repeating unit [II] derived from the chain-like conjugated diene compound as the main component It is preferably composed of a block copolymer hydrogenated product obtained by hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains of the block copolymer [D] composed of block [C], and the carbon-carbon unsaturated bonds of the aromatic ring. As such a block copolymer hydride, International Publication No. 2000/32646, International Publication No. 2001/081957, Japanese Laid-open Patent Publication No. 2002-105151, Japanese Laid-open Patent Publication 2006-195242, Japanese Laid-open Patent Publication 2011-13378 No., International Publication No. 2015/002020, etc., and the high molecular compound of description is mentioned.

[3.2.1. plasticizer and softener]

In this invention, it is preferable that a base film contains a plasticizer and/or a softener (any one or both of a plasticizer and a softener). By containing a plasticizer and/or a softener, the phase difference which arises in a base film when a polarizing plate is obtained by extending|stretching a laminated body can be made small.

As the plasticizer and softener, those that can be uniformly dissolved or dispersed in the resin forming the base film can be used. Specific examples of the plasticizer and softener include an ester-based plasticizer composed of a polyhydric alcohol and monohydric carboxylic acid (hereinafter referred to as a “polyhydric alcohol ester plasticizer”), and an ester-type plasticizer composed of polyhydric carboxylic acid and monohydric alcohol. ester plasticizers such as plasticizers (hereinafter referred to as "polyvalent carboxylic acid ester plasticizers"), phosphoric acid ester plasticizers, carbohydrate ester plasticizers, and other polymer softeners.

Examples of the polyhydric alcohol, which is a raw material of the ester plasticizer preferably used in the present invention, are not particularly limited, but ethylene glycol, glycerin, and trimethylolpropane are preferable.

Examples of polyhydric alcohol ester plasticizers include ethylene glycol ester plasticizers, glycerin ester plasticizers, and other polyhydric alcohol ester plasticizers.

Examples of polyvalent carboxylic acid ester plasticizers include dicarboxylic acid ester plasticizers and other polyvalent carboxylic acid ester plasticizers.

Specific examples of the phosphoric acid ester plasticizer include phosphoric acid alkyl esters such as triacetyl phosphate and tributyl phosphate; phosphoric acid cycloalkyl esters such as tricyclopentyl phosphate and cyclohexyl phosphate; Aryl esters of phosphoric acid, such as a triphenyl phosphate and a tricresyl phosphate, are mentioned.

Specific examples of the carbohydrate ester plasticizer include preferably glucospentaacetate, glucospentapropionate, glucospentabutyrate, saccharose octaacetate, saccharose octabenzoate and the like, among which saccharose octaacetate is more preferred. .

Specifically, as the polymer softener, aliphatic hydrocarbon-based polymers, alicyclic hydrocarbon-based polymers, polyethyl acrylate, polymethyl methacrylate, copolymers of methyl methacrylate and 2-hydroxyethyl methacrylate, methacrylic acid acrylic polymers such as copolymers of methyl acid, methyl acrylate, and 2-hydroxyethyl methacrylate; vinyl polymers such as polyvinylisobutyl ether and polyN-vinylpyrrolidone; styrenic polymers such as polystyrene and poly 4-hydroxystyrene; polyesters such as polybutylene succinate, polyethylene terephthalate, and polyethylene naphthalate; polyethers such as polyethylene oxide and polypropylene oxide; Polyamide, polyurethane, polyurea, etc. are mentioned.

Specific examples of the aliphatic hydrocarbon-based polymer include low molecular weight materials such as polyisobutylene, polybutene, poly-4-methylpentene, poly-1-octene, and ethylene/α-olefin copolymers, and hydrides thereof; Low molecular weight substances, such as polyisoprene and a polyisoprene-butadiene copolymer, and their hydrides, etc. are mentioned. From the standpoint of uniformly dissolving or dispersing in the cycloolefin resin, the aliphatic hydrocarbon-based polymer preferably has a number average molecular weight of 300 to 5,000.

These polymer softeners may be homopolymers composed of one type of repeating unit or copolymers having a plurality of repeating structures. Moreover, you may use the said polymer in combination of 2 or more types.

In the present invention, as the plasticizer and/or softener, ester-based plasticizers, aliphatic hydrocarbon-based polymers, and mixtures thereof are preferable.

The ratio of the plasticizer and/or softener (hereinafter also referred to as “plasticizer, etc.”) in the base film is preferably 0.2 part by weight or more, more preferably 0.5 part by weight, based on 100 parts by weight of the resin forming the base film. Above, more preferably 1.0 parts by weight or more, while preferably 40 parts by weight or less, more preferably 30 parts by weight or less. By making the ratio of a plasticizer etc. into the said range, even if a base film goes through the manufacturing process of the polarizing plate including an extending|stretching process, the appearance property of a phase difference can be made into a thing low enough.

[3.2.2. optional ingredient]

A base film may contain arbitrary components other than a resin and a plasticizer. Examples of the optional component include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; resin modifiers such as lubricants; coloring agents such as dyes and pigments; and antistatic agents. These compounding agents can be used individually by 1 type or in combination of 2 or more types, and the compounding quantity is suitably selected in the range which does not impair the objective of this invention.

[3.3. Manufacturing method of base film]

The base film can be produced by molding a composition (hereinafter, also referred to as “resin composition”) containing components (resin and components added as necessary) for forming the base film into a film shape by any molding method. can

Melt extrusion molding is mentioned as an example of the method of shape|molding a resin composition into a film shape. The melt extrusion step is performed by melting the resin composition with an extruder, extruding it into a film form from a T die attached to the extruder, forming the extruded film by adhering it to one or more cooling rolls, and taking it off. . Molding conditions in melt extrusion molding can be appropriately set according to conditions such as the composition and molecular weight of the resin composition to be used.

The thickness of the base film is preferably 5 μm or more, more preferably 10 μm or more, preferably 50 μm or less, and more preferably 30 μm or less. When the thickness of the base film is more than the lower limit of the above range, a laminate in a good bonding surface state can be obtained, and when the thickness of the base film is less than or equal to the upper limit of the above range, the phase difference generated in the base film is small when the laminate is stretched to obtain a polarizing plate. can do.

[3.4. Laminate [A]]

Fig. 3 is a cross-sectional view schematically showing a layered product [A] obtained through step (b). As shown in FIG. 3 , in this embodiment, the layered product 10 includes the stretched polarizer material film 11 , the adhesive layer 13 , and the base film 12 . In the manufacturing method of this invention, the structure which does not contain an adhesive bond layer may be sufficient as the laminated body obtained through process (b). In the present application, in order to distinguish the laminate [A] before stretching treatment in the process of producing a polarizing plate and the laminate after stretching treatment in the process of manufacturing a polarizing plate, the latter is referred to as "stretched laminate". is sometimes called.

[4. Process (c)]

Step (c) is a step of stretching the layered product [A] obtained through step (b) at a draw ratio Z in one or more directions. The method of stretching the layered product [A] is not particularly limited, but wet stretching is preferable.

The draw ratio Z of the layered product [A] in the step (c) is 1.2 or more and 5.0 or less, and satisfies the above-described formula (2) (1.2 ≤ Z ≤ 5.0). The draw ratio Z is preferably 1.5 or more, more preferably 2.0 or more, and preferably 4.5 or less, more preferably 4.0 or less. If the stretching ratio of the layered product [A] is equal to or less than the upper limit of the above range, even after the manufacturing process of the polarizing plate including the stretching treatment, the expression of the retardation of the base film is still low, and the occurrence of breakage of the polarizing plate can be prevented. And, when the stretching ratio is equal to or greater than the lower limit of the above range, a polarizing plate having sufficient polarization performance can be obtained.

In the present invention, the product of the draw ratio X in step (a) and the draw ratio Z of the layered product in step (c) (hereinafter also referred to as “draw ratio product”) is 5.1 or more and 9.0 or less. , which satisfies the above-described equation (3) (5.1 ≤ X * Z ≤ 9.0). The product (X*Z) of the stretching ratio is preferably 5.5 or more, more preferably 6.0 or more, and is preferably 8.0 or less, more preferably 7.0 or less. When the product of the stretching ratio is equal to or less than the upper limit of the range, even after the manufacturing process of the polarizing plate including the stretching treatment, the expression of the retardation of the base film is lowered, and the occurrence of breakage of the polarizing plate can be prevented, and the stretching ratio A polarizing plate having sufficient polarization performance can be obtained if it is set to the lower limit of the above range or more.

The stretching temperature of the layered product [A] in step (c) is not particularly limited. For example, when using a polyvinyl alcohol-based resin as the material of the polarizer, the specific stretching temperature is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, particularly preferably 60 ° C. or higher, and preferably 160°C or lower, more preferably 120°C or lower, particularly preferably 110°C or lower. When the extending|stretching temperature is equal to or more than the lower limit of the said range, extending|stretching can be performed smoothly, and, when it is equal to or less than the upper limit of the said range, effective orientation can be performed by extending|stretching. The range of the stretching temperature is preferable for either dry stretching or wet stretching, but is particularly preferable in the case of wet stretching.

The stretching treatment of the layered product [A] in step (c) is a treatment including stretching in at least one direction, and may include stretching in only one direction or stretching in two or more directions. As the stretching treatment of the layered product [A], uniaxial stretching is preferably performed, free end uniaxial stretching is more preferable, and free end uniaxial stretching in the vertical direction is particularly preferable. In the stretching process involving only one-way stretching, stretching is performed so that the stretching ratio of the stretching falls within the range of the above-described predetermined stretching ratio. Further, in the stretching treatment including stretching in two or more directions, stretching is performed so that the product of the stretching ratios of each stretching falls within the range of the aforementioned predetermined stretching ratio. In the stretching treatment including stretching in two or more directions, the stretching may be performed simultaneously or sequentially.

The relationship between the stretching direction in step (a) and the stretching direction in step (c) will be described. The stretching direction of the raw film in the step (a) and the stretching direction of the layered product [A] in the step (c) are not particularly limited, but can be set to the aspects shown in the following (1) to (6) there is. In the present application, in the calculation of θ1 and θ2 described below, when stretching is performed in two or more directions in one process, the stretching direction of the larger stretching ratio is used as the stretching direction in the process. Also, θ1 and θ2 may include tolerances within a range not impairing the effects of the present invention. For example, when θ1 and θ2 are 0° or 90°, a tolerance of ±0.5° may be included.

Angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film, and angle θ2 formed by the stretching direction and the width direction of the layered product [A] in the step (c) can be made into the following aspects.

(1) θ1 is 90° and θ2 is 90°.

(2) θ1 is 0° and θ2 is 0°.

(3) Among θ1 and θ2, either one is 90° and the other is 0°.

(4) θ1 is 90° and θ2 (°) satisfies Expression (4) below.

θ2 ≠ 90 … (4)

(5) θ1 (°) satisfies the following formula (5), and θ2 is 90°.

θ1 ≠ 90 … (5)

(6) θ1 (°) and θ2 (°) satisfy the following formula (6) and the following formula (7).

θ1 ≠ 90 … (6)

θ2 ≠ 90 … (7)

The above aspect (1) is preferable when the application of the polarizing plate is a polarizing plate for a liquid crystal display device, and (4) to (6) are preferable when the polarizing plate is for an EL display device.

In aspects (4) to (6), the absolute value of the difference between θ1 and θ2 is preferably 50 or less, more preferably 30 or less, and even more preferably 10 or less.

[5. Process (d)]

A process (d) is a process of dyeing a polarizer material film with a dichroic substance. Although the manufacturing method of this embodiment includes the process (d), it is an arbitrary process in the manufacturing method of this invention. Step (d) may be performed after step (b) or before step (c). In addition, dyeing of the polarizer material film may be performed with respect to the polarizer material film before forming the layered product [A]. By passing through a process (c) and a process (d), a polarizer material film is extended|stretched and dyed arbitrarily, and as a result, it becomes a film which can function as a polarizer.

Iodine, an organic dye, etc. are mentioned as a dichroism substance which dye|stains the polarizer material film in a process (d). A dyeing method using these dichroic substances is arbitrary. For example, dyeing may be performed by immersing the layer of the polarizer material film in a dyeing solution containing a dichroic substance. In addition, when using iodine as a dichroic substance, from a viewpoint of improving dyeing efficiency, a dyeing solution may contain iodides, such as potassium iodide.

Although there is no particular restriction on the dichroic substance, organic dyes are preferable as the dichroic substance when the polarizing plate is used in a vehicle-mounted display device.

[6. Characteristics of each layer in polarizing plate]

Through process (a) - process (d), the polarizing plate of this embodiment is obtained.

Thickness T of the polarizer material film after passing through a process (c) (after laminated body extension) is 20 micrometers or less. The thickness T of the polarizer material film is preferably 15 μm or less, more preferably 10 μm or less, preferably 1 μm or more, and more preferably 3 μm or more. When the thickness T is equal to or less than the upper limit value, the thickness of the polarizing plate can be reduced, and when the thickness T is equal to or greater than the lower limit value, a polarizing plate having a sufficiently high degree of polarization can be obtained.

It is preferable that the retardation Re of the in-plane direction of the base film after passing through the process (c) is 20 nm or less. The retardation Re of the in-plane direction of the base film is more preferably 15 nm or less, still more preferably 10 nm or less, and preferably 0 nm or more. When the retardation Re of the in-plane direction of the base film is within the above range, even if the base film passes through the manufacturing process of a polarizing plate including stretching treatment, the occurrence of retardation can be sufficiently low.

[7. Effects of the present embodiment]

According to this embodiment, since a polarizing plate is manufactured by extending|stretching the laminated body [A] containing the prestretched polarizer material film obtained by process (a), when the polarizing plate is manufactured by extending|stretching the laminated body [A] The draw ratio of can be made low. Thereby, since the expression of the phase difference in the base film after carrying out the extending|stretching process of layered product [A] can be suppressed, it can be used as a protective film of one side of a polarizer material film as it is, without peeling a base film, and also , can reduce wasted materials. In addition, in this embodiment, since the prestretched polarizer material film obtained by process (a) is used, when laminating a base film on a polarizer material film to make a layered product [A], the unstretched polarizer material film As in the case of use, a base film having a very wide width is unnecessary, and the polarizing plate can be manufactured efficiently. From the above, according to this embodiment, a base film can be used also as a protective film, and even if thickness is thin, the manufacturing method of the polarizing plate which can manufacture efficiently can be provided.

[Embodiment 2: Manufacturing method of polarizing plate]

A method for manufacturing a polarizing plate according to Embodiment 2 of the present invention will be described with reference to FIG. 5 .

5 is a cross-sectional view schematically showing a polarizing plate 120 obtained by a method for manufacturing a polarizing plate according to Embodiment 2 of the present invention. In this polarizing plate 120, as shown in FIG. 5, a base film 112 is laminated on one side (upper side in the figure) of the polarizer material film 111, and the other side of the polarizer material film 111 is laminated. A protective film 115 is laminated on the surface side (lower surface in the illustration). In Fig. 5, 113 and 114 are adhesive layers. The same thing as the adhesive agent which bonds a base film to a polarizer material film can be used for the adhesive agent for bonding a protective film to a polarizer material film.

The method for manufacturing the polarizing plate 120 according to the present embodiment is to the polarizer material film of the stretched laminate after the above-described steps (a), (b), (d), and (c), and the step (c). , Step (e1) of bonding the protective film together directly or through an adhesive agent.

Specifically, as shown in FIG. 4 , the polarizing plate 100 of Embodiment 1 is conveyed to the bonding device 308, and on the surface of the polarizer material film 111 on the side where the base film 112 is not laminated. The polarizing plate 120 provided with the protective film 115 is obtained by apply|coating adhesive and bonding it with the protective film 115 unwound from the unwinding apparatus 307 (process (e1)). The manufactured polarizing plate 120 is wound up by the winding device 310 and can be used in an additional step in the form of a roll.

Embodiment It has the same action and effect as 1.

[Embodiment 3: Manufacturing method of polarizing plate]

A method for manufacturing a polarizing plate according to Embodiment 3 of the present invention will be described with reference to FIG. 6 .

6 is a cross-sectional view schematically showing a polarizing plate 130 obtained by a method for manufacturing a polarizing plate according to Embodiment 3 of the present invention. In this polarizing plate 130, as shown in FIG. 6, a base film 112 is laminated on one side (upper side in the figure) of the polarizer material film 111, and the other side of the polarizer material film 111 is laminated. An adhesive layer 116 is laminated on the surface side (lower surface shown).

The manufacturing method of the polarizing plate of this embodiment forms an adhesive layer in the polarizer material film of the stretched laminate after the above-mentioned process (a), process (b), process (d), process (c), and process (c) It includes the step (e2) of doing.

As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, commercially available various pressure-sensitive adhesives, for example, pressure-sensitive adhesives containing acrylic polymers as a polymer as a main component can be used.

In the polarizing plate 130 according to Embodiment 3, for example, a commercially available adhesive is applied to the surface of the polarizing plate 100 of Embodiment 1 on which the base film 112 of the polarizer material film 111 is not laminated. It is obtained by transferring an adhesive layer from a layered film (for example, "Mastag series" manufactured by Fujimori Industries) to form an adhesive layer.

Embodiment It has the same action and effect as 1.

[liquid crystal display device]

The polarizing plate obtained by the manufacturing method of the polarizing plate of the present invention can be a material for a liquid crystal display device.

Usually, a liquid crystal display device includes a light source, a light source-side polarizing plate, a liquid crystal cell, and a viewer-side polarizing plate in this order, but the polarizing plate obtained by the present invention may be used for either the light source-side polarizing plate or the viewing-side polarizing plate.

As a driving method of the liquid crystal cell, for example, in-plane switching (IPS) mode, vertical alignment (VA) mode, multi-domain vertical alignment (MVA) mode, continuous pinwheel alignment (CPA) mode, hybrid alignment nematic ( HAN) mode, twisted nematic (TN) mode, super twisted nematic (STN) mode, and optically compensated bend (OCB) mode.

[Embodiment 4: Manufacturing method of liquid crystal display device]

A method of manufacturing a display device according to Embodiment 4 provided with a polarizing plate obtained by the manufacturing method of the present invention will be described with reference to FIG. 7 . In this embodiment, a display device is manufactured by laminating the polarizing plate of the present invention on a liquid crystal panel as a light source side polarizing plate and a viewing side polarizing plate, respectively.

7 is a cross-sectional view schematically showing a liquid crystal display device 400 obtained by a manufacturing method according to Embodiment 4. As shown in FIG. As shown in FIG. 7 , the liquid crystal display device 400 is disposed outside the two substrates 410 and 420 and the liquid crystal layer 430 positioned therebetween, and the two substrates 410 and 420, respectively. It has a polarizing plate (100, 100) to be. The two polarizing plates 100 are the polarizing plates of Embodiment 1. As shown in FIG. 7 , two polarizing plates 100 are laminated so that the base film 112 is disposed between the polarizer material film 111 and the liquid crystal layer 430, respectively, as shown in FIG. 7 . there is.

According to this embodiment, a base film can be used also as a protective film, and the manufacturing method of the display apparatus provided with the polarizing plate of this invention which can manufacture efficiently even if thickness can be thin can be provided.

[Embodiment 5: Manufacturing method of liquid crystal display device]

A manufacturing method of a display device according to Embodiment 5 provided with a polarizing plate obtained by the manufacturing method of the present invention will be described with reference to FIG. 8 . In this embodiment, a display device is manufactured by using the polarizing plate of the present invention as one of the light source side polarizing plate and the viewer side polarizing plate, and laminating the polarizing plate on a liquid crystal panel.

8 is a cross-sectional view schematically showing a liquid crystal display device 450 obtained by a manufacturing method according to Embodiment 5 of the present invention. As shown in FIG. 8 , the liquid crystal display device 450 is disposed on the outer side (lower side of the drawing) of the two substrates 410 and 420, the liquid crystal layer 430 located therebetween, and the lower substrate 410. It has a polarizing plate 120 to be. The polarizing plate 120 is the polarizing plate of Embodiment 2. As shown in FIG. 8 , the polarizing plate 120 is laminated so that the base film 112 is disposed between the polarizer material film 111 and the liquid crystal layer 430 .

According to this embodiment, a base film can be used also as a protective film, and the manufacturing method of the display apparatus provided with the polarizing plate of this invention which can manufacture efficiently even if thickness can be thin can be provided.

[EL Display Device]

A polarizing plate obtained by the manufacturing method of a polarizing plate of the present invention can be a material for an EL display device.

Usually, an organic EL display device includes a substrate, a transparent electrode, a light emitting layer, and a metal electrode layer in order from the light output side, but the polarizing plate obtained by the manufacturing method of the present invention is disposed on the light output side of the substrate.

An EL display device has two substrates, a light emitting layer positioned between them, and a polarizing plate disposed outside one of the two substrates. The display device can be manufactured by laminating the polarizing plate of the present invention on an organic EL panel or an inorganic EL panel.

[Embodiment 6: Manufacturing method of organic EL display device]

A manufacturing method of a display device according to Embodiment 6 provided with a polarizing plate obtained by the manufacturing method of the present invention will be described with reference to FIG. 9 . In this embodiment, a display device is manufactured by laminating the polarizing plate of this invention on an organic electroluminescent panel.

Fig. 9 is a cross-sectional view schematically showing an organic EL display device 500 obtained by a manufacturing method according to Embodiment 6 of the present invention. The organic EL display device 500 includes two substrates 510 and 520, a light emitting layer 530 disposed between them, and a polarizing plate 100 disposed outside (lower side of the illustration) of the lower substrate 510. have The polarizing plate 100 is the polarizing plate of Embodiment 1. As shown in FIG. 9 , the polarizing plate 100 is laminated so that the base film 112 is disposed between the polarizer material film 111 and the light emitting layer 530 .

According to this embodiment, the display device provided with the polarizing plate of this invention which can use a base film also as a protective film and can manufacture efficiently even if thickness is thin can be provided.

[Embodiment 7: Manufacturing method of organic EL display device]

A method for manufacturing a display device according to Embodiment 7 provided with a polarizing plate obtained by the manufacturing method of the present invention will be described with reference to FIG. 10 . In this embodiment, a display device is manufactured by laminating the polarizing plate of this invention on an organic electroluminescent panel.

Fig. 10 is a cross-sectional view schematically showing an organic EL display device 550 obtained by a manufacturing method according to Embodiment 7 of the present invention. The organic EL display device 550 includes two substrates 510 and 520, a light emitting layer 530 disposed therebetween, and a polarizing plate 120 disposed outside (lower side of the illustration) of the lower substrate 510. have The polarizing plate 120 is the polarizing plate of Embodiment 2. As shown in FIG. 10 , the polarizing plate 120 is laminated so that the base film 112 is disposed between the polarizer material film 111 and the light emitting layer 530 .

According to this embodiment, the display device provided with the polarizing plate of this invention which can use a base film also as a protective film and can manufacture efficiently even if thickness is thin can be provided.

[Other Embodiments]

(1) In Embodiment 4, it was shown that the polarizing plate of Embodiment 1 was used for the light source-side polarizing plate and the viewer-side polarizing plate, respectively. You may use two polarizing plates of 3.

(2) In Embodiment 5, the polarizing plate of Embodiment 2 is used as one of the light source-side polarizing plate and the viewer-side polarizing plate, but the polarizing plate of Embodiment 1 or 3 may be used.

(3) In Embodiments 6 and 7, examples were shown in which the polarizing plate of Embodiment 1 and the polarizing plate of Embodiment 2 were respectively used in the organic EL display device, but are not limited thereto. For example, you may use the polarizing plate of Embodiment 3 for an inorganic EL display device.

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 the following Examples. In the following, "parts" and "%" regarding the quantity ratio of components represent parts by weight unless otherwise indicated.

[Assessment Methods]

[Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn)]

The molecular weight of the block copolymer and block copolymer hydride was measured at 38°C as a standard polystyrene equivalent value by GPC using THF as an eluent. As a measuring device, Tosoh Corporation HLC8020GPC was used.

[Hydrogenation rate]

The hydrogenation rate of the block copolymer hydride was calculated by ¹ H-NMR spectrum or GPC analysis. The region with a hydrogenation rate of 99% or less was calculated by measuring the ¹ H-NMR spectrum, and the region with a hydrogenation rate of 99% or less was calculated from the ratio of the peak areas by the UV detector and the RI detector by GPC analysis.

[Method of measuring in-plane phase difference Re and Nz coefficient]

Re and Rth were measured at a wavelength of 590 nm using a retardation measuring device (manufactured by Axometric, product name "Axoscan"), and the Nz coefficient was determined based on them.

[Thickness measurement method]

The thickness of the raw film before and after stretching, the thickness of the base film, and the thickness of each layer included in the polarizing plate were measured by the following method.

After cutting the polarizing plate using a microtome, the cross section was observed using TEM. The size in the thickness direction was measured at five locations, and the average of the measured values was adopted as the thickness.

[Evaluation of bonding surface state of laminate]

The laminate was visually observed, and those without streaks or voids were rated "good", and those with occurrence were rated "poor".

[Measurement of degree of polarization]

The single transmittance (Ts), the parallel transmittance (Tp), and the orthogonal transmittance (Tc) of the polarizing plate were measured using an ultraviolet and visible spectrophotometer (manufactured by Nippon Spectroscopy Co., Ltd., product name "V7100"), and the degree of polarization (P) was determined by the following equation saved by On the other hand, Ts, Tp, and Tc are Y values obtained by measuring with a 2-degree field of view (C light source) in accordance with JIS Z 8701 and performing visibility correction.

Polarization degree (P) (%) = {(Tp - Tc)/(Tp + Tc)} ^1/2 × 100

On the other hand, the measurement was performed by arranging the polarizer material film side of the polarizing plate to be the light incident side.

[Evaluation of stretchability]

Process stability in the process of producing a polarizing plate by stretching the laminate was evaluated according to the following criteria.

A... Breakage does not occur (0 breakage after 10 notifications).

B... Breakage rarely occurs (1 break after 10 notifications).

C... Breakage occurs frequently and polarization cannot be performed.

[Example 1]

(1-1) Preparation of base film

(1 - 1 - 1) Preparation of Polymer X

Referring to the production example described in Japanese Laid-open Patent Publication No. 2002 - 105151, 25 parts of styrene monomer was polymerized in the first step, 30 parts of styrene monomer and 25 parts of isoprene monomer were polymerized in the second step, then in the third step After polymerizing 20 parts of the styrene monomer to obtain a block copolymer [D1], the block copolymer was hydrogenated to synthesize a block copolymer hydrogenated product [E1]. The block copolymer hydride [E1] had Mw of 84,500, Mw/Mn of 1.20, and hydrogenation rates of the main chain and aromatic rings were approximately 100%.

To 100 parts of block copolymer hydride [E1], as an antioxidant, pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (Matsubara Sangyo Co., Ltd.) Production, product name "Songnox1010") 0.1 part was melt-kneaded and blended, and then formed into pellets to obtain Polymer X for molding.

(1 - 1 - 2) Preparation of base film A

Polymer X prepared in (1-1-1) was supplied to a hot melt extrusion film molding machine equipped with a T die. The polymer X was formed into a film by extruding the polymer X from the T die and winding it around a roll at a take-up speed of 4 m/min. In this way, a long substrate film A (thickness: 20 μm) made of the polymer X was obtained.

(1-2) Manufacture of polarizer material film (step (a))

As a raw film, an unstretched polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol%, thickness of 20 μm, also referred to as “PVA20” below) was used.

The raw film was dry stretched at a draw ratio of 3.0 in the longitudinal direction at a stretching temperature of 130°C using a longitudinal uniaxial stretching machine to obtain a polarizer material film. The thickness T1 of the polarizer material film was 12 μm, the retardation Re1 in the in-plane direction was 345 nm, and the Nz coefficient was 1.0.

(1-3) Manufacture of laminate (step (b))

100 parts by weight of water, 3 parts by weight of a polyvinyl alcohol-based adhesive (“Z-200” manufactured by Nippon Synthetic Chemical Co., Ltd.), and 0.3 parts by weight of a crosslinking agent (“SPM-01” manufactured by Nippon Synthetic Chemical Co., Ltd.) were mixed to obtain an adhesive composition. Corona treatment was performed on one side of the base film A obtained in (1-1-2), and this adhesive composition was coated thereon, and bonded to one side of the polarizer material film. In this state, the adhesive composition was heat-dried at 70 degreeC for 5 minutes. Thereby, a layered product [A] having a layer structure of "polarizer material film"/"adhesive layer"/"substrate film A" was obtained. The thickness of the adhesive layer was 1 μm. In the layered product [A], the base film A is an unstretched film.

The bonding surface state of the obtained layered product [A] was evaluated. The results are shown in Table 1.

(1-4) Production of polarizing plate (wet) (step (d), step (c))

The following operation was performed while continuously conveying the layered product [A] obtained in (1-3) in the longitudinal direction through a guide roll.

A dyeing treatment of immersing the layered product [A] in a dyeing solution containing iodine and potassium iodide and a first stretching treatment of stretching the layered product after the dyeing treatment were performed. Next, a second stretching treatment was performed in which the layered product after the first stretching treatment was stretched in a 65°C acidic bath containing boric acid and potassium iodide. The total draw ratio represented by the product of the draw ratio in the first stretching treatment and the draw ratio in the second stretching treatment was set to be 2.0. The stretching direction in the first stretching treatment and the second processing was both set to the longitudinal direction (longitudinal uniaxial stretching, θ2 = 90°).

The stretched laminate after the second stretching treatment was dried in a dryer at 70°C for 5 minutes to obtain a polarizing plate. Measure the thickness of the polarizing plate (total thickness), the thickness of the base film in the polarizing plate (substrate thickness) and retardation Re (substrate Re), the thickness T of the polarizer material film, and the degree of polarization (%) at a single transmittance of 42.8%. Thus, it is shown in Table 1 together with the evaluation results of the stretchability.

[Example 2]

Except for using the polarizer material film obtained in the following (2-2) instead of the polarizer material film obtained in (1-2), a polarizing plate was manufactured in the same manner as in Example 1, and evaluated in the same manner as in Example 1, , the results are shown in Table 1.

(2-2) Preparation of polarizer material film

As a raw film, an unstretched polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol%, thickness of 30 μm, also referred to as “PVA30” below) was used.

A raw film (PVA30) was stretched at a draw ratio of 3.0 in the longitudinal direction at a stretching temperature of 130°C using a longitudinal uniaxial stretching machine, to obtain a polarizer material film. Thickness T1 of the polarizer material film was 17 μm, and Re1 was 520 nm.

[Example 3]

Instead of the polarizer material film obtained in (1-2), the laminate [A] was manufactured using the polarizer material film obtained in the following (3-2), and the draw ratio was changed in (1-4) And, thereby, a polarizing plate was manufactured in the same manner as in Example 1 except that the total draw ratio was changed to 3.0, and evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(3-2) Manufacture of Polarizer Material Film

The raw film (PVA20) was stretched at a fixed end at a stretching ratio of 2.0 in the longitudinal direction at a stretching temperature of 130°C using a tenter stretching machine, to obtain a polarizer material film. Thickness T1 of the polarizer material film was 10 μm, and Re1 was 280 nm (biaxial longitudinal stretching).

[Example 4]

Using the polarizer material film obtained in (4-2) below instead of the polarizer material film obtained in (1-2), a polarizing plate was produced by the method of (4-3) and the method of (4-4) below. And, evaluation was performed in the same way as in Example 1, and the results are shown in Table 1.

(4-2) Manufacture of Polarizer Material Film

The raw film (PVA20) was stretched at a draw ratio of 3.0 in the width direction at a stretching temperature of 130°C using a tenter stretching machine to obtain a polarizer material film. Thickness T1 of the polarizer material film was 7 μm, and Re1 was 240 nm (transverse uniaxial stretching).

(4-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (4-2) instead of the polarizer material film obtained in (1-2), in the same manner as in (1-3), "polarizer material film" / "adhesive layer" / "base film A layered product [A] having a layer structure of "A" was obtained.

(4 - 4) Manufacture of polarizer

The laminate [A] obtained in (4-3) was used instead of the laminate [A] obtained in (1-3), and the stretching ratio and the stretching direction were changed, thereby changing the total stretching ratio to 2.0. And a polarizing plate was prepared in the same manner as in (1-4) except that the stretching direction was changed to transverse uniaxial stretching (θ2 = 0 °).

[Example 5]

Instead of the polarizer material film obtained in (1-2), using the polarizer material film obtained in the following (5-2), a polarizing plate was produced by the method of (5-3) and the method of (5-4) And, evaluation was performed in the same way as in Example 1, and the results are shown in Table 1.

(5-2) Manufacture of Polarizer Material Film

The raw film (PVA20) was stretched at a draw ratio of 1.5 in the width direction at a stretching temperature of 130°C using a tenter stretching machine to obtain a polarizer material film. Thickness T1 of the polarizer material film was 13 μm, and Re1 was 250 nm (transverse uniaxial stretching).

(5-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (5-2) instead of the polarizer material film obtained in (1-2), in the same manner as in (1-3), "polarizer material film" / "adhesive layer" / "base film A layered product [A] having a layer structure of "A" was obtained.

(5 - 4) Manufacture of polarizer

Except that the laminate [A] obtained in (5-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 5.0. A polarizing plate was prepared in the same manner as in (1-4).

[Example 6]

Using the polarizer material film obtained in (6-2) below instead of the polarizer material film obtained in (1-2), a polarizing plate was produced by the method of (6-3) and the method of (6-4) below. And, evaluation was performed in the same way as in Example 1, and the results are shown in Table 1.

(6-2) Manufacture of Polarizer Material Film

Except having stretched the raw film (PVA20) by the draw ratio of 1.5, it carried out similarly to (1-2), and obtained the polarizer material film. Thickness T1 of the polarizer material film was 16 μm, and Re1 was 345 nm.

(6-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (6-2) instead of the polarizer material film obtained in (1-2), in the same manner as in (1-3), "polarizer material film" / "adhesive layer" / "base film A layered product [A] having a layer structure of "A" was obtained.

(6 - 4) Manufacture of polarizer

The laminate [A] obtained in (6-3) was used instead of the laminate [A] obtained in (1-3), and the stretching ratio and the stretching direction were changed, thereby changing the total stretching ratio to 5.0. And a polarizing plate was prepared in the same manner as in (1-4) except that the stretching direction was changed to transverse uniaxial stretching (θ2 = 0 °).

[Example 7]

Using the laminate [A] obtained in (1-3), a polarizing plate was manufactured by the method of (7-4) below, evaluated in the same manner as in Example 1, and the results are shown in Table 2.

(7 - 4) Manufacture of polarizer

The layered product [A] obtained in (1-3) was stretched in an oblique direction (θ2 = 45°) at a stretching temperature of 110° C. so that the stretch ratio was 1.8. The stretched laminate was dyed by being immersed in a dyeing solution containing iodine, potassium iodide and boric acid, and dried with warm air at 60°C. Next, the dyed layered product was stretched in an oblique direction (θ2 = 45°) at a stretching temperature of 90° C. so that the draw ratio was 1.1 to obtain a polarizing plate (dry oblique stretching).

[Example 8]

Except for using the polarizer material film obtained in the following (8-2) instead of the polarizer material film obtained in (1-2), a polarizing plate was manufactured in the same manner as in Example 1, and evaluation was carried out in the same manner as in Example 1. and the results are shown in Table 2.

(8-2) Manufacture of Polarizer Material Film

The raw film (PVA20) was stretched in an oblique direction (θ1 = 45°) at a stretching ratio of 3.0 at a stretching temperature of 130° C. using a tenter stretching machine for oblique stretching to obtain a polarizer material film. Thickness T1 of the polarizer material film was 7 µm, and Re1 was 310 nm.

[Example 9]

Using the polarizer material film obtained in (9-2) below instead of the polarizer material film obtained in (1-2), a polarizing plate was produced by the method of (9-3) and the method of (9-4) below. And, evaluation was performed in the same way as in Example 1, and the results are shown in Table 2.

(9-2) Manufacture of Polarizer Material Film

The raw film (PVA20) was stretched in an oblique direction (θ1 = 45°) at a stretching ratio of 3.0 at a stretching temperature of 130° C. using a tenter stretching machine for oblique stretching, to obtain a polarizer material film. Thickness T1 of the polarizer material film was 7 µm, and Re1 was 310 nm.

(9-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (9-2) instead of the polarizer material film obtained in (1-2), in the same manner as in (1-3), "polarizer material film" / "adhesive layer" / "base film A layered product [A] having a layer structure of "A" was obtained.

(9 - 4) Manufacture of polarizer

The laminate [A] obtained in (9 - 3) was used instead of the laminate [A] obtained in (1 - 3), and the stretching ratio was 1.8 at a stretching temperature of 110 ° C in an oblique direction (θ2 = 45 °). stretched to The stretched laminate was dyed by being immersed in a dyeing solution containing iodine, potassium iodide and boric acid, and dried with warm air at 60°C. Next, the dyed layered product was stretched in an oblique direction (θ2 = 45°) at a stretching temperature of 90° C. so that the draw ratio was 1.1 to obtain a polarizing plate (dry oblique stretching).

[Example 10]

(10-1) Preparation of Base Film B

In (1-1-2), except that the conditions for extrusion molding the polymer X were changed so that the thickness was 25 μm, in the same manner as in (1-1), a long base film B made of the polymer X ( thickness of 25 μm) was obtained.

(10 - 2) Preparation of polarizer material film

Except having changed the draw ratio to 1.5, it carried out similarly to (1-2) of Example 1, and obtained the polarizer material film. Thickness T1 of the polarizer material film was 16 μm, and Re1 was 230 nm.

(10 - 3) laminate [A]

(1-3) except that the polarizer material film obtained in (10-2) was used instead of the polarizer material film obtained in (1-2) and the base film B obtained in (10-1) was used instead of the base film A. In the same manner as, a layered product [A] having a layer structure of "polarizer material film"/"adhesive layer"/"substrate film B" was obtained.

(10 - 4) Manufacture of polarizer

Except that the laminate [A] obtained in (10-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 4.5. A polarizing plate was manufactured in the same manner as in Example 1 (1-4), evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[Example 11]

(11-2) Preparation of polarizer material film

Except having changed the draw ratio to 5.5, it was carried out similarly to (1-2), and the polarizer material film was obtained. Thickness T1 of the polarizer material film was 9 μm, and Re1 was 325 nm.

(11 - 3) Laminate [A]

Except for using the polarizer material film obtained in (11-2) instead of the polarizer material film obtained in (1-2) and using the base film B obtained in (10-1) instead of the base film A, (1-3) In the same manner as, a layered product [A] having a layer structure of "polarizer material film"/"adhesive layer"/"substrate film B" was obtained.

(11-4) Manufacture of polarizer

Except that the laminate [A] obtained in (11-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 1.2. A polarizing plate was manufactured in the same manner as in Example 1 (1-4), evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[Example 12]

(12-2) Manufacture of Polarizer Material Film

Except having stretched the raw film (PVA20) by the draw ratio of 3.5, it carried out similarly to (1-2), and obtained the polarizer material film. Thickness T1 of the polarizer material film was 11 µm, and Re1 was 340 nm.

(12 - 3) Laminate [A]

Except for using the polarizer material film obtained in (12-2) instead of the polarizer material film obtained in (1-2) and using the base film B obtained in (10-1) instead of the base film A, (1-3) In the same manner as, a layered product [A] having a layer structure of "polarizer material film"/"adhesive layer"/"substrate film B" was obtained.

(12 - 4) Manufacture of polarizer

Except that the laminate [A] obtained in (12-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 2.5. A polarizing plate was manufactured in the same manner as in Example 1, evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[Example 13]

(13-2) Manufacture of Polarizer Material Film

Except having changed the draw ratio to 2.6, it was carried out similarly to (1-2), and the polarizer material film was obtained. Thickness T1 of the polarizer material film was 12 μm, and Re1 was 335 nm.

(13 - 3) Laminate [A]

Except for using the polarizer material film obtained in (13-2) instead of the polarizer material film obtained in (1-2) and using the base film B obtained in (10-1) instead of the base film A, (1-3) In the same manner as, a layered product [A] having a layer structure of "polarizer material film"/"adhesive layer"/"substrate film B" was obtained.

(13 - 4) Manufacture of polarizer

Except for using the laminate [A] obtained in (13-3) instead of the laminate [A] obtained in (1-3), a polarizing plate was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. and the results are shown in Table 3.

[Example 14]

A polarizing plate was prepared in the same manner as in Example 1 except for using the base film D obtained in (14-1) below instead of the base film A obtained in (1-1), and evaluated in the same manner as in Example 1. , the results are shown in Table 3.

(14-1) Preparation of base film D

Polymer X prepared in (1-1-1) and polyisobutene added at a rate of 20 parts by weight based on 100 parts by weight of Polymer X ("Nisseki Polybutene HV-300" manufactured by JX Nikko Nippon Energy Co., Ltd., water Average molecular weight 1,400) was fed to a hot melt extrusion film forming machine equipped with a T die. A mixture of Polymer X and polyisobutene was extruded from a T die and wound on a roll at a take-up speed of 4 m/min to obtain a base film D forming a long film shape (thickness: 25 µm).

[Example 15]

Using the layered product [A] obtained in the following (15-3), a polarizing plate was manufactured by the method of the following (15-4), evaluated in the same manner as in Example 1, and the results were shown in Table 3.

(15-3) Manufacture of laminate [A]

Except for using the base film B instead of the base film A, it was carried out in the same manner as (1-3), "polarizer material film" / "adhesive layer" / "base film B" Layered body having a layer structure [A] was obtained .

(15 - 4) Manufacture of polarizer

The following operation was performed while continuously conveying the layered product [A] obtained in (15-3) in the longitudinal direction through a guide roll.

Dyeing treatment of immersing the laminate [A] in a dyeing solution containing C.I. Direct Red 81, sodium tripolyphosphate, and anhydrous sodium sulfate, and a first step of stretching the laminate [A] subjected to the dyeing treatment Stretching treatment was performed. Next, a second stretching treatment was performed in which the stretched laminate [A] was stretched in a 65°C acidic bath containing boric acid. The total draw ratio represented by the product of the draw ratio in the first stretching treatment and the draw ratio in the second stretching treatment was set to be 2.0 times. Thereafter, the stretched layered product [A] was dried in a dryer at 70°C for 5 minutes to obtain a polarizing plate.

[Example 16]

Using the layered product [A] obtained in (16-3), a polarizing plate was manufactured by the method of (16-4) below, evaluated in the same manner as in Example 1, and the results are shown in Table 3.

(16-3) Manufacture of laminate [A]

Except for using the base film B instead of the base film A, it was carried out in the same manner as (1-3), "polarizer material film" / "adhesive layer" / "base film B" Layered body having a layer structure [A] was obtained .

(16 - 4) Manufacture of polarizer

The layered product [A] obtained in (16-3) was subjected to a dyeing treatment by immersing the laminate [A] in a dyeing solution containing C.I. Direct Red 81, sodium tripolyphosphate, and anhydrous sodium sulfate, in a dryer at 70°C for 5 minutes. dried. The treated material of the obtained layered product [A] was stretched at a stretching ratio of 2.0 in the longitudinal direction at a stretching temperature of 110°C using a longitudinal uniaxial stretching machine. Subsequently, crosslinking treatment was performed by immersing in an acidic bath containing boric acid, and drying was performed at 70°C for 5 minutes to obtain a polarizing plate. The thickness of the base film was 18 μm, and the phase difference was 1 nm. In addition, the thickness of the polarizer material film of the stretched laminate was 8 μm.

[Example 17]

A polarizing plate was manufactured by the following method, and evaluation was performed in the same manner as in Example 1, and the results were shown in Table 3.

(17-1) Preparation of Base Film E

An acrylic resin (Sumipex HT55X, manufactured by Sumitomo Chemical Co., Ltd.) was supplied to a hot melt extrusion film molding machine equipped with a T die. The acrylic resin was molded into a film by extruding the acrylic resin from the T die and winding it around a roll at a take-up speed of 4 m/min. In this way, a long base film E (thickness: 25 µm) made of an acrylic resin was obtained.

(17-3) Manufacture of laminate [A]

In (1-3), except that the base film E prepared in (17-1) was used instead of the base film A, in the same manner as in (1-3) of Example 1, the polarizer material film / adhesive layer / base film A layered product [A] having the layer structure of E was obtained.

(17 - 4) Manufacture of polarizer

The layered product [A] obtained in (17-3) was stretched using a longitudinal uniaxial stretching machine at a stretching temperature of 110°C so that the stretching ratio was 1.8. The stretched laminate was dyed by being immersed in a dyeing solution containing iodine, potassium iodide and boric acid, and dried with warm air at 60°C. Next, the dyed layered product was stretched at a stretching temperature of 90°C so that the draw ratio was 1.1 using a longitudinal uniaxial stretching machine, and a polarizing plate was obtained.

[Example 18]

Using the layered product [A] obtained in (18-3), a polarizing plate was manufactured by the method of (18-4) below, evaluated in the same manner as in Example 1, and the results are shown in Table 3.

(18-3) Manufacture of laminate [A]

Except for using the base film B instead of the base film A, it was carried out in the same manner as (1-3), "polarizer material film" / "adhesive layer" / "base film B" Layered body having a layer structure [A] was obtained .

(18 - 4) Manufacture of polarizer

The layered product [A] obtained in (18-3) was stretched at a stretching temperature of 110°C so that the stretching ratio was 1.8. The stretched laminate was dyed by being immersed in a dyeing solution containing iodine, potassium iodide and boric acid, and dried with warm air at 60°C. Next, the dyed layered product was stretched at a stretching temperature of 90°C so that the draw ratio was 1.1 using a longitudinal uniaxial stretching machine, and a polarizing plate was obtained.

[Comparative Example 1]

(C1-2) Preparation of Polarizer Material Film

Except having changed the draw ratio to 1.2, it carried out similarly to (1-2), and obtained the polarizer material film. Thickness T1 of the polarizer material film was 18 µm, and Re1 was 200 nm.

(C1-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (C1-2) instead of the polarizer material film obtained in (1-2) and using the base film B instead of the base film A, in the same manner as in (1-3), "polarizer A layered product [A] having a layer structure of "material film"/"adhesive layer"/"substrate film B" was obtained.

(C1-4) Manufacture of Polarizer

Except that the laminate [A] obtained in (C1-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 5.1. A polarizing plate was manufactured in the same manner as in Example 1 (1-4), evaluated in the same manner as in Example 1, and the results are shown in Table 4. Compared with the polarizer material film, the base film was difficult to elongate, fracture occurred in the base film, and production of a stable polarizing plate could not be performed.

[Comparative Example 2]

(C2-2) Preparation of Polarizer Material Film

Except having changed the draw ratio to 5.7, it was carried out similarly to (1-2), and the polarizer material film was obtained. Thickness T1 of the polarizer material film was 8 µm, and Re1 was 320 nm.

(C2-3) Manufacture of laminate [A]

Except for using the polarizer material film obtained in (C2-2) instead of the polarizer material film obtained in (1-2) and using the base film B instead of the base film A, in the same manner as in (1-3), "polarizer A layered product [A] having a layer structure of "material film"/"adhesive layer"/"substrate film B" was obtained.

(C2-4) Manufacture of Polarizer

Except that the laminate [A] obtained in (C2-3) was used instead of the laminate [A] obtained in (1-3), and the draw ratio was changed, thereby changing the total draw ratio to 1.2. A polarizing plate was manufactured in the same manner as in Example 1 (1-4), evaluated in the same manner as in Example 1, and the results are shown in Table 4. The runability of the film in the process was poor, and breakage occurred frequently, so that a stable polarizing plate could not be manufactured.

[Comparative Example 3]

(C3-3) Manufacture of laminate [A]

In (1-3), it is the same as (1-3) except that a raw film (PVA20: unstretched polyvinyl alcohol film) was used instead of the polarizer material film and the base film B was used instead of the base film A. Thus, a layered product [A] having a layer structure of "raw film"/"adhesive layer"/"base film B" was obtained.

(C3-4) Manufacture of Polarizer

(1-4) except that the laminate [A] obtained in (C3-3) was used instead of the laminate [A] obtained in (1-3) and the stretching treatment was performed so that the total draw ratio was 6.0. A polarizing plate was manufactured in the same way, and evaluated in the same manner as in Example 1, and the results were shown in Table 4. Compared with the polarizer material film, the base film was difficult to elongate, fracture occurred in the base film, and production of a stable polarizing plate could not be performed.

[Comparative Example 4]

(C4-3) Manufacture of laminate [A]

In the following procedure, a polyvinyl alcohol (PVA) layer was formed on the surface of the base film C4 to prepare a layered product [A].

As the base film C4, a continuous web base film (thickness: 200 μm) of amorphous polyethylene terephthalate (amorphous PET, glass transition temperature: 75° C.) copolymerized with 6 mol% of isophthalic acid was used. As the PVA aqueous solution forming the PVA layer, an aqueous solution obtained by dissolving PVA powder having a degree of polymerization of 1000 or more, a degree of saponification of 99% or more, and a glass transition temperature of 80 ° C. in water to a concentration of 4 to 5% by weight was used.

Laminate having a PVA layer/base film C4 layer structure by applying a PVA aqueous solution to one side of the base film C4 and drying it at a temperature of 50 to 60° C. to form a PVA layer on the surface of the base film C4 [A] got Although the PVA layer in this comparative example is formed by application and drying of the PVA aqueous solution, the thickness of the layer and the phase difference in the in-plane direction are expressed in Table 4 in the columns of "thickness after stretching T1" and "phase difference after stretching Re1" are described in each.

(C4-4) Manufacture of Polarizer

The layered product [A] obtained in (C4-3) was subjected to free end uniaxial stretching so that the stretching ratio was 1.8 times by hanging it on a stretching device arranged in an oven set to a stretching temperature environment of 130°C (first 1 stretching treatment).

A dyeing treatment was performed in which the layered product [A] after the first stretching treatment was immersed in a dyeing solution containing iodine and potassium iodide. Next, the layered product [A] after the dyeing treatment was hung on a stretching device provided in a treatment device set with a 65° C. boric acid aqueous solution containing boric acid and potassium iodide, and a free end uniaxial stretching treatment was performed so that the stretching ratio was 3.3 times. (second stretching treatment). The stretching direction was set to the longitudinal direction in both the first stretching treatment and the second stretching treatment.

The layered product [A] after the second stretching treatment was taken out of the boric acid aqueous solution, and the boric acid adhering to the surface of the 3 μm-thick PVA layer formed on the amorphous PET substrate was washed with an aqueous potassium iodide solution, followed by 60° C. warm air. It dried by the drying process and obtained the polarizing plate. The thickness and retardation Re of the base film in the polarizing plate, the thickness T of the PVA layer, the total thickness, and the polarization degree were measured and shown in Table 4 together with the evaluation results of the stretchability.

The results of Examples and Comparative Examples are shown in Tables 1 to 4.

In the table, Acryl means an acrylic resin.

In the table, the stretching direction (°) is an angle when the width direction of the film is set to 0°.

In the table, amorphous PET means amorphous polyethylene terephthalate.

From the results of Tables 1 to 4, according to the present invention, the phase difference expressed in the base film after passing through the step of stretching the laminate can be reduced, and thereby the base film can be used also as a protective film, even if the thickness is thin. It turns out that the manufacturing method of the polarizing plate which can manufacture efficiently can be provided.

One … fabric film
10 … laminate
11 … polarizer material film
12 … base film
13 … adhesive layer
100, 120, 130... polarizer
111 … polarizer material film
112 … base film
113, 114... adhesive layer
115 … protective film
116 … adhesive layer
200 … manufacturing device
201, 202... unwinding device
203 … take-up device
204 … stretching device
205 … bonding device
300 … manufacturing device
301, 307... unwinding device
302 to 305... processing unit
306, 309... drying device
308 … bonding device
310 … take-up device
400, 450... Liquid crystal display (display device)
410, 420... Board
430 … liquid crystal layer
500, 550... Organic EL display device (display device)
510, 520... Board
530 … light emitting layer

Claims (22)

As a method for producing a polarizing plate,
Step (a) of obtaining a polarizer material film by stretching a raw film containing the material of the polarizer at a draw ratio X in one or more directions;
Step (b) of providing a base film on the polarizer material film to obtain a layered product [A];
A step (c) of stretching the layered product [A] in one or more directions at a stretching ratio Z is included in this order,
X and Z satisfy the relationship of the following formulas (1) to (3),
The manufacturing method of the polarizing plate whose thickness T of the polarizer material film after passing through a process (c) is 20 micrometers or less.
1.5 ≤ X ≤ 5.5 . (One)
1.2 ≤ Z ≤ 5.0 . (2)
5.1 ≤ X * Z ≤ 9.0 . (3) According to claim 1,
The manufacturing method of the polarizing plate including the process (d) of dyeing the said polarizer material film with a dichroic substance after the said process (b). According to claim 1,
The manufacturing method of the polarizing plate which performs the said process (c) on temperature conditions of 50 degreeC - 160 degreeC. According to claim 1,
The manufacturing method of the polarizing plate in which the said polarizer material film consists of polyvinyl alcohol resin. According to claim 1,
The manufacturing method of the polarizing plate whose retardation of the in-plane direction of the base film after passing through the said process (c) is 20 nm or less. According to claim 1,
Step (e1) of attaching a protective film to the polarizer material film of the layered product [A] directly or through an adhesive after the step (c), or step (e2) of forming an adhesive layer on the polarizer material film ) A method for producing a polarizing plate comprising a. According to claim 1,
The manufacturing method of the polarizing plate in which the said base film is a film which consists of at least 1 sort(s) chosen from a cycloolefin resin, an amorphous polyester resin, a polyolefin resin, and an acrylic resin. According to claim 1,
The base film is a film made of a cycloolefin resin,
The cycloolefin resin includes a cycloolefin-based polymer,
The manufacturing method of the polarizing plate in which the said cycloolefin type polymer consists of at least 1 sort(s) chosen from the hydride of the ring-opening polymer of a norbornene type monomer, the addition copolymer of a norbornene type monomer and an alpha olefin, and its hydride. According to claim 1,
The base film is a film made of a cycloolefin resin,
The cycloolefin resin includes a cycloolefin-based polymer,
The cycloolefin-based polymer comprises a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound;
A polymer block [B] comprising a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or
Polymer block [C] comprising a repeating unit [II] derived from a chain-like conjugated diene compound
A block copolymer [D] consisting of
The manufacturing method of the polarizing plate which consists of a hydrogenated block copolymer hydride. According to claim 1,
The manufacturing method of the polarizing plate in which the said base film contains a plasticizer, a softener, or both. According to claim 10,
A method for producing a polarizing plate comprising an ester plasticizer as the plasticizer, an aliphatic hydrocarbon polymer as the softener, or both. According to claim 1,
The angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film is 90 °, and the angle θ2 formed by the stretching direction of the step (c) and the width direction of the laminate [A] is 90 °, A method for producing a polarizing plate. According to claim 1,
The angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film is 0 °, and the angle θ2 formed by the stretching direction of the step (c) and the width direction of the laminate [A] is 0 °, A method for producing a polarizing plate. According to claim 1,
Of the angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film, and the angle θ2 formed by the stretching direction and the width direction of the layered product [A] in the step (c), either one is 90°. , A method for producing a polarizing plate in which the other side is 0°. According to claim 1,
The angle θ1 formed by the stretching direction of the step (a) and the width direction of the polarizer material film is 90°, and the angle θ2 (°) formed by the stretching direction of the step (c) and the width direction of the laminate [A] is as follows. A method for producing a polarizing plate that satisfies Expression (4).
θ2 ≠ 90 … (4) According to claim 1,
The angle θ1 (°) formed by the stretching direction of the step (a) and the width direction of the polarizer material film satisfies the following formula (5),
The manufacturing method of the polarizing plate in which the angle θ2 formed by the stretching direction in the step (c) and the width direction of the layered product [A] is 90°.
θ1 ≠ 90 … (5) According to claim 1,
The angle θ1 (°) formed between the stretching direction of the step (a) and the width direction of the polarizer material film, and the angle θ2 (°) formed between the stretching direction and the width direction of the laminate [A] in the step (c), The manufacturing method of the polarizing plate which satisfies the following formula (6) and the following formula (7).
θ1 ≠ 90 … (6)
θ2 ≠ 90 … (7) According to any one of claims 15 to 17,
The absolute value of the difference between the θ1 and the θ2 is 50 or less, the manufacturing method of the polarizing plate. According to claim 2,
A method for producing a polarizing plate in which the dichroic material is an organic dye. The manufacturing method of the display device which laminates|stacks the polarizing plate obtained by the manufacturing method in any one of Claims 12-14 on a liquid crystal panel. The manufacturing method of the display apparatus which laminates the polarizing plate obtained by the manufacturing method in any one of Claims 15-17 on an organic electroluminescent panel or an inorganic electroluminescent panel. A method for manufacturing a display device, wherein the polarizing plate obtained by the manufacturing method according to claim 19 is laminated on a vehicle-mounted display panel.

Images