JPWO2019131666A1 - Laminating body for polarizing plate, polarizing plate, laminate film roll for polarizing plate, method for manufacturing laminated body for polarizing plate and method for manufacturing polarizing plate - Google Patents

Abstract

A laminate for a polarizing plate having a resin film made of a cycloolefin resin and a polyvinyl alcohol layer laminated by coating on at least one surface of the resin film, wherein the cycloolefin resin is a cycloolefin polymer. The cycloolefin-based polymer contains a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, a repeating unit [I] derived from an aromatic vinyl compound, and a chain-conjugated diene. Both a block composed of a polymer block [B] containing a repeating unit [II] derived from a compound as a main component or a polymer block [C] containing a repeating unit [II] derived from a chain conjugated diene compound as a main component. A laminate for a polarizing plate, which is a hydride of a block copolymer obtained by hydrogenating the polymer [D].

Description

The present invention relates to a polarizing plate laminate, a polarizing plate, a polarizing plate laminate film roll, a method for producing a polarizing plate laminate, and a method for producing a polarizing plate.

Conventionally, display devices such as liquid crystal display devices and organic electroluminescence (EL) display devices have been required to have a large display area, a light weight, and a thin thickness. Therefore, the panel constituting the display device has been conventionally required to be thin.

A polarizing plate including a polarizer and a protective film that protects the polarizer is generally used as the display device. In order to construct a display device having a thin thickness, a thinner polarizing plate is required. In particular, since the polarizer may shrink in the usage environment of the display device, warpage due to such shrinkage may become a problem in a display device having a thin and large area. Therefore, by adopting a thin polarizer having a thickness of 10 μm or less, in addition to reducing the thickness of the display device by reducing the thickness of the polarizer itself, it can be expected to reduce the occurrence of warpage as described above.

However, when an attempt is made to produce a polarizer of such a thin polyvinyl alcohol by a conventional production method, the polarizer frequently fluctuates. Several methods have been proposed as a method for producing such a polarizing plate containing a thin polarizing element while preventing fusing of the polarizer.
For example, in Patent Document 1, a polyvinyl alcohol-based resin layer is formed into a laminate by applying an aqueous solution containing a polyvinyl alcohol-based resin to a resin film made of an amorphous ester-based thermoplastic resin to form a laminate. A method has been proposed in which a bicolor substance is oriented to form a colored laminate, and the colored laminate is stretched to obtain an optical film.

Japanese Patent No. 46910205 (Corresponding Gazette: US Pat. No. 8314987)

When a thin polarizing plate is produced by the method described in Patent Document 1, a phase difference may occur in the resin film after the stretching treatment due to the stretching of the laminated body at a high stretching ratio. In such a case, it is difficult to use the resin film as it is as a polarizing plate protective film, and the resin film is peeled off and discarded, so that wasteful material is generated. Further, a protective film for protecting the polarizing plate may be separately prepared and attached to the polarizing plate.

Therefore, in the present invention, a resin film can also be used as a protective film, and a polarizing plate laminate and a method for producing the same can be efficiently produced even if the thickness is thin, a polarizing plate using the laminate, and a polarizing plate using the laminate. An object of the present invention is to provide a method for producing the same and a laminated film roll for a polarizing plate using the laminated body.

As a result of studies to solve the above problems, the present inventor has a resin film made of a cycloolefin resin containing a predetermined cycloolefin polymer and polyvinyl laminated on at least one surface of the resin film. The present invention has been completed by finding that the above-mentioned problems can be solved by using a laminate having an alcohol layer.
Therefore, according to the present invention, the following [1] to [12] are provided.
[1] A resin film made of a cycloolefin resin and
A polarizing plate laminate having a polyvinyl alcohol layer laminated by coating on at least one surface of the resin film.
The cycloolefin-based resin contains a cycloolefin-based polymer and contains
The cycloolefin-based polymer contains a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, and
A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound. Polymer block [C] as the main component and
A laminate for a polarizing plate, which is a hydride of a block copolymer composed of hydrogenated block copolymer [D].
[2] The thickness T of the polyvinyl alcohol layer is 45 μm or less, and
The in-plane retardation Re2 of the stretched product of the resin film is 0 nm or more and 20 nm or less, and the retardation Re2 makes the laminate 6.0 times free-end uniaxial under temperature conditions of 50 ° C. to 120 ° C. The laminate for a polarizing plate according to [1], which is the phase difference possessed by the stretched product when the resin film is stretched to form the stretched product.
[3] The laminate for a polarizing plate according to [1] or [2], wherein the cycloolefin-based resin contains a plasticizer, a softener, or both.
[4] The laminate for a polarizing plate according to [3], wherein the plasticizer, the softener, or both of them is one or more selected from an ester plasticizer and an aliphatic hydrocarbon polymer.
[5] The laminate for a polarizing plate according to any one of [1] to [4], wherein the resin film contains an organometallic compound.
[6] The laminate for a polarizing plate according to any one of [1] to [5], wherein the polyvinyl alcohol layer is a layer directly laminated on the resin film.
[7] A polarizing plate obtained by uniaxially stretching the laminate for polarizing plate according to any one of [1] to [6].
[8] The polarizing plate laminate according to any one of [1] to [6], and the separator film laminated on the surface of the resin film of the laminate opposite to the polyvinyl alcohol layer. Have,
A laminated film roll for polarizing plates, which is wound into a roll shape.
[9] A first step of coating a polyvinyl alcohol resin on at least one surface of a resin film made of a cycloolefin resin to form a polyvinyl alcohol layer.
The second step of drying the polyvinyl alcohol layer formed in the first step is included in this order.
The cycloolefin-based resin contains a cycloolefin-based polymer and contains
The cycloolefin-based polymer contains a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, and
A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound. Polymer block [C] as the main component and
A method for producing a laminate for a polarizing plate, which is a hydride of a block copolymer composed of hydrogenated block copolymer [D].
[10] The method for producing a laminate for a polarizing plate according to [9], wherein the polyvinyl alcohol layer is formed by one or more methods selected from solution coating, emulsion coating, and melt extrusion coating.
[11] For a polarizing plate obtained by the method for producing a polarizing plate laminate according to any one of [1] to [6] or the polarizing plate laminate according to [9] or [10]. A method of manufacturing a polarizing plate using a laminate,
A third step of dyeing the laminate with a dichroic dye, and
A method for producing a polarizing plate, which comprises a fourth step of uniaxially stretching the laminate.
[12] After going through the third step, the fourth step, or both of them, a fifth step of laminating a protective film on the surface of the polyvinyl alcohol layer of the laminate opposite to the resin film. The method for producing a polarizing plate according to [11], which comprises.

According to the present invention, a resin film can also be used as a protective film, and a polarizing plate laminate and a method for producing the same can be efficiently produced even if the thickness is thin, a polarizing plate using the laminate, and a polarizing plate using the laminate. A method for producing the same and a laminated film roll for a polarizing plate can be provided.

FIG. 1 is a cross-sectional view schematically showing a polarizing plate laminate according to a first embodiment of the present invention. FIG. 2 is a diagram schematically showing an example of an apparatus for manufacturing a polarizing plate laminate according to the first embodiment. FIG. 3 is a cross-sectional view schematically showing a polarizing plate laminate film roll produced by using the polarizing plate laminate according to the first embodiment of the present invention. FIG. 4 is a diagram schematically showing an example of a manufacturing apparatus for manufacturing a polarizing plate using the polarizing plate laminate according to the first embodiment. FIG. 5 is a cross-sectional view schematically showing a polarizing plate manufactured by using the polarizing plate laminate according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing the polarizing plate according to the second embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be arbitrarily modified and carried out within the scope of the claims of the present invention and the equivalent scope thereof.

In the present application, the "long" film means a film having a length of 5 times or more, preferably 10 times or more, specifically, a length of 5 times or more with respect to the width of the film. It has a length that allows it to be rolled up and stored or transported. The upper limit of the ratio of the length to the width of the film is not particularly limited, but may be, for example, 100,000 times or less.

In the present application, the phase difference Re in the in-plane direction and the phase difference Rth in the thickness direction of the film are calculated according to the formulas Re = (nx-ny) × d and Rth = [{(nx + ny) / 2} -nz] × d. To do. Further, the Nz coefficient of the film is a value represented by [(nx-nz) / (nx-ny)] and can also be expressed as [(Rth / Re) +0.5]. Here, nx is the in-plane refractive index of the film (maximum in-plane refractive index), and ny is the in-plane refractive index perpendicular to the in-plane retardation axis of the film. Yes, nz is the refractive index in the thickness direction of the film, and d is the thickness (nm) of the film. Unless otherwise specified, the measurement wavelength shall be 550 nm, which is a typical wavelength in the visible light region.

[Embodiment 1: Laminated Polarizer and Method for Manufacturing thereof, Laminated Film Roll for Polarizing Plate, Polarizing Plate and Method for Manufacturing thereof]
Hereinafter, a polarizing plate laminate (hereinafter, also simply referred to as “laminate”) and a method for producing the same, which is an embodiment of the present invention, a polarizing plate laminate film roll using the laminate, and a polarizing plate film roll using the laminate, and , A polarizing plate using the laminated body and a method for producing the same will be described with reference to FIGS. 1 to 5.

[1. Laminated body for polarizing plate]
The polarizing plate laminate of the present invention has a resin film made of a cycloolefin resin and a polyvinyl alcohol layer laminated on at least one surface of the resin film. The polyvinyl alcohol layer is a layer (coating layer) laminated by coating.

FIG. 1 is an example of a cross-sectional view schematically showing the laminated body 10 of the first embodiment according to the present invention. As shown in FIG. 1, the laminate 10 of the present embodiment has a resin film 12 and a polyvinyl alcohol layer 11 provided on one surface (upper surface of the drawing) of the resin film. The laminate 10 of the present invention is a material for producing a polarizer (polarizing plate).

[Polyvinyl alcohol layer]
In the present invention, the polyvinyl alcohol layer is a layer made of a polyvinyl alcohol resin. Hereinafter, "polyvinyl alcohol" may be abbreviated as "PVA".

In the present invention, the PVA resin (polyvinyl alcohol resin) forming the PVA layer is not necessarily limited, but is produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate from the viewpoint of availability. It is preferable to use it. The PVA contained in the PVA resin 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 polarizer. preferable. Here, the degree of polymerization is the 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 preferable range of the degree of polymerization is 1000 to 6000, and more preferably 1500 to 4000. A more preferable range of the saponification degree is 95 mol% or more, more preferably 99 mol% or more. The PVA may be a copolymer of vinyl acetate and another monomer copolymerizable, or a graft polymer.

In the present invention, the PVA resin contains a plasticizer such as a polyhydric alcohol such as glycerin in an amount of 0.01 to 30% by weight based on PVA in order to improve mechanical properties and process passability during secondary processing. It is preferable to contain it, and in order to improve the handleability and the appearance of the film, a surfactant such as an anionic surfactant and a nonionic surfactant should be contained in an amount of 0.01 to 1% by weight based on PVA. Is preferable.

PVA resins include antioxidants, UV absorbers, lubricants, pH adjusters, inorganic fine particles, colorants, preservatives, fungicides, polymer compounds other than those mentioned above, moisture, etc., as required. Other components may be further contained. The PVA resin can contain one or more of these other components.

The thickness T of the PVA layer is preferably 45 μm or less, more preferably 35 μm or less, still more preferably 25 μm or less, preferably 5 μm or more, more preferably 10 μm or more, still more preferably 15 μm or more. When the thickness of the PVA layer is not more than the upper limit value of the above range, the contraction force of the polarizing plate can be effectively reduced, and when it is not more than the lower limit value of the above range, the polarizing plate having sufficiently high polarization performance can be obtained. Obtainable.

The in-plane retardation Re1 of the PVA layer is preferably 50 nm or less, more preferably 40 nm or less, further preferably 30 nm or less, preferably 0 nm or more, and more preferably 3 nm or more. When the phase difference Re1 in the in-plane direction of the PVA layer is not more than the upper limit of the above range, the laminated body can be stretched at a sufficient magnification, and a polarizing plate having high polarization performance can be obtained.

[Resin film]
The resin film is made of a cycloolefin resin. The cycloolefin-based resin is a resin containing a cycloolefin-based polymer. In the present invention, the cycloolefin resin is preferably a resin having flexibility capable of stretching at a low temperature (for example, 50 to 120 ° C.) and a high stretching ratio (for example, 6.0 times).

[Cycloolefin resin]
The cycloolefin-based polymer contained in the cycloolefin-based resin includes a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, a repeating unit [I] derived from an aromatic vinyl compound, and a repeating unit [I]. A polymer block [B] whose main component is a repeating unit [II] derived from a chain-conjugated diene compound, or a polymer block [C] whose main component is a repeating unit [II] derived from a chain-conjugated diene compound. It is a block copolymer hydride obtained by hydrogenating the block polymer [D] composed of the above. Examples of such block copolymer hydrides include WO2000 / 32646, WO2001 / 081957, JP-A-2002-105151, JP-A-2006-195242, JP-A-2011-13378, and WO2015 / 00220. , And the like.

[Plasticizer and softener]
In the present invention, the cycloolefin-based resin forming the resin film preferably contains a plasticizer and / or a softening agent (one or both of the plasticizer and the softening agent). By containing a plasticizer and / or a softening agent, it is possible to reduce the phase difference generated in the resin film when the laminate is stretched to obtain a polarizing plate.

As the plasticizer and the softening agent, those that can be uniformly dissolved or dispersed in the cycloolefin resin forming the resin film can be used. Specific examples of the plasticizer and the softening agent include an ester-based plasticizer composed of a polyhydric alcohol and a monovalent carboxylic acid (hereinafter referred to as "polyhydric alcohol ester-based plasticizer"), and a polyvalent carboxylic acid and a monovalent carboxylic acid. Ester-based plasticizers such as ester-based plasticizers composed of alcohol (hereinafter referred to as "polyvalent carboxylic acid ester-based plasticizers"), phosphoric acid ester-based plasticizers, carbohydrate ester-based plasticizers, and other polymer softeners. Can be mentioned.

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

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

Examples of the polyvalent carboxylic acid ester-based plasticizer include a dicarboxylic acid ester-based plasticizer and other polyvalent carboxylic acid ester-based plasticizers.

Specific examples of phosphoric acid ester-based plasticizers include phosphoric acid alkyl esters such as triacetyl phosphate and tributyl phosphate; phosphoric acid cycloalkyl esters such as tricycloventyl phosphate and cyclohexyl phosphate; triphenyl phosphate and tricresyl phosphate. Phosphoric acid aryl esters such as.

Specific examples of the carbohydrate ester-based plasticizer include glucose pentaacetate, glucose pentapropionate, glucose pentabutyrate, saccharose octaacetate, saccharose octabenzoate, and the like, of which saccharose octaacetate is more preferable. preferable.

Specific examples of the polymer softener include an aliphatic hydrocarbon polymer, an alicyclic hydrocarbon polymer, ethyl polyacrylate, methyl polymethacrylate, methyl methacrylate and -2-hydroxyethyl methacrylate. Acrylic polymers such as copolymers, copolymers of methyl methacrylate, methyl acrylate and -2-hydroxyethyl methacrylate; vinyl polymers such as polyvinylisobutyl ether, poly N-vinylpyrrolidone; polystyrene, poly 4 -Sterite polymers such as hydroxystyrene; polyesters such as polybutylene succinate, polyethylene terephthalate and polyethylene naphthalate; polyethers such as polyethylene oxide and polypropylene oxide; polyamides, polyurethanes, polyureas and the like.

Specific examples of the aliphatic hydrocarbon polymer include low molecular weight polymers such as polyisobutylene, polybutane, poly-4-methylpentene, poly-1-octene, ethylene / α-olefin copolymers, and hydrides thereof; polyisobutylene. , Low molecular weight compounds such as polyisobutylene-butadiene copolymer and hydrides thereof. From the viewpoint of easy uniform dissolution or dispersion in the cycloolefin resin, the aliphatic hydrocarbon 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. Further, two or more of the above polymers may be used in combination.

In the present invention, the plasticizer and / or the softening agent is one or more selected from ester-based plasticizers and aliphatic hydrocarbon polymers because they are particularly excellent in compatibility with the resin forming the resin film. preferable.

The ratio of the plasticizer and / or the softening agent (hereinafter, also referred to as “plasticizer”) in the resin film is preferably 0.2 parts by weight or more, more preferably 0.2 parts by weight or more, based on 100 parts by weight of the cycloolefin resin forming the resin film. Is 0.5 parts by weight or more, more preferably 1.0 part by weight or more, while preferably 50 parts by weight or less, more preferably 40 parts by weight or less. By setting the ratio of the plasticizer and the like within the above range, it is possible to make the resin film sufficiently low in the development of the phase difference even after undergoing the manufacturing process of the polarizing plate including the stretching treatment.

[Organometallic compound]
In the present invention, the resin film preferably contains an organometallic compound. By containing the organometallic compound, it is possible to more effectively suppress the occurrence of peeling of the resin film when the laminate is stretched at a high stretching ratio (for example, wet stretching at a stretching ratio of 6.0).

The organometallic compound is a compound containing at least one of a chemical bond between a metal and carbon and a chemical bond between a metal and oxygen, and is a metal compound having an organic group. Examples of the organometallic compound include organosilicon compounds, organotitanium compounds, organoaluminum compounds, and organoziryl compounds. Of these, organosilicon compounds, organotitanium compounds and organozirconium compounds are preferable, and organosilicon compounds are more preferable because they are excellent in reactivity with polyvinyl alcohol. The organometallic compound may be used alone or in combination of two or more.

Examples of the organometallic compound include, but are not limited to, an organosilicon compound represented by the following formula (1).
R ¹ _a Si (OR ² ) _3-a (1)
(In the formula (1), R ¹ and R ² are independently hydrogen atom, halogen atom, hydrocarbon group having 1 to 10 carbon atoms, epoxy group, amino group, thiol group, isocyanate group and carbon. It represents a group selected from the group consisting of organic groups having 1 to 10 atoms, and a represents an integer of 0 to 3).

In the formula (1), and preferred examples as ^{R 1,} an epoxy group, an amino group, a thiol group, isocyanate group, vinyl group, aryl group, acrylic group, alkyl group having 1 to 8 carbon atoms, _-CH 2 OC _n H _{2n + 1} (n represents an integer of 1 to 4) and the like.
Further, in the formula (1), preferred examples of R ² include a hydrogen atom, a vinyl group, an aryl group, an acrylic group, an alkyl group having 1 to 8 carbon atoms, and −CH ₂ OC _n H _{2n + 1} (n is 1). It represents an integer of ~ 4.) And the like.

Examples of organosilicon compounds include epoxy-based organosilicon compounds such as 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-. Amino-based organosilicon compounds such as 2- (aminoethyl) -3-aminopropyltrimethoxysilane, isocyanurate-based organosilicon compounds such as tris- (trimethoxysilylpropyl) isocyanurate, 3-mercaptopropyltrimethoxysilane and the like. Examples thereof include isocyanate-based organosilicon compounds such as mercapto-based organosilicon compounds and 3-isocyanate propyltriethoxysilane.

Examples of the organic titanium compound include titanium alkoxide such as tetraisopropyl titanate, titanium chelate such as titanium acetylacetonate, and titanium acylate such as titanium isostearate.

Examples of the organic zirconium compound include zirconium alkoxides such as normal propyl zirconium, zirconium chelates such as zirconium tetraacetylacetonate, and zirconium acylates such as zirconium stearate.

Examples of organoaluminum compounds include aluminum alkoxides such as aluminum secondary butoxide and aluminum chelates such as aluminum trisacetylacetonate.

The ratio of the organic metal compound in the resin film is preferably 0.05 parts by weight or more, more preferably 0.01 parts by weight or more, and even more preferably 0, with respect to 100 parts by weight of the cycloolefin resin forming the resin film. It is 0.03 parts by weight or more, preferably 1.0 part by weight or less, and more preferably 0.5 parts by weight or less. By setting the ratio of the organometallic compound within the above range, it is possible to more effectively suppress the occurrence of peeling of the resin film when the laminate is wet-stretched at a high magnification (for example, a stretching ratio of 6.0). ..

[Arbitrary component]
The resin film may contain arbitrary components in addition to resins, plasticizers, organometallic compounds and the like. Examples of optional components include stabilizers such as antioxidants, UV absorbers, light stabilizers; resin modifiers such as lubricants; colorants such as dyes and pigments; and antistatic agents. These compounding agents can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected.

[Manufacturing method of resin film]
The resin film is a film-like composition (hereinafter, also referred to as “resin composition”) containing components (cycloolefin-based resin and components added as necessary) for forming the resin film by an arbitrary molding method. It can be manufactured by molding into.

Examples of the method for molding the resin composition into a film include a cast molding method, an extrusion molding method, an inflation molding method, and the like.

The thickness of the resin film is preferably 1 μm or more, more preferably 3 μm or more, preferably 50 μm or less, and more preferably 20 μm or less. When the thickness of the resin film is at least the lower limit of the above range, a good laminated surface-like laminate can be obtained, and when it is at least the upper limit of the above range, the laminate is stretched to obtain a polarizing plate. It is possible to reduce the phase difference generated in the resin film when the above is obtained.

The shape and dimensions of the resin film can be appropriately adjusted to suit the desired application. From the viewpoint of production efficiency, the resin film is preferably a long film.

[Re2 of resin film]
The in-plane retardation Re2 of the stretched product of the resin film is preferably 0 nm or more and 20 nm or less. Re2 is more preferably 0 nm or more, more preferably 10 nm or less, and particularly preferably 5 nm or less. When Re2 is not more than the upper limit value, the phase difference developed on the resin film when the laminate 10 is stretched to form a polarizing plate can be reduced.
In Re2, when the laminated body 10 is stretched 6.0 times at a free end uniaxially under a temperature condition of 50 ° C. to 120 ° C. and the resin film in the laminated body is made into a stretched product, the surface of the stretched product of the resin film is obtained. This is the inward phase difference. That is, Re2 is not the phase difference of the resin film itself in the laminate, but the phase difference that occurs in the stretched product of the resin film after the laminate is subjected to a specific stretching treatment.
The stretching temperature for obtaining such a stretched product may be any temperature within the range of 50 ° C. to 120 ° C. Therefore, a plurality of operating conditions can be considered for stretching to obtain a stretched product. When the stretched product exhibits a phase difference of 0 nm or more and 20 nm or less by any one of the plurality of operating conditions, the laminate satisfies the above requirements.
However, it is preferable that the stretched product exhibits a phase difference of 0 nm or more and 20 nm or less depending on all of the plurality of possible operating conditions. In that case, a high degree of freedom in setting stretching conditions can be obtained in the production of the polarizing plate using the polarizing plate laminate of the present invention.
Generally, in the temperature range, a larger phase difference occurs when the stretching temperature is lower. Therefore, if both the phase difference of the stretched product by stretching at 50 ° C. and the phase difference of the stretched product by stretching at 120 ° C. are within the range of 0 nm or more and 20 nm or less, the drawn product is 0 nm under all of the plurality of operating conditions. It can be judged that a phase difference of 20 nm or less is exhibited.

[2. Laminated body manufacturing method]
The method for producing a laminate according to the present embodiment is a first step of coating a PVA resin on at least one surface of a resin film made of a cycloolefin resin to form a PVA layer, and a first step of forming the PVA layer. A second step of drying the resulting PVA layer is included in this order. The cycloolefin-based polymer contained in the resin film used for producing the laminate includes the polymer block [A] containing the repeating unit [I] derived from the aromatic vinyl compound as a main component and the repeating unit derived from the aromatic vinyl compound. A polymer block [B] containing the unit [I] and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a polymer block containing a repeating unit [II] derived from a chain conjugated diene compound as a main component. It is a block copolymer hydride obtained by hydrogenating the block copolymer [D] composed of [C] and [D].

[Layer manufacturing equipment]
FIG. 2 is a schematic view schematically showing an example of a manufacturing apparatus 200 used in the method for manufacturing a laminated body according to the present embodiment. The manufacturing apparatus 200 includes a feeding device 201, a coating device 202, a winding device 203, and a drying device 205.

[Manufacturing method of laminate]
As shown in FIG. 2, the surface of the resin film 12 unwound from the feeding device 201 is coated with PVA resin in the coating device 202 to form the PVA layer 11 (first step), and then dried in the drying device 205. The laminated body 10 is obtained by going through the step of making the laminate (second step). The manufactured laminate 10 can be wound by the winding device 203 into a roll shape and used for a further step. Each step will be described below.

[First step]
The first step is a step of coating at least one surface of the resin film 12 made of a cycloolefin resin with a PVA resin to form the PVA layer 11. The method of coating the resin film 12 with the PVA resin (coating method) is not particularly limited, but for example, one or more methods selected from solution coating, emulsion coating, and melt extrusion coating are preferable, and high-speed coating is preferable. Solution coating is more preferred because it provides a PVA layer with a possible and uniform film thickness.

When solution coating is performed, PVA (PVA or PVA film) used for forming the PVA layer 11 and components added as necessary are dissolved in a solvent to obtain a PVA composition, and the PVA composition is coated on the resin film 11. .. That is, the phrase "coating the resin" includes both the case of coating only the resin and the case of coating the resin composition containing the resin and other components.

[Second step]
The second step is a step of drying the PVA layer formed in the first step.
In the second step, it is preferable to dry the PVA layer in a dryer having a temperature of 50 ° C. to 120 ° C. for 0.5 to 10 minutes. The drying temperature of the PVA layer is more preferably 60 ° C. or higher, and more preferably 100 ° C. or lower. By setting the drying temperature to the lower limit or higher, the drying time can be shortened to prevent the occurrence of cracks in the PVA layer, and by setting the drying temperature to the upper limit or lower, crystallization of the PVA layer can be suppressed. it can.

[Arbitrary process]
The method for producing a laminate of the present invention may include a step of easily adhering the surface of the resin film on which the PVA layer is formed before the first step. Examples of the easy-adhesion treatment method in the step include corona treatment, saponification treatment, primer treatment, anchor coating treatment and the like. By easily adhering the surface of the resin film in this step, the adhesiveness between the resin film and the PVA layer can be enhanced, and the peeling of the PVA layer during the formation of the PVA layer can be suppressed.

[Use of laminate]
The laminate 10 of the present invention is a material for producing a polarizing plate. The laminate is used as a polarizing plate after undergoing predetermined treatments such as stretching treatment and dyeing treatment. When the laminate 10 is used as the material for the polarizing plate, the laminate wound by the winding device 203 shown in FIG. 2 may be used as it is, or the resin film of the laminate 10 wound by the winding device 203. A separator film may be laminated on 12 and wound into a roll shape to be used as a laminated film roll. Hereinafter, the laminated film roll and the polarizing plate of the present embodiment using the laminated body 10 of the present embodiment will be described in order.

[3. Laminated film roll for polarizing plate]
FIG. 3 is a cross-sectional view schematically showing a laminated film roll for a polarizing plate using the laminated body according to the present embodiment.
As shown in FIG. 3, the polarizing plate film roll 15 of the present embodiment is formed on a surface (lower side surface in the drawing) opposite to the PVA layer 11 of the laminate 10 and the resin film 12 of the laminate 10. It is a film roll having a laminated separator film 13 and being wound into a roll shape. The laminated film roll 15 of the present embodiment has a laminated body 10 having a resin film 12 and a PVA layer 11 laminated on one surface of the resin film 12, and a PVA layer 11 of the resin film 12 of the laminated body 10. It has a separator film 13 laminated on the surface opposite to the above.

The separator film 13 is not particularly limited as long as it is a film made of a material that can be peeled off from the resin film 12, and for example, a cycloolefin resin, an acrylic resin, a polyethylene terephthalate resin, a polyethylene resin, a polypropylene resin, and a triacetyl cellulose resin. A film made of one or more resins selected from the above can be used.

[4. Method for manufacturing polarizing plate]
The polarizing plate 100 of the present invention is obtained by uniaxially stretching the laminate 10 of the present embodiment. FIG. 4 is a diagram schematically showing an example of a manufacturing apparatus for manufacturing a polarizing plate using the polarizing plate laminate according to the present embodiment.

The method for producing a polarizing plate of the present invention includes a third step of dyeing the laminate with a dichroic dye and a fourth step of uniaxially stretching the laminate.
Further, in the method for producing a polarizing plate of the present invention, after passing through the third step and / or the fourth step, a protective film is attached to the surface of the PVA layer of the laminate opposite to the resin film. May include the steps of. In the present embodiment, the polarizing plate is manufactured by a manufacturing method that does not include the fifth step.

[Device for manufacturing polarizing plates]
As shown in FIG. 4, the manufacturing apparatus 300 for manufacturing the polarizing plate includes feeding devices 301 and 307, processing devices 302 to 305, drying devices 306 and 309, bonding devices 308, and winding device 310.

[Manufacturing method of polarizing plate]
In the present embodiment, the laminated body 10 unwound from the feeding device 301 is conveyed to the processing devices 302 to 305, and the PVA layer 11 of the laminated body 10 is dyed (third step). A stretching process (fourth step) for uniaxial stretching and a predetermined process are performed. The polarizing plate 100 is obtained by performing a treatment (drying step) in which the laminated body after performing these treatments is dried by the drying apparatus 306. Hereinafter, each step will be described in detail.

[Third step]
The third step is a step of dyeing the PVA layer 11 of the laminated body 10.

Examples of the substance for dyeing the PVA layer in the third step include a dichroic substance, and examples of the dichroic substance include iodine and an organic dye. The dyeing method using these dichroic substances is arbitrary. For example, dyeing may be performed by immersing the PVA layer in a dyeing solution containing a dichroic substance. When iodine is used as the dichroic substance, the dyeing solution may contain iodide such as potassium iodide from the viewpoint of increasing the dyeing efficiency. The dichroic substance is not particularly limited, but when the polarizing plate is used in an in-vehicle display device, an organic dye is preferable as the dichroic substance.

[Fourth step]
The fourth step is a step of uniaxially stretching the laminate. The method for stretching the laminate is not particularly limited, but wet stretching is preferable. The fourth step may be performed at any time before the third step, after the third step, and at the same time as the third step. Further, the fourth step may be performed once or a plurality of times (twice or more). When the fourth step is performed a plurality of times, it may be divided into two or more periods among the above periods, or may be performed a plurality of times in a temporary period.

The draw ratio of the laminate is preferably 5.0 or more, more preferably 5.5 or more, preferably 7.0 or less, and more preferably 6.5 or less. When the draw ratio of the laminate is set to be equal to or less than the upper limit of the above range, the occurrence of the phase difference of the resin film is lowered and the occurrence of breakage of the polarizing plate is prevented even after the manufacturing process of the polarizing plate including the stretching treatment. When the draw ratio is set to the lower limit of the above range or more, a polarizing plate having sufficient polarization performance can be obtained. When the laminate is stretched twice or more, it is preferable that the total stretch ratio represented by the product of the stretch ratios of each stretch is within the above range.

The stretching temperature of the laminate is not particularly limited, but is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, particularly preferably 50 ° C. or higher, preferably 140 ° C. or lower, more preferably 90 ° C. or lower, particularly. It is preferably 70 ° C. or lower. When the stretching temperature is at least the lower limit of the above range, stretching can be smoothly performed, and when it is at least the upper limit of the above range, effective orientation can be performed by stretching. The range of the stretching temperature is preferably either dry stretching or wet stretching, but it is particularly preferable in the case of wet stretching.

The stretching treatment of the laminate can be any of a longitudinal stretching treatment for stretching in the longitudinal direction of the film, a transverse stretching treatment for stretching in the film width direction, and a diagonal stretching treatment for stretching in an oblique direction that is neither parallel nor perpendicular to the film width direction. May be done. The stretching treatment of the laminate is preferably free-end uniaxial stretching, and more preferably free-end uniaxial stretching in the longitudinal direction.

[Drying process]
The drying step is a step of drying the laminate that has undergone the treatment steps such as the third step and the fourth step. In the drying step, it is preferable to dry the laminate after the treatment step in a dryer having a temperature of 50 ° C. to 100 ° C. for 0.5 to 10 minutes. The drying temperature of the laminate is more preferably 60 ° C. or higher, and more preferably 90 ° C. or lower. By setting the drying temperature to the lower limit or higher, the drying time can be shortened to prevent the PVA layer from cracking, and by setting the drying temperature to the upper limit or lower, the PVA layer can be prevented from cracking. it can. The drying time of the laminate is more preferably 1 minute or more, and more preferably 5 minutes or less. By setting the drying time to the lower limit value or more, the drying of the laminated body is sufficient, and by setting the drying time to the upper limit value or less, cracking of the PVA layer in the laminated body can be prevented.

In the conventional polarizing element of a thin film made of only PVA resin, cracks may occur after the drying step, but the polarizing plate of this embodiment is a laminate containing a PVA layer and a resin film made of a cycloolefin resin. Since it is manufactured using the above, it is possible to suppress the occurrence of cracking of the polarizer even after the drying step.

[5. Polarizer]
A polarizing plate can be obtained by the method for producing a polarizing plate according to the present embodiment described above. The polarizing plate of the present embodiment is a polarizing plate obtained by uniaxially stretching the laminate of the present embodiment. FIG. 5 is a cross-sectional view schematically showing a polarizing plate manufactured by using the laminate according to the present embodiment.
As shown in FIG. 5, in the polarizing plate 100, the resin film 112 is laminated on one surface (lower side surface in the drawing) of the PVA layer 111.

[Characteristics of each layer in the polarizing plate]
The thickness of the PVA layer 111 in the polarizing plate 100 is preferably 20 μm or less, more preferably 10 μm or less, more preferably 3 μm or more, and even more preferably 5 μm or more. When the thickness is not more than the upper limit value, the thickness of the polarizing plate can be reduced, and when the thickness is not more than the lower limit value, a polarizing plate having sufficiently high polarization performance can be obtained.

The in-plane phase difference of the resin film in the polarizing plate is preferably 20 nm or less, more preferably 15 nm or less, further preferably 10 nm or less, and preferably 0 nm or more. When the phase difference of the resin film in the polarizing plate in the in-plane direction is within the above range, it is possible to suppress the black color shift when the polarizing plate is mounted on the liquid crystal display device.

[Use of polarizing plate]
The polarizing plate manufactured by using the polarizing plate laminate of the present invention can be used as a material for a liquid crystal display device.
Normally, the liquid crystal display device includes a light source, a light source side polarizing plate, a liquid crystal cell, and a viewing side polarizing plate in this order, but the polarizing plate obtained by the present invention can be used as either a light source side polarizing plate or a viewing side polarizing plate. You may use it. The liquid crystal display device can be manufactured by laminating the polarizing plate of the present invention on a liquid crystal panel as both or one of a light source side polarizing plate and a viewing side polarizing plate.

Further, the polarizing plate manufactured by using the polarizing plate laminate of the present invention can be used as a material for an organic EL display device, an inorganic EL display device, and the like.
Normally, an organic EL display device includes a substrate, a transparent electrode, a light emitting layer, and a metal electrode layer in this order from the light emitting side, but the polarizing plate obtained by the production method of the present invention is arranged on the light emitting side of the substrate. To.
The EL display device has two substrates, a light emitting layer located between them, and a polarizing plate arranged on the outside of 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.

[6. Action / effect of this embodiment]
In the present embodiment, since the polarizing plate is produced by stretching the laminate having the resin film and the PVA layer laminated on the resin film, PVA is produced even when the laminate is stretched at a low temperature and at a high magnification. The occurrence of fusing of the layer can be suppressed, and the occurrence of the phase difference in the resin film after stretching can be suppressed. As a result, according to the present embodiment, the resin film can be used as it is as a protective film on one surface of the PVA layer without peeling off, and the amount of wasted material can be reduced. Therefore, the resin film can be used as a protective film. It is possible to provide a method for producing a polarizing plate, which can be efficiently produced even if the thickness is thin.

Further, according to the present embodiment, a laminate in which the PVA layer 11 is directly laminated on the resin film 12 is used, and no other material is interposed between the resin film 12 and the PVA layer 11, so that the effect of suppressing breakage is obtained. It is excellent and can prevent environmental pollution by other substances in the production environment and prevent contamination (contamination of foreign substances) in the product.

[Embodiment 2: Polarizing Plate and Method for Manufacturing It]
Hereinafter, the polarizing plate 120 according to the second embodiment and the manufacturing method thereof will be described with reference to FIGS. 4 and 6. The polarizing plate 120 according to the present embodiment is manufactured by using the polarizing plate 100 according to the first embodiment. The same components and embodiments as in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

[Polarizer]
FIG. 6 is a cross-sectional view schematically showing the polarizing plate 120 according to the second embodiment of the present invention. In the polarizing plate 120, as shown in FIG. 6, a resin film 112 is laminated on one surface (lower side surface in the drawing) of the PVA layer 111, and a protective film is formed on the other surface side (upper side surface in the drawing) of the PVA layer 111. 115 are laminated. In FIG. 6, 114 is an adhesive.

In the method for producing the polarizing plate 120 of the present embodiment, after passing through the third step and the fourth step, a protective film is attached to the surface of the PVA layer of the laminated body on the opposite side to the resin film. Including the process. This will be described in detail below.

The polarizing plate 120 of the present embodiment is manufactured by using the apparatus shown in FIG. In the method for producing the polarizing plate 120 of the present embodiment, after a dyeing treatment for dyeing the PVA layer of the laminate 10 (third step) and a stretching treatment for uniaxially stretching the laminate (fourth step), a drying apparatus A polarizing plate 100 obtained by drying at 306 is used.

The polarizing plate 120 transports the polarizing plate 100 obtained through the dyeing treatment (third step) and the stretching treatment (fourth step) to the bonding device 308, and is different from the resin film of the PVA layer of the laminated body. By applying the adhesive 114 to the opposite surface (the surface on which the resin film is not laminated: the upper side in the drawing) and adhering the protective film 115 unwound from the feeding device 307 (fifth step). can get. The obtained polarizing plate 120 can be wound by a winding device 310 into a roll shape and used for a further step.

The adhesive 114 used in the fifth step for adhering the protective film 115 to the PVA layer 111 is not particularly limited, and is, for example, an acrylic adhesive, an epoxy adhesive, a urethane adhesive, or a polyester. Adhesives based on polyvinyl alcohol, polyolefin adhesives, modified polyolefin adhesives, polyvinyl alkyl ether adhesives, rubber adhesives, vinyl chloride-vinyl acetate adhesives, SEBS (styrene-ethylene-butylene- (Styrene copolymer) -based adhesive, ethylene-based adhesive such as ethylene-styrene copolymer, acrylic acid ester such as ethylene- (meth) methyl acrylate copolymer, ethylene- (meth) ethyl acrylate copolymer Examples include system adhesives.

Examples of the protective film 115 used in the fifth step include a film made of one or more resins selected from cycloolefin resin, acrylic resin, polyethylene terephthalate resin, and triacetyl cellulose resin.

Similar to the polarizing plate of the first embodiment, the polarizing plate of the present embodiment also manufactures a polarizing plate by stretching a laminate having a resin film and a PVA layer directly laminated on the resin film. It has the same effect as that of Form 1.

Further, according to the present embodiment, since the protective film 115 is provided on the surface of the PVA layer 111 on the non-laminated side of the resin film 112, the effect of preventing the surface of the PVA layer 111 from being scratched is also obtained.

[Other Embodiments]
(1) In the first embodiment, a polarizing plate laminate in which a PVA layer is laminated on one surface of a resin film is shown, and in the first and second embodiments, a polarizing plate manufactured by using the laminated body is shown. , The present invention is not limited to this. The polarizing plate laminate may be a laminate in which PVA layers are laminated on both sides of a resin film, and the polarizing plate may be a polarizing plate manufactured by using the laminate.
(2) In the first embodiment, a laminate for a polarizing plate having a resin film and a PVA layer directly laminated on the resin film is shown, but the resin film and the PVA layer are sandwiched between the resin film and the PVA layer. It may be a laminated body further provided with a layer that enhances the bonding force with the material.

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 "%" relating to the amount ratio of components represent parts by weight unless otherwise specified.

〔Evaluation method〕
[Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn]
The molecular weights of the block copolymer and the block copolymer hydride were measured at 38 ° C. as standard polystyrene-equivalent values by GPC using THF as an eluent. As a measuring device, HLC8020GPC manufactured by Tosoh Corporation was used.

[Hydrogenation rate]
The hydrogenation rate of the block copolymer hydride was calculated by ^{1 1} H-NMR spectrum or GPC analysis. The region having a hydrogenation rate of 99% or less was calculated by measuring ^{1 1} H-NMR spectrum, and the region exceeding 99% was calculated from the ratio of the peak areas by the UV detector and the RI detector by GPC analysis.

[Measurement method of phase difference]
The in-plane retardation Re1 of the polyvinyl alcohol layer, the in-plane retardation Re2 of the stretched resin film, and the in-plane retardation of the resin film in the polarizing plate are measured by a phase difference meter (Opt Science Co., Ltd.). The film was measured using a product, trade name "Mula Matrix Polarimeter (Axo Scan)"). At the time of measurement, the measurement wavelength was 550 nm.
The phase difference Re2 was measured by measuring the phase difference in the in-plane direction of the resin film generated when the laminate was stretched 6.0 times at free ends and uniaxially at predetermined temperatures (50 ° C. and 120 ° C.). In the present application, the phase difference in the in-plane direction of the resin film generated when the laminate is stretched 6.0 times at the free end uniaxially under the temperature condition of 50 ° C., and the laminate is subjected to the temperature condition of 120 ° C. If both the in-plane phase differences of the resin film generated when the free-end uniaxially stretched 0 times are within the range of 0 nm or more and 20 nm or less, the laminated body is subjected to a temperature condition of 50 ° C. to 120 ° C. It was determined that the in-plane phase difference Re2 of the resin film generated when the free end uniaxially stretched 0 times was 0 nm or more and 20 nm or less.

[Thickness measurement method]
The thickness of each layer (polyvinyl alcohol layer and resin film) contained in the laminate and the thickness of each layer contained in the polarizing plate are measured by a thickness meter (manufactured by Mitutoyo Co., Ltd., trade name "ABS Digimatic Thickness Gauge (547-401)". ) Was measured 5 times, and the average value was taken as the thickness of each layer.

[Evaluation of adhesion]
In the process up to the second stretching treatment in the production of the polarizing plate of each example, A was the one in which no peeling occurred between the polyvinyl alcohol layer and the resin film, B was the one in which peeling was partially observed, and complete. The one peeled off was designated as C.

[Evaluation of drying process]
In the production of the polarizing plate of each example, those in which no cracks were generated in the polarizer in the drying step at 70 ° C. for 5 minutes were designated as A, and those in which cracks were generated were designated as C.

[Black color shift]
The liquid crystal display panel is removed from the liquid crystal display device (manufactured by LG Electronics Japan, trade name "IPS panel monitor (23MP47)"), and the polarizing plate arranged on the viewing side is peeled off to produce the examples and comparative examples. The polarizing plate was attached so that the resin film was on the panel side. In addition, a single polarizing element without a protective film was attached next to the polarizing plates produced in Examples and Comparative Examples, and the liquid crystal display device was reassembled. The absorption axes of the polarizing plate and the polarizing element without the protective film prepared in Examples and Comparative Examples were bonded so as to be in the same direction as the absorption axis of the polarizing plate before peeling.
When the direction of the absorption axis of the polarizing plate arranged on the viewing side is 0 ° in the azimuth and the vertical direction of the panel is 0 °, the panel is displayed in black (that is, a black color is displayed on the entire display screen of the panel). A, the one with the same color change as the case of the polarizer without the protective film, B, the one with a slight color change, visually viewed from the azimuth angle of 45 ° and the polar angle of 45 °. The one with a large change was judged to be C.

[Example 1]
(1-1) Preparation of Polymer X With reference to the production example described in JP-A-2002-105151, 25 parts of the styrene monomer was polymerized in the first step, and then 30 parts of the styrene monomer and 30 parts in the second step. After polymerizing 25 parts of isoprene monomer and then polymerizing 20 parts of styrene monomer in the third step to obtain a block copolymer [D1], the block copolymer is hydrogenated to form a block copolymer hydride [ E1] was synthesized. The Mw of the block copolymer hydride [E1] was 84,500, the Mw / Mn was 1.20, and the hydrogenation rate of the main chain and the aromatic ring was almost 100%.
Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Matsubara Sangyo Co., Ltd.) in 100 parts of block copolymer hydride [E1] as an antioxidant. Name "Songnox 1010") 0.1 part was melt-kneaded and blended, and then pelletized to obtain polymer X for molding.

(1-2) Production of Resin Film After dissolving the polymer X produced in (1-1) in cyclohexane, 40 parts by weight of polyisobutene (manufactured by JX Nippon Oil Energy Co., Ltd.) with respect to 100 parts by weight of the polymer X Nisseki Polybutene HV-300 ”, number average molecular weight 1,400), and 0.1 parts by weight of organosilicon compound (3-aminopropyltriethoxysilane, KBM903, manufactured by Shin-Etsu Chemical Co., Ltd.) are added for cast film formation. A coating solution was prepared.
The obtained coating liquid for film formation was applied to a separator film (manufactured by Mitsubishi Chemical Corporation, "MRV38") using a die coater and dried. As a result, a resin film made of polymer X having a width of 650 mm, a length of 500 m, and a thickness of 10 μm was obtained.

(1-3) Production of Laminated Unstretched polyvinyl alcohol resin film (average degree of polymerization about 2400, saponification degree 99.9 mol%, thickness 20 μm, hereinafter also referred to as “PVA20”) is placed in hot water at 95 ° C. It was dissolved to prepare a polyvinyl alcohol aqueous solution having a concentration of 10% by weight. The above-mentioned polyvinyl alcohol aqueous solution was applied to the resin film produced in (1-2) and then dried at 100 ° C. for 10 minutes to obtain a long laminate having a width of 600 mm and a thickness of 5 μm formed of a polyvinyl alcohol layer. ..
The thickness of the resin film, the thickness of the polyvinyl alcohol layer, the in-plane retardation Re1 and the retardation Re2 (temperature conditions 50 ° C., 120 ° C.) in the obtained laminate were measured. The results are shown in Table 1.

(1-3) Production of Polarizing Plate The following operation was performed while continuously transporting the laminate produced in (1-2) in the longitudinal direction via a guide roll.
The above-mentioned laminate was subjected to a swelling treatment by immersing it in water, a dyeing treatment by immersing it in a dyeing solution containing iodine and potassium iodide, and a first stretching treatment for stretching the laminate after the dyeing treatment. Next, the laminate after the first stretching treatment was subjected to a second stretching treatment in which the laminate was stretched in a bathtub containing boric acid and potassium iodide. The total stretching ratio represented by the product of the stretching ratio in the first stretching treatment and the stretching ratio in the second stretching treatment was set to be 6.0. The stretching temperature was 57 ° C. The laminate after the second stretching treatment was dried at 70 ° C. for 5 minutes in a dryer (drying step) to obtain a polarizing plate.
Adhesion was evaluated in the steps up to the second stretching treatment, drying processability was evaluated in the drying step, and black color shift was evaluated for the obtained polarizing plate. The evaluation results are shown in Table 1.
In addition, the thickness and phase difference of the resin film in the obtained polarizing plate and the thickness of the polyvinyl alcohol layer were measured. The measurement results are shown in Table 1.

[Example 2]
In (1-2) of Example 1, instead of 0.1 parts by weight of the organosilicon compound, 0.1 parts by weight of the organotitanium compound (tetraisopropyl titanate, Organix TA-8, manufactured by Matsumoto Fine Chemicals Co., Ltd.) was used. A laminate and a polarizing plate were prepared in the same manner as in Example 1 except that a resin film was formed using the added coating liquid for film formation, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
In Example 1 (1-2), instead of 0.1 parts by weight of the organosilicon compound, 0.1 parts by weight of the organozylon compound (normal propyl zirconate, Organix ZA-45, manufactured by Matsumoto Fine Chemicals Co., Ltd.) A laminate and a polarizing plate were produced in the same manner as in Example 1 except that a resin film was formed using the coating liquid for film formation to which the above was added, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
In Example 1 (1-2), when the film-forming coating liquid is applied to the separator film using a die coater and dried, the coating amount and the like are adjusted to obtain a long length of 5 μm. A laminate and a polarizing plate were produced in the same manner as in Example 1 except that the resin film (width and length were the same as in Example 1) was produced, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
A laminate and a polarizing plate were prepared in the same manner as in Example 1 except that polyisobutene was not used in (1-2) of Example 1, and evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[Example 6]
In Example 1 (1-2), when the organosilicon compound was not used, and when the film-forming coating liquid was applied to the separator film using a die coater and dried, the coating amount and the like were adjusted. A laminate and a polarizing plate were prepared in the same manner as in Example 1 except that a long resin film having a thickness of 5 μm (the width and length were the same as in Example 1) was produced by adjusting. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
In (1-3) of Example 1, instead of the laminate produced in (1-2), only an unstretched polyvinyl alcohol resin film (PVA20) is used, and the same operation as in (1-3) is performed. As a result, fusing occurred frequently in the first stretching treatment and the second stretching treatment, and fractures frequently occurred in the drying step, so that the adhesion and the black color shift could not be evaluated.

[Comparative Example 2]
In (1-3) of Example 1, instead of the resin film produced in (1-2), a cycloolefin resin film (Zeonoa film, ring-opening polymer hydride of alicyclic hydrocarbon, Nippon Zeon Co., Ltd.) A laminate was produced in the same manner as in Example 1 except that the product was manufactured and used (thickness 13 μm). When the same operation as in (1-4) of Example 1 was performed using the laminated body, fracture occurred in the first stretching treatment and a polarizing plate could not be produced.

The evaluation results of Examples, Comparative Examples and Reference Examples are shown in Tables 1 and 2.
In the table, "COP" means a cycloolefin resin.
In the table, "Re2 (50 ° C.)" means the phase difference in the in-plane direction of the resin film generated when the laminated body is stretched 6.0 times at the free end uniaxially under the temperature condition of 50 ° C. "Re2 (120 ° C.)" means the phase difference in the in-plane direction of the resin film generated when the laminated body is stretched 6.0 times at the free end uniaxially under the temperature condition of 120 ° C.
In the table, "Re1" means the phase difference of the polyvinyl alcohol layer in the laminated body in the in-plane direction.
In the table, "coating" refers to a PVA layer formed by applying an aqueous polyvinyl alcohol solution to a resin film.

From the results shown in Tables 1 and 2, according to the present invention, the phase difference developed on the resin film after the step of stretching the laminate can be reduced, and the adhesion, the drying process, and the optical properties are excellent. It can be seen that a polarizing plate can be obtained. As a result, the resin film can also be used as a protective film, and a polarizing plate laminate and a method for producing the same can be efficiently produced even if the thickness is thin, and a polarizing plate using the laminate and a method for producing the same. , And a laminate film roll for polarizing plates can be provided.

10 ... Laminated body (laminated body for polarizing plate)
11 ... Polyvinyl alcohol layer (PVA layer)
12 ... Resin film 13 ... Separator film 15 ... Laminated film rolls 100, 120 ... Polarizing plate 111 ... Polyvinyl alcohol layer (PVA layer)
112 ... Resin film 114 ... Adhesive layer 115 ... Protective film 200 ... Manufacturing equipment 201, 202 ... Feeding device 203 ... Winding device 205 ... Drying device 300 ... Manufacturing equipment 301, 307 ... Feeding device 302 to 305 ... Processing device 306, 309 ... Drying device 308 ... Laminating device 310 ... Winding device

Claims (12)

A resin film made of cycloolefin resin and
A polarizing plate laminate having a polyvinyl alcohol layer laminated by coating on at least one surface of the resin film.
The cycloolefin-based resin contains a cycloolefin-based polymer and contains
The cycloolefin-based polymer contains a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, and
A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound. Polymer block [C] as the main component and
A laminate for a polarizing plate, which is a hydride of a block copolymer composed of hydrogenated block copolymer [D]. The thickness T of the polyvinyl alcohol layer is 45 μm or less, and
The in-plane retardation Re2 of the stretched product of the resin film is 0 nm or more and 20 nm or less, and the retardation Re2 makes the laminate 6.0 times free-end uniaxial under temperature conditions of 50 ° C. to 120 ° C. The laminate for a polarizing plate according to claim 1, which is the phase difference possessed by the stretched product when the resin film is stretched to form the stretched product. The laminate for a polarizing plate according to claim 1 or 2, wherein the cycloolefin resin contains a plasticizer, a softening agent, or both of them. The laminate for a polarizing plate according to claim 3, wherein the plasticizer, the softener, or both of them is one or more selected from an ester plasticizer and an aliphatic hydrocarbon polymer. The laminate for a polarizing plate according to any one of claims 1 to 4, wherein the resin film contains an organometallic compound. The laminate for a polarizing plate according to any one of claims 1 to 5, wherein the polyvinyl alcohol layer is a layer directly laminated on the resin film. A polarizing plate obtained by uniaxially stretching the laminate for polarizing plate according to any one of claims 1 to 6. A polarizing plate laminate according to any one of claims 1 to 6 and a separator film laminated on a surface of the resin film of the laminate opposite to the polyvinyl alcohol layer.
A laminated film roll for polarizing plates, which is wound into a roll shape. The first step of coating a polyvinyl alcohol resin on at least one surface of a resin film made of a cycloolefin resin to form a polyvinyl alcohol layer, and
The second step of drying the polyvinyl alcohol layer formed in the first step is included in this order.
The cycloolefin-based resin contains a cycloolefin-based polymer and contains
The cycloolefin-based polymer contains a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component, and
A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound. Polymer block [C] as the main component and
A method for producing a laminate for a polarizing plate, which is a hydride of a block copolymer composed of hydrogenated block copolymer [D]. The method for producing a laminate for a polarizing plate according to claim 9, wherein the polyvinyl alcohol layer is formed by one or more methods selected from solution coating, emulsion coating, and melt extrusion coating. Polarized light using the polarizing plate laminate according to any one of claims 1 to 6 or the polarizing plate laminate obtained by the method for producing a polarizing plate laminate according to claim 9 or 10. It ’s a method of manufacturing a board,
A third step of dyeing the laminate with a dichroic dye, and
A method for producing a polarizing plate, which comprises a fourth step of uniaxially stretching the laminate. After going through the third step, the fourth step, or both of them, the fifth step of laminating a protective film on the surface of the polyvinyl alcohol layer of the laminate opposite to the resin film is included. The method for manufacturing a polarizing plate according to claim 11.

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