KR20200101915A - Polarizing plate laminate, polarizing plate, polarizing plate laminate film roll, polarizing plate laminate manufacturing method and polarizing plate manufacturing method - Google Patents

Abstract

A laminate for polarizing plates 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 contains a cycloolefin polymer, and The olefin-based polymer comprises a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, a repeating unit [I] derived from an aromatic vinyl compound, and a repeating unit [II] derived from a chain conjugated diene compound. A polarizing plate, which is a block copolymer hydride obtained by hydrogenation of a block copolymer [D] consisting of a polymer block [B] 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. Dragon laminate.

Description

Polarizing plate laminate, polarizing plate, polarizing plate laminate film roll, polarizing plate laminate manufacturing method and polarizing plate manufacturing method

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

BACKGROUND ART As a display device such as a liquid crystal display device and an organic electroluminescent (EL) display device, conventionally, a display device having a large display area, a light weight, and a thin thickness has been demanded. Therefore, the panel constituting the display device has conventionally been required to be thin.

In a display device, a polarizing plate provided with a polarizer and a protective film for protecting the polarizer is generally used. In order to construct a thin display device, a thinner polarizing plate is also required. In particular, since the polarizer may shrink in the use environment of the display device, in a display device having a thin and large area, warping due to such shrinkage may be a problem. Accordingly, by employing a thin polarizer having a thickness of 10 μm or less, in addition to a 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 a polarizer of such a thin polyvinyl alcohol is to be manufactured by a conventional manufacturing method, melting of the polarizer is frequent. As a method of preventing the melting of the polarizer and manufacturing a polarizing plate including a thin polarizer, several methods have been proposed.

For example, in Patent Document 1, a polyvinyl alcohol-based resin layer is formed 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, and the laminate is stretched. After the treatment, a method of orienting a dichroic substance to obtain a colored laminate, and stretching the colored laminate to obtain an optical film has been proposed.

Japanese Patent No. 491205 (corresponding publication: US patent No. 8314987 specification)

When manufacturing a thin polarizing plate by the method described in Patent Document 1, a phase difference may occur in the resin film after the stretching treatment due to stretching the laminate 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 since it is peeled and discarded, a waste material is generated. In addition, a protective film for protecting the polarizing plate may be separately prepared and affixed to the polarizing plate may occur.

Accordingly, in the present invention, a resin film can also be used as a protective film, and a laminate for a polarizing plate that can be efficiently produced even if the thickness is thin, a method for producing the same, a polarizing plate using the laminate and a method for producing the same, and the laminate It aims at providing a laminated body film roll for polarizing plates using a sieve.

As a result of examining in order to solve the above problems, the present inventors found that a resin film made of a cycloolefin-based resin containing a predetermined cycloolefin-based polymer, and a polyvinyl alcohol layer laminated on at least one surface of the resin film. The present invention was completed by finding out that the above-described problems can be solved by using a laminate having a laminate.

Therefore, according to the present invention, the following [1] to [12] are provided.

(1) a resin film made of a cycloolefin-based resin, and

A laminate for a polarizing plate having a polyvinyl alcohol layer laminated on at least one side of the resin film by coating,

The cycloolefin-based resin contains a cycloolefin-based polymer,

The cycloolefin polymer is a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, and

A polymer block [B] containing as main components a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or a repeating unit [II] derived from a chain conjugated diene compound as a main component Polymer block [C]

A laminate for a polarizing plate, which is a block copolymer hydride obtained by hydrogenating the block copolymer [D] consisting of.

[2] The thickness T of the polyvinyl alcohol layer is 45 μm or less, and

The retardation Re2 in the in-plane direction of the stretched product of the resin film is 0 nm or more and 20 nm or less, and the retardation Re2 is the free end uniaxially stretched by 6.0 times the layered product under a temperature condition of 50°C to 120°C, and the resin The laminate for polarizing plates according to [1], which is a retardation of the stretched product when the film is used as 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 are at least one selected from an ester plasticizer and an aliphatic hydrocarbon polymer.

[5] The laminate for polarizing plates according to any one of [1] to [4], in which 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 plates according to any one of [1] to [6].

[8] having the laminate for a polarizing plate according to any one of [1] to [6], and a separator film laminated on a surface of the resin film of the laminate on the side opposite to the polyvinyl alcohol layer,

A laminate film roll for polarizing plates wound up in a roll shape.

[9] a first step of forming a polyvinyl alcohol layer by coating a polyvinyl alcohol resin on at least one surface of a resin film made of a cycloolefin resin;

A second step of drying the polyvinyl alcohol layer formed in the first step in this order,

The cycloolefin-based resin contains a cycloolefin-based polymer,

The cycloolefin polymer is a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, and

A polymer block [B] containing as main components a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or a repeating unit [II] derived from a chain conjugated diene compound as a main component Polymer block [C]

A method for producing a laminate for a polarizing plate, which is a block copolymer hydride obtained by hydrogenating the block copolymer [D] consisting of.

[10] The method for producing a laminate for polarizing plates according to [9], wherein the polyvinyl alcohol layer is formed by at least one method selected from solution coating, emulsion coating, or melt extrusion coating.

[11] A polarizing plate using the laminate for polarizing plates according to any one of [1] to [6], or the laminate for polarizing plates obtained by the method for producing a laminate for polarizing plates according to [9] or [10]. As a method of manufacturing,

A third step of dyeing the laminate with a dichroic dye, and

A manufacturing method of a polarizing plate including a fourth step of uniaxially stretching the laminate.

[12] After passing through the third step, the fourth step, or both, the polyvinyl alcohol layer of the laminate includes a fifth step of attaching a protective film to the surface opposite to the resin film. [11 ].

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

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

Hereinafter, the present invention is 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 carried out with arbitrary changes within the scope not departing from the claims of the present invention and their equivalent ranges.

In the present application, the term "long picture" refers to a film having a length of 5 times or more with respect to the width of the film, and preferably has a length of 10 times or more, and specifically, the degree to which it is wound in rolls and stored or transported. It refers to having a length of. 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 retardation Re in the in-plane direction of the film and the retardation Rth in the thickness direction are, according to the formula Re = (nx-ny) × d, and Rth = [{(nx + ny)/2}-nz] × d Calculate. In addition, the Nz coefficient of the film is a value represented by [(nx-nz)/(nx-ny)], and can also be represented by [(Rth/Re) + 0.5]. Here, nx is the refractive index of the film in the in-plane slow axis direction (maximum refractive index in the plane), ny is the refractive index in the in-plane direction perpendicular to the in-plane slow axis of the film, and nz is the refractive index in the thickness direction of the film , d is the thickness (nm) of the film. The measurement wavelength is set to 550 nm, which is a typical wavelength in the visible region, unless otherwise stated.

[Embodiment 1: A laminate for a polarizing plate and its manufacturing method, a laminate film roll for a polarizing plate, a polarizing plate, and a manufacturing method thereof]

Hereinafter, the laminated body for polarizing plates of Embodiment 1 which is an embodiment of the present invention (hereinafter, simply referred to as "laminated body") and its manufacturing method, a laminate film roll for polarizing plates using the laminated body, and the laminated body A polarizing plate using and a manufacturing method thereof will be described with reference to FIGS. 1 to 5.

[One. Laminate for polarizing plate]

The laminate for polarizing plates 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.

1 is an example of a cross-sectional view schematically showing a layered product 10 of Embodiment 1 according to the present invention. As shown in FIG. 1, the laminated body 10 of this embodiment has the resin film 12, and the polyvinyl alcohol layer 11 formed on one surface (the upper surface of an illustration) of the resin film. The laminate 10 of the present invention is a material for manufacturing 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 some cases.

In the present invention, the PVA resin (polyvinyl alcohol resin) forming the PVA layer is not necessarily limited, but for availability, it is preferable to use one produced by saponifying polyvinyl acetate obtained by polymerization of vinyl acetate. Do. The PVA contained in the PVA resin is preferably in the range of 500 to 8000, and the degree of saponification is preferably 90 mol% or more from the viewpoint of excellent stretchability and polarization performance of the obtained polarizer. 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 preferable range of the degree of polymerization is 1000 to 6000, and still more preferably 1500 to 4000. A more preferable range of the degree of saponification is 95 mol% or more, and still more preferably 99 mol% or more. PVA may be a copolymer of vinyl acetate and another monomer copolymerizable or may be a graft polymer.

In the present invention, the PVA resin preferably contains a plasticizer such as 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, In addition, in order to improve handling properties and film appearance, it is preferable to contain surfactants such as anionic surfactants and nonionic surfactants in an amount of 0.01 to 1% by weight based on PVA.

If necessary, the PVA resin may further contain other components such as antioxidants, ultraviolet absorbers, lubricants, pH adjusters, inorganic fine particles, colorants, preservatives, flame retardants, polymer compounds other than the above-described components, and moisture. The PVA resin may contain one or two 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, even more preferably Is not less than 15 μm. When the thickness of the PVA layer is equal to or less than the upper limit of the above range, the shrinking force of the polarizing plate can be effectively lowered, and when the thickness is equal to or greater than the lower limit of the above range, a polarizing plate having sufficiently high polarization performance can be obtained.

The retardation Re1 in the in-plane direction of the PVA layer is preferably 50 nm or less, more preferably 40 nm or less, still more preferably 30 nm or less, preferably 0 nm or more, and more preferably 3 nm or more. When the retardation Re1 in the in-plane direction of the PVA layer is equal to or less than the upper limit of the above range, the laminate can be stretched at a sufficient magnification, and a polarizing plate with high polarization performance can be obtained.

[Resin Film]

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

[Cycloolefin resin]

The cycloolefin-based polymer contained in the cycloolefin-based resin is a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, a repeating unit [I] derived from an aromatic vinyl compound, and a chain conjugated diene compound. Hydrogenated block copolymer [D] consisting of a polymer block [B] containing the derived repeating unit [II] 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. It is a block copolymer hydride. As such block copolymer hydrides, WO2000/32646, WO2001/081957, Japanese Patent Application Publication No. 2002-105151, Japanese Patent Application Publication No. 2006-195242, Japanese Patent Application Publication No. 2011-13378, and WO2015/002020 No. The polymers described in the etc. are mentioned.

[Plasticizer and softener]

In the present invention, it is preferable that the cycloolefin-based resin forming the resin film contains a plasticizer and/or a softener (either or both of a plasticizer and a softener). By containing a plasticizer and/or a softener, the phase difference generated in the resin film can be made small when the laminate is stretched to obtain a polarizing plate.

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

Although it does not specifically limit as an example of the polyhydric alcohol which is a raw material of the ester plasticizer preferably used in the present invention, 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 the polyhydric carboxylic acid ester plasticizer include dicarboxylic acid ester plasticizers and other polyhydric carboxylic acid ester plasticizers.

Specific examples of the phosphate ester plasticizer include phosphate alkyl esters such as triacetyl phosphate and tributyl phosphate; Phosphate cycloalkyl esters such as tricyclopentyl phosphate and cyclohexyl phosphate; And phosphate aryl esters such as triphenyl phosphate and tricresyl phosphate.

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

As the polymer softener, specifically, an aliphatic hydrocarbon polymer, an alicyclic hydrocarbon polymer, ethyl polyacrylate, polymethyl methacrylate, a copolymer of methyl methacrylate and 2-hydroxyethyl methacrylate, and methacrylic acid Acrylic polymers such as a copolymer of methyl, methyl acrylate, and 2-hydroxyethyl methacrylate; Vinyl polymers such as polyvinyl isobutyl ether and poly N-vinylpyrrolidone; Styrenic polymers such as polystyrene and poly4-hydroxystyrene; Polyesters such as polybutylene succinate, polyethylene terephthalate, and polyethylene naphthalate; Polyethers such as polyethylene oxide and polypropylene oxide; Polyamide, polyurethane, polyurea, and the like.

Specific examples of the aliphatic hydrocarbon polymer include low molecular weight substances such as polyisobutylene, polybutene, poly-4-methylpentene, poly-1-octene, and ethylene/α-olefin copolymer, and hydrides thereof; And low molecular weight substances such as polyisoprene and polyisoprene-butadiene copolymer, and hydrides thereof. From the viewpoint of being easily dissolved or dispersed uniformly 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 a homopolymer composed of one type of repeating unit, or may be a copolymer having a plurality of repeating structures. Moreover, you may use in combination of 2 or more types of said polymers.

In the present invention, the plasticizer and/or softener is preferably at least one selected from ester plasticizers and aliphatic hydrocarbon polymers from the viewpoint of particularly excellent compatibility with a resin forming a resin film.

The ratio of the plasticizer and/or softener (hereinafter also referred to as ``plasticizer, etc.'') in the resin film is preferably 0.2 parts by weight or more, and more preferably 0.5 parts by weight based on 100 parts by weight of the cycloolefin resin forming the resin film. It is at least 1.0 part by weight, even more preferably at least 1.0 part by weight, while it is preferably at most 50 parts by weight, and more preferably at most 40 parts by weight. By making the ratio of a plasticizer etc. into the said range, even if the resin film passes through the manufacturing process of a polarizing plate including an extending|stretching process, the expression property of a retardation can be made low enough.

[Organic metal compound]

In the present invention, it is preferable that the resin film contains an organometallic compound. By including the organometallic compound, the occurrence of peeling of the resin film can be more effectively suppressed when the laminate is stretched at a high draw ratio (for example, wet stretch at a draw 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. As an organometallic compound, an organosilicon compound, an organotitanium compound, an organoaluminum compound, an organozirconium compound, etc. are mentioned. Among these, an organosilicon compound, an organotitanium compound, and an organozirconium compound are preferable, and an organosilicon compound is more preferable from the viewpoint of excellent reactivity with polyvinyl alcohol. The organometallic compounds may be used singly or in combination of two or more.

As an organometallic compound, an organosilicon compound represented by the following formula (1) can be mentioned, for example, but is not limited thereto.

R ¹ _a Si(OR ² ) _3-a (1)

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an epoxy group, an amino group, a thiol group, an isocyanate group, and a carbon atom number 1 Represents a group selected from the group consisting of -10 organic groups, and a represents an integer of 0-3.)

In formula (1), preferred examples of R ¹ include an epoxy group, an amino group, a thiol group, an isocyanate group, a vinyl group, an aryl group, an acrylic group, an alkyl group having 1 to 8 carbon atoms, -CH ₂ OC _n H _{2n +1} (n represents the integer of 1-4.) etc. are mentioned.

In addition, in the formula (1), for example preferred as R ² , a hydrogen atom, a vinyl group, an aryl group, an acrylic group, an alkyl group having 1 to 8 carbon atoms, -CH ₂ OC _n H _2n+1 (n is The integer of 1-4 is shown.) etc. are mentioned.

Examples of organosilicon compounds include epoxy-based organosilicon compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-aminopropyltrimethoxysilane. , Amino-based organosilicon compounds such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, isocyanurate-based organosilicon compounds such as tris-(trimethoxysilylpropyl)isocyanurate, Mercapto-based organosilicon compounds, such as 3-mercaptopropyl trimethoxysilane, and isocyanate-based organosilicon compounds, such as 3-isocyanate propyltriethoxysilane, are mentioned.

Examples of the organic titanium compound include titanium alkoxides such as tetraisopropyl titanate, titanium chelates such as titanium acetylacetonate, and titanium acylates such as titanium isostearate.

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

Examples of the organic aluminum compound include aluminum alkoxides such as aluminum secondary butoxide, and aluminum chelates such as aluminum trisacetylacetonate.

The proportion of the organometallic 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 0.03 parts by weight based on 100 parts by weight of the cycloolefin resin forming the resin film. It is not less than a part by weight, on the other hand, it is preferably 1.0 part by weight or less, and more preferably 0.5 part by weight or less. By setting the ratio of the organometallic compound within the above range, the occurrence of peeling of the resin film can be more effectively suppressed in the case of wet stretching the laminate at a high magnification (for example, a draw ratio of 6.0).

[Optional ingredient]

The resin film may contain an optional component in addition to a resin, a plasticizer, an organometallic compound, and the like. Examples of the optional components include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; Resin modifiers such as lubricants; Coloring agents such as dyes and pigments; And an antistatic agent. These blending agents can be used alone or in combination of two or more, and the blending amount is appropriately selected.

[Production method of resin film]

In the resin film, a composition (hereinafter, also referred to as ``resin composition'') containing a component for forming a resin film (a cycloolefin resin and a component added as needed) is formed into a film by an arbitrary molding method. It can be manufactured by doing.

As an example of a method of forming a resin composition into a film, a cast molding method, an extrusion molding method, an inflation molding method, etc. are mentioned, for example.

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 not less than the lower limit of the above range, a laminate having a good bonding surface state can be obtained, and when it is less than the upper limit of the above range, the retardation generated in the resin film when the laminate is stretched to obtain a polarizing plate is reduced. can do.

The shape and dimensions of the resin film can be appropriately adjusted according to the intended use. From the viewpoint of production efficiency, the resin film is preferably a long film.

[Re2 of resin film]

It is preferable that the retardation Re2 in the in-plane direction of the stretched product of the resin film is 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 equal to or less than the upper limit, when the layered product 10 is stretched to form a polarizing plate, the retardation expressed in the resin film can be reduced.

Re2, when the laminate 10 is uniaxially stretched at a free end by 6.0 times under a temperature condition of 50°C to 120°C, and the resin film in the laminate is used as a stretched product, the stretched product of the resin film has, It is the phase difference in the in-plane direction. That is, Re2 is not the retardation of the resin film itself in the laminate, but is a retardation generated in the stretched product of the resin film after applying a specific stretching treatment to the laminate.

The stretching temperature for obtaining such a stretched product may be any temperature within the range of 50°C to 120°C. Accordingly, a plurality of operating conditions for stretching to obtain a stretched product can be considered. In the case where the stretched product exhibits a phase difference of 0 nm or more and 20 nm or less under any of these plurality of operating conditions, the laminate satisfies the above requirements.

However, it is preferable that the stretched product exhibits a retardation of 0 nm or more and 20 nm or less depending on all of the plurality of operation conditions that can be taken. In that case, in the manufacture of a polarizing plate by the laminated body for polarizing plates of this invention, a high degree of freedom in setting the stretching conditions can be obtained.

In general, in the temperature range, when the stretching temperature is lower, a larger phase difference is expressed. Therefore, if both of the retardation of the stretched product by stretching at 50°C and the retardation of the stretched product by stretching at 120°C are within the range of 0 nm or more and 20 nm or less, the stretched product is 0 nm or more according to all of the plurality of operating conditions. It can be determined that a retardation of 20 nm or less is expressed.

[2. Manufacturing method of laminated body]

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

[Laminate Manufacturing Equipment]

2 is a schematic diagram schematically showing an example of a manufacturing apparatus 200 used in the method for manufacturing a laminate according to the present embodiment. The manufacturing apparatus 200 includes a unwinding device 201, a coating device 202, a winding device 203, and a drying device 205.

[Method of manufacturing laminate]

As shown in Fig. 2, the surface of the resin film 12 unwound from the unwinding device 201 is coated with a PVA resin in the coating device 202 to form the PVA layer 11 (first step), Thereafter, the layered product 10 is obtained by passing through a step (second step) of drying in the drying device 205. The manufactured laminated body 10 is wound up by the take-up device 203, and can be made into the shape of a roll, and can be provided to other processes. Each step will be described below.

[First step]

The first step is a step of forming the PVA layer 11 by coating a PVA resin on at least one surface of the resin film 12 made of a cycloolefin resin. The method of coating the PVA resin on the resin film 12 (coating method) is not particularly limited, but is preferably at least one method selected from solution coating, emulsion coating, or melt extrusion coating, and high speed Solution coating is more preferable in that application is possible and a PVA layer having a uniform film thickness is obtained.

In the case of performing solution coating, PVA (PVA or PVA film) used for formation of the PVA layer 11 and components added as necessary are dissolved in a solvent to obtain a PVA composition, and the PVA composition is applied to the resin film 11. To coat. That is, the phrase "coating a resin" includes both when coating only a resin and when coating a resin composition containing a resin and other components.

[Second process]

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 for 0.5 to 10 minutes in a dryer having a temperature of 50°C to 120°C. The drying temperature of the PVA layer is more preferably 60°C or higher, and more preferably 100°C or lower. By making the drying temperature more than the lower limit, the drying time can be shortened, the occurrence of cracks in the PVA layer can be prevented, and the crystallization of the PVA layer can be suppressed by making the drying temperature less than the upper limit.

[Random process]

The manufacturing method of the laminated body of the present invention may include a step of treating the surface on which the PVA layer of the resin film is formed to be easily adhered before the first step. Corona treatment, saponification treatment, primer treatment, anchor coating treatment, etc. are mentioned as a method of adhesion easy treatment in the said process. In this step, by treating the surface of the resin film with easy adhesion, the adhesion between the resin film and the PVA layer can be improved, and peeling of the PVA layer at the time of forming the PVA layer can be suppressed.

[Use of laminate]

The laminate 10 of the present invention is a material for manufacturing a polarizing plate. The layered product becomes a polarizing plate after performing predetermined treatments such as stretching treatment and dyeing treatment. When the layered product 10 is used as a material for a polarizing plate, the layered product wound up by the take-up device 203 shown in FIG. 2 may be used as it is, and the resin film of the layered product 10 wound up in the take-up device 203 You may use it after laminating a separator film on (12), winding up in a roll shape, and setting it as a laminated film roll. Hereinafter, the laminated film roll and the polarizing plate of the present embodiment using the laminate 10 of the present embodiment will be described in order.

[3. Laminate film roll for polarizing plate]

3 is a cross-sectional view schematically showing a laminate film roll for polarizing plates using the laminate according to the present embodiment.

As shown in FIG. 3, the laminate film roll 15 for polarizing plates of this embodiment is on the opposite side of the laminate 10 and the PVA layer 11 of the resin film 12 of the laminate 10. It is a film roll which has the separator film 13 laminated|stacked on the surface (shown lower side surface), and wound up in a roll shape. The laminate film roll 15 of the present embodiment includes a resin film 12, a laminate 10 having a PVA layer 11 laminated on one surface of the resin film 12, and a laminate 10 ) Has a separator film 13 laminated on the side opposite to the PVA layer 11 of the resin film 12.

The separator film 13 is not particularly limited as long as it is a film made of a material that can be peeled 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 film made of at least one resin selected from triacetylcellulose resins can be used.

[4. Manufacturing method of polarizing plate]

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

The manufacturing method of a polarizing plate of this invention includes a 3rd process of dyeing a layered product with a dichroic dye, and a 4th process of uniaxially stretching a layered product.

In addition, after passing through the 3rd process and/or 4th process, the manufacturing method of the polarizing plate of this invention may include a 5th process of bonding a protective film on the side opposite to the resin film of the PVA layer of a laminated body. . In this embodiment, a polarizing plate is manufactured by the manufacturing method which does not include a 5th process.

[Device for manufacturing a polarizing plate]

As shown in FIG. 4, the manufacturing apparatus 300 which manufactures a polarizing plate is unwinding apparatuses 301, 307, processing apparatuses 302-305, drying apparatuses 306, 309, bonding apparatus 308, and winding up It has a device 310.

[Polarizing plate manufacturing method]

In this embodiment, the layered product 10 unwound from the unwinding device 301 is conveyed to the processing devices 302 to 305 to dye the PVA layer 11 of the layered product 10 (product Step 3), a stretching treatment for uniaxially stretching the laminate (4th step), and a predetermined treatment. The polarizing plate 100 is obtained by performing a treatment (drying step) of drying the laminate after performing these treatments in the drying device 306. Hereinafter, each process will be described in detail.

[Third process]

The 3rd process is a process of dyeing the PVA layer 11 of the laminated body 10.

As a substance for dyeing the PVA layer in the third step, a dichroic substance is mentioned, and as a dichroic substance, iodine, an organic dye, etc. are mentioned. 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. In addition, when iodine is used as the dichroic substance, the dyeing solution may contain iodide such as potassium iodide from the viewpoint of increasing dyeing efficiency. The dichroic material is not particularly limited, but when the polarizing plate is used in a vehicle-mounted display device, an organic dye is preferable as the dichroic material.

[4th process]

The 4th process is a process of uniaxially extending a laminated body. Although it does not specifically limit as a method of extending|stretching a laminated body, Wet stretching is preferable. The 4th process may be performed before the 3rd process, after the 3rd process, and at any time simultaneously with the 3rd process. Moreover, the 4th process may be performed once or may be performed multiple times (two or more times). When performing the fourth step a plurality of times, it may be performed by dividing into two or more of the above periods, or may be performed a plurality of times in one 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. If the draw ratio of the laminate is less than or equal to the upper limit of the above range, the expression of the retardation of the resin film can still be lowered even after the manufacturing process of the polarizing plate including the stretching treatment, thereby preventing the occurrence of breakage of the polarizing plate. When the magnification is more than the lower limit of the above range, a polarizing plate having sufficient polarization performance can be obtained. In the case where stretching of the laminate is performed two or more times, it is preferable that the total stretching ratio represented by the product of the stretching ratios for each time 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, and more preferably 90°C or lower. , Particularly preferably 70°C or less. When the stretching temperature is equal to or greater than the lower limit of the range, stretching can be smoothly performed, and when the stretching temperature is equal to or less than the upper limit of the range, effective orientation can be performed by stretching. The range of the stretching temperature is preferably any method of dry stretching and wet stretching, but particularly preferably in the case of wet stretching.

The stretching treatment of the laminate may be any of a longitudinal stretching treatment that stretches in the longitudinal direction of the film, a transverse stretching treatment that stretches in the width direction of the film, and an oblique stretching treatment that stretches in an oblique direction that is neither parallel nor perpendicular to the film width direction. You may do it. The stretching treatment of the laminate is preferably uniaxial stretching at the free end, and more preferably uniaxial stretching at the free end in the longitudinal direction.

[Drying process]

The drying process is a process of drying the layered product that has been subjected to treatment processes such as a third process and a fourth process. In the drying process, it is preferable to dry the layered product after the treatment process in a dryer at 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 a lower limit or higher, the drying time can be shortened and the occurrence of cracks in the PVA layer can be prevented, and by setting the drying temperature to an upper limit or lower, the cracking of the PVA layer can be prevented. 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 be equal to or more than the lower limit, drying of the laminate is sufficient, and by setting the drying time to be equal to or less than the upper limit, cracking of the PVA layer in the laminate can be prevented.

In the conventional thin film polarizer composed of only PVA resin, cracks may occur after the drying process, but the polarizing plate of this embodiment is manufactured using a laminate comprising a PVA layer and a resin film composed of a cycloolefin resin. Therefore, even after passing through the drying process, it is possible to suppress the occurrence of cracks in the polarizer.

[5. Polarizer]

The polarizing plate is obtained by the manufacturing method of the polarizing plate of this embodiment mentioned above. The polarizing plate of this embodiment is a polarizing plate obtained by uniaxially stretching the laminate of this embodiment. 5 is a cross-sectional view schematically showing a polarizing plate manufactured using the laminate according to the present embodiment.

As shown in FIG. 5, in the polarizing plate 100, a resin film 112 is laminated on one surface (shown lower side surface) of the PVA layer 111.

[Characteristics of each layer in a 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, preferably 3 μm or more, and more preferably 5 μm or more. When the thickness is equal to or less than the upper limit, the thickness of the polarizing plate can be reduced, and when the thickness is equal to or greater than the lower limit, a polarizing plate having sufficiently high polarization performance can be obtained.

The retardation in the in-plane direction 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 retardation in the in-plane direction of the resin film in the polarizing plate is within the above range, the black color shift when the polarizing plate is mounted on a liquid crystal display can be suppressed.

[Use of polarizing plate]

A polarizing plate manufactured by using the laminate for a 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 viewing-side polarizing plate in this order, but the polarizing plate obtained by the present invention may be used for any of a light-source-side polarizing plate and a viewing-side polarizing plate. The said liquid crystal display device can be manufactured by laminating|stacking the polarizing plate of this invention on a liquid crystal panel as both or either of a light source-side polarizing plate and a viewing-side polarizing plate.

Further, the polarizing plate produced by using the laminate for polarizing plates of the present invention can be a material such as an organic EL display device or an inorganic EL display device.

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

The EL display device has two substrates, a light-emitting layer positioned therebetween, and a polarizing plate disposed outside one of the two substrates. This 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 and effect of this embodiment]

In this embodiment, since a polarizing plate is manufactured by stretching a laminate having a resin film and a PVA layer laminated on the resin film, the occurrence of melting of the PVA layer can be suppressed even when the laminate is stretched at a low temperature and high magnification. In addition, it is possible to suppress the expression of the retardation in the resin film after stretching. As a result, according to the present embodiment, the resin film can be used as a protective film on one side of the PVA layer as it is without peeling off, and since waste materials can be reduced, the resin film can also be used as a protective film, and the thickness Even if it is thin, it is possible to provide a method for producing a polarizing plate that can be efficiently manufactured.

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, It is excellent in the rupture suppression effect, and it is possible to prevent environmental pollution by other substances in the production environment and to prevent conformation to the product (contamination of foreign substances).

[Embodiment 2: Polarizing plate and manufacturing method thereof]

Hereinafter, the polarizing plate 120 and the manufacturing method according to the second embodiment will be described with reference to FIGS. 4 and 6. The polarizing plate 120 according to the present embodiment was manufactured using the polarizing plate 100 according to the first embodiment. The same reference numerals are assigned to the same configurations and aspects as those of the first embodiment, and duplicate descriptions are omitted.

[Polarizer]

6 is a cross-sectional view schematically showing a polarizing plate 120 according to Embodiment 2 of the present invention. In this polarizing plate 120, as shown in FIG. 6, a resin film 112 is laminated on one side (shown lower side) of the PVA layer 111, and the other side of the PVA layer 111 (shown The protective film 115 is laminated on the upper side). In Fig. 6, 114 is an adhesive.

After passing through the said 3rd process and 4th process, the manufacturing method of the polarizing plate 120 of this embodiment includes a 5th process of bonding a protective film on the side opposite to the resin film of the PVA layer of a laminated body. It will be described in detail below.

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

The polarizing plate 120 conveys the polarizing plate 100 obtained through dyeing treatment (third step) and stretching treatment (fourth step) to the bonding device 308, and the side opposite to the resin film of the PVA layer of the laminate (5th step) by applying the adhesive 114 to the surface of (the side on which the resin film is not laminated: the upper side shown in the figure) to attach the protective film 115 unwound from the unwinding device 307 Obtained by The obtained polarizing plate 120 is wound up by the take-up device 310, and it can be made into a roll shape, and can be provided to other processes.

The adhesive 114 for bonding the protective film 115 to the PVA layer 111 used in the fifth step is not particularly limited, and, for example, an acrylic adhesive, an epoxy adhesive, a urethane adhesive, a polyester adhesive Adhesives, polyvinyl alcohol adhesives, polyolefin adhesives, modified polyolefin adhesives, polyvinylalkyl 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-(meth)acrylate-based adhesives such as methyl acrylate copolymers, and ethylene-(meth)ethyl acrylate copolymers.

As the protective film 115 used in the fifth step, a film made of at least one resin selected from cycloolefin resin, acrylic resin, polyethylene terephthalate resin, and triacetylcellulose resin is exemplified.

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

In addition, according to the present embodiment, since the protective film 115 is provided on the side of the PVA layer 111 on the side where the resin film 112 is not laminated, it is possible to prevent scratches and the like on the surface of the PVA layer 111. It also exerts a preventive effect.

[Other embodiments]

(1) In Embodiment 1, a laminate for a polarizing plate in which a PVA layer is laminated on one side of a resin film is shown, and in Embodiments 1 and 2, a polarizing plate manufactured using the laminate is shown, but the present invention Is not limited to this. The laminate for polarizing plates may be a laminate in which PVA layers are laminated on both surfaces of a resin film, and the polarizing plate may be a polarizing plate manufactured using the laminate.

(2) In Embodiment 1, a laminate for a polarizing plate having a resin film and a PVA layer directly laminated on the resin film was shown, but a layer for enhancing the bonding strength between the resin film and the PVA layer was provided between the resin film and the PVA layer. It may be a laminated body further provided.

[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 "%" related to the amount ratio of components represent parts by weight unless otherwise stated.

〔Assessment Methods〕

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

The molecular weight of the block copolymer and the block copolymer hydride was measured at 38°C as a standard polystyrene conversion value 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 H-NMR spectrum or GPC analysis. A region with a hydrogenation rate of 99% or less was calculated by measuring a ¹ H-NMR spectrum, and a region exceeding 99% was calculated from the ratio of the peak area by the UV detector and the RI detector by GPC analysis.

[Measurement method of phase difference]

The retardation Re1 in the in-plane direction of the polyvinyl alcohol layer, the retardation Re2 in the in-plane direction of the stretched resin film, and the retardation in the in-plane direction of the resin film in the polarizing plate are determined by a retardation meter (manufactured by Opto Science Co., Ltd., brand name ``Muller Matrix''. It was measured using a polar limiter (Axo Scan)"). At the time of measurement, the measurement wavelength was set to 550 nm.

In the measurement of the retardation Re2, the retardation in the in-plane direction of the resin film generated when the laminate was uniaxially stretched by 6.0 times at a predetermined temperature (50° C. and 120° C.) was measured. In the present application, the retardation in the in-plane direction of the resin film that occurs when the laminate is uniaxially stretched at a free end of 6.0 times under a temperature condition of 50°C, and when the laminate is uniaxially stretched at the free end by 6.0 times under a temperature condition of 120°C. When both of the retardation in the in-plane direction of the generated resin film are in the range of 0 nm or more and 20 nm or less, a resin film that occurs when the laminate is uniaxially stretched at the free end by 6.0 times under a temperature condition of 50°C to 120°C. The retardation Re2 in the in-plane direction of was judged to be 0 nm or more and 20 nm or less.

[Measurement method of thickness]

The thickness of each layer (polyvinyl alcohol layer and resin film) included in the laminate and the thickness of each layer included in the polarizing plate are measured by a thickness meter (manufactured by Mitsutoyo Corporation, brand name ``ABS Digimatic Thinness Gauge (547-401)). )") was measured 5 times, and the average value was taken as the thickness of each layer.

[Evaluation of adhesion]

In the step up to the second stretching treatment in the manufacture of the polarizing plate of each example, A was defined as A, a partly peeled off was B, and C was completely peeled off between the polyvinyl alcohol layer and the resin film.

[Evaluation of drying fairness]

In the drying process at 70°C for 5 minutes in the manufacture of the polarizing plate of each example, the one where no crack was generated in the polarizer was set as A, and the one with occurrence of the crack was set as C.

〔Black color shift〕

The liquid crystal display panel was removed from the liquid crystal display device (manufactured by LG Electronics Japan, brand name ``IPS panel monitor (23MP47)''), the polarizing plate disposed on the viewer side was peeled off, and the polarizing plates produced in Examples and Comparative Examples were removed. , The resin film was bonded to be the panel side. Further, a single polarizer without a protective film was bonded to the side of the polarizing plate produced in Examples and Comparative Examples to reassemble the liquid crystal display device. The absorption axes of the polarizing plate produced in Examples and Comparative Examples and the polarizer alone without a protective film were bonded 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 viewer side is 0° in azimuth and 0° in the vertical direction of the panel, the panel is displayed in black (ie, black is displayed on the entire display screen of the panel). Thus, visually viewed from an azimuth of 45° and an azimuth of 45°, it was determined that A was the same as that of a polarizer without a protective film, B was a slight color change, and C was a large change.

[Example 1]

(1-1) Preparation of polymer X

Referring to the preparation example described in Japanese Patent Application Laid-Open No. 2002-105151, after polymerizing 25 parts of styrene monomer in the first step, 30 parts of styrene monomer and 25 parts of isoprene monomer are polymerized in the second step, and then in the third step. After polymerizing 20 parts of a styrene monomer to obtain a block copolymer [D1], the block copolymer was hydrogenated to synthesize a block copolymer hydride [E1]. Mw of the block copolymer hydride [E1] was 84,500, Mw/Mn was 1.20, and the hydrogenation rate of the main chain and the aromatic ring was approximately 100%.

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

(1-2) Preparation of resin film

After dissolving the polymer X prepared in (1-1) in cyclohexane, 40 parts by weight of polyisobutene (``Nisseki Polybutene HV-300'' manufactured by JX Nikko-Niseki Energy Co., Ltd.), based on 100 parts by weight of the polymer X An average molecular weight of 1,400) and 0.1 parts by weight of an organosilicon compound (3-aminopropyltriethoxysilane, KBM903, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to prepare a coating liquid for cast film formation.

The obtained coating liquid for film formation was applied and dried on a separator film (manufactured by Mitsubishi Chemical Corporation, "MRV38") using a die coater. Thereby, 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) Preparation of laminate

Unstretched polyvinyl alcohol resin film (average degree of polymerization of about 2400, saponification degree of 99.9 mol%, thickness of 20 μm, hereinafter also referred to as “PVA20”) is dissolved in hot water at 95° C., and a polyvinyl alcohol aqueous solution having a concentration of 10% by weight Was prepared. After applying the polyvinyl alcohol aqueous solution to the resin film prepared in (1-2), it was dried at 100° C. for 10 minutes to form a long laminate having a polyvinyl alcohol layer having a width of 600 mm and a thickness of 5 μm. Got it.

The thickness of the resin film in the obtained laminate, the thickness of the polyvinyl alcohol layer, and the retardation Re1 in the in-plane direction, and the retardation Re2 (temperature conditions 50°C, 120°C) were measured. Table 1 shows the results.

(1-3) Preparation of polarizing plate

The following operation was performed while continuously conveying the laminated body manufactured in (1-2) in the longitudinal direction through a guide roll.

The above laminate was subjected to a swelling treatment by immersing in water, a dyeing treatment by immersing in a dyeing solution containing iodine and potassium iodide, and a first stretching treatment of stretching the laminate after the dyeing treatment. Next, a second stretching treatment was performed in which the laminate after the first stretching treatment was stretched in a bath containing boric acid and potassium iodide. It was set so that the total draw ratio indicated by the product of the draw ratio in the first drawing treatment and the draw ratio in the second drawing treatment was 6.0. The stretching temperature was 57°C. The laminate after the second stretching treatment was dried in a dryer at 70° C. for 5 minutes (drying step) to obtain a polarizing plate.

In the steps up to the second stretching treatment, adhesion was evaluated, in the drying step, drying fairness was evaluated, and the obtained polarizing plate was evaluated for black color shift. Table 1 shows the evaluation results.

Further, the thickness and retardation of the resin film in the obtained polarizing plate, and the thickness of the polyvinyl alcohol layer were measured. Table 1 shows the measurement results.

[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 an organic titanium compound (tetraisopropyl titanate, Orgatics TA-8, manufactured by Matsumoto Fine Chemical) was added to the film formation. Except having formed the resin film using the solvent coating liquid, it carried out similarly to Example 1, and produced the laminated body and a polarizing plate, and evaluated similarly to Example 1. Table 1 shows the results.

[Example 3]

In Example 1 (1-2), instead of 0.1 parts by weight of the organosilicon compound, 0.1 parts by weight of an organic zirconium compound (normal propyl zirconate, Orgatics ZA-45, manufactured by Matsumoto Fine Chemical) was added to the film formation. Except having formed the resin film using the solvent coating liquid, it carried out similarly to Example 1, and produced the laminated body and a polarizing plate, and evaluated similarly to Example 1. Table 1 shows the results.

[Example 4]

In Example 1 (1-2), when performing the operation of applying and drying the film-forming coating liquid to the separator film using a die coater, the coating amount, etc. were adjusted, and a long resin film having a thickness of 5 μm Except having produced (the width and length are the same as in Example 1), a laminate and a polarizing plate were produced in the same manner as in Example 1, and evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

[Example 5]

In Example 1 (1-2), except not using polyisobutene, a laminate and a polarizing plate were produced in the same manner as in Example 1, and evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[Example 6]

In Example 1 (1-2), when performing the operation of applying and drying the one without using the organosilicon compound and the film-forming coating liquid on the separator film using a die coater, the amount of coating, etc., was adjusted. , Except for preparing a long resin film (width and length is the same as in Example 1) having a thickness of 5 μm, in the same manner as in Example 1, to prepare a laminate and a polarizing plate, and evaluated in the same manner as in Example 1. Was done. The results are shown in Table 2.

[Comparative Example 1]

As a result of performing the same operation as in (1-3) in (1-3) of Example 1, using only the unstretched polyvinyl alcohol resin film (PVA20) instead of the laminate produced in (1-2) , In the first stretching treatment and the second stretching treatment, the fusing occurred frequently, and in the drying step, the fusing occurred frequently, and the adhesion and the black color shift could not be evaluated.

[Comparative Example 2]

In (1-3) of Example 1, in place of the resin film produced in (1-2), a cycloolefin resin film (Zeonoa film, a ring-opening polymer hydride of an alicyclic hydrocarbon, manufactured by Nippon Xeon Corporation, thickness 13 μm) was used, and a laminate was produced in the same manner as in Example 1. As a result of performing the same operation as in Example 1 (1-4) using the laminate, fracture occurred in the first stretching treatment, and a polarizing plate could not be produced.

The evaluation results of Examples and Comparative Examples are shown in Tables 1 and 2.

In the table, "COP" means a cycloolefin resin.

In the table, "Re2 (50°C)" refers to the phase difference in the in-plane direction of the resin film that occurs when the laminate is uniaxially stretched at a free end of 6.0 times under a temperature condition of 50°C, and "Re2 (120°C)" Means a retardation in the in-plane direction of a resin film that occurs when the laminate is uniaxially stretched at a free end of 6.0 times under a temperature condition of 120°C.

In the table, "Re1" means the phase difference in the in-plane direction of the polyvinyl alcohol layer in the laminate.

In the table, "coating" indicates that a PVA layer was formed by applying an aqueous solution of polyvinyl alcohol to a resin film.

From the results of Tables 1 and 2, according to the present invention, it is possible to reduce the retardation expressed in the resin film after passing through the step of stretching the laminate, and to obtain a polarizing plate excellent in adhesion, drying processability and optical properties. Able to know. Thereby, a resin film can also be used as a protective film, and a laminate for a polarizing plate that can be efficiently produced even if the thickness is thin, a method for producing the same, a polarizing plate using the laminate and a method for producing the same, and a roll for a laminate film for a polarizing plate You can see what you can offer.

10… Laminate (Laminate for Polarizing Plates)
11... Polyvinyl alcohol layer (PVA layer)
12... Resin film
13... Separator film
15... Laminate film roll
100, 120... Polarizer
111... Polyvinyl alcohol layer (PVA layer)
112... Resin film
114... Adhesive layer
115... Protective film
200… Manufacturing device
201, 202... Unwinding device
203... Winding device
205... Drying device
300… Manufacturing device
301, 307... Unwinding device
302~305... Processing unit
306, 309... Drying device
308... Bonding device
310... Winding device

Claims (12)

A resin film made of a cycloolefin-based resin,
A laminate for a polarizing plate having a polyvinyl alcohol layer laminated on at least one side of the resin film by coating,
The cycloolefin-based resin contains a cycloolefin-based polymer,
The cycloolefin polymer is a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, and
A polymer block [B] containing as main components a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or a repeating unit [II] derived from a chain conjugated diene compound as a main component Polymer block [C]
A laminate for a polarizing plate, which is a block copolymer hydride obtained by hydrogenating the block copolymer [D] consisting of The method of claim 1,
The thickness T of the polyvinyl alcohol layer is 45 μm or less, and,
The retardation Re2 in the in-plane direction of the stretched product of the resin film is 0 nm or more and 20 nm or less, and the retardation Re2 is the free end uniaxially stretched by 6.0 times the layered product under a temperature condition of 50°C to 120°C, and the resin A laminate for a polarizing plate which is a retardation of the stretched product when the film is used as the stretched product. The method according to claim 1 or 2,
A laminate for a polarizing plate, wherein the cycloolefin resin contains a plasticizer, a softener, or both. The method of claim 3,
A laminate for a polarizing plate, wherein the plasticizer, the softener, or both are at least one selected from an ester plasticizer and an aliphatic hydrocarbon polymer. The method according to any one of claims 1 to 4,
The laminated body for polarizing plates in which the said resin film contains an organometallic compound. The method according to any one of claims 1 to 5,
The polyvinyl alcohol layer is a layer laminated directly on the resin film, a laminate for a polarizing plate. A polarizing plate obtained by uniaxially stretching the laminate for polarizing plates according to any one of claims 1 to 6. It has the laminated body for polarizing plates in any one of Claims 1-6, and the separator film laminated on the side opposite to the said polyvinyl alcohol layer of the resin film of the said laminated body,
A laminate film roll for polarizing plates wound up in a roll shape. A first step of forming a polyvinyl alcohol layer by coating a polyvinyl alcohol resin on at least one surface of a resin film made of a cycloolefin resin;
A second step of drying the polyvinyl alcohol layer formed in the first step in this order,
The cycloolefin-based resin contains a cycloolefin-based polymer,
The cycloolefin polymer is a polymer block [A] containing as a main component a repeating unit [I] derived from an aromatic vinyl compound, and
A polymer block [B] containing as main components a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound, or a repeating unit [II] derived from a chain conjugated diene compound as a main component Polymer block [C]
A method for producing a laminate for a polarizing plate, which is a block copolymer hydride obtained by hydrogenating the block copolymer [D] consisting of. The method of claim 9,
A method for producing a laminate for a polarizing plate, wherein the polyvinyl alcohol layer is formed by at least one method selected from solution coating, emulsion coating, or melt extrusion coating. To prepare a polarizing plate using the laminate for polarizing plates according to any one of claims 1 to 6, or the laminate for polarizing plates obtained by the method for producing the laminate for polarizing plates according to claim 9 or 10. As a method,
A third step of dyeing the laminate with a dichroic dye, and
A manufacturing method of a polarizing plate including a fourth step of uniaxially stretching the laminate. The method of claim 11,
After passing through the said 3rd process, the said 4th process, or both, the manufacturing method of a polarizing plate comprising a 5th process of bonding a protective film to the surface of the polyvinyl alcohol layer of said laminated body opposite to the resin film.

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