TW201930066A - Layered body for polarizing plate, polarizing plate, layered body film roll, manufacturing method for layered body for polarizing plate, and manufacturing method for polarizing plate - Google Patents

Abstract

This layered body for a polarizing plate includes: a polyvinyl alcohol resin film having a transmittance of at least 50% for light with a wavelength of 550nm; and a resin layer directly layered on at least one surface of the polyvinyl alcohol resin film. The resin layer is preferably formed by coating a resin on the polyvinyl alcohol resin film. The present disclosure also provides a manufacturing method for the layered body for the polarizing plate, a polarizing plate manufactured by using the layered body for the polarizing plate, a layered body film roll, and a manufacturing method for the polarizing plate.

Description

Stacker for polarizing plate, polarizing plate, stacked film roll, method for manufacturing stacked body for polarizing plate, and manufacturing method of polarizing plate

The present invention relates to a stacked body for a polarizing plate, a polarizing plate, a stacked film roll, a method for producing a stacked body for a polarizing plate, 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 small thickness. Therefore, the panels constituting the display device have been required to be thinner in the past.

In the display device, a polarizing plate having a polarizing member and a protective film for protecting the polarizing member is generally used. In order to form a thin display device, a polarizing plate is also required to be thinner. In particular, since the polarizer sometimes shrinks in the use environment of the display device, such bending due to shrinkage may become a problem in a thin and large display device. Therefore, by using a thin polarizer having a thickness of 10 μm or less, in addition to the reduction in the thickness of the display device due to the reduction in the thickness of the polarizer itself, reduction in the occurrence of the aforementioned bending can be expected.

However, in the case where a polarizing member of such a thin polyvinyl alcohol is to be produced by a conventional manufacturing method, the melting of the polarizing member frequently occurs. As a method of manufacturing such a polarizing plate that prevents the fuse from being blown and includes a thin polarizer, several methods have been proposed.

For example, in Patent Document 1, it is proposed to apply an aqueous solution containing a polyvinyl alcohol-based resin to a resin film made of an amorphous ester-based thermoplastic resin, thereby producing a polyvinyl alcohol-based resin layer to form a stacked body. After the stack is subjected to the stretching treatment, the dichroic substance is oriented to form a colored stack, and the colored stack is further subjected to a stretching treatment to obtain an optical film.

"Patent Literature"
Patent Document 1: Japanese Patent No. 4691205 (corresponding publication: US Patent No. 8314987)

When a thin polarizing plate is produced by the method described in Patent Document 1, the stacked body is stretched at a high stretching ratio, and a phase difference occurs in the resin film after the stretching treatment. In this case, since it is difficult to directly use the resin film as a polarizing plate protective film, it is peeled off and discarded, so that a wasteful material is generated. Furthermore, it is possible to add a work for separately preparing a protective film for protecting the polarizing plate and attaching it to the polarizing plate.

In view of the above, it is an object of the present invention to provide a stack for a polarizing plate which can be efficiently produced even if a resin film (resin layer) is used as a protective film, and which can be efficiently manufactured even if the thickness is thin, and a method for producing the same, and a stack using the same A polarizing plate and a method of manufacturing the same, and a stacked film roll for a polarizing plate using the aforementioned stacked body.

As a result of research conducted to solve the above problems, the inventors have found that by using a polyvinyl alcohol resin film having a transmittance of 50% or more of light having a specified wavelength and a resin layer directly stacked on the film. The stack has to solve the above problems, and the present invention has been completed.

Therefore, according to the present invention, the following [1] to [18] can be provided.

[1] A stack for a polarizing plate, comprising:
A polyvinyl alcohol resin film having a transmittance of light having a wavelength of 550 nm of 50% or more and a resin layer directly stacked on at least one side of the polyvinyl alcohol resin film.

[2] The stacked body for a polarizing plate according to [1], wherein the resin layer is a resin layer formed by coating a resin with the polyvinyl alcohol resin film.

[3] The stack for polarizing plates according to [1], wherein the phase difference Re1 in the in-plane direction of the polyvinyl alcohol resin film is 50 nm or less.

The laminate for polarizing plates according to any one of the above aspects, wherein the polyvinyl alcohol resin film has a thickness T of 45 μm or less and an in-plane direction of the extension of the resin layer. The phase difference Re2 is 0 nm or more and 20 nm or less, and the phase difference Re2 is uniaxially extended to 6.0 times the free end of the stack for polarizing plates at a temperature of 50 ° C to 120 ° C, and the resin layer is formed. When the extension is formed, the extension has a phase difference.

[5] The stack for polarizing plates according to any one of [1], wherein the thickness of the resin layer is 50 μm or less.

[6] The stack for polarizing plates of any one of [1] to [5], wherein the resin layer is made of a cycloolefin resin.

[7] The stack for polarizing plates according to the above [6], wherein the cycloolefin-based resin contains a cycloolefin polymer.
The cycloolefin-based polymer is a block copolymer hydrogenated product obtained by hydrogenating the block copolymer [D], and the block copolymer [D] is composed of:
a polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as a main component, and a repeating unit [I] derived from an aromatic vinyl compound and a chain conjugated diene compound The repeating unit [II] is a polymer block [B] as a main component, or a polymer block [C] having a repeating unit [II] derived from a chain conjugated diene compound as a main component.

[8] The stack for polarizing plates of any one of [1] to [7], wherein the resin layer contains a plasticizer, a softener, or both.

The above-mentioned plasticizer, the softener or both are selected from one or more of an ester plasticizer and an aliphatic hydrocarbon polymer, in the stack for a polarizing plate according to the above aspect.

[10] The stack for polarizing plates of any one of [1], wherein the resin layer contains an organometallic compound.

[11] A polarizing plate according to any one of [1] to [10], wherein the stack for polarizing plates is uniaxially stretched.

[12] A stacked film roll which is wound into a roll and has:
The separator for a polarizing plate according to any one of [1] to [10], and a separator which is laminated on a surface of the resin layer of the polarizing plate stack opposite to the polyvinyl alcohol resin film.

[13] A method for producing a stack for a polarizing plate, comprising:
a first step of coating a resin with at least one surface of a polyvinyl alcohol resin film having a transmittance of 50% or more at a wavelength of 550 nm to form a resin layer; and drying the resin layer formed in the first step The second process.

[14] The method for producing a stack for a polarizing plate according to [13], wherein the coating method is one or more selected from the group consisting of solution coating, emulsion coating or melt extrusion coating.

[15] The method for producing a stack for a polarizing plate according to [13] or [14], comprising a third step of heat-treating the polyvinyl alcohol resin film before the first step.

The method for producing a stack for a polarizing plate according to any one of the aspects of the present invention, comprising: activating the surface of the polyvinyl alcohol resin film before the first step The fourth process.

[17] A method of producing a polarizing plate according to any one of [1] to [10], wherein the stack of polarizing plates according to any one of [13] to [16] is used. A method for manufacturing a polarizing plate by using a stacked body for a polarizing plate obtained by a method for manufacturing a stacked body of a polarizing plate, comprising:
The fifth step of dyeing the stack for polarizing plates with a dichroic dye and the sixth step of uniaxially stretching the stack for polarizing plates.

[18] The method for producing a polarizing plate according to [17], comprising: a resin of a polyvinyl alcohol resin film and a resin in the stack for a polarizing plate after the fifth step and/or the sixth step The surface on the opposite side of the layer is bonded to the seventh step of the protective film.

According to the present invention, it is possible to provide a stack for a polarizing plate which can be used even if a resin film (resin layer) is used as a protective film, and which can be efficiently manufactured even if the thickness is thin, a method for producing the same, and a polarizing plate using the above-mentioned stacked body. And its manufacturing method, as well as stacked film rolls.

The embodiments and examples are disclosed below to explain the present invention in detail. However, the present invention is not limited by the embodiments and the examples described below, and may be arbitrarily changed without departing from the scope of the invention and the scope of the invention.

In the present application, the term "long strip" refers to a length of 5 times or more with respect to the width of the film, preferably 10 times or more, and specifically means that it has a rollable shape. The length of the degree of storage or handling in the form of a roll. The upper limit of the ratio with respect to the length of the film width is not particularly limited, but is, for example, 100,000 times or less.

In the present application, the phase difference Re of the in-plane direction of the film and the phase difference Rth in the thickness direction are follows: Re=(nx-ny)×d and Rth={[(nx+ny)/2]-nz}×d And calculated. And the Nz coefficient of the film is a value represented by [(nx-nz)/(nx-ny)], and is also expressed as [(Rth/Re)+0.5]. Here, the refractive index in the slow axis direction of the nx-based film (the maximum refractive index in the plane), the refractive index of the ny-line in the in-plane direction perpendicular to the slow axis in the plane of the film, and the thickness direction of the nz-based film. The refractive index, the thickness (nm) of the d-type film. The measurement wavelength, unless otherwise noted, is set to a representative wavelength of 550 nm in the visible region.

[Embodiment 1: Stack for polarizing plate, manufacturing method thereof, stacked film roll, polarizing plate, and manufacturing method thereof]

Hereinafter, a stack for a polarizing plate according to an embodiment 1 of the present invention (hereinafter also simply referred to as a "stack"), a method for manufacturing the same, and a stack using the stacked body will be described with reference to FIG. 1 to FIG. A film roll, a polarizing plate using the same, and a method of manufacturing the same.

[1. Stack]

The stacked body of the present invention has a polyvinyl alcohol resin film having a transmittance of light having a wavelength of 550 nm of 50% or more, and a resin layer directly stacked on at least one side of the polyvinyl alcohol resin film.

As the article clearly states, in the present application, the "resin layer" is a layer different from the polyvinyl alcohol resin film.

In the present application, the resin layer which is "directly stacked" on the surface of the polyvinyl alcohol resin film is a resin layer in the following state: it is formed on the surface of the layer body of the material constituting the polyvinyl alcohol resin film, and as a result, The faces of the polyvinyl alcohol resin film are directly joined.

Fig. 1 is a cross-sectional view showing an example of a stack 10 of an embodiment 1 of the present invention. As shown in Fig. 1, the stacked body 10 of the present embodiment comprises an unstretched polyvinyl alcohol resin film 11 and a resin layer 12 provided on one surface (the upper side in the figure) of the polyvinyl alcohol resin film 11. The stacked body 10 of the present invention is used to manufacture a material of a polarizing member (polarizing plate).

[Polyvinyl alcohol resin film]

In the present invention, the polyvinyl alcohol resin film is a transmittance of light having a wavelength of 550 nm (hereinafter, "the transmittance of light having a wavelength of 550 nm" is referred to as "light transmittance") is 50% or more. film. In the present invention, as the polyvinyl alcohol resin film, an uncolored film is used. The light transmittance of the polyvinyl alcohol resin film is preferably 55% or more, more preferably 60% or more, and most preferably 99% or less, and more preferably 97% or less.

The polyvinyl alcohol resin film is an unstretched film made of a polyvinyl alcohol resin (hereinafter, "polyvinyl alcohol" is abbreviated as "PVA"). In the present application, the term "unstretched film" means a person who is not supplied with an extension processor.

In the present invention, the PVA resin film (polyvinyl alcohol resin film) is not limited, but in terms of availability, etc., it is produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. good. The PVA contained in the PVA resin is preferably in the range of 500 to 8,000, and the degree of saponification is preferably 90 mol% or more from the viewpoint of excellent extensibility or polarizing performance of the polarizer which can be obtained. Here, the degree of polymerization is an average degree of polymerization measured in accordance with the description of JIS K6726-1994, and the degree of saponification is a value measured in accordance with the description of JIS K6726-1994. The polymerization degree is preferably in the range of 1,000 to 6,000, more preferably 1,500 to 4,000. The preferred range of saponification degree is 95 mol% or more, and more preferably 99 mol% or more. PVA can also be a copolymer or graft polymer of vinyl acetate with other monomers copolymerizable.

In the present invention, the method for producing the PVA resin film is not particularly limited, and it can be produced by any method such as a well-known method. Examples of the production method include a cast film forming method using a PVA solution in which a PVA is dissolved in a solvent, a wet film forming method (discharging into a poor solvent), and a dry-wet film forming method. A gel film forming method (a method in which a PVA aqueous solution is cooled and gelated, and a solvent is removed to obtain a PVA resin film), and a combination thereof. Another example of the production method is a melt extrusion film formation method in which a material obtained by melting a solvent containing PVA is used as a film forming stock solution. Among these, it is preferable to obtain a resin film of PVA having high transparency and low coloration by a casting film forming method and a melt extrusion film forming method, and melt extruding in order to obtain a high film forming speed. The film forming method is preferred.

In the present invention, the PVA resin film is preferably contained in an amount of 0.01 to 30% by weight based on the PVA, such as a polyhydric alcohol such as glycerin, in order to improve mechanical properties or work smoothness in secondary processing, and to improve the operation. The surfactant or the film appearance or the like is preferably 0.01 to 1% by weight based on the surfactant containing an anionic surfactant or a nonionic surfactant with respect to PVA.

The PVA resin film may further contain an optional component such as an antioxidant, an ultraviolet absorber, a slip agent, a pH adjuster, an inorganic fine particle, a colorant, a preservative, a fungicide, a polymer compound other than the above components, and moisture. The PVA resin film may contain one or more of the above-mentioned optional components.

The thickness T of the PVA resin film is preferably 45 μm or less, preferably 35 μm or less, more preferably 25 μm or less, more preferably 5 μm or more, more preferably 10 μm or more, and 15 μm or more. Better. When the thickness of the PVA resin film is less than or equal to the upper limit of the above range, the contraction force of the polarizing plate can be effectively reduced, and a polarizing plate having a sufficiently high degree of polarization can be obtained by being equal to or higher than the lower limit of the above range.

The phase difference Re1 in the in-plane direction of the PVA resin film is preferably 50 nm or less, preferably 40 nm or less, more preferably 30 nm or less, more preferably 0 nm or more, and preferably 3 nm or more. When the phase difference Re1 in the in-plane direction of the PVA resin film is equal to or less than the upper limit of the above range, the stacked body can be stretched at a sufficient magnification to obtain a polarizing plate having a high degree of polarization.

The shape and size of the PVA resin film are appropriately adjusted to correspond to the intended use. In terms of manufacturing efficiency, the PVA resin film is preferably a long film.

[resin layer]

The resin layer is a layer made of a resin. The resin layer is a resin layer formed by coating a resin with a PVA resin film. In the present invention, the resin forming the resin layer is preferably a resin having flexibility which can be extended at a high stretching ratio (for example, 6.0 times) at a low temperature (for example, 50 to 120 ° C), specifically, a cycloolefin resin. It is better. The cycloolefin resin is a resin containing a cycloolefin polymer.

[resin]

The cycloolefin polymer contained in the cycloolefin resin is preferably a hydrogenated block copolymer obtained by hydrogenating the block copolymer [D], and the block copolymer [D] is derived from: The repeating unit of the aromatic vinyl compound [I] as the main component of the polymer block [A], and the repeating unit derived from the aromatic vinyl compound [I] and the repeating unit derived from the chain conjugated diene compound [ II] A polymer block [B] as a main component or a polymer block [C] having a repeating unit [II] derived from a chain conjugated diene compound as a main component. Examples of such a block copolymer hydride include WO2000/32646, WO2001/081957, Japanese Patent Publication No. 2002-105151, Japanese Patent Publication No. 2006-195242, and Japanese Patent Publication No. 2011- A polymer described in, for example, No. 13378 and WO2015/002020.

[Plasticizers and Softeners]

In the present invention, the resin forming the resin layer preferably contains a plasticizer and/or a softener (either or both of a plasticizer and a softener). By containing a plasticizer and/or a softening agent, the phase difference generated in the resin layer when the polarizing plate is obtained by extending the stacked body can be reduced.

As the plasticizer and the softener, those which can be uniformly dissolved or dispersed to the resin forming the resin layer are used. Specific examples of the plasticizer and the softener include an ester-based plasticizer composed of a polyhydric alcohol and a monocarboxylic acid (hereinafter referred to as a "polyol ester-based plasticizer"), and a polycarboxylic acid and a polycarboxylic acid. An ester-based plasticizer such as an ester-based plasticizer (hereinafter referred to as "polycarboxylic acid ester-based plasticizer"), a phosphate-based plasticizer, a sugar ester-based plasticizer, and other polymerizations Softener.

The polyol which is a raw material of the ester-based plasticizer which is preferably used in the present invention is not particularly limited, but ethylene glycol, glycerin or trimethylolpropane is preferred.

Examples of the polyol ester-based plasticizer include a glycol ester-based plasticizer, a glyceride-based plasticizer, and other polyol ester-based plasticizers.

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

Specific examples of the phosphate ester plasticizer include alkyl phosphates such as triethyl decyl phosphate and tributyl phosphate; cycloalkyl phosphates such as tricyclopentyl phosphate and cyclohexyl phosphate; and triphenyl phosphate. An aryl phosphate such as an ester or a tricresyl phosphate.

Specific examples of the sugar ester plasticizer include glucose pentaacetate, glucose pentapropionate, glucose pentabutyrate, sucrose octaacetate, sucrose octacarboxylate, and the like. Sucrose octaacetate is preferred.

Specific examples of the polymer softener include an aliphatic hydrocarbon polymer, an alicyclic hydrocarbon polymer, polyethyl acrylate, polymethyl methacrylate, methyl methacrylate and -2-hydroxy methacrylate. Acrylic polymer such as copolymer of ethyl ester, methyl methacrylate and copolymer of methyl acrylate and 2-hydroxyethyl methacrylate; polyvinyl isobutyl ether, poly-N-ethylene hydropyrrolidone Ethylene polymer; styrene polymer such as polystyrene or poly-4-hydroxystyrene; polyester such as polybutylene succinate, polyethylene terephthalate or polyethylene naphthalate Polyethers such as polyethylene oxide and polypropylene oxide; polyamines, polyurethanes, polyureas, 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. a hydride; a low molecular weight substance such as a polyisoprene, a polyisoprene-butadiene copolymer, a hydride thereof, or the like. The aliphatic hydrocarbon-based polymer preferably has a number average molecular weight of from 300 to 5,000 from the viewpoint of being easily dissolved uniformly or even dispersed to a cycloolefin resin.

These polymer softeners may be homopolymers composed of one repeating unit or copolymers having a plurality of repeating structures. Further, the above polymers may be used in combination of two or more kinds.

In the present invention, the plasticizer and/or the softening agent are preferably excellent in compatibility with the resin forming the resin layer, and more preferably one or more selected from the group consisting of an ester plasticizer and an aliphatic hydrocarbon polymer. .

The ratio of the plasticizer and/or softener (hereinafter also referred to as "plasticizer" or the like) in the resin layer is preferably 0.2 parts by weight or more, based on 100 parts by weight of the resin forming the resin layer, and is 0.5 weight. The above is preferably 1.0 part by weight or more, more preferably 50 parts by weight or less, and still more preferably 40 parts by weight or less. By setting the ratio of the plasticizer or the like within the above range, even if the manufacturing process of the polarizing plate including the stretching treatment is carried out, the resin layer can be made sufficiently low in phase difference.

[Organic Metal Compounds]

In the present invention, the resin layer preferably contains an organometallic compound. By including the organometallic compound, occurrence of peeling of the resin layer in the case where the stacked body is stretched at a high stretching ratio (for example, wet stretching at a stretching ratio of 6.0) can be more effectively suppressed.

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 an organic ruthenium compound, an organic titanium compound, an organoaluminum compound, and an organic zirconium compound. Among these, in terms of excellent reactivity with polyvinyl alcohol, an organic ruthenium compound, an organic titanium compound, and an organic zirconium compound are preferred, and an organic ruthenium compound is preferred. The organometallic compound may be used alone or in combination of two or more.

The organometallic compound is, for example, an organic ruthenium compound represented by the following formula (1), but is not limited thereto.
R ¹ _a Si(OR ² ) _{3 − a} (1)
(In the formula (1), R ¹ and R ² are each independently selected from a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an epoxy group, an amine group, a decyl group, an isocyanate group, and a carbon atom. A group of groups of 1 to 10 organic groups, and a represents an integer of 0 to 3.)

In the formula (1), a preferred example is as R ¹ , which may, for example, be an epoxy group, an amine group, an anthracenyl group, an isocyanato group, a vinyl group, an acryl group, an aryl group or a —CH ₂ OC _n H _2n+1 (n represents an integer of 1 to 4), an alkyl group having 1 to 8 carbon atoms, or the like.

Further, in the formula (1), a preferable example is as R ² , and examples thereof include a hydrogen atom, a vinyl group, an aryl group, an acryl fluorenyl group, an alkyl group having 1 to 8 carbon atoms, and -CH ₂ OC _{n .} H _2n+1 (n represents an integer of 1 to 4).

Examples of the organic ruthenium compound include epoxy-based organic ruthenium compounds such as 3-glycidoxypropyltrimethoxydecane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane. An amine-based organic ruthenium compound such as 3-aminopropyltrimethoxydecane or N-2-(aminoethyl)-3-aminopropyltrimethoxydecane, or isocyanuric acid (trimethoxydecyl) An isocyanate-based organic ruthenium compound such as an isocyanate-based organic ruthenium compound such as a propyl) ester or an oxime-based organic ruthenium compound such as 3-mercaptopropyltrimethoxydecane or 3-isocyanatopropyltriethoxydecane.

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

Examples of the organic zirconium compound include zirconium alkoxide such as n-propyl zirconate, zirconium chelate such as zirconium tetraacetate acetone, and zirconium zirconium oxide such as zirconium stearate.

Examples of the organoaluminum compound include an alkane alumina such as secondary butyl alumina and an aluminum chelate compound such as aluminum triacetate.

The proportion of the organometallic compound in the resin layer is preferably 0.005 parts by weight or more, more preferably 0.01 parts by weight or more, even more preferably 0.03 parts by weight or more, based on 100 parts by weight of the resin forming the resin layer. On the one hand, it is preferably 1.0 part by weight or less, 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 layer in the case of wet-extending the stacked body at a high magnification (for example, elongation ratio of 6.0) can be more effectively suppressed.

[arbitrary ingredients]

The resin layer may contain an optional component in addition to a resin, a plasticizer, an organometallic compound, or the like. Examples of the optional component include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; resin modifiers such as slip agents; colorants such as dyes and pigments; and antistatic agents. These admixtures may be used singly or in combination of two or more kinds, and the blending amount thereof may be appropriately selected.

[Thickness of Resin Layer]

The thickness of the resin layer is preferably 1 μm or more, more preferably 3 μm or more, and most preferably 50 μm or less, and preferably 20 μm or less. When the thickness of the resin layer is equal to or greater than the lower limit of the above range, it is possible to effectively prevent the polarizing member from being blown in the polarizing plate forming step, and it is possible to reduce the stretching of the stacked body by being equal to or less than the upper limit of the above range. The phase difference generated in the resin layer when the polarizing plate is obtained.

[Re2 of resin layer]

The Re2 of the resin layer is preferably 0 nm or more and 20 nm or less. Re2 is preferably 0 nm or more, and preferably 10 nm or less, and more preferably 5 nm or less. By making Re2 equal to or less than the upper limit, it is possible to reduce the phase difference which appears in the resin layer when the stacked body 10 is stretched to form a polarizing plate.

Re2 is uniaxially stretched to 6.0 times the free end of the stack 10 at a temperature of 50 ° C to 120 ° C, and the surface of the resin layer is formed when the resin layer in the stack is formed as an extension. The phase difference in the inner direction. That is, Re2 is not the phase difference of the resin layer itself in the stack, but the phase difference generated in the extension of the resin layer after a specific extension treatment is applied to the stacked body.

The extension temperature for obtaining such an extension may be any temperature in the range of 50 °C to 120 °C. Thus, a number of operating conditions for obtaining an extension of the extension are contemplated. In the case where the extension exhibits a phase difference of 0 nm or more and 20 nm or less in any of a plurality of operating conditions, the stack satisfies the aforementioned requirements.

However, it is preferable that the extension exhibits a phase difference of 0 nm or more and 20 nm or less due to all of the plurality of operating conditions obtained. In this case, in the manufacture of the polarizing plate that has passed through the stacked body for a polarizing plate of the present invention, a high degree of "degree of freedom in setting extension conditions" can be obtained.

In general, in this temperature range, when the extension temperature is low, a large phase difference appears. Therefore, as long as the "phase difference between the extensions formed by the extension of 50 ° C" and the "phase difference of the extensions formed by the extension of 120 ° C" are in the range of 0 nm or more and 20 nm or less, It is judged that the extension exhibits a phase difference of 0 nm or more and 20 nm or less due to all of the aforementioned plurality of operating conditions.

[2. Method of manufacturing stacked body]

The manufacturing method of the stacked body according to the present embodiment includes, in order, a first step of coating a resin layer on at least one side of a PVA resin film having a transmittance of 50% or more at a wavelength of 550 nm to form a resin layer, and The second step of drying the resin layer formed in the first step.

Further, the method of manufacturing the stacked body may include any one or two steps selected from the following steps: a third step of heat-treating the PVA resin film before the first step, and an activation treatment on the surface of the PVA resin film. The fourth process.

[Manufacturing device of stack]

Fig. 2 is a schematic view showing an example of a manufacturing apparatus 200 used in the method of manufacturing a stacked body according to the present embodiment. The manufacturing apparatus 200 includes a winding device 201, a coating device 202, a winding device 203, a processing device 204 that performs processes such as heat treatment and activation processing, and a drying device 205.

[Manufacturing method of stack]

As shown in FIG. 2, the PVA resin film 11 taken out from the unwinding device 201 is transported to the processing device 204, and is selected from the heat treatment (third process) and the activation process (fourth process) in the processing device 204. After the treatment (treatment step), the resin layer 12 is formed in the coating device 202 (first step), and the drying device 205 is dried (second step) to obtain the stacked body 10. The manufactured stack 10 can be wound into a roll shape by the winding device 203 for further processing. Each step will be described below.

[First process]

The first step is a step of coating a resin on at least one side of the PVA resin film 11 to form the resin layer 12. The method of coating the resin on the PVA resin film 11 (the method of coating) is not particularly limited, but it is preferably one or more methods selected from, for example, solution coating, emulsion coating or melt extrusion coating. A resin layer which can be coated at a high speed and which can obtain a uniform film thickness is preferably coated with a solution.

When the resin layer 12 is formed by solution coating, the resin used for forming the resin layer 12 and the component added as needed are dissolved in a solvent to form a resin composition, and the resin composition is coated. Covered with PVA resin film 11. That is, the term "coating resin" includes both "in the case of coating only a resin" and "in the case of coating a resin composition containing a resin and components other than the resin".

[Second process]

The second step is a step of drying the resin layer formed in the first step.

In the second step, the resin layer is preferably dried in a dryer at a temperature of from 50 ° C to 120 ° C for from 0.5 minute to 10 minutes. The drying temperature of the resin layer is preferably 60 ° C or higher, more preferably 70 ° C or higher, and most preferably 100 ° C or lower, and more preferably 90 ° C or lower. The drying time can be shortened by setting the drying temperature to the lower limit or more, and the crystallization of the PVA resin film can be suppressed by setting the drying temperature to the upper limit or lower.

[Processing procedure]

The treatment step is a step of performing a treatment selected from the group consisting of a heat treatment (third step) and an activation treatment (fourth step).

[Third process]

The third step is a step of heat-treating the PVA resin film before the first step. In the present invention, the third step is optional, and may or may not be included. By heat-treating the PVA resin film in the third step, wrinkles existing in the PVA resin film can be removed, and flatness can be improved. By smoothing the PVA resin film, the film thickness accuracy of the resin layer formed in the first step can be improved. The heating temperature of the PVA resin film is preferably 50 ° C or higher, more preferably 60 ° C or higher, and most preferably 100 ° C or lower, and preferably 90 ° C or lower.

[Fourth process]

The fourth step is a step of activating the surface of the PVA resin film on which the resin layer is to be formed, before the first step. In the present invention, the fourth step is an optional step and may or may not be included. In the fourth step, the surface of the PVA resin film is activated to remove the plasticizer which has bleed out to the surface of the PVA resin film, and the surface of the PVA resin film is oxidized, thereby improving the bonding property of the resin layer and suppressing the formation of the resin layer. The resin layer was peeled off.

Examples of the method of the activation treatment include corona treatment, plasma treatment, saponification treatment, primer treatment, and anchor coating treatment.

The time for performing the fourth step may be performed before the third step, after the third step, or at the same time as the third step, as long as it is not limited before the first step. The plasticizer contained in the PVA resin film may be oozing out to the surface of the PVA resin film by the third step, and the fourth step is preferably performed after the third step.

[Use of stack]

The stacked body 10 of the present invention is a material for manufacturing a polarizing plate. The stacked body is subjected to a predetermined process such as elongation processing and dyeing treatment, and is then formed into a polarizing plate. In the case where the stacked body 10 is used as the material of the polarizing plate, the stacked body wound up by the winding device 203 shown in Fig. 2 can be directly used, or the resin layer 12 of the stacked body wound by the winding device 203 can be used. Stacked on the separator and wound into a roll to form a stack of film rolls for reuse. The stacked film roll and the polarizing plate of this embodiment using the stacked body 10 of the present embodiment will be described in order below.

[3. Stack film roll]

Fig. 3 is a schematic cross-sectional view showing a stacked film roll using the stack of the present embodiment.

As shown in FIG. 3, the stacked film roll 15 of the present embodiment has a stacked body 10, and a face (the upper side in the figure) stacked on the side opposite to the PVA resin film 11 of the resin layer 12 of the stacked body 10. The separator 13 is a film roll wound in a roll shape.

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

[4. Method of manufacturing polarizing plate]

The polarizing plate 100 of the present invention can be obtained by uniaxially stretching the polarizing plate 10 of the present embodiment. FIG. 4 is a schematic view showing an example of a manufacturing apparatus for manufacturing a polarizing plate using the stacked body for a polarizing plate according to the present embodiment.

The method for producing a polarizing plate of the present invention comprises a fifth step of dyeing the stacked body with a dichroic dye and a sixth step of uniaxially stretching the stacked body.

Further, the method for producing a polarizing plate of the present invention may include, after the fifth step and/or the sixth step, bonding the protective film to the surface of the PVA resin film of the stack opposite to the resin layer. Seven processes. The seventh step is an arbitrary step, and in the embodiment, an example in which a polarizing plate is produced by a manufacturing method that does not include the seventh step will be described.

[Device for manufacturing polarizing plate]

As shown in FIG. 4, the manufacturing apparatus 300 for manufacturing a polarizing plate is provided with the winding-out apparatus 301 & 307, the processing apparatus 302-305, the drying apparatus 306 & 309, the bonding apparatus 308, and the winding-up apparatus 310.

[Method of Manufacturing Polarizing Plate]

In the present embodiment, the stacked body 10 taken up from the unwinding device 301 is transported to the processing apparatuses 302 to 305, and the dyeing process (fifth process) of dyeing the PVA resin film 11 of the stacked body 10 is performed, and the stacked body is stacked. The uniaxially extended stretching process (sixth process), and the specified processing. The polarizing plate 100 can be obtained by performing a process (drying process) of "drying the stacked body after the treatment is performed in the drying device 306". Each step will be described in detail below.

[Fifth process]

The fifth step is a step of dyeing the PVA resin film 11 of the stacked body 10. In the present embodiment, although the PVA resin film of the stacked body is dyed, the dyeing of the PVA resin film can be performed on the PVA resin film before the formation of the stacked body.

The substance which dyes the PVA resin film in the fifth step is 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, the layering of the PVA resin film may be performed by immersing in a dyeing solution containing a dichroic substance. Further, when iodine is used as the dichroic substance, the dyeing solution may contain an iodide such as potassium iodide from the viewpoint of improving the dyeing efficiency. The dichroic substance is not particularly limited. However, when a polarizing plate is used for a display device for a vehicle, an organic dye is preferable as the dichroic substance.

[Sixth process]

The sixth step is a step of uniaxially stretching the stack. The method of extending the stacked body is not particularly limited, but it is preferably wet-extended. The sixth step may be performed before the fifth step, after the fifth step, or at the same time as the fifth step. Further, the sixth step may be divided a plurality of times before the fifth step, after the fifth step, or at the same time as the fifth step. The stretching step can be carried out once or twice or more.

The stretching ratio of the stacked body is preferably 5.0 or more, more preferably 5.5 or more, and most preferably 7.0 or less, and more preferably 6.5 or less. When the stretching ratio of the stacked body is set to be equal to or less than the upper limit of the above range, even if the manufacturing process of the polarizing plate including the stretching treatment is performed, the appearance of the phase difference of the resin layer can be reduced, and the occurrence of breakage of the polarizing plate can be prevented. By setting the stretching ratio to be equal to or higher than the lower limit of the above range, a polarizing plate having sufficient polarizing performance can be obtained. When the stacking of the stack is performed twice or more, it is preferable that the total stretch ratio expressed by the product of the respective stretch ratios is within the above range.

The stretching temperature of the stacked body is not particularly limited, but is preferably 30 ° C or higher, preferably 40 ° C or higher, more preferably 50 ° C or higher, and preferably 140 ° C or lower, and preferably 90 ° C or lower. It is especially preferable to be below 70 °C. The elongation can be smoothly performed by extending the temperature to be equal to or higher than the lower limit of the above range, and effective stretching can be performed by extending the extension below the upper limit of the above range. The range of the extension temperature is preferably either dry extension or wet extension, but it is particularly preferable in the case of wet stretching.

The stacking process may be performed by any of the following: a longitudinal stretching process extending along the longitudinal direction of the film, a lateral stretching process extending along the width direction of the film, and a process of neither parallel nor perpendicular to the width direction of the film. An oblique extension process that extends obliquely. The extension of the stack is preferably uniaxially extended at the free end, preferably uniaxially extending at the free end of the longitudinal direction.

[Drying process]

The drying step is a step of drying the stacked body in the fifth step and the sixth step. In the drying step, it is preferred to dry the stack in a dryer at a temperature of from 50 ° C to 100 ° C for from 0.5 minutes to 10 minutes. The drying temperature of the above-mentioned stacked body is preferably 60 ° C or higher, and preferably 90 ° C or lower. The drying time can be shortened by setting the drying temperature to be lower than the lower limit, and the cracking of the PVA resin film can be prevented by setting the drying temperature to the upper limit or lower. The drying time of the above-mentioned stacked body is preferably 1 minute or more, and preferably 5 minutes or less. By setting the drying time to the lower limit or more, the stacked body can be sufficiently dried, and by setting it to the upper limit or less, cracking of the PVA resin film in the stacked body can be prevented.

In the polarizing material of the film made only of the conventional PVA resin, cracking may occur after the drying process. However, since the polarizing plate of this embodiment uses a resin having a PVA resin film and directly stacked on the PVA resin film. Since the stack of layers is manufactured, the occurrence of cracking of the polarizer can be suppressed even after the drying process.

[5. Polarizer]

According to the method for producing a polarizing plate of the present embodiment described above, a polarizing plate can be obtained. The polarizing plate of this embodiment is a polarizing plate of the present embodiment in which the stacked body is uniaxially extended. Fig. 5 is a schematic cross-sectional view showing a polarizing plate manufactured by using the stacked body according to the embodiment.

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

[Characteristics of layers in polarizing plates]

The thickness of the PVA resin film 111 in the polarizing plate 100 is preferably 20 μm or less, more preferably 10 μm or less, still more preferably 3 μm or more, and 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 if the thickness is equal to or greater than the lower limit, a polarizing plate having a sufficiently high degree of polarization can be obtained.

The phase difference in the in-plane direction of the resin layer in the polarizing plate is preferably 20 nm or less, preferably 15 nm or less, more preferably 10 nm or less, and more preferably 0 nm or more. When the phase difference in the in-plane direction of the resin layer in the polarizing plate is within the above range, the black shift when the polarizing plate is mounted on the liquid crystal display device can be suppressed.

[Use of polarizing plate]

A polarizing plate manufactured by using the stacked body for a polarizing plate of the present invention is used as a material of a liquid crystal display device.

In general, the liquid crystal display device is provided with 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 is used for either the light source side polarizing plate and the viewing side polarizing plate. can. The liquid crystal display device can be manufactured by providing the polarizing plate of the present invention as one of a light source side polarizing plate and a viewing side polarizing plate, or one of them, on a liquid crystal panel.

Further, the polarizing plate produced by using the stacked body for a polarizing plate of the present invention is used as a material such as an organic EL display device or an inorganic EL display device.

In general, the 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. However, the polarizing plate obtained by the manufacturing method of the present invention can be disposed on the light-emitting side of the substrate.

The EL display device has two substrates, a light-emitting layer interposed therebetween, and a polarizing plate disposed on the outer side of one of the two substrates. The display device can be manufactured by providing 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 the present embodiment, the polarizing plate is manufactured by extending a stack of a "PVA resin film having a light transmittance of 50% or more" and a "resin layer directly stacked on the surface of the PVA resin film". Therefore, even when the stacked body is stretched at a high magnification at a low temperature, the occurrence of melting of the PVA resin film can be suppressed, and the appearance of the phase difference in the resin layer after stretching can be suppressed. As a result, according to the present embodiment, it is possible to use the protective film as one of the PVA resin films without peeling off the resin layer, and it is possible to reduce the wasted material, so that it is possible to provide "even if the resin layer is used as a protective film. A stacked body for a polarizing plate which can be efficiently produced even if the thickness is thin, a method for producing the same, a polarizing plate using the above-described stacked body, a method for producing the same, and a stacked film roll.

Further, according to the present embodiment, since the resin layer 12 is directly stacked on the stack of the PVA resin film 11, no other material is interposed between the resin layer and the PVA resin film, so that the fracture suppressing effect is excellent and the production environment can be prevented. Environmental pollution caused by other substances in the medium, or the effect of preventing the entanglement of the product (mixing foreign matter).

[Embodiment 2: Polarizing plate and manufacturing method thereof]

Hereinafter, a polarizing plate 120 according to Embodiment 2 and a method of manufacturing the same will be described with reference to FIGS. 4 and 6. The polarizing plate 120 according to this embodiment is manufactured by using the polarizing plate 100 according to the first embodiment. The same structures and aspects as those of the embodiment 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[Polarizer]

Fig. 6 is a cross-sectional view 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 layer 112 is stacked on one surface (the upper side surface of the figure) of the PVA resin film 111, and the other side of the PVA resin film 111 (the lower side of the figure) A protective film 115 is stacked. 114 of Fig. 5 is a bonding agent.

The method for producing the polarizing plate 120 of the present embodiment includes a seventh step of bonding the protective film to the surface of the PVA resin film of the stacked body opposite to the resin layer after the fifth step and the sixth step. The details are described below.

The polarizing plate 120 of this embodiment is manufactured using the apparatus shown in FIG. In the method of manufacturing the polarizing plate 120 of the present embodiment, a dyeing process (fifth process) of dyeing the PVA resin film 11 of the stack 10 and an extension process of uniaxially extending the stack (the sixth process) are used. After that, the polarizing plate 100 obtained by drying in the drying device 306 is used.

The polarizing plate 120 can be transported to the bonding device 308 by the polarizing plate 100 obtained by the dyeing process (fifth process) and the elongation process (sixth process), on the side opposite to the resin layer of the PVA resin film of the stack. The surface (the surface on the side where the resin layer is not stacked) is applied with the bonding agent 114 and bonded to the protective film 115 (the seventh step) which is unwound from the winding device 307. The obtained polarizing plate 120 can be wound into a roll shape by the winding device 310 for further processing.

The bonding agent 113 used for bonding the protective film 115 to the PVA resin film 111 used in the seventh step is not particularly limited, and examples thereof include an acrylic adhesive, an epoxy adhesive, and a urethane. Bonding agent, polyester binder, polyvinyl alcohol binder, polyolefin binder, modified polyolefin binder, polyvinyl alkyl ether binder, rubber binder, vinyl chloride-acetic acid Vinyl ester-based bonding agent, SEBS (styrene-ethylene-butylene-styrene copolymer) bonding agent, ethylene-based bonding agent such as ethylene-styrene copolymer, ethylene-methyl (meth) acrylate copolymer, ethylene An acrylate-based bonding agent such as an ethyl (meth)acrylate copolymer.

The protective film 115 used in the seventh step is exemplified by one or more resins selected from the group consisting of a cycloolefin resin, an acrylic resin, a polyethylene terephthalate resin, and a triacetyl cellulose resin. film.

The polarizing plate of this embodiment is similar to the polarizing plate of the embodiment 1 in that a PVA resin film having a light transmittance of 50% or more and a resin layer directly stacked on the surface of the PVA resin film are used. Since the polarizing plate is stretched by the stack to manufacture a polarizing plate, it has the same effects as those of the first embodiment.

Further, according to the present embodiment, since the protective film 115 is provided on the surface of the PVA resin film 111 on the side where the resin layer 112 is not stacked, it is also possible to prevent the surface of the PVA resin film 111 from being scratched.

[Other implementations]

In the first embodiment, a stack for a polarizing plate in which a resin layer is stacked on one side of a PVA resin film is disclosed. In Embodiments 1 and 2, a polarizing plate manufactured by using the above stacked body is disclosed, but The invention is not limited to this.

『Example』

The invention will be further described in detail below with reference to the examples and comparative examples, but the invention is not limited by the following examples. In the following, "parts" and "%" of the ratio of the components, unless otherwise noted, represent parts by weight.

[Evaluation method]

[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 equivalent value of GPC which is a lysate of THF. A HLC8020GPC manufactured by TOSOH Corporation was used as a measuring device.

[Hydration rate]

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

[Measurement method of phase difference]

The phase difference Re1 in the in-plane direction of the polyvinyl alcohol resin film, the phase difference Re2, and the phase difference in the in-plane direction of the resin layer in the polarizing plate are phase difference meters (manufactured by OPTO SCIENCE, INC., trade name " Mueller matrix polarimeter (AxoScan)"). When measuring, the measurement wavelength was set at 550 nm.

The measurement of the phase difference Re2 measures the phase difference in the in-plane direction of the resin layer produced when the free end of the stack is uniaxially extended to 6.0 times at a specified temperature (50 ° C and 120 ° C). In the present application, "the phase difference in the in-plane direction of the resin layer produced when the free end of the stack is uniaxially extended to 6.0 times at a temperature of 50 ° C" and "the stacking temperature at a temperature of 120 ° C" When the phase difference of the in-plane direction of the resin layer generated when the free end of the body is uniaxially extended to 6.0 times is in the range of 0 nm or more and 20 nm or less, it is judged that "at a temperature of 50 ° C to 120 ° C The phase difference Re2" in the in-plane direction of the resin layer generated when the free end of the stacked body is uniaxially extended to 6.0 times is 0 nm or more and 20 nm or less.

[Measurement method of thickness]

The thickness of each film (polyvinyl alcohol resin film and resin layer) contained in the stacked body and the thickness of each film included in the polarizing plate were measured by a thickness meter (manufactured by Mitutoyo Corporation, trade name "ABS digital thickness gauge (547). -401)") The measurement was performed 5 times, and the average value was defined as the thickness of each film.

[Evaluation of adhesion]

In the process from the production of the polarizing plate of each of the examples to the second stretching treatment, the peeling between the polyvinyl alcohol resin film and the resin layer is defined as A, and the portion where the peeling is found is defined as B. The complete stripper is designated as C.

[Evaluation of drying processability]

In the drying process at 70 ° C for 5 minutes in the production of the polarizing plate of each example, the crack was not determined to be A in the case where the polarizer was not cracked, and the crack was determined as C.

[Evaluation of the surface state of the laminated body]

The number of bubbles of 10 cm square (100 cm ² ) of the stack was visually observed.

[black offset]

The liquid crystal display panel is removed from the liquid crystal display device (trade name "IPS panel display (23MP47), manufactured by LG Electronics Japan, Inc.), and the polarizing plate disposed on the viewing side is peeled off, and the resin layer is attached to the panel side. The polarizing plates produced in the examples and comparative examples were combined. Further, a single unprotected film polarizer was attached to the polarizing plate produced in the examples and the comparative examples to recombine the liquid crystal display device. The absorption axes of the polarizing plates produced in the examples and the comparative examples and the polarizers of the single unprotected film were bonded 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 disposed on the viewing side is set to an azimuth angle of 0°, and the vertical direction of the panel is set to a polar angle of 0°, the panel is set to a black display state (ie, the entire display of the panel) The screen displays a black state. From the azimuth angle of 45° and the polar angle of 45°, the same color change as in the case of the non-protective film polarizer is judged as A, and a slight change in color is judged as B. The change is judged as C.

[Example 1]

(1-1) Production of Polymer X

According to the production example described in Japanese Laid-Open Patent Publication No. 2002-105151, after 25 parts of the styrene monomer is polymerized in the first stage, 30 parts of the styrene monomer and 25 parts of the isoprene monomer are obtained in the second stage. After polymerization, 20 parts of the styrene monomer was polymerized in the third stage to obtain a block copolymer [D1], and then the block copolymer was hydrogenated to synthesize a block copolymer hydride [E1]. The block copolymer hydride [E1] had a Mw of 84,500, a Mw/Mn of 1.20, and a hydrogenation ratio of the main chain and the aromatic ring of almost 100%.

In the 100 parts of the block copolymer hydride [E1], melt-kneaded 肆{3-[3,5-di(tributyl)-4-hydroxyphenyl]propanoic acid} pentaerythritol ester (Songyuan) 0.1 part of the product name "Songnox 1010" manufactured by Industrial Co., Ltd. was blended as an antioxidant, and then pelletized to obtain a polymer X for molding.

(1-2) Fabrication of the stack

After dissolving the polymer X produced in (1-1) in cyclohexane, 40 parts by weight of polyisobutylene (JX Nippon Nippon Energy Co., Ltd. "Nissan Polybutene" was added to 100 parts by weight of the polymer X. HV-300", a number average molecular weight of 1,400) and 0.1 part by weight of an organic ruthenium compound (3-aminopropyltriethoxydecane, KBM903, manufactured by Shin-Etsu Chemical Co., Ltd.) to prepare a coating liquid for film formation.

The obtained coating liquid for film formation was applied to an unstretched polyvinyl alcohol resin film by a die coater (average polymerization degree: about 2,400, saponification degree: 99.9 mol%, width: 650 mm, thickness: 20 μm, also referred to below) Make one of the "PVA20" and dry. Thereby, a long stack of a PVA resin film and a resin layer (polymer width 600 mm, thickness 10 μm) containing the polymer X was obtained.

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

(1-3) Manufacture of polarizing plate

The stacked intermediate guide rolls manufactured in (1-2) are continuously conveyed in the longitudinal direction while performing the following operations.

The above-mentioned stacked body is subjected to a swell treatment of immersion in water, a dyeing treatment immersed in a dyeing solution containing iodine and potassium iodide, and a first stretching treatment of extending the dyed processed stack. Subsequently, the second extension treatment in which the stack after the first extension treatment is extended in a bath containing boric acid and potassium iodide is performed. The total stretch ratio indicated by the product of the stretch ratio at the time of the first stretching process and the stretch ratio at the time of the second stretching process is set to 6.0. The extension temperature was set at 57 °C. The second stretched laminate was dried in a dryer at 70 ° C for 5 minutes (drying step) to obtain a polarizing plate.

The adhesion was evaluated in the process up to the second extension process, and the drying processability was evaluated in the drying process, and the obtained polarizing plate was evaluated for black shift. The evaluation results are disclosed in Table 1.

Further, the thickness and phase difference of the resin layer in the obtained polarizing plate and the thickness of the polyvinyl alcohol resin film were measured, and the measurement results are shown in Table 1.

[Embodiment 2]

In addition to the addition of 0.1 part by weight of an organotitanium compound (tetraisopropyl titanate, ORGATIX TA-8, manufactured by Matsumoto Fine Chemical Co., Ltd.), 0.1 part by weight was used. A stack and a polarizing plate were produced in the same manner as in Example 1 except that the resin layer was formed by the coating liquid for film formation of the organic cerium compound, and evaluated in the same manner as in Example 1. The results are disclosed in Table 1.

[Example 3]

In addition to the addition of 0.1 part by weight of an organic zirconium compound (n-propyl zirconate, ORGATIX ZA-45, manufactured by Matsumoto Fine Chemical Co., Ltd.) in an amount of 0.1 part by weight, in addition to (1-2) of Example 1, A stack and a polarizing plate were produced in the same manner as in Example 1 except that the resin layer was formed by the coating liquid for film formation of the organic cerium compound, and evaluated in the same manner as in Example 1. The results are disclosed in Table 1.

[Example 4]

In the case of performing the operation of applying the coating liquid for film forming to the polyvinyl alcohol resin film and drying it using a die coater, the coating amount and the like are adjusted so that the thickness becomes 5 μm. A laminate and a polarizing plate were produced in the same manner as in Example 1 except that the resin layer (the width was the same as in Example 1) was formed, and the evaluation was carried out in the same manner as in Example 1. The results are disclosed in Table 1.

[Example 5]

A stack and a polarizing plate were prepared in the same manner as in Example 1 except that polyisobutylene was not used in (1-2) of Example 1, and evaluation was carried out in accordance with Example 1. The results are disclosed in Table 2.

[Embodiment 6]

In the operation of (1-2) of the first embodiment, the organic ruthenium compound is not used, and when the coating liquid for coating film is applied to a polyvinyl alcohol resin film by a die coater and dried, the coating amount and the like are adjusted. A laminate and a polarizing plate were produced in the same manner as in Example 1 except that the resin layer was formed to have a thickness of 5 μm (the width was the same as in Example 1), and the evaluation was carried out in the same manner as in Example 1. The results are disclosed in Table 2.

[Comparative Example 1]

In (1-3) of Example 1, the same operation as (1-3) was carried out by using only the unstretched polyvinyl alcohol resin film (PVA20) in place of the stack produced in (1-2). As a result, the first stretching treatment and the second stretching treatment were performed many times in the first stretching treatment and the second stretching treatment, and the fracture occurred many times in the drying step, and the adhesion and the black offset could not be evaluated.

[Reference Example 1]

In (1-3) of Example 1, the polarizing plate was produced by substituting the stack of the following (R1-2) in the stack produced in (1-2), and the same evaluation as in Example 1 was carried out. The results are disclosed in Table 2.

(R1-2) Fabrication of the stack

In (1-2) of the first embodiment, the coating liquid for film formation was applied to a separator ("MRV38" manufactured by Mitsubishi Chemical Corporation) using a die coater instead of applying the coating liquid for film formation to a polyvinyl alcohol resin film. And drying it, thereby obtaining a long film (resin film) containing a polymer X having a width of 650 mm, a length of 500 m, and a thickness of 10 μm.

100 parts by weight of water, 3 parts by weight of a polyvinyl alcohol-based adhesive ("Z-200" manufactured by Nippon Synthetic Chemical Co., Ltd.), and 0.3 parts by weight of a crosslinking agent ("SPM-01" manufactured by Nippon Synthetic Chemical Co., Ltd.) were mixed to obtain a joint. Agent. The bonding agent is applied to one side of the resin film, and an unstretched polyvinyl alcohol resin film is bonded (average polymerization degree is about 2,400, saponification degree is 99.9 mol%, width is 650 mm, thickness is 20 μm, and is also referred to below as " PVA20"). In this state, the bonding agent was dried by heating at 70 ° C for 5 minutes to obtain a stacked body.

The evaluation results of the examples, comparative examples and reference examples are shown in Tables 1 and 2.

In the table, "Re2 (50 ° C)" means a phase difference in the in-plane direction of the resin layer which is produced when the free end of the stack is uniaxially extended to 6.0 times at a temperature of 50 ° C. Re2 (120 ° C)" means a phase difference in the in-plane direction of the resin layer produced when the free end of the stack is uniaxially stretched to 6.0 times at a temperature of 120 °C.

In the table, "Re1" means a phase difference in the in-plane direction of the polyvinyl alcohol resin film in the stack.

In the table, the term "coating" is used to form a resin layer by coating a coating liquid (resin composition) for coating a film of a polyvinyl alcohol resin film, and the term "bonding" means bonding a resin film intermediate bonding agent to a polymer. A vinyl alcohol resin film.

"Table 1"

"Table 2"

As is apparent from the results of Tables 1 and 2, according to the present invention, it is possible to reduce the phase difference exhibited by the resin layer after the step of extending the stacked body, and to obtain a polarizing plate excellent in adhesion, drying processability, and optical physical properties. . According to the above, it is possible to provide a stack for a polarizing plate which can be used even if the resin layer is used as a protective film, and which can be efficiently produced even if the thickness is thin, a method for producing the same, a polarizing plate using the same, and a method for producing the same , as well as stacked film rolls.

10‧‧‧Stacks (stacks for polarizers)

11‧‧‧Plastic Alcohol Resin Film (PVA Resin Film)

12‧‧‧ resin layer

13‧‧‧Separator

15‧‧‧Stack film roll

100, 120‧‧‧ polarizing plate

111‧‧‧Plastic Alcohol Resin Film (PVA Resin Film)

112‧‧‧ resin layer

114‧‧‧Adhesive layer

115‧‧‧Protective film

200‧‧‧ manufacturing equipment

201, 202‧‧‧ rolled out device

203‧‧‧ Winding device

205‧‧‧Drying device

300‧‧‧ manufacturing equipment

301, 307‧‧‧ rolled out device

302～305‧‧‧Processing device

306, 309‧‧‧Drying device

308‧‧‧Fitting device

310‧‧‧Winding device

Fig. 1 is a schematic cross-sectional view showing a stack for a polarizing plate according to Embodiment 1 of the present invention.

Fig. 2 is a schematic view showing an example of a manufacturing apparatus of a stack for a polarizing plate according to Embodiment 1.

Fig. 3 is a schematic cross-sectional view showing a stacked film roll produced by using the stacked body for a polarizing plate according to Embodiment 1 of the present invention.

FIG. 4 is a schematic view showing an example of a manufacturing apparatus for manufacturing a polarizing plate using the stacked body for a polarizing plate according to the first embodiment.

Fig. 5 is a schematic cross-sectional view showing a polarizing plate manufactured by using the stacked body for a polarizing plate according to Embodiment 1 of the present invention.

Fig. 6 is a cross-sectional view showing a polarizing plate according to an embodiment 2 of the present invention.

Claims (18)

A stack for a polarizing plate comprising: a polyvinyl alcohol resin film having a transmittance of light having a wavelength of 550 nm of 50% or more, and a resin layer directly stacked on at least one side of the polyvinyl alcohol resin film. The stack for a polarizing plate according to claim 1, wherein the resin layer is a resin layer formed by coating a resin with the polyvinyl alcohol resin film. The stack for polarizing plates according to claim 1 or 2, wherein a phase difference Re1 of the in-plane direction of the polyvinyl alcohol resin film is 50 nm or less. The stack for polarizing plates according to claim 1 or 2, wherein the polyvinyl alcohol resin film has a thickness T of 45 μm or less, and a phase difference Re2 of the in-plane direction of the extension of the resin layer is 0 nm or more. 20 nm or less, the phase difference Re2 is uniaxially extended to 6.0 times with respect to the free end of the stacked body at a temperature of 50 ° C to 120 ° C, and when the resin layer is formed into the extension, the extension The phase difference. The stack for a polarizing plate according to claim 1 or 2, wherein the resin layer has a thickness of 50 μm or less. The stack for a polarizing plate according to claim 1 or 2, wherein the resin layer is made of a cycloolefin resin. The stack for polarizing plates according to claim 6, wherein the cycloolefin-based resin contains a cycloolefin-based polymer which is a block copolymer hydrogenated product obtained by hydrogenating the block copolymer [D]. The block copolymer [D] is composed of a polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as a main component, and a repeating unit derived from an aromatic vinyl compound [ I] and a repeating unit derived from a chain conjugated diene compound [II] as a main component of the polymer block [B], or a repeating unit [II] derived from a chain conjugated diene compound as a main component Made of polymer block [C]. The stack for a polarizing plate according to claim 1 or 2, wherein the resin layer contains a plasticizer, a softener or both. The stack for polarizing plates according to claim 8, wherein the plasticizer, the softener or both are selected from one or more of an ester plasticizer and an aliphatic hydrocarbon polymer. The stack for a polarizing plate according to claim 1 or 2, wherein the resin layer contains an organometallic compound. A polarizing plate which is uniaxially stretched by the stack for a polarizing plate according to any one of claims 1 to 10. A stacked film roll which is wound into a roll and has a stack for a polarizing plate according to any one of claims 1 to 10, and a resin layer stacked on the stack for the polarizing plate A separator on the opposite side of the polyvinyl alcohol resin film. A method for producing a stack for a polarizing plate, comprising: a first step of coating a resin on at least one side of a polyvinyl alcohol resin film having a transmittance of 50% or more at a wavelength of 550 nm to form a resin layer; And a second step of drying the resin layer formed in the first step. The method for producing a stack for a polarizing plate according to claim 13, wherein the coating method is one or more selected from the group consisting of solution coating, emulsion coating or melt extrusion coating. The method for producing a stack for a polarizing plate according to claim 13 or 14, comprising a third step of heat-treating the polyvinyl alcohol resin film before the first step. The method for producing a stack for a polarizing plate according to claim 13 or 14, comprising a fourth step of activating the surface of the polyvinyl alcohol resin film before the first step. A method of producing a polarizing plate, which is a stack for a polarizing plate according to any one of claims 1 to 10, or a stack for a polarizing plate according to any one of claims 13 to A method for producing a polarizing plate by using a stacked body of a polarizing plate obtained by a manufacturing method, comprising: a fifth step of dyeing the stacked body for a polarizing plate with a dichroic dye, and uniaxially stretching the stacked body for a polarizing plate The sixth process. The method for producing a polarizing plate according to claim 17, comprising: after the fifth step and/or the sixth step, the polyvinyl alcohol resin film of the polarizer stack is opposite to the resin layer The side surface is attached to the seventh step of the protective film.