TW202005804A - Polarizing plate - Google Patents

Abstract

An object of the present invention is to provide a polarizing plate capable of maintaining a high degree of polarization even in a humid heat environment. The polarizing plate contains a polarizer layer, a retardation layer, and a resin layer disposed between the polarizer layer and the retardation layer, wherein the retardation layer uses a cured product of the liquid crystal composition as a forming material, and the Martens hardness of the resin layer measured in accordance with ISO14577 is 160 N / mm2 or more and 500 N / mm2 or less.

Description

Polarizer

The invention relates to a polarizing plate and an organic electroluminescence display device.

Previously, polarizing plates have been widely used as polarizing light supply elements in display devices such as liquid crystal display devices and organic electroluminescent display devices (hereinafter also referred to as organic EL display devices), and as polarizing detection elements. It is known that a polarizing plate is formed by bonding a protective film (protective layer) to one side or both sides of a polarizing film (polarizer layer) using an adhesive or the like.

As the polarizing film, a dichroic dye such as iodine is known to be aligned with a thin film formed of a polyvinyl alcohol-based resin. The iodine in the polarizing film exists as an iodine complex, and the alignment of the iodine complex itself depends on the alignment of the polyvinyl alcohol-based resin. It is known that the iodine complex causes the polarizing film to exhibit polarization characteristics (polarization degree) by absorbing light in the visible region.

The image display device widely uses a polarizing plate provided with a polarizer layer and a phase difference layer. (For example, Patent Document 1).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2017-54093

However, when the polarizing plate described in Patent Document 1 is placed in a hot and humid environment (for example, an environment with a temperature of 80° C. and a relative humidity of 90%), the degree of polarization may decrease.

The present invention was made in view of such circumstances, and its object is to provide a polarizing plate and an organic EL display device that can maintain a high degree of polarization even in a hot and humid environment.

The results of the intensive research by the inventors presumed that the reason why the polarization degree is reduced in a hot and humid environment is that the components contained in the phase difference layer migrate to the polarizer layer or the iodine complex that contributes to polarized light, or to maintain The cross-linking point of the iodine complex reacts and the iodine complex disappears.

For the reason estimated, the present inventors found that the use of the following polarizing plate can maintain a high degree of polarization even in a hot and humid environment, and completed the present invention.

An aspect of the present invention provides a polarizing plate including a polarizer layer, a phase difference layer, and a resin layer disposed between the polarizer layer and the phase difference layer, the phase difference layer is a cured product of a liquid crystal composition as the material for forming the Martens hardness, measured according to ISO14577 of the resin layer is 160N / mm ² or more 500N / mm ² or less.

In one aspect of the present invention, the phase difference layer may be a layer that imparts a phase difference of 1/4 wavelength.

An aspect of the present invention provides a polarizing plate including a polarizer layer, a first retardation layer, a resin layer disposed between the polarizer layer and the first retardation layer, and the polarizer layer as a reference On the second retardation layer on the resin layer side, the first retardation layer uses the cured product of the first liquid crystal composition as a forming material, and the second retardation layer uses the cured product of the second liquid crystal composition as a forming material, based on ISO14577 Martens hardness of the resin layer was measured of 160N / mm ² or more 500N / mm ² or less.

In one aspect of the present invention, the first retardation layer has the refractive index in the in-plane slow axis direction as n _x and the refractive index in the plane orthogonal to the slow axis direction as n _y 3. When the refractive index in the thickness direction is set to n _z , it can be set to a layer structure satisfying the relationship of n _z >n _x ≧n _y .

In one aspect of the present invention, the second retardation layer may be disposed between the resin layer and the first retardation layer and in contact with the resin layer.

In one aspect of the present invention, the second retardation layer may be disposed between the resin layer and the polarizer layer and in contact with the resin layer.

In one aspect of the present invention, the resin layer may be in contact with the first retardation layer.

In one aspect of the present invention, the second phase difference layer may be configured to provide a phase difference of 1/4 wavelength.

An aspect of the present invention provides an organic electroluminescence display device including an organic electroluminescence display element and the polarizing plate disposed on a viewing side of the organic electroluminescence display element.

According to one aspect of the present invention, a polarizing plate and an organic EL display device that can maintain a high degree of polarization even in a hot and humid environment can be provided.

1, 2, 3, 4, 5‧‧‧ Polarizer

10‧‧‧Display panel

11‧‧‧Protective layer

11a‧‧‧The side of the protective layer

12‧‧‧ Polarizer layer

12a‧‧‧One side of polarizer layer

12b‧‧‧The other side of the polarizer layer

13‧‧‧Resin layer

13a‧‧‧One side of the resin layer

13b‧‧‧The other side of the resin layer

14‧‧‧1st adhesive layer

15‧‧‧ 2nd adhesive layer

16‧‧‧ phase difference layer

16b‧‧‧Face of retardation layer

17‧‧‧First phase difference layer

17b‧‧‧The other side of the first phase difference layer

18‧‧‧ 2nd phase difference layer

19‧‧‧Alignment layer

19b‧‧‧The face of the alignment layer

20‧‧‧ 1st alignment layer

21‧‧‧ 2nd alignment layer

21b‧‧‧The other side of the 2nd alignment layer

22‧‧‧Next layer

23‧‧‧The third adhesive layer

24‧‧‧4th adhesive layer

25‧‧‧ 5th adhesive layer

100‧‧‧ organic EL display device

130‧‧‧Resin composition

140‧‧‧The first adhesive

150‧‧‧The second adhesive

200‧‧‧ organic EL element

201‧‧‧Substrate

202‧‧‧Anode

203‧‧‧ organic EL layer

204‧‧‧Cathode

205‧‧‧Sealing layer

230‧‧‧The third adhesive

250‧‧‧Fifth adhesive

A, B, C, D, E, F, G, H, I‧‧‧Layered body

FIG. 1 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the first embodiment.

FIG. 2 is a schematic diagram showing an example of a method of manufacturing a polarizing plate of the first embodiment.

FIG. 3 is a schematic cross-sectional view showing an example of the structure of the organic EL display device of the first embodiment.

FIG. 4 is a schematic cross-sectional view showing an example of the layer configuration of an organic EL element.

FIG. 5 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the second embodiment.

FIG. 6 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the second embodiment.

FIG. 7 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the third embodiment.

FIG. 8 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the third embodiment.

FIG. 9 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the fourth embodiment.

Fig. 10 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the fourth embodiment.

FIG. 11 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the fifth embodiment.

Fig. 12 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the fifth embodiment.

<First Embodiment>

[Polarizer]

Hereinafter, the polarizing plate of the first embodiment will be described based on FIG. 1.

In addition, the drawings used in the following description are for the purpose of emphasizing the feature part, and the feature part is expediently enlarged and displayed, and the size ratio of each constituent element and the like are not necessarily the same as the actual ones. Also, for the same purpose, there may be cases where non-featured parts are omitted in the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the first embodiment. As shown in FIG. 1, the polarizing plate 1 of this embodiment includes a protective layer 11, a polarizer layer 12, a resin layer 13, a first adhesive layer 14, a second adhesive layer 15, a retardation layer 16, and an alignment layer 19. As shown in FIG. 1, the polarizing plate 1 is a layer structure provided with a protective layer 11 (protective film) only on one side 12 a of the polarizer layer 12. Among the polarizing plates, especially the polarizing plate having a protective film on only one side of the polarizer layer, since the degree of polarization is easily reduced, the effect of the present invention is remarkable.

In this specification, the "polarizer layer" refers to an optical layer that has the property of transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis when light without polarization is incident.

The phase difference layer 16 is disposed on the other surface 12 b side of the polarizer layer 12.

A resin layer 13 is arranged between the polarizer layer 12 and the retardation layer 16. The resin layer 13 is in contact with the polarizer layer 12 on one side 13a.

The first adhesive layer 14 is disposed between the resin layer 13 and the retardation layer 16 and adheres the resin layer 13 and the retardation layer 16.

The alignment layer 19 is arranged on the opposite side of the resin layer 13 with the phase difference layer 16 as a reference, and is in contact with the surface 16 b of the phase difference layer 16.

The second adhesive layer 15 is arranged on the opposite side of the retardation layer 16 with the alignment layer 19 as a reference, and is in contact with the surface (the other surface) 19b of the alignment layer 19. When the polarizing plate 1 is applied to an organic EL display device described later, the polarizing plate 1 is adhered to the display panel via the second adhesive layer 15.

One side 12a side of the polarizer layer 12 is the side that becomes the viewing side when the polarizing plate 1 is applied to an organic EL display device described later. The protective layer 11 is disposed on one side 12 a side of the polarizer layer 12. The protective layer 11 and the polarizer layer 12 are bonded via an adhesive (not shown).

The polarizing plate 1 may be elongated, or may be a monolithic body obtained by cutting the elongated polarizing plate into a predetermined length. The strip-shaped polarizing plate includes a strip-shaped protective layer, a strip-shaped polarizer layer and a strip-shaped resin layer.

Hereinafter, each layer constituting the polarizing plate 1 of the first embodiment will be described in detail.

(Polarizer layer)

As the polarizer layer 12, any appropriate polarizer layer can be used. For example, the resin film forming the polarizer layer 12 may be a single-layer resin film or a laminated film of two or more layers. The polarizer layer 12 may be a cured film obtained by aligning a dichroic dye with a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound.

Specific examples of the polarizer layer 12 composed of a single-layer resin film include, for example, a hydrophilic polymer film subjected to dyeing treatment using dichroic substances such as iodine and dichroic dyes, and stretching treatment. Thin films, polyene-based alignment films, etc.

Examples of highly hydrophilic molecular films include polyvinyl alcohol (hereinafter also abbreviated as PVA)-based films, partially formalized PVA-based films, and ethylene/vinyl acetate copolymer-based partially saponified films.

Examples of polyene-based alignment films include PVA dehydration treatment products and polyvinyl chloride dehydrochlorination treatment products.

As the polarizer layer 12 has excellent optical characteristics, it is preferable to use a film obtained by dyeing a PVA-based film with iodine and uniaxially stretching it.

The iodine in the polarizer layer exists as an iodine complex, and the alignment of the iodine complex itself also depends on the alignment of the PVA-based resin. It is known that the iodine complex absorbs light in the visible region and the polarizer layer exhibits polarization characteristics (polarization degree).

The saponification degree of the PVA-based resin is about 85 to 100 mol%, preferably 98 mol% or more. The PVA-based resin can also be modified, for example, polyvinyl acetal modified with aldehydes, Polyvinyl acetal, etc. The degree of polymerization of the PVA resin is about 1,000 to 10,000, preferably about 1,500 to 5,000.

The thickness of the polarizer layer 12 is preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. The thickness of the polarizer layer 12 is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less. In addition, the above upper limit value and lower limit value may be arbitrarily combined.

When the thickness of the polarizer layer 12 becomes thinner, iodine at the end of the polarizer layer 12 is easily removed in an environment of high temperature and high humidity. Therefore, the thickness of the polarizer layer 12 is preferably 5 μm or more. In addition, when the thickness of the polarizer layer 12 is thick, the polarizer layer 12 is likely to crack in the cold-heat exchange test. Therefore, the thickness of the polarizer layer is preferably 15 μm or less.

In this specification, "layer thickness" refers to the dimension in the layering direction of the layer of the polarizing plate. Examples of the "layer" in this embodiment include a protective layer, a polarizer layer, a resin layer, a first adhesive layer, a retardation layer, and a second adhesive layer.

The thickness of the layer can be obtained by measuring an arbitrary point 9 points of the layer using a white dry-type non-contact film thickness meter or a contact type film thickness meter, and calculating the average value thereof.

Using a non-contact film thickness timer allows accurate measurement without touching the measurement object. Therefore, even if the measurement object is a layer of a part of the laminate, the film thickness of the measurement object can be measured without peeling off each layer.

(The protective layer)

As the protective layer 11, for example, a film formed of a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, extensibility, and the like can be used.

Specific examples of such thermoplastic resins include cellulose resins such as cellulose triacetate, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether resins, and polyester resins Polyamide resins such as resins, polycarbonate resins, nylon, aromatic polyamides, polyimide resins, polyethylene, polypropylene, ethylene/propylene copolymers, etc., with ring systems and norbornene Structured cyclic polyolefin resin (also known as norbornene-based resin), (meth)acrylic resin, polyarylate resin, polystyrene resin, polyvinyl alcohol resin, and mixtures thereof.

In order to improve the adhesion to the polarizer layer formed of PVA resin and dichroic material, the film formed of thermoplastic resin can be subjected to surface treatment (such as corona treatment, etc.), and a primer layer can also be formed ( Also known as undercoat) and other thin layers.

The protective layer 11 is at a temperature of 40°C and a relative humidity of 90% RH, and the moisture permeability is from 1 to 1500 g/m ² . 24hr is better. The moisture permeability system can be measured according to JIS Z 0208:1976.

The thickness of the protective layer 11 is preferably 3 μm or more, more preferably 5 μm or more, or 15 μm or more. In addition, the thickness of the protective layer 11 is preferably 50 μm or less, more preferably 30 μm or less. In addition, the above upper limit value and lower limit value may be arbitrarily combined.

(Phase difference layer)

The phase difference layer 16 may be, for example, a positive A layer, a negative A layer, a positive C layer, or a negative C layer. Specifically, when the phase difference layer 16 is the A layer, it is preferable to use a layer that imparts a front phase difference of 1/4 wavelength or a layer that imparts a front phase difference of 1/2 wavelength.

When the phase difference layer 16 is the C layer, the phase difference value Rth in the thickness direction of the wavelength of 550 nm is preferably -90 nm to -10 nm. The C layer system in such a range has excellent durability and can also be made thin.

In this specification, the "layer that imparts a frontal phase difference of 1/4 wavelength" refers to a phase difference layer that converts linearly polarized light having a wavelength in the visible light region into circularly polarized light (or converts circularly polarized light into linearly polarized light). The "layer imparting a frontal phase difference of 1/4 wavelength" is that the frontal phase difference value at a wavelength of 550 nm may be 110 to 160 nm, and may be 130 nm to 150 nm. The so-called "layer that imparts a frontal phase difference of 1/2 wavelength" is a phase difference layer that converts the polarized orientation of linearly polarized light having a wavelength in the visible light region by 90°. The "layer imparting a frontal phase difference of 1/2 wavelength" is that the frontal phase difference value at a wavelength of 550 nm may be 250 nm to 300 nm, and may be 260 nm to 280 nm.

In this specification, the so-called "positive C layer" means that the refractive index in the in-plane slow axis direction is set to n _x , and the refractive index in the in-plane fast axis direction is set to n _y , and that in the thickness direction When the refractive index is set to n _z , the layer satisfying the relationship of n _z >n _x ≧n _y . The so-called n _x and n _y systems can be substantially equal. Specifically, when the difference between n _x and n _y is within 0.01, n _x and n _y can be said to be substantially equal.

In this specification, the so-called "negative C layer" means that the refractive index in the in-plane slow axis direction is n _x , and the refractive index in the in-plane fast axis direction is n _y , and that in the thickness direction When the refractive index of n is set to n _z , the layer satisfying the relationship of n _z <n _y ≦n _x . n _x and n _y can be substantially equal. Specifically, when the difference between n _x and n _y is within 0.01, n _x and n _y can be said to be substantially equal.

The polarizing plate 1 provided with the polarizer layer 12 and the phase difference layer 16 preferably has a function as a circular polarizing plate. That is, the phase difference layer 16 is preferably a layer that can impart a phase difference of 1/4 wavelength.

The phase difference layer 16 uses a hardened liquid crystal composition as a forming material. The liquid crystal composition contains a liquid crystal compound.

The type of liquid crystal compound used in the present embodiment is not particularly limited, but it can be classified into a rod-shaped type (rod-shaped liquid crystal compound) and a disc-shaped type (disk-shaped liquid crystal compound, dish-shaped) from its shape Liquid crystal compound). And each has a low molecular type and a high molecular type. In addition, the term polymer refers to a polymer having a degree of polymerization of 100 or more.

In this embodiment, any liquid crystal compound can be used. Furthermore, two or more rod-shaped liquid crystal compounds, two or more disc-shaped liquid crystal compounds, or a mixture of a rod-shaped liquid crystal compound and a disc-shaped liquid crystal compound may also be used.

In addition, conventional materials can be used for the rod-shaped liquid crystal compound and the disc-shaped liquid crystal compound.

The hardened liquid crystal compound is preferably formed by using a rod-like liquid crystal compound having a polymerizable group or a disc-like liquid crystal compound having a polymerizable group. With this, the temperature change and humidity change of the optical characteristics can be reduced.

Two or more liquid crystal compounds may be used in combination. In this case, it is preferable that at least one type has two or more polymerizable groups in the molecule. That is, the hardened material of the liquid crystal compound is preferably a rod-shaped liquid crystal compound having a polymerizable group or a disc-shaped liquid crystal compound having a polymerizable group formed by polymerization. In this case, it is not necessary to display liquid crystallinity after becoming a cured product.

When the rod-shaped liquid crystal compound or the disc-shaped liquid crystal compound has a polymerizable group, the type of the polymerizable group is not particularly limited. As the polymerizable group, for example, a functional group that can undergo addition polymerization reaction, such as a polymerizable ethylenically unsaturated group and a ring polymerizable group, is preferable. More specifically, examples of the polymerizable group include (meth)acryloyl, vinyl, styryl, and allyl groups. Among them, (meth)acryloyl is preferred. The (meth)acryloyl group is a concept including both methacryloyl group and acryloyl group.

The liquid crystal composition may contain components other than the above liquid crystal compound.

For example, the liquid crystal composition may contain a polymerization initiator. The polymerization initiator used can be selected according to the form of the polymerization reaction, for example, thermal polymerization initiator and photopolymerization initiator.

For example, as the photopolymerization initiator, examples include: α-carbonyl compound, acetoin ether, α-hydrocarbon substituted aromatic acetoin compound, polynuclear quinone compound, triarylimidazole dimer and p-aminophenyl ketone Combination.

With respect to the total solid content in the liquid crystal composition, the amount of the polymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass.

For the purpose of improving the uniformity of the film coated with the liquid crystal composition and the strength of the film, the liquid crystal composition may contain a polymerizable monomer. Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Among them, polyfunctional radical polymerizable monomers are preferred.

In addition, the polymerizable monomer is preferably one that can be copolymerized with the above-mentioned liquid crystal compound having a polymerizable group (hereinafter also referred to as a polymerizable liquid crystal compound).

As the polymerizable single system, conventional materials can be used.

The use amount of the polymerizable monomer is preferably 1 to 50% by mass relative to the total mass of the liquid crystal compound, and more preferably 2 to 30% by mass.

For the purpose of improving the uniformity of the film coated with the liquid crystal composition and the strength of the film, the liquid crystal composition may contain a conventional surfactant. As the surfactant, there may be mentioned, for example, conventionally known compounds. Among them, fluorine-based compounds are particularly preferred.

The liquid crystal composition may contain a solvent, and an organic solvent is preferably used.

Examples of organic solvents include: amides such as N,N-dimethylformamide; sulfoxides such as dimethylsulfoxide; heterocyclic compounds such as pyridine; hydrocarbons such as benzene and hexane; chloroform and methylene chloride. Alkyl halide; methyl acetate, ethyl acetate, butyl acetate and other esters; acetone, methyl ethyl ketone and other ketones; tetrahydrofuran, 1,2-dimethoxyethane and other ethers. Among them, the organic solvent is preferably an alkyl halide or ketone. In addition, two or more organic solvents may be used in combination.

The liquid crystal composition system may contain an adhesion improver, a plasticizer, a polymer, etc. in addition to the above components.

The hardened material of the liquid crystal composition can be formed by applying the liquid crystal composition on the alignment layer 19 described later to make it horizontally, vertically or obliquely aligned and then hardening it.

The thickness of the phase difference layer 16 is preferably 0.1 μm or more. The thickness of the retardation layer 16 is preferably 10 μm or less, and more preferably 5 μm or less. In addition, the above upper limit value and lower limit value may be arbitrarily combined.

When the thickness of the retardation layer 16 is within the above range, it can have both durability and thinness.

The thickness of the phase difference layer 16 may be adjusted in such a manner that the required in-plane phase difference value and thickness direction phase difference value can be obtained.

When a polarizer with a polarizer layer such as polarizer layer 12 and a phase difference layer such as phase difference layer 16 is placed in a hot and humid environment (for example, an environment with a temperature of 80°C and a relative humidity of 90%), there will be a degree of polarization Reduce the situation.

As the reason why the polarization degree of the polarizing plate is reduced in a hot and humid environment, the present inventors presume that the iodine complex disappears. As the cause of the disappearance of iodine complex, it is believed that the components contained in the phase difference layer migrate to the polarizer layer and react with the iodine complex that contributes to polarized light, or the crosslinking point used to maintain the iodine complex reason.

For the estimated reason, the present inventors assumed that it is possible to suppress the decrease in the degree of polarization by suppressing the migration of the components contained in the phase difference layer to the polarizer layer. As a result of repeated research, the present inventors found that by providing the following resin layer between the polarizer layer and the retardation layer, the polarization degree can be kept high even in a hot and humid environment, and the present invention has been completed.

(Resin layer)

The resin layer 13 is preferably composed of a reaction product of a (meth)acrylic resin and a resin composition containing a polyfunctional monomer.

((Meth)acrylic resin)

The (meth)acrylic resin contained in the resin composition is a structural unit containing an alkyl (meth)acrylate derived from urethane (meth)acrylate or the following formula (I) ( A polymer (hereinafter also referred to as a structural unit (I)) (hereinafter, also referred to as a (meth)acrylate polymer) is preferred.

In this specification, "(meth)acrylic acid" refers to either acrylic acid or methacrylic acid. "(Meth)" such as (meth)acrylate also has the same meaning.

In this specification, “derived from” means that the chemical structure changes due to the polymerization of the raw material monomer and no other structural changes occur.

The urethane (meth)acrylate may be an aliphatic urethane (meth)acrylate or an aromatic urethane (meth)acrylate. The urethane acrylate system can be prepared using, for example, (meth)acrylic acid and/or (meth)acrylate, polyol, and diisocyanate. Specifically, a method of preparing a hydroxy (meth)acrylate having at least one residual hydroxyl group from (meth)acrylic acid and/or (meth)acrylate and a polyol, and reacting it with a diisocyanate , And can manufacture urethane acrylate.

Examples of (meth)acrylates used in the manufacture of urethane acrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( (Meth)acrylic acid isopropyl ester and (meth)acrylic acid butyl ester (meth)acrylic acid alkyl ester; such as (meth)acrylic acid cyclohexyl ester (meth)acrylic acid cycloalkyl ester.

The polyol used in the manufacture of urethane acrylate is a compound having at least two hydroxyl groups in the molecule. Specific examples include: ethylene glycol, trimethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6 -Hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol Alcohol, neopentyl glycol ester of hydroxytrimethylacetic acid, cyclohexanedimethanol, 1,4-cyclohexanediol, spiroglycol, tricyclodecanedimethanol, hydrogenated bisphenol A, epoxy Ethane addition bisphenol A, propylene oxide addition bisphenol A, trimethylolethane, tri-dimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, Neopentaerythritol, di-pentaerythritol, tri-pentaerythritol, glucose, etc.

The diisocyanates used in the production of urethane acrylates can be aromatic, aliphatic, or alicyclic diisocyanates. Specific examples include: tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenyl-4, 4'-diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4' -Diisocyanates and hydrides of compounds having aromatic rings among these diisocyanates.

The weight average molecular weight of urethane (meth)acrylate (hereinafter also simply referred to as Mw) is preferably from 100 to 1,000.

In formula (I), R ¹⁰ represents a hydrogen atom or a methyl group. R ²⁰ represents an alkyl group having 1 to 20 carbon atoms. The aforementioned alkyl group may have any structure of linear, branched or cyclic. The hydrogen atom of the aforementioned alkyl group may be substituted with a C 1-10 alkoxy group or a C 1-10 urethane group.

Examples of the (meth)acrylate represented by the formula (I) include: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate Ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, (meth)acrylic acid N-heptyl ester, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- and isononyl (meth)acrylate, (meth)acrylic acid N-decyl ester, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, Third butyl (meth)acrylate, etc.

Specific examples of the alkoxy-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate.

Especially as the (meth)acrylate represented by the formula (I), it is preferable to contain n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and to contain (meth)acrylic acid Butyl ester is better.

The (meth)acrylate polymer system may contain structural units derived from monomers other than structural unit (I). The structural unit derived from other monomers may be one type or two or more types. Examples of other monomers that the (meth)acrylate polymer may contain include monomers having a polar functional group, monomers having an aromatic group, and acrylamide-based monomers.

Examples of the monomer having a polar functional group include (meth)acrylate having a polar functional group. Examples of polar functional groups include hydroxyl groups, carboxyl groups, substituted amine groups, and unsubstituted amine groups. Examples of polar functional groups include heterocyclic groups such as epoxy groups.

The content of the structural unit derived from the monomer having a polar functional group in the (meth)acrylate polymer is preferably 20 parts by mass or less relative to 100 parts by mass of the total structural unit of the (meth)acrylate polymer. It is more preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, and particularly preferably 0.5 parts by mass or more and 10 parts by mass or less.

Examples of the monomer having an aromatic group include a (meth)acryloyl group and one or more aromatic rings (for example, benzene ring and naphthalene ring) in the molecule, and a phenyl group and phenoxyethyl group. By containing these structural units, (meth)acrylic acid ester of benzyl group or benzyl group can suppress the white spot phenomenon of the polarizing plate generated under high temperature and high humidity environment.

The content of the structural unit derived from the monomer having an aromatic group in the (meth)acrylate polymer is preferably 50 parts by mass or less relative to 100 parts by mass of the total structural unit of the (meth)acrylate polymer. It is more preferably 4 parts by mass or more and 50 parts by mass or less, and more preferably 4 parts by mass or more and 25 parts by mass or less.

Examples of acrylamide-based monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, and N-(propoxymethyl)acrylamide. , N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, etc. By containing these structural units, the bleed-out of additives such as antistatic agents described below can be suppressed.

Furthermore, as a structural unit derived from a monomer other than the structural unit (I), a structural unit derived from a styrene-based monomer, a structural unit derived from a vinyl-based monomer, and a plurality of molecular units The structural unit of the monomer of (meth)acryloyl group.

The weight average molecular weight (Mw) of the (meth)acrylate polymer is preferably 500,000 to 2.5 million. When the weight average molecular weight is 500,000 or more, the durability of the resin layer 13 in an environment of high temperature and high humidity can be improved. When the weight average molecular weight is 2.5 million or less, the workability when coating the resin composition becomes good. The molecular weight distribution (Mw/Mn) expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (hereinafter also referred to simply as Mn) is, for example, 2 to 10.

In this specification, the "weight average molecular weight" and "number average molecular weight" refer to polystyrene conversion values measured by gel permeation chromatography (GPC).

From the viewpoint of coexistence of adhesion and durability, the glass transition temperature of the (meth)acrylic resin is preferably -60°C to -10°C. In addition, the glass transition temperature can be measured using a differential scanning calorimeter (DSC).

The (meth)acrylic resin may contain two or more (meth)acrylate polymers.

(Multifunctional monomer)

In this specification, the term "multifunctional monomer" refers to a multifunctional (meth)acrylate monomer having three or more (meth)acryloyloxy groups in the molecule.

Examples of trifunctional or more polyfunctional (meth)acrylate monomers include, for example, glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, and bistrimethylolpropane trioxide. (Meth)acrylate, bistrimethylolpropane tetra(meth)acrylate, neopentaerythritol tri(meth)acrylate, neopentaerythritol tetra(meth)acrylate, dipentaerythritol Poly(meth)acrylates of 3 or more aliphatic polyols of tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate . In addition, examples include: poly(meth)acrylates of trifunctional or higher halogen-substituted polyols, tri(meth)acrylates of alkylene oxide adducts of glycerin, and alkylene oxide additions of trimethylolpropane Tri(meth)acrylate, 1,1,1-tris[(meth)acryloxyethoxyethoxy]propane, tris(hydroxyethyl)isocyanurate tri(meth) Methacrylates, urethane (meth)acrylates, etc.

The resin composition preferably contains a conventional radical polymerization initiator.

(Other ingredients)

The resin composition may contain additives such as ultraviolet absorbers, antistatic agents, solvents, cross-linking catalysts, adhesion-imparting resins (tackifiers), plasticizers, etc. alone or two or more kinds. In addition, after the resin composition is prepared by mixing an ultraviolet curable compound to form the resin layer 13, it is also useful to irradiate ultraviolet rays to harden it to become a hard resin layer.

The reaction product system of such a resin composition forms a cross-linked structure. Therefore, it is considered that the resin layer 13 can suppress the component contained in the phase difference layer 16 to migrate to the polarizer layer 12. In addition, it is considered that the closer the cross-linked structure is, the component contained in the phase difference layer 16 stays in the resin layer 13 and does not easily move to the polarizer layer 12.

The degree of density of the cross-linked structure can be indirectly confirmed by measuring the Martens hardness of the resin layer 13 according to ISO14577. In the resin layer 13, when the cross-linking point increases, the inter-molecular distance of the polymer molecules becomes smaller, so the cross-linking structure becomes dense. In addition, since the binding force between polymer molecules is improved and is not easily deformed, the hardness of the resin layer 13 becomes large. That is, in the resin layer 13, it can be said that the greater the hardness, the tighter the cross-linked structure.

Martens hardness [0108] The resin layer 13 is 160N / mm ² or more 500N / mm ² or less, it may also be less than 500N / mm ^2. When the Martens hardness of the resin layer 13 is 500 N/mm ² or less, since the polymer molecular chain of the resin layer 13 may move, the flexibility of the resin layer 13 becomes sufficiently high. It is considered that when the flexibility of the resin layer 13 is sufficiently high, the resin layer is less likely to be broken due to expansion and contraction of the polarizer layer. As a result, the flexibility of the polarizing plate 1 becomes sufficiently high. On the other hand, it is considered that when the Martens hardness is 160 N/mm ² or more, the cross-linked structure becomes sufficiently tight, and the component contained in the phase difference layer 16 can be sufficiently transferred to the polarizer layer 12 to be sufficiently suppressed. As a result, even in a hot and humid environment (for example, an environment with a temperature of 80° C. and a relative humidity of 90%), the polarization degree of the polarizing plate 1 is not easily reduced.

The Martens hardness is preferably 170 N/mm ² or more, and more preferably 190 N/mm ² or more. In addition, the Martens hardness system is more preferably 400 N/mm ² or less, and may be less than 400 N/mm ² . In addition, the above upper limit value and lower limit value may be arbitrarily combined.

In this embodiment, the Martens hardness was based formulations to 160N / mm ² or more 500N / mm manner appropriately adjusted range to be used is ² or less (meth) acrylic resin, a polyfunctional monomer ratio can . For example, the compounding ratio of the polyfunctional monomer and the (meth)acrylic resin may be 15:85 to 85:15, or may be 40:60 to 80:20.

Generally, a resin layer having such a Martens hardness is rarely arranged inside the laminate (polarizing plate). The reason is that in the state where the resin layer is fixed in the laminate, even if the Martens hardness is 500 N/mm ² or less, the resin layer may be broken due to expansion and contraction of the polarizer layer.

On the other hand, in this embodiment, the resin layer 13 having such a Martens hardness is arranged inside the polarizing plate 1. In order to suppress the breakage of the resin layer 13 due to the expansion and contraction of the polarizer layer 12, the breaking load of the resin layer 13 is preferably 500 g or more and 2000 g or less, or may be less than 2000 g.

1mm者。壓頭之壓入速度係設為0.33cm/秒。進行斷裂荷重的測定之環境溫度係設為23℃。使用手持式壓縮試驗機(KES-G5)時，靈敏度係設為10且電壓設為5mm/10V。 The breaking load system of the resin layer 13 can be measured as follows. For the measurement system, a hand-held compression tester (KES-G5) manufactured by KATOTECH Co., Ltd. can be used. The test piece (resin layer) was sandwiched between the test pieces (resin layer) using a jig having a through hole (diameter 11 mm) in the center of the test machine, and the test piece was set in the test machine. Here, the size of the test piece used may be the size covering the through hole, and the thickness of the test piece is the thickness of the resin layer. Next, press the indenter into the test piece. The load when the test piece breaks due to the indenter or the indenter penetrates the test piece is defined as the breaking load (unit: g). The indenter uses a spherical tip and is

1mm. The pressing speed of the indenter was set to 0.33 cm/sec. The ambient temperature at which the breaking load was measured was set to 23°C. When using a handheld compression tester (KES-G5), the sensitivity is set to 10 and the voltage is set to 5mm/10V.

In the present embodiment, the compounding ratio of the (meth)acrylic resin, polyfunctional monomer, and the like that form the resin layer may be appropriately adjusted so that the breaking load is in the range of 500 g or more and 2000 g or less. For example, the compounding ratio of the polyfunctional monomer and the (meth)acrylic resin may be 15:85 to 85:15, or may be 40:60 to 80:20.

The method of measuring the Martens hardness of the resin layer 13 will be described below. The resin layer 13 was subjected to a press-in test in accordance with ISO14577 to measure the Martens hardness of the resin layer 13. Specifically, as described in the column of Examples, as the film hardness tester, a nanoindentation tester (ENT-2100) manufactured by Elionix Corporation can be used. The sample formed of the resin layer 13 is set in the above-mentioned test machine, and the Markov hardness can be measured by contacting the sample with a Berkovich indenter and pressing in. Set the initial load to 0 mN and the maximum load to 0.5 mN.

The maximum load retention, that is, the time to maintain the maximum load can be set to 1000m seconds. The ambient temperature at which the Martens hardness is measured can be set to 23°C.

It is also preferable to make the thickness of the resin layer 13 more than a predetermined value. The thickness of the resin layer 13 is preferably 0.5 μm or more, may be 1 μm or more, may be 3 μm or more, or may be 8 μm or more. The upper limit of the thickness of the resin layer 13 is not particularly limited. For example, in order to reduce the degree of curing shrinkage of the resin layer 13, the thickness of the resin layer 13 may be 20 μm or less, or 15 μm or less.

(1st adhesive layer)

In this specification, the so-called "adhesive agent" is a soft rubber-like material that exhibits adhesiveness by attaching itself to the adherend. In addition, the active energy ray-curable adhesive described below can adjust the adhesive force by irradiating energy rays.

The adhesive constituting the first adhesive layer 14 is not particularly limited, and a conventionally known adhesive with excellent optical transparency can be used. For example, an acrylic, urethane, polysiloxane, or Adhesive for matrix polymers such as polyvinyl ether series. In addition, the adhesive constituting the first adhesive layer 14 may be an active energy ray-curable adhesive, a thermosetting adhesive, or the like.

The so-called "active energy ray hardening type" refers to the property of being hardened by irradiation with energy rays such as ultraviolet rays and electron beams. The active energy ray-curable adhesive has adhesion even before the energy ray is irradiated. Therefore, the active energy ray hardening type adhesive can be adjusted by adhering to the adherend and irradiating the energy ray to harden to adjust the adhesion force.

The active energy ray-curable adhesive system contains an acrylic adhesive and an energy ray polymerizable compound. The active energy ray-curable adhesive is preferably formulated with a cross-linking agent. In addition, according to the necessary active energy ray hardening type adhesive, a photopolymerization initiator, a photosensitizer, etc. may be blended.

Among these adhesives, an acrylic resin having excellent transparency, adhesion, re-peelability, weather resistance, heat resistance, etc. is preferably used as the adhesive of the matrix polymer.

The thickness of the first adhesive layer 14 is preferably 3 μm or more, and more preferably 5 μm or more. The thickness of the first adhesive layer 14 is preferably 40 μm or less, and more preferably 30 μm or less. In addition, the above upper limit value and lower limit value may be arbitrarily combined. When the thickness of the first adhesive layer 14 is 3 μm or more, the resin layer 13 and the retardation layer 16 can be sufficiently bonded. When the thickness of the first adhesive layer 14 is 40 μm or less, the retardation layer 16 is less likely to shift.

When manufacturing the polarizing plate 1 of the present embodiment, when the resin layer 13 and the retardation layer 16 are bonded via the first adhesive layer 14 using a strong pressure, compared to when using a weaker pressure, the first 1 The thickness of the adhesive layer 14 may become thinner. This is because the first adhesive layer 14 has elasticity. If the resin layer 13 and the retardation layer 16 are temporarily placed after being bonded, the thickness of the first adhesive layer 14 is restored to the original. Therefore, when the resin layer 13 and the retardation layer 16 are laminated with a strong pressure through the first adhesive layer 14, for example, after leaving for 5 minutes, measuring the thickness of the first adhesive layer 14 can obtain a certain value .

(Alignment layer)

The alignment layer 19 is not limited to a vertical alignment layer that aligns the molecular axis of the liquid crystal compound vertically, and may also be a horizontal alignment layer that aligns the molecular axis of the liquid crystal compound horizontally, or an inclined alignment layer that aligns the molecular axis of the liquid crystal compound obliquely. .

As the alignment layer 19, a material having solvent resistance that does not dissolve by application of the liquid crystal composition or the like is preferable. In addition, the alignment layer 19 is preferably a material having heat resistance to heat treatment for removing the alignment of the solvent and the liquid crystal compound.

Examples of the material of the alignment layer 19 include: an alignment film containing an alignment polymer; and a groove alignment film in which a concave-convex pattern and a plurality of grooves are formed on the optical alignment film or surface to align them.

The thickness of the alignment layer 19 is, for example, a range of 10 nm or more and 10000 nm or less, preferably 10 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm or less, and even more preferably 10 nm or more and 200 nm or less.

The resin used for the alignment layer 19 is not particularly limited as long as it is used as a material for a conventional alignment film, and a previously known monofunctional or polyfunctional (meth)acrylate monomer can be used in A hardened product made by curing under a polymerization initiator.

Specifically, as the resin used for the alignment layer 19, examples of (meth)acrylate-based monomers include 2-ethylhexyl acrylate, cyclohexyl acrylate, and diethylene glycol mono-2- Ethylhexyl ether acrylate, diethylene glycol monophenyl ether acrylate, tetraethylene glycol monophenyl ether acrylate, trimethylolpropane triacrylate, lauryl acrylate, lauryl methacrylate, isopropyl acrylate Camphenate, isocamphoryl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxypropyl acrylate, benzyl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxymethacrylate Ethyl ester, benzyl methacrylate, cyclohexyl methacrylate, methacrylic acid, urethane acrylate, etc.

The resin used for the alignment layer 19 may be one kind of these resins or a mixture of two or more kinds.

(2nd adhesive layer)

The adhesive constituting the second adhesive layer 15 is not particularly limited, and a conventionally known adhesive having excellent optical transparency can be used.

As the adhesive constituting the second adhesive layer 15, the same materials as those exemplified as the adhesive constituting the above-mentioned first adhesive layer 14 can be used. The thickness of the first adhesive layer 14 and the thickness of the second adhesive layer 15 may be the same or different.

The thickness of the second adhesive layer 15 is preferably 3 μm or more, and more preferably 5 μm or more. In addition, the thickness of the second adhesive layer 15 is preferably 40 μm or less, and more preferably 30 μm or less. In addition, the above-mentioned limit value and lower limit value system can be arbitrarily combined.

When the thickness of the second adhesive layer 15 is 3 μm or more, the retardation layer can be sufficiently bonded to the display panel described later. When the thickness of the second adhesive layer 15 is 40 μm or less, the phase difference layer 16 disposed through the second adhesive layer 15 is unlikely to be shifted from the display panel described later.

When manufacturing the organic EL display device described later, when the phase difference layer 16 is bonded to the display panel with a strong pressure through the second adhesive layer 15, the second adhesion is compared to when the pressure is bonded with a weaker pressure The thickness of the agent layer 15 may become thin. This is because the second adhesive layer 15 has elasticity. When the retardation layer 16 is bonded to the display panel and temporarily placed, the thickness of the second adhesive layer 15 is restored to the original. Therefore, when the retardation layer 16 is bonded to the display panel via the second adhesive layer 15 with a strong pressure, for example, after leaving it for 5 minutes, a certain value can be obtained by measuring the thickness of the second adhesive layer 15.

(Polarizer)

The total thickness of the polarizing plate 1 is preferably 30 μm or more. In addition, the total thickness of the polarizing plate 1 is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less. In addition, the above upper limit value and lower limit value may be arbitrarily combined.

When the total thickness of the polarizing plate is 500 μm or less, it contributes to the thinning of the polarizing plate 1. When the total thickness of the polarizing plate 1 is 30 μm or more, the intensity of the polarizing plate 1 is improved.

In this specification, the "total thickness of the polarizing plate" refers to the dimension of the polarizing plate in the layering direction. The total thickness of the polarizing plate can be obtained, for example, by measuring any 5 points of the polarizing plate using a micrometer and calculating the average value.

In addition, the "total thickness of the polarizing plate" is the total value of the film thickness finally included in the image display device. That is, the "total thickness of the polarizing plate" does not include the thickness of the film that is not finally included in the image display device. Examples of thin films that are not included in the image display device at the end include peeling films and surface protective films.

The total thickness of the polarizer 1 can also be measured by measuring the protective layer 11, polarizer layer 12, resin layer 13, first adhesive layer 14, phase difference layer 16, second adhesive layer 15, and other polarizers. The thicknesses of all optical film layers, adhesive layers, and adhesive layers contained and finally incorporated into the image display device are obtained by adding these values.

The protective layer 11, the polarizer layer 12, the resin layer 13, the first adhesive layer 14, the retardation layer 16, the second adhesive layer 15, and all the optical film layers and adhesive layers contained in other polarizing plates, The thickness of the adhesive layer can be measured using the method described in this specification.

In this specification, the polarization degree of the polarizing plate can be evaluated based on two parameters called "luminous factor (also called visual sensitivity) corrected monomer transmittance (Ty)" and "luminous factor corrected polarized degree (Py)" . Ty and Py are the transmittance and polarization degree in the visible region (wavelength 380 to 780 nm) corrected so that the weighted value around 550 nm where the sensitivity of the human eye is the highest is maximized. Since light with a wavelength less than 380nm is usually invisible to the human eye, it is not considered in Ty and Py.

The Ty of the polarizing plate 1 is a value obtained by an image display device such as an organic EL display device using the polarizing plate 1. The Ty system of the polarizing plate 1 is preferably 40% or more and 47% or less, and more preferably 41% or more and 45% or less. With the above range, the balance between Ty and Py changes well. When the Ty of the polarizing plate 1 is 40% or more, the brightness of the image display device becomes sufficiently high. When Ty of the polarizing plate 1 is 47% or less, Py becomes sufficiently high and the contrast becomes good. On the other hand, when Ty of the polarizing plate 1 is less than 40%, in order to sufficiently increase the brightness of the image display device, the power input to the image display device may be increased.

The Py system of the polarizing plate 1 is preferably 99.9% or more, more preferably 99.95% or more, or 99.99% or more.

When the polarizing plate 1 is subjected to a humid heat test for 24 hours in an environment with a temperature of 80° C. and a relative humidity of 90%, the absolute value of the difference in Py before and after the polarizing plate 1 (hereinafter also referred to as ΔPy) is 0% or more Below 13%. In addition, the difference of Ty before and after the test of the polarizing plate 1 (hereinafter also referred to as ΔTy) is 0% to 5%. When ΔPy and ΔTy are within the above-mentioned ranges, it can be said that even if the polarizing plate 1 is in a hot and humid environment, a high degree of polarization can be maintained.

From the viewpoint of moisture resistance, the ΔPy of the polarizing plate 1 is preferably 10% or less, more preferably 8% or less, and even more preferably 5% or less.

In addition, from the viewpoint of moisture resistance, the ΔTy of the polarizing plate 1 is preferably 4% or less, and more preferably 3% or less.

In this specification, Ty of the polarizing plate 1 is measured using a spectrophotometer with an integrating sphere ("V7100" manufactured by Japan Spectroscopy Co., Ltd.). The MD transmittance and TD transmittance are determined in the wavelength range of 380 nm to 780 nm, and the single transmittance at each wavelength is calculated according to equation (1).

Next, the luminous factor correction is performed according to the 2 degree field of view (C light source) of JIS Z 8701 to obtain the luminous factor corrected single transmittance. Here, the "MD transmittance" refers to the transmittance when the polarization direction emitted from Glan-Thomson 稜鏡 is parallel to the transmission axis of the polarizing plate sample. In addition, the "TD transmittance" refers to the transmittance when the direction of polarization emitted from Gran-Thomson Hirano is orthogonal to the transmission axis of the polarizing plate sample.

In this specification, Py of the polarizing plate 1 calculates the degree of polarization at each wavelength from the above-mentioned MD transmittance and TD transmittance according to equation (2). In addition, the luminous factor correction is performed based on the 2 degree field of view (C light source) of JIS Z 8701, and the luminous factor corrected single transmittance is obtained.

[Manufacturing method of polarizing plate]

Hereinafter, the method of manufacturing the polarizing plate of the first embodiment will be described based on FIG. 2.

The polarizing plate 1 of the present embodiment can be manufactured by sequentially laminating the layers constituting the polarizing plate 1, or can be manufactured by laminating adjacent layers in advance and stacking their laminates. Moreover, each layer which comprises the polarizing plate 1 can be manufactured using a conventional method, and a commercially available material can also be used.

FIG. 2 is a schematic diagram of an example of a method of manufacturing a polarizing plate according to the first embodiment. As shown in FIG. 2, first, the laminate A including the polarizer layer 12, the laminate B including the retardation layer 16, the first adhesive 140 that becomes the first adhesive layer 14, and the second adhesive layer are prepared 15的第一个粘胶150。 The second adhesive 150 15.

The laminate A is a laminate in which the protective layer 11, the polarizer layer 12, and the resin layer 13 are sequentially laminated.

The laminate B is a laminate in which the phase difference layer 16 and the alignment layer 19 are laminated.

The manufacturing method of the laminate A and the laminate B is not particularly limited.

Next, the resin layer 13 of the laminate A and the retardation layer 16 of the laminate B face each other, and the first adhesive 140 is disposed between the laminate A and the laminate B to obtain a composite laminate.

Next, the composite laminate is pressed from both sides of the laminate A or the laminate B to laminate the laminate A and the laminate B. In this way, a composite laminate in which the laminate A, the first adhesive layer 14 and the laminate B are sequentially laminated can be obtained.

Next, the second adhesive 150 is laminated on the other surface 19b of the alignment layer 19 of the obtained composite laminate. With this, the polarizing plate 1 can be obtained.

In addition, the lamination order of the layers constituting the polarizing plate 1 is not limited to this.

Since the polarizing plate 1 of the present embodiment includes the resin layer 13 described above, it is considered that the components contained in the retardation layer 16 can be transferred to the polarizer layer 12 to be suppressed. It is believed that this is the main reason why the components contained in the retardation layer 16 stay in the resin layer 13 and cannot easily move to the polarizer layer 12. Therefore, the polarizing plate 1 of this embodiment can maintain a high degree of polarization even in a hot and humid environment.

[Organic EL display device]

Hereinafter, an organic EL display device provided with the polarizing plate of the first embodiment will be described while referring to FIG. 3.

FIG. 3 is a schematic cross-sectional view showing an example of the structure of the organic EL display device of the first embodiment. As shown in FIG. 3, the organic EL display device 100 includes a display panel 10 and a polarizing plate 1.

The polarizing plate 1 is arranged on the viewing side of the display panel 10. The polarizing plate 1 is adhered to the display panel 10 via the second adhesive layer 15 included in the polarizing plate 1. One surface 11 a of the protective layer 11 included in the polarizing plate 1 is the surface on the viewing side of the organic EL display device 100.

The display panel 10 includes an organic electroluminescence display element (hereinafter also referred to as an organic EL element). That is, the polarizing plate 1 is arranged on the viewing side of the organic EL element.

FIG. 4 is a schematic cross-sectional view showing an example of the layer configuration of the organic EL device. As shown in FIG. 4, the organic EL element 200 includes a substrate 201, an anode 202, an organic EL layer 203, a cathode 204, and a sealing layer 205 covering these. In addition, the organic EL element 200 may be provided with a planarization layer (not shown) on the substrate 201 as necessary, or may be provided with an insulating layer (not shown) between the anode 202 and the cathode 204 to prevent short circuits.

Conventional materials can be used for each layer constituting the organic EL device.

The organic EL device 200 series can be manufactured continuously in a conventional reel process. Furthermore, the organic EL element 200 can be continuously laminated with the elongated polarizing plate 1 in the reel-type process to continuously manufacture the organic EL display device 100.

When the organic EL display device 100 configured as above is used, high display quality can be maintained even in a hot and humid environment.

<Second Embodiment>

[Polarizer]

Hereinafter, the polarizing plate of the second embodiment will be described while referring to FIG. 5. The polarizing plate of the second embodiment is common to the polarizing plate of the first embodiment. Therefore, in this embodiment, constituent elements common to those of the first embodiment are given the same symbols, and detailed descriptions are omitted.

FIG. 5 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the second embodiment. As shown in FIG. 5, the polarizing plate 2 of this embodiment includes a protective layer 11, a polarizer layer 12, a resin layer 13, a first adhesive layer 14, a second adhesive layer 15, a first retardation layer 17, a first 2 The retardation layer 18, the first alignment layer 20, the second alignment layer 21, and the adhesive layer 22.

The polarizing plate 2 of this embodiment includes a first retardation layer 17 and a second retardation layer 18 as retardation layers. The first phase difference layer 17 and the second phase difference layer 18 are arranged on the other surface 12b side of the polarizer layer 12. A resin layer 13 is arranged between the polarizer layer 12 and the first retardation layer 17. The second retardation layer 18 is arranged on the resin layer 13 side with the polarizer layer 12 as a reference. The second retardation layer 18 is arranged between the resin layer 13 and the first retardation layer 17.

The first retardation layer 17 and the second retardation layer 18 are joined via the adhesion layer 22.

The surface (the other surface) 17 b of the first retardation layer 17 on the opposite side to the adhesive layer 22 is in contact with the second alignment layer 21.

The surface (one surface) 18 a of the second retardation layer 18 opposite to the adhesive layer 22 side is in contact with the first alignment layer 20. The first alignment layer 20 and the resin layer 13 are bonded via the first adhesive layer 14. The first adhesive layer 14 is provided on the other surface 13b of the resin layer 13.

The second adhesive layer 15 is in contact with the surface (the other surface) 21b of the second alignment layer 21 on the opposite side to the first retardation layer 17 side.

Hereinafter, each layer constituting the polarizing plate 2 of the second embodiment will be described in detail.

(1st phase difference layer, 2nd phase difference layer)

The first retardation layer 17 and the second retardation layer 18 are independently, for example, a positive A layer, a negative A layer, etc., such as a layer imparting a phase difference of 1/2 wavelength and a layer imparting a phase difference of 1/4 wavelength. Positive C layer or negative C layer. The first retardation layer 17 and the second retardation layer may be the same material or different materials.

In this specification, the "layer that imparts a phase difference of 1/2 wavelength" refers to a phase difference layer that converts the polarization direction of linearly polarized light of a specific wavelength by 90°.

As an aspect of this embodiment, any one of the first retardation layer 17 and the second retardation layer 18 is a layer that imparts a phase difference of 1/4 wavelength and the other is a layer that imparts a half wavelength. The layer with the phase difference is better. Furthermore, it is preferable that either the first retardation layer 17 or the second retardation layer 18 is a layer that imparts a retardation of 1/4 wavelength, and the other is a positive C layer.

Therefore, the thicknesses of the first retardation layer 17 and the second retardation layer 18 and the materials constituting these retardation layers are adjusted in such a way that the required in-plane retardation value and thickness direction retardation value can be obtained. can.

When the first retardation layer 17 is a layer imparting a retardation of 1/4 wavelength, and the second retardation layer 18 is a layer imparting a retardation of 1/2 wavelength, the thickness of the first retardation layer 17 is, for example, 1 μm It is preferably 10 μm or more and the thickness of the second retardation layer 18 is, for example, 1 μm or more and 10 μm or less.

When the first retardation layer 17 is a positive C layer and the second retardation layer 18 is a layer that imparts a retardation of 1/4 wavelength, the thickness of the first retardation layer 17 is, for example, 1 μm or more and 10 μm or less, and the second phase difference layer The thickness of 18 is, for example, 1 μm or more and 10 μm or less.

In addition, the thickness of the first retardation layer 17 and the thickness of the second retardation layer 18 can be obtained by the method of measuring the thickness of the layer described in the first embodiment.

The first retardation layer 17 uses a cured product of the first liquid crystal composition as a forming material. The second retardation layer 18 uses a cured product of the second liquid crystal composition as a forming material. For the first liquid crystal composition and the second liquid crystal composition, the same materials as those exemplified in the phase difference layer 16 of the first embodiment can be used. The first liquid crystal composition and the second liquid crystal composition may be the same or different.

The polarizing plate provided with a polarizer layer such as the polarizer layer 12 and a phase difference layer such as the first phase difference layer 17 and the second phase difference layer 18 under a hot and humid environment (for example, a temperature of 80°C and a relative humidity of 90%) (Environment), when placed, there may be a decrease in polarized light.

In the polarizing plate 2 of the present embodiment, it is also considered that by providing the resin layer 13 between the polarizer layer 12 and the first retardation layer 17 and the second retardation layer 18, it is possible The migration of the contained component to the polarizer layer 12 is suppressed. As a result, the inventors found that by providing the resin layer 13 between the polarizer layer 12 and the first retardation layer 17 and the second retardation layer 18, even in a hot and humid environment, high polarized light can be maintained This completed the present invention.

(1st alignment layer, 2nd alignment layer)

For the first alignment layer 20 and the second alignment layer 21, the same materials as those exemplified in the alignment layer 19 of the first embodiment can be used. The first alignment layer 20 and the second alignment layer 21 may be the same or different.

(Next layer)

In this specification, the "adhesive layer" refers to an adhesive layer or an adhesive layer. As the adhesive layer, the above materials can be suitably used. The following describes when the adhesive layer 22 is an adhesive layer. The "adhesive agent" is one that can be applied to the substrate in a liquid state when it is applied to the substrate, and the adhesive property is exhibited by curing (that is, the adhesive property is not exhibited until curing).

Examples of the adhesive for bonding the first retardation layer 17 and the second retardation layer 18 include, for example, an aqueous adhesive or an active energy ray-curable adhesive.

Examples of the water-based adhesive include an adhesive prepared by dissolving or dispersing a PVA-based resin in water.

Examples of the active energy ray-curable adhesive include adhesives containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays.

As the active energy ray-curable adhesive, since it exhibits good adhesiveness, it is preferable to contain either or both of the cation polymerizable curable compound and the radical polymerizable curable compound. The active energy ray-curable adhesive agent may further contain either or both of a cationic polymerization initiator and a radical polymerization initiator for starting the hardening compound.

Conventional materials can be used for the cation polymerizable hardenable compound and the radical polymerizable hardenable compound.

Active energy ray-curable adhesives can contain cationic polymerization accelerators, ion scavengers, antioxidants, chain transfer agents, adhesion-imparting agents, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers as necessary , Antistatic agent, leveling agent, solvent and other additives.

The thickness of the next layer 22 is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.05 μm or more and 5 μm or less. When the thickness of the next layer 22 is 0.01 μm or more, the polarizing plate 2 is less likely to crack because it has sufficient strength. When the thickness of the next layer 22 is 10 μm or less, floating and peeling are unlikely to occur between the first retardation layer 17 and the second retardation layer 18. In addition, the appearance of the polarizing plate 2 caused by the adhesive during hardening and shrinking is not likely to occur.

[Manufacturing method of polarizing plate]

Hereinafter, the method of manufacturing the polarizing plate according to the second embodiment will be described based on FIG. 6.

The polarizing plate 2 of the present embodiment can be manufactured by sequentially laminating the layers constituting the polarizing plate 2, or the adjacent layers can be laminated in advance, and can also be manufactured by laminating their laminates. Moreover, each layer which comprises the polarizing plate 2 can be manufactured according to a conventional method, and a commercially available material can also be used.

FIG. 6 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the second embodiment. As shown in FIG. 6, first, a laminate A including the polarizer layer 12, a laminate C including the first retardation layer 17 and the second retardation layer 18, and a first adhesive that becomes the first adhesive layer 14 are prepared 140, and the second adhesive 150 that becomes the second adhesive layer 15.

The laminate A is the same as the laminate used in the method of manufacturing the polarizing plate of the first embodiment.

The laminate C is a laminate in which the first alignment layer 20, the second retardation layer 18, the adhesion layer 22, the first retardation layer 17, and the second alignment layer 21 are laminated in this order. The layered body C can be formed by combining the layered body of the first alignment layer 20 and the second phase difference layer 18, the layered body of the first phase difference layer 17 and the second alignment layer 21, In a state where the phase difference layer 18 faces each other, it is obtained by bonding using the adhesive layer 22.

Next, the resin layer 13 of the laminate A is opposed to the first alignment layer 20 of the laminate C, and the first adhesive 140 is disposed between the laminate A and the laminate C to obtain a composite laminate.

Next, the composite laminate is pressed from both sides of the laminate A or the laminate C to laminate the laminate A and the laminate C. Thereby, a composite laminate in which the laminate A, the first adhesive layer 14 and the laminate C are laminated in this order can be obtained.

Next, the second adhesive 150 is laminated on the other surface 21b of the second alignment layer 21 of the obtained composite laminate. Thereby, the polarizing plate 2 can be obtained.

In addition, the stacking order of the layers constituting the polarizing plate 2 is not limited to this.

Since the polarizing plate 2 of this embodiment includes the resin layer 13 described above, it is considered that the components contained in the first retardation layer 17 and the second retardation layer 18 can be transferred to the polarizer layer 12 to be suppressed. It is believed that this is because the components contained in the first retardation layer 17 and the second retardation layer 18 stay in the resin layer 13 and thus become the main cause of the difficulty in moving to the polarizer layer 12. Therefore, the polarizing plate 2 of the present embodiment can maintain a high degree of polarization even in a hot and humid environment.

<Third Embodiment>

[Polarizer]

Hereinafter, the polarizing plate of the third embodiment will be described while referring to FIG. 7. The polarizing plate of the third embodiment is partially common to the polarizing plate of the second embodiment. Therefore, in this embodiment, constituent elements common to the second embodiment are given the same symbols and detailed descriptions are omitted.

FIG. 7 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the third embodiment. As shown in FIG. 7, the polarizing plate 3 of this embodiment includes a protective layer 11, a polarizer layer 12, a resin layer 13, a second adhesive layer 15, a first retardation layer 17, a second retardation layer 18, and a third 1 Alignment layer 20, second alignment layer 21, adhesion layer 22, and third adhesive layer 23

Unlike the polarizing plate 2 of the second embodiment, the first alignment layer 20 is directly formed on the other surface 13b of the resin layer 13. In addition, the polarizer layer 12 and the resin layer 13 are bonded via the third adhesive layer 23.

As the adhesive constituting the third adhesive layer 23, the same materials as those exemplified as the adhesive constituting the first adhesive layer 14 of the first embodiment can be used.

The thickness of the second adhesive layer 15 and the thickness of the third adhesive layer 23 may be the same or different.

[Manufacturing method of polarizing plate]

Hereinafter, the method of manufacturing the polarizing plate according to the third embodiment will be described based on FIG. 8.

The polarizing plate 3 of the present embodiment can be manufactured by sequentially laminating the layers constituting the polarizing plate 3, or the adjacent layers can be laminated in advance, and can also be manufactured by laminating the laminates thereof. In addition, each layer constituting the polarizing plate 3 can be manufactured according to a conventional method, and commercially available materials can also be used.

FIG. 8 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the third embodiment. As shown in FIG. 8, first, the laminated body D including the polarizer layer 12, the laminated body E including the resin layer 13 and the first retardation layer 17 and the second retardation layer 18, and the third adhesive layer 23 are prepared The third adhesive 230 and the second adhesive 150 that becomes the second adhesive layer 15.

The laminate D is a laminate in which the protective layer 11 and the polarizer layer 12 are laminated.

The laminate E is a laminate in which the resin layer 13, the first alignment layer 20, the second retardation layer 18, the adhesion layer 22, the first retardation layer 17, and the second alignment layer 21 are laminated in this order.

The layered body E can make the first phase difference by the layered body of the resin layer 13 and the first alignment layer 20 and the second phase difference layer 18, the layered body of the first phase difference layer 17 and the second alignment layer 21 The layer 17 is obtained by bonding with the adhesive layer 22 in a state where the second retardation layer 18 faces each other.

Hereinafter, a method of manufacturing a laminate of the resin layer 13, the first alignment layer 20 and the second retardation layer 18 will be described. First, the resin layer 13 is formed. Next, the first alignment layer 20 is directly formed on the surface of the resin layer 13. Next, the second retardation layer 18 is formed on the surface of the first alignment layer 20. In this way, a laminate of the resin layer 13, the first alignment layer 20 and the second retardation layer 18 can be obtained.

Next, the polarizer layer 12 of the laminate D is opposed to the resin layer 13 of the laminate E, and the third adhesive 230 is disposed between the laminate D and the laminate E to obtain a composite laminate.

Next, the composite laminate is pressed from both sides of the laminate D or the laminate E to laminate the laminate D and the laminate E. Thereby, a composite laminate in which the laminate D, the third adhesive layer 23, and the laminate E are laminated in order can be obtained.

Next, the second adhesive 150 is laminated on the other surface 21b of the second alignment layer 21 of the obtained composite laminate. With this, the polarizing plate 3 can be obtained.

In addition, the stacking order of the layers constituting the polarizing plate 3 is not limited to this.

Since the polarizing plate 3 of the present embodiment includes the resin layer 13 described above, it is considered that the components contained in the first retardation layer 17 and the second retardation layer 18 can be transferred to the polarizer layer 12 to be suppressed. It is believed that this is because the components contained in the first retardation layer 17 and the second retardation layer 18 stay in the resin layer 13 and thus become the main cause of the difficulty in moving to the polarizer layer 12. Therefore, the polarizing plate 3 of the present embodiment can maintain a high degree of polarization even in a hot and humid environment.

<Fourth Embodiment>

[Polarizer]

Hereinafter, the polarizing plate of the fourth embodiment will be described while referring to FIG. 9. The polarizing plate of the fourth embodiment is common to the polarizing plate of the third embodiment. Therefore, in this embodiment, constituent elements common to the third embodiment are given the same symbols and detailed descriptions are omitted.

FIG. 9 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the fourth embodiment. As shown in FIG. 9, the polarizing plate 4 of this embodiment includes a protective layer 11, a polarizer layer 12, a resin layer 13, a second adhesive layer 15, a first retardation layer 17, a second retardation layer 18, a third 1 Alignment layer 20, second alignment layer 21, adhesion layer 22, fourth adhesive layer 24, and fifth adhesive layer 25.

Unlike the polarizing plate 3 of the third embodiment, the resin layer 13 is disposed between the first retardation layer 17 and the second retardation layer 18. That is, the first retardation layer 17 is arranged on the opposite side to the polarizer layer 12 with the resin layer 13 as a reference. On the other hand, the second retardation layer 18 is disposed between the resin layer 13 and the polarizer layer 12.

Although the reason is not clear, it has been clarified that the positive C layer has a greater effect of reducing the degree of polarization in a humid and hot environment than a layer that gives a quarter-wave retardation. Therefore, as in the present embodiment, with the resin layer 13 as a reference, when at least the first retardation layer 17 exists on the opposite side of the polarizer layer 12 side, the first retardation layer 17 is the positive C layer and the second retardation The layer 18 is preferably a layer that imparts a phase difference of 1/4 wavelength. At this time, even in a hot and humid environment, it is easy to obtain the effect of the present invention that maintains a high degree of polarization.

As the adhesive constituting the fourth adhesive layer 24 and the fifth adhesive layer 25, the same materials as those exemplified as the adhesive constituting the first adhesive layer 14 of the first embodiment can be used.

The thickness of the fourth adhesive layer 24 and the thickness of the fifth adhesive layer 25 may be the same or different.

[Manufacturing method of polarizing plate]

Hereinafter, the method of manufacturing the polarizing plate according to the fourth embodiment will be described based on FIG. 10.

The polarizing plate 4 of the present embodiment can be manufactured by sequentially laminating the layers constituting the polarizing plate 4, or the adjacent layers can be laminated in advance, and the laminated body can be manufactured by laminating the laminates thereof. Moreover, each layer which comprises the polarizing plate 4 can be manufactured according to a conventional method, and a commercially available material can also be used.

Fig. 10 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the fourth embodiment. As shown in FIG. 10, first, a laminate F including the polarizer layer 12 and the resin layer 13 and the second retardation layer 18, a laminate G including the first retardation layer 17, and a fifth adhesive layer 25 are prepared The fifth adhesive 250 and the second adhesive 150 that becomes the second adhesive layer 15.

The laminate F is a laminate in which the protective layer 11, the polarizer layer 12, the fourth adhesive layer 24, the second retardation layer 18, the first alignment layer 20, and the resin layer 13 are laminated in this order.

The layered body G is a layered body formed by laminating the first retardation layer 17 and the second alignment layer 21.

The manufacturing method of the laminated body F and the laminated body G is not specifically limited.

Next, the resin layer 13 of the laminate F is opposed to the first retardation layer 17 of the laminate G, and the fifth adhesive 250 is disposed between the laminate F and the laminate G to obtain a composite laminate.

Next, the composite laminate is pressed from both sides of the laminate F or the laminate G to laminate the laminate F and the laminate G. Thereby, a composite laminate in which the laminate F, the fifth adhesive layer 25, and the laminate G are laminated in this order can be obtained.

Next, the second adhesive 150 is laminated on the other surface 21b of the second alignment layer 21 of the obtained composite laminate. With this, the polarizing plate 4 can be obtained.

In addition, the stacking order of the layers constituting the polarizing plate 4 is not limited to this.

Since the polarizing plate 3 of the present embodiment includes the resin layer 13 described above, it is considered that the components contained in the first retardation layer 17 and the second retardation layer 18 can be transferred to the polarizer layer 12 to be suppressed. It is believed that this is because the component contained in the first retardation layer 17 stays in the resin layer 13 and becomes the main reason that it is not easy to move to the polarizer layer 12. Therefore, the polarizing plate 4 of this embodiment can maintain a high degree of polarization even in a hot and humid environment.

<Fifth Embodiment>

[Polarizer]

Hereinafter, the polarizing plate of the fifth embodiment will be described while referring to FIG. 11. The polarizing plate of the fifth embodiment is common to the polarizing plate of the fourth embodiment. Therefore, in this embodiment, constituent elements common to the fourth embodiment are given the same symbols and detailed descriptions are omitted.

Fig. 11 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing plate of the fifth embodiment. As shown in FIG. 11, the polarizing plate 5 of this embodiment includes a protective layer 11, a polarizer layer 12, a resin layer 13, a second adhesive layer 15, a first retardation layer 17, a second retardation layer 18, and a third 1 Alignment layer 20, second alignment layer 21, adhesion layer 22, and fourth adhesive layer 24.

Unlike the polarizing plate of the fourth embodiment, the first retardation layer 17 and the second retardation layer 18 are in contact with each other via the resin layer 13. That is, the resin layer 13 not only serves to suppress the components contained in the first retardation layer 17 from moving to the polarizer layer 12, but also serves to join the first retardation layer 17 and the second retardation layer 18.

Although the reason is not clear, it has been clarified that the positive C layer has a greater effect of reducing the degree of polarization in a humid and hot environment than a layer that gives a quarter-wave retardation. Therefore, as in the present embodiment, with the resin layer 13 as a reference, when at least the first retardation layer 17 exists on the opposite side of the polarizer layer 12 side, the first retardation layer 17 is the positive C layer and the second retardation The layer 18 is preferably a layer that imparts a phase difference of 1/4 wavelength. At this time, even in a hot and humid environment, it is easy to obtain the effect of the present invention that maintains a high degree of polarization.

[Manufacturing method of polarizing plate]

The manufacturing method of the polarizing plate of the fifth embodiment will be described below based on FIG. 12.

The polarizing plate 5 of the present embodiment can be manufactured by sequentially laminating the layers constituting the polarizing plate 5, or the adjacent layers can be laminated in advance, and the laminated body can be manufactured by laminating the layers. Moreover, each layer which comprises the polarizing plate 5 can be manufactured according to a conventional method, and a commercially available material can also be used.

FIG. 12 is a schematic diagram showing an example of a method of manufacturing a polarizing plate according to the fifth embodiment. As shown in FIG. 12, first, a laminate H including the polarizer layer 12 and the second retardation layer 18, a laminate I including the resin composition 130 that becomes the resin layer 13 and the first retardation layer 17 are prepared, and The second adhesive 150 of the second adhesive layer 15.

The laminate H is a laminate in which a protective layer 11, a polarizer layer 12, a fourth adhesive layer 24, a first alignment layer 20, and a second retardation layer 18 are laminated in this order.

The laminate I is a laminate in which the resin composition 130, the first retardation layer 17 and the second alignment layer 21 are laminated in this order.

The manufacturing method of the laminate H and the laminate I is not particularly limited.

Next, the second retardation layer 18 of the laminate H and the resin composition 130 of the laminate I are joined to obtain a composite laminate. Thereby, a composite laminate in which the laminate H and the laminate I are laminated can be obtained. By hardening the resin composition 130 of the composite laminate, the resin layer 13 is formed between the first retardation layer 17 and the second retardation layer 18.

Next, the second adhesive 150 is laminated on the other surface 21b of the second alignment layer 21 of the obtained composite laminate. With this, the polarizing plate 5 can be obtained.

In addition, the stacking order of the layers constituting the polarizing plate 5 is not limited to this.

Since the polarizing plate 5 of the present embodiment is provided with the resin layer 13 described above, it is considered that the component contained in the first retardation layer 17 can be suppressed from migrating to the polarizer layer 12 and restricted. It is believed that this is because the component contained in the first retardation layer 17 stays in the resin layer 13 and becomes the main reason that it is not easy to move to the polarizer layer 12. Therefore, the polarizing plate 5 of the present embodiment can maintain a high degree of polarization even in a hot and humid environment.

In the above, the preferred embodiments of the present invention have been described while referring to the attached drawings, but it goes without saying that the present invention is not limited by these examples. The various shapes, combinations, etc. of the constituent members shown in the above examples are only examples, and various changes can be made according to design requirements and the like without departing from the gist of the present invention.

[Example]

The present invention is described below by examples, but the present invention is not limited by these examples. In addition, in this embodiment, a positive C layer having a large effect of reducing the degree of polarization in a hot and humid environment is used as the phase difference layer as compared to the layer that imparts a phase difference of 1/4 wavelength. The Martens hardness of the resin layer and Ty and Py of the polarizing plate in this example were determined using the following method.

[Martens hardness of resin layer]

The Martens hardness of the resin layer was measured by performing a press-in test on the resin layer according to ISO14577. Specifically, a nanoindentation tester (ENT-2100) manufactured by Elionix Corporation was used as a film hardness tester. The sample formed of the resin layer was set in the above-mentioned testing machine, and the Markov hardness was measured by bringing a Berkovich indenter into contact with the side of the sample and pressing in. The initial load system was set to 0 mN, and the maximum load system was set to 0.5 mN. The maximum load retention system is set to 1000m seconds. The ambient temperature at which the Martens hardness is measured is 23°C.

[Fracture load of resin layer]

1mm者。壓頭之壓入速度係設為0.33cm/秒。進行斷裂荷重的測定之環境溫度係設為23℃。靈敏度設為10且電壓設為5mm/10V。 The breaking load of the resin layer was measured as follows. As the measurement system, a hand-held compression tester (KES-G5) manufactured by KATOTECH Co., Ltd. was used. The test piece (resin layer) was sandwiched between the test pieces (resin layer) using a jig having a through hole (diameter 11 mm) in the center provided in the test machine, and the test piece was set in the test machine. Here, the size of the test piece used is such that it can cover the through hole, and the thickness of the test piece is the thickness of the resin layer. Next, press the indenter into the test piece. The load when the test piece breaks due to the indenter or the indenter penetrates the test piece is defined as the breaking load (unit: g). The indenter uses a spherical tip and is

1mm. The pressing speed of the indenter was set to 0.33 cm/sec. The ambient temperature at which the breaking load was measured was set to 23°C. The sensitivity is set to 10 and the voltage is set to 5mm/10V.

[Ty, Py of polarizer]

The Ty of the polarizing plate was measured using a spectrophotometer with an integrating sphere ("V7100" manufactured by Japan Spectroscopy Co., Ltd.). The MD transmittance and TD transmittance are determined in the wavelength range of 380 nm to 780 nm, and the single transmittance at each wavelength is calculated according to equation (1). Next, the luminous factor correction is performed according to the 2 degree field of view (C light source) of JIS Z 8701 to obtain the luminous factor corrected single transmittance.

The Py of the polarizing plate calculates the degree of polarization at each wavelength from the above MD transmittance and TD transmittance according to equation (2). In addition, the luminous factor correction is performed in accordance with the 2 degree field of view (C light source) of JIS Z 8701 and the luminous factor corrected single transmittance is obtained.

[Examples 1 to 4, Comparative Example 1]

[Manufacture of polarizing film]

The PVA film with a thickness of 20 μm (average degree of polymerization of about 2400 and saponification degree of 99.9 mol% or more) was uniaxially stretched to about 6 times by dry stretching, and was immersed in pure water at 40°C while maintaining tension. Seconds.

Next, the film was dyed by immersing the film in a 28°C dyeing aqueous solution with a mass ratio of iodine/potassium iodide/water of 0.044/5.7/100 for 30 seconds.

Next, the cross-linking treatment was performed by immersing the dyed film in a 70°C boric acid aqueous solution with a mass ratio of potassium iodide/boric acid/water of 11.0/6.2/100 for 120 seconds.

Next, after washing the cross-linked film with pure water at 8°C for 15 seconds, the film was dried at 60°C for 50 seconds and then at 75°C for 20 seconds while maintaining a tension of 300 N/m. In this way, a polarizing film having a thickness of 7 μm with iodine adsorption orientation on the PVA film was obtained.

[Manufacture of laminate (1)]

As the protective film, a cycloolefin resin film (COP, ZF-14 UV manufactured by ZEON Co., Ltd., Japan, which has no absorption characteristics and a thickness of 13 μm) is prepared. The water-based adhesive was injected between the obtained polarizing film and cycloolefin-based resin film and bonded using a nip roller. The obtained laminate was dried at 60° C. for 2 minutes while maintaining the tension of 430 N/m to obtain a laminate (1) provided with a polarizer layer and a protective layer disposed on one side of the polarizer layer. The thickness of the laminate A is 20 μm.

Moreover, the said water-based adhesive system added 3 mass parts of carboxy-modified polyvinyl alcohol (made by KURARAY Co., Ltd.; KURARAY POVAL (registered trademark) KL318) to 100 mass parts of water, and a water-soluble polyamide epoxy resin (Tagaoka) It is manufactured by Chemical Industry Co., Ltd.; Sumirez Resin (registered trademark) 650; an aqueous solution with a solid concentration of 30%) prepared by 1.5 parts by mass.

[Manufacture of laminate (2)]

As a transparent base material, a base material formed of a polyethylene terephthalate film with a thickness of 38 μm was prepared. The composition for the vertical alignment layer was applied to one side of the transparent substrate so as to have a film thickness of 3 μm, and ultraviolet rays were irradiated so that the cumulative light amount became 20 mJ/cm ² to form an alignment layer.

In addition, the composition for the vertical alignment layer includes 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxyethyl) ether at 1:1. : Mix in a ratio of 4:5, and prepare by adding LUCIRIN (registered trademark) TPO as a polymerization initiator at a ratio of 4% relative to the total mass of the resulting mixture.

On the formed alignment layer, a liquid crystal composition containing a polymerizable nematic liquid crystal compound (manufactured by Merck, RMM28B) was coated on the alignment layer by die coating.

The liquid crystal composition was prepared by using methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) with a boiling point of 155°C as a solvent at a mass ratio (MEK: MIBK: CHN) A mixed solvent of 35:30:35. Then, the liquid crystal composition prepared so that the solid content per 100 g of the liquid crystal composition becomes 1 to 1.5 g is coated on the alignment layer so that the coating amount before drying becomes 4 to 5 g.

After the liquid crystal composition was coated on the alignment layer, the obtained coating layer was subjected to drying treatment under the conditions that the drying temperature was 75° C. and the drying time was 120 seconds. Subsequently, the liquid crystal compound is polymerized and hardened by ultraviolet (UV) irradiation. In this way, a laminate (2) composed of a phase difference layer, an alignment layer, and a transparent substrate is obtained. This phase difference layer system satisfies the relationship of n _z >n _x =n _y and is a positive C layer. The total thickness of the phase difference layer and the alignment layer is 4 μm.

[Preparation of resin composition]

Dipentaerythritol hexaacrylate (hereinafter also referred to as DPHA) (ARONIX (registered trademark) M-403 polyfunctional acrylate manufactured by East Asia Synthetic Co., Ltd.), acrylate resin (EBECRYL (registered trademark) 4858 Daicel UCB shares Co., Ltd., aliphatic urethane acrylate) combined to 100 parts by mass, 2-methyl-1-[4-(methylthio)phenyl]-2-N-morpholinylpropane-1- Ketone (IRGACURE (registered trademark) 907; manufactured by Ciba Specialty Chemicals) 3 parts by mass, fluorine-based leveling agent (F-554 DIC Co., Ltd. fluorine-containing/lipophilic group oligomer) 0.25 parts by mass dissolved in an A solution was prepared from 250 parts by mass of propanol, and a resin composition containing acrylic resin was prepared. In addition, DPHA and acrylate resin were blended in the mass blending ratio shown in Table 1.

[Manufacture of laminate (3)]

The resin composition was applied on the retardation layer of the laminate (2) using a bar coater. After drying the obtained coating film at 80°C for 1 minute, ultraviolet light (accumulated light amount at a wavelength of 365 nm under a nitrogen atmosphere by using a high-pressure mercury lamp ("UNICURE VB-15201BY-A", manufactured by USHIO Electric Co., Ltd.)): 400mJ/cm ² ) to form a resin layer. In this way, a laminate (3) composed of a transparent base material, an alignment layer, a retardation layer, and a resin layer is manufactured.

[Manufacture of laminate (4)]

After corona treatment of the polarizer layer of the laminated body (1), the laminated body (3) and the laminated body (1) manufactured above are sandwiched by the adhesive (1) (pressure-sensitive adhesive manufactured by Lintec Co., Ltd.) Thickness 15μm). After the lamination, only the transparent substrate is peeled off to produce a laminate (4).

[Manufacture of polarizer]

After the alignment layer of the laminate (4) was corona-treated, the adhesive (2) (pressure-sensitive adhesive 25 μm manufactured by LINTEC Co., Ltd.) was bonded to produce the laminate (5) (polarizing plate). The laminate (5) is provided with an adhesive (2), an alignment layer, a phase difference layer, a resin layer, an adhesive (1), a polarizer layer, and a protective layer in this order.

[Manufacture of polarizing plate for evaluation]

Using the adhesive (2), the laminate (5) was bonded to the alkali-free glass as a sample.

[Comparative Example 2]

A sample was produced in the same manner as in Example 1, except that the resin layer was not formed.

[Damp heat endurance test]

The samples of Examples 1 to 4 and Comparative Example 1 and Comparative Example 2 were placed in an environment with a temperature of 80° C. and a relative humidity of 90% for 24 hours to perform a damp heat endurance test. Obtain the △Py and △Ty of the polarizing plate before and after the test.

Table 1 shows the results of the thickness, Martens hardness, breaking load, and damp heat endurance test of the resin layer.

[Table 1]

As shown in Table 1, compared with △Py and △Ty of the polarizing plates of Comparative Examples 1 and 2, any one of △Py and △Ty of the polarizing plates of Examples 1 to 4 applying the aspect of the present invention Are smaller. Thus, considered as a polarizer-based aspect of the present invention includes the Martens hardness was measured according to ISO14577 160N / mm ² or more 500N / mm ² or less of the resin layer, the retardation layer may be contained in the composition to migrate The situation of the polarizer layer is suppressed. Xian believes that this is because the components contained in the retardation layer stay in the resin layer, which is the main reason why it is not easy to move to the polarizer layer. Therefore, the polarizing plate of the aspect of the present invention can maintain a high degree of polarization even in a hot and humid environment.

Therefore, it can be confirmed that the present invention is useful.

1‧‧‧ Polarizer

11‧‧‧Protective layer

12‧‧‧ Polarizer layer

12a‧‧‧One side of polarizer layer

12b‧‧‧The other side of the polarizer layer

13‧‧‧Resin layer

13a‧‧‧One side of the resin layer

13b‧‧‧The other side of the resin layer

14‧‧‧1st adhesive layer

15‧‧‧ 2nd adhesive layer

16‧‧‧ phase difference layer

16b‧‧‧Face of retardation layer

19‧‧‧Alignment layer

19b‧‧‧The face of the alignment layer

Claims (9)

A polarizing plate includes a polarizer layer, a phase difference layer, and a resin layer disposed between the polarizer layer and the phase difference layer, The aforementioned retardation layer system uses a hardened liquid crystal composition as a forming material, Measured according to ISO14577 resin layer of the Martens hardness of 160N / mm ² or more 500N / mm ² or less. The polarizing plate as described in item 1 of the patent application range, wherein the phase difference layer is a layer that imparts a phase difference of 1/4 wavelength. A polarizing plate includes a polarizer layer, a first retardation layer, a resin layer disposed between the polarizer layer and the first retardation layer, and the polarizer layer as a reference is disposed on the resin layer side The second phase difference layer, The first phase difference layer system uses the cured product of the first liquid crystal composition as a forming material, and the second phase difference layer system uses the cured product of the second liquid crystal composition as a forming material, Martens hardness of the resin layer is measured according to ISO14577 to 160N / mm ² or more 500N / mm ² or less. The polarizing plate as described in item 3 of the patent application range, wherein the first retardation layer has a refractive index in the in-plane slow axis direction of n _x and an in-plane orthogonal to the slow axis direction When the refractive index in the direction is n _y and the refractive index in the thickness direction is n _z , a layer satisfying the relationship of n _z >n _x ≧n _y . The polarizing plate as described in item 4 of the patent application range, wherein the second retardation layer is disposed between the resin layer and the first retardation layer and is in contact with the resin layer. The polarizing plate as described in item 4 of the patent application range, wherein the second retardation layer is disposed between the resin layer and the polarizer layer and is in contact with the resin layer. The polarizing plate as described in item 6 of the patent application range, wherein the resin layer is in contact with the first phase difference layer. The polarizing plate according to any one of claims 3 to 7, wherein the second phase difference layer is a layer that imparts a phase difference of 1/4 wavelength. An organic electroluminescence display device is provided with an organic electroluminescence display element, and a polarizing plate as described in any one of claims 1 to 8 disposed on the viewing side of the organic electroluminescence display element.

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