JP7397683B2 - Laminated body for organic EL display and circularly polarizing plate used therein - Google Patents

Description

The present invention relates to a laminate for an organic EL display, and particularly to a laminate for an organic EL display including a specific circularly polarizing plate.

In recent years, along with the spread of thin displays, displays equipped with organic EL panels (organic EL display devices) have become popular. Organic EL panels have the problem that a clear black display cannot be obtained because external light is reflected by internal metal electrodes. To solve this problem, prevention of external light reflection can be suppressed by providing a circularly polarizing plate on the viewing surface. That is, the stacking order from the viewer's perspective is: protective glass → circularly polarizing plate → organic EL panel. A circularly polarizing plate can generally be produced by laminating a polarizing plate and a retardation plate. Polarizing plates are generally made by laminating a transparent protective film on a polarizer made of stretched polyvinyl alcohol (PVA) film and dyed with iodine, while retardation plates are made by laminating a stretched film or a λ/4 film with oriented liquid crystal molecules. A plate or the like is used, and among them, a λ/4 plate is preferably used, which exhibits a property that birefringence increases as the wavelength increases (inverse wavelength dispersion property). In addition, for the purpose of suppressing changes in reflection hue when viewed from an oblique direction, a circularly polarizing plate further includes a vertically aligned liquid crystal cured film that is polymerized and cured in a state in which rod-shaped liquid crystals are vertically aligned. This is proposed in Japanese Patent Publication No. 2015-163935.

Japanese Patent Application Publication No. 2015-163935

Regarding organic EL display devices, application in a flexible form is being considered, and studies are being made to avoid using glass on the outermost surface of the device. However, it has been found that when an organic EL panel is operated without the barrier properties of glass against water (water vapor) and oxygen, deterioration may proceed. It was also found that in order to obtain good flexibility, the circularly polarizing plate itself needs to be made thinner.

Therefore, the present invention provides a laminate for an organic EL display that includes a circularly polarizing plate that can protect an organic EL panel even when there is no glass on the outermost surface, and based on the laminate that has excellent display characteristics, flexibility, and aging deterioration. An object of the present invention is to provide an organic EL display device and a circularly polarizing plate used therein.

The present invention comprises the following aspects:
[1] A laminate in which a circularly polarizing plate and an adhesive layer are laminated,
The thickness of the laminate is 100 μm or less,
The circularly polarizing plate includes a polarizing plate and a retardation plate,
The polarizing plate includes a polarizer and a protective film, and has the protective film only on the opposite side of the polarizer to the surface on which the retardation plate is laminated,
A laminate for an organic EL display, wherein the circularly polarizing plate has a water vapor transmittance of 100 g/m ² /24 hrs or less, and a 380 nm transmittance of the circularly polarizing plate is 1% or less.
[2] The laminate for an organic EL display according to [1], wherein the polarizer is a polarizer formed from a polyvinyl alcohol resin film.
[3] The laminate for an organic EL display according to [1] or [2], wherein the circularly polarizing plate has a transmittance of 1% or less at 400 nm.
[4] The retardation plate includes only one retardation layer containing a polymer of a polymerizable liquid crystal compound, and satisfies all of the following formulas (1), (2), and (3). The laminate for an organic EL display according to any one of [1] to [3].
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
100nm≦Re(550)≦180nm (3)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.)
[5] The laminate for an organic EL display according to [4], wherein the angle between the slow axis of the retardation plate and the absorption axis of the polarizing plate is substantially 45 degrees.
[6] The retardation plate includes a first retardation layer and a second retardation layer in order from the polarizing plate side,
The first retardation layer and the second retardation layer are each a polymer of a polymerizable liquid crystal compound,
The first retardation layer satisfies the relationship of formula (4) below,
The second retardation layer satisfies the relationship of formula (3),
The laminate for an organic EL display according to any one of [1] to [3], wherein the retardation plate satisfies the relationships of formulas (1) and (2).
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
100nm≦Re(550)≦180nm (3)
200nm≦Re(550)≦300nm (4)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.)
[7] The laminate for an organic EL display according to any one of [1] to [6], further comprising an optical compensator made of a polymer of a polymerizable liquid crystal compound satisfying the following formula (5).
-30nm ≦ Rth (550) ≦ -100nm (5)
(Rth(550) represents the in-plane retardation in the film thickness direction for light with a wavelength of 550 nm.)
[8] The laminate for an organic EL display according to any one of [1] to [6], wherein the circularly polarizing plate includes an adhesive layer having a transmittance of 10% or less at 400 nm.
[9] The laminate for an organic EL display according to any one of [1] to [7], wherein the protective film is a cycloolefin film.
[10] The laminate for an organic EL display according to any one of [1] to [7], wherein the protective film is a polyimide film or a polyamide-imide film.
[11] A circularly polarizing plate in which at least a polarizing plate, an adhesive layer, and a retardation plate are laminated in this order,
The polarizing plate includes a polarizer and a protective film, and has the protective film only on the opposite side of the polarizer to the surface on which the retardation plate is laminated,
the retardation plate satisfies the relationships of formulas (1) and (2),
A circularly polarizing plate, wherein a water vapor transmittance of the circularly polarizing plate is 100 g/m ² /24hrs or less, and a 380 nm transmittance of the circularly polarizing plate is 1% or less.
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
[12] The circularly polarizing plate of [11], wherein the polarizer is a polarizer formed from a polyvinyl alcohol resin film.
[13] The circularly polarizing plate according to [11] or [12], wherein the 400 nm transmittance of the circularly polarizing plate is 1% or less.
[14] The circularly polarizing plate according to any one of [11] to [13], wherein the adhesive layer has a transmittance of 10% or less at 400 nm.
[15] The circularly polarizing plate according to any one of [11] to [14], wherein the protective film is a cycloolefin film.
[16] The circularly polarizing plate according to any one of [11] to [15], wherein the protective film is a polyimide film or a polyamide-imide film.

The present invention makes it possible to provide an organic EL display device with excellent display characteristics, flexibility, and aging deterioration even when the organic EL display device does not have glass on the outermost surface, and a circularly polarizing plate used therein.

The laminate for organic EL display of the present invention is a laminate in which a circularly polarizing plate and an adhesive layer are laminated, wherein the circularly polarizing plate includes a polarizing plate and a retardation plate, and the polarizing plate includes a polarizer and a protective layer. Including film. The polarizing plate has a protective film on the opposite side of the polarizer on which the retardation plate is laminated. The retardation plate may be composed of one retardation layer or two retardation layers, and in the case of two layers, they can be distinguished by calling them the first retardation layer and the second retardation layer. There is. A polarizing plate and a retardation plate are usually bonded together with an adhesive layer to form a circularly polarizing plate. The circularly polarizing plate may be combined with an adhesive layer to form the organic EL display laminate of the present invention, but may also be further combined with an optical compensator. Therefore, the laminate for an organic EL display of the present invention is composed of a circularly polarizing plate and an adhesive layer, and an optical compensator is provided between the circularly polarizing plate and the adhesive layer with another adhesive layer. It may also be glued to.

<Polarizing plate>
The polarizing plate includes a film having a light absorption anisotropic function (hereinafter sometimes referred to as a polarizer). The polarizer may be a stretched film on which a dichroic dye is adsorbed.

Polarizers, which are stretched films with dichroic dyes adsorbed, are usually produced by uniaxially stretching a polyvinyl alcohol resin film or by dyeing the polyvinyl alcohol resin film with a dichroic dye. The polyvinyl alcohol resin film with the dichroic dye adsorbed thereon is treated with an aqueous boric acid solution, and after the treatment with the aqueous boric acid solution, the film is washed with water.

Polyvinyl alcohol resin is obtained by saponifying polyvinyl acetate resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith can be used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfonic acid compounds, and acrylamide compounds having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably 1,500 to 5,000.

A film made of such a polyvinyl alcohol resin is used as a raw film of a polarizing film. The method of forming a polyvinyl alcohol resin into a film is not particularly limited, and any known method can be used to form the film. The thickness of the polyvinyl alcohol base film can be, for example, about 10 to 150 μm.

Uniaxial stretching of the polyvinyl alcohol resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Moreover, it is also possible to perform uniaxial stretching in these plural steps. In the uniaxial stretching, it may be uniaxially stretched between rolls having different circumferential speeds, or it may be uniaxially stretched using hot rolls. Further, the uniaxial stretching may be dry stretching in which the film is stretched in the atmosphere, or wet stretching in which the polyvinyl alcohol resin film is stretched in a swollen state using a solvent. The stretching ratio is usually about 3 to 8 times.

Staining of a polyvinyl alcohol resin film with a dichroic dye is carried out, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye.

Specifically, iodine or a dichroic organic dye is used as the dichroic dye. As a dichroic organic dye, C.I. I. Examples include dichroic direct dyes made of disazo compounds such as DIRECT RED 39, and dichroic direct dyes made of compounds such as trisazo and tetrakisazo. It is preferable that the polyvinyl alcohol resin film is immersed in water before being dyed.

When using iodine as a dichroic dye, a method is usually employed in which a polyvinyl alcohol resin film is immersed in an aqueous solution containing iodine and potassium iodide for dyeing.
The content of iodine in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. Further, the content of potassium iodide is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time (staining time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when using a dichroic organic dye as the dichroic dye, a method of dyeing by immersing a polyvinyl alcohol resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed.
The content of the dichroic organic dye in this aqueous solution is usually about 1 x 10 ^-4 to 10 parts by weight, preferably 1 x 10 -3 to 1 part by weight, and more preferably about 1 x 10 ^-4 to 1 part by weight, per 100 parts by weight of water. is 1×10 ⁻³ to 1×10 ⁻² parts by mass. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. The immersion time (staining time) in this aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye can usually be carried out by immersing the dyed polyvinyl alcohol resin film in an aqueous boric acid solution. The content of boric acid in this boric acid aqueous solution is usually about 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye, the boric acid aqueous solution preferably contains potassium iodide, and the content of potassium iodide in this case is usually 0.1 to 100 parts by mass of water. The amount is about 15 parts by mass, preferably 5 to 12 parts by mass. The immersion time in the boric acid aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid treatment is usually 50°C or higher, preferably 50 to 85°C, more preferably 60 to 80°C.

The polyvinyl alcohol resin film treated with boric acid is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the washing process is usually about 5 to 40°C.
The immersion time is usually about 1 to 120 seconds.

After washing with water, a drying process is performed to obtain a polarizer. The drying process can be performed using, for example, a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The drying process reduces the moisture content of the polarizer to a practical level. Its moisture content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. If the moisture content is less than 5% by weight, the flexibility of the polarizer is lost and the polarizer may be damaged or broken after drying. Furthermore, if the moisture content exceeds 20% by weight, the thermal stability of the polarizer may deteriorate.

The thickness of the polarizer obtained by uniaxially stretching the polyvinyl alcohol resin film, dyeing with a dichroic dye, boric acid treatment, washing with water, and drying is preferably 5 to 40 μm, more preferably 5 to 20 μm. be.

The polarizing plate of the present invention can be obtained by laminating a protective film on only one side of a polarizer obtained by the method described above, via an adhesive layer. The protective film is laminated on the opposite side of the polarizer to the side on which the retardation plate is laminated. The adhesive layer is formed using a known adhesive composition.

<Protective film>
A protective film means a transparent base material that can transmit light (particularly visible light). Transparency refers to a property in which the transmittance for light rays having a wavelength of 380 to 780 nm is 80% or more. Specific protective films include polyolefins such as polyethylene and polypropylene; cycloolefin resins such as norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic esters; polyacrylic esters; triacetyl cellulose, diacetyl cellulose, and cellulose acetate. Cellulose esters such as propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cycloolefin resin, or polycarbonate is preferred. Cellulose ester is obtained by esterifying some or all of the hydroxyl groups contained in cellulose, and can be easily obtained from the market. Cellulose ester base materials are also readily available on the market.
Examples of commercially available cellulose ester base materials include "Fujitac Film" (Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY", and "KC4UY" (Konica Minolta Opto Co., Ltd.).

The characteristics required of the protective film vary depending on the configuration of the polarizing plate, but it is usually preferable to use a film with as small a retardation as possible. Examples of films with as small a retardation as possible include cellulose ester films having no retardation such as Zerotack (Konica Minolta Opto Co., Ltd.) and Ztack (Fuji Film Co., Ltd.). Further, an unstretched cyclic olefin resin film is also preferred. Other preferable protective films include polyimide films, polyamideimide films, and the like. The surface of the protective film on which the polarizing plate is not laminated may be subjected to hard coat treatment, antireflection treatment, antistatic treatment, or the like.

In the present invention, the resin forming the protective film is, for example, cycloolefin, polyamide or gelatin compound having an amide bond in the molecule, polyimide having an imide bond in the molecule, polyamic acid which is a hydrolyzate thereof, polyvinyl alcohol, It may also be alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic ester. It is preferable that the protective film has a transmittance of 10% or less at 400 nm. When the transmittance at 400 nm is 10% or less, it has the effect of suppressing deterioration (discoloration) of the organic EL panel.

The thickness of the protective film is usually 10 to 80 μm, preferably 20 to 60 μm, and more preferably 20 to 40 μm in terms of improving strength and workability.

<Retardation plate>
The retardation plate may be a stretched film that provides a retardation by stretching a polymer, but from the viewpoint of making the laminate for an organic EL display of the present invention thinner, horizontally or vertically oriented polymerizable liquid crystals may be used. Preferably, the retardation layer includes a polymer of a compound. When the retardation plate is composed of a retardation layer, it may be only the retardation layer, or it may include an alignment film and a base material, which will be described later.

When the retardation plate includes only one retardation layer containing a polymer of a polymerizable liquid crystal compound, it is preferable that all of the following formulas (1), (2), and (3) are satisfied:
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
100nm≦Re(550)≦180nm (3)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.)
A retardation plate that satisfies the above formula (1) has so-called reverse wavelength dispersion and exhibits excellent polarization performance. The value of Re(450)/Re(550) is preferably 0.93 or less, more preferably 0.88 or less, even more preferably 0.86 or less, preferably 0.80 or more, more preferably 0. 82 or higher. The above formula (3) preferably satisfies 100 nm≦Re(550)≦180 nm, more preferably 120 nm≦Re(550)≦160 nm.
Note that Re(550) can be measured by the method described in Examples.

In the circularly polarizing plate of the present invention, the angle between the slow axis of the retardation plate and the absorption axis of the polarizing plate is preferably substantially 45°. In the present invention, "substantially 45°" means 45°±5°.

When the retardation plate includes a first retardation layer and a second retardation layer, and each retardation layer is a retardation layer made of a polymer of a polymerizable liquid crystal compound, the first retardation layer is It is preferable that the following formula (4) is satisfied, the second retardation layer satisfies the above formula (3), and the entire retardation plate satisfies the above formulas (1) and (2).
200nm≦Re(550)≦300nm (4)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.)

The polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (A)") forming the retardation layer means a liquid crystal compound having a polymerizable functional group, particularly a photopolymerizable functional group. The photopolymerizable functional group refers to a group that can participate in a polymerization reaction by active radicals, acids, etc. generated from a photopolymerization initiator. Examples of the photopolymerizable functional group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group, and the like. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferred, and acryloyloxy group is more preferred. The liquid crystal property may be a thermotropic liquid crystal or a lyotropic liquid crystal, and the phase order structure may be a nematic liquid crystal or a smectic liquid crystal. As the polymerizable liquid crystal compound, only one type may be used, or two or more types may be used in combination.

Examples of the polymerizable liquid crystal compound (A) include compounds that satisfy all of the following (a) to (e) from the viewpoint of ease of film formation and imparting retardation properties.

(a) A compound having thermotropic liquid crystallinity;
(a) The polymerizable liquid crystal compound has π electrons in the long axis direction (a).
(c) It has π electrons in the direction [intersecting direction (b)] that intersects with the major axis direction (a).
(d) Polymerization defined by the following formula (i) where the total of π electrons existing in the major axis direction (a) is N (πa) and the total molecular weight present in the major axis direction (a) is N (Aa) π electron density in the long axis direction (a) of the liquid crystal compound:
D(πa)=N(πa)/N(Aa) (i)
and a polymerizable liquid crystal compound defined by the following formula (ii) where the total of π electrons existing in the intersecting direction (b) is N (πb), and the total molecular weight existing in the intersecting direction (b) is N (Ab) π electron density in the crossing direction (b):
D(πb)=N(πb)/N(Ab) (ii)
Toga,
0≦[D(πa)/D(πb)]≦1
[That is, the π electron density in the cross direction (b) is larger than the π electron density in the major axis direction (a)].
In addition, the polymerizable liquid crystal compound (A) that satisfies all of the above (a) to (e) can be applied to an alignment film formed by rubbing treatment and heated to a temperature higher than the phase transition temperature to form a nematic phase. is possible. In the nematic phase formed by aligning this polymerizable liquid crystal compound (A), the long axes of the polymerizable liquid crystal compound (A) are usually oriented in parallel to each other, and this long axis direction is the orientation direction of the nematic phase. becomes.

で表される化合物が挙げられる。前記式（Ｉ）で表される化合物は単独または２種以上組み合わせて使用できる。 The polymerizable liquid crystal compound (A) having the above characteristics generally exhibits reverse wavelength dispersion in many cases. Specifically, as a compound satisfying the characteristics (a) to (e) above, for example, the following formula (I):

Examples include compounds represented by: The compounds represented by formula (I) can be used alone or in combination of two or more.

In formula (I), Ar represents a divalent aromatic group which may have a substituent. The aromatic group referred to herein is a group having a planar cyclic structure, and the number of π electrons in the cyclic structure is [4n+2] according to Huckel's rule. Here, n represents an integer. In the case where a ring structure is formed containing heteroatoms such as -N= and -S-, it also satisfies Huckel's rule including non-covalently bonded electron pairs on these heteroatoms and has aromaticity. Preferably, the divalent aromatic group contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom.

G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. The carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with 1 to 4 alkoxy groups, cyano groups, or nitro groups, and oxygen atoms, sulfur atoms Alternatively, it may be substituted with a nitrogen atom.

L ¹ and L ² are each independently a divalent linking group having an ester structure.
B ¹ and B ² are each independently a single bond or a divalent linking group.

k and l each independently represent an integer from 0 to 3, and satisfy the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.

E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and the alkanediyl group The -CH ₂ - contained therein may be substituted with -O-, -S-, -Si-, or -COO-. P ¹ and P ² each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms. , a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferably a 1,4-cyclohexanediyl group substituted with a methyl group. ,4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group, or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group. Further, at least one of the plurality of G ¹ and G ² is preferably a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² More preferably, one is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably -R ^a1 COOR ^a2 - (R ^a1 and R ^a2 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms), more preferably - COOR ^a2-1 - (R ^a2-1 represents a single bond, -CH ₂ -, or -CH ₂ CH ₂ -), more preferably -COO- or -COOCH ₂ CH ₂ -.

B ¹ and B ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -, -R ^a11 COOR ^a12 -, -R ^a13 OCOR ^a14 -, or R ^a15 OC=OOR ^a16 -. Here, R ^a9 to R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently more preferably a single bond, -OR ^a10-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a12-1 -, or OCOR ^a14-1 - . Here, R ^a10-1 , R ^a12-1 , and R ^a14-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ . B ¹ and B ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, -OCO-, or OCOCH ₂ CH ₂ - .

k and l preferably have a range of 2≦k+l≦6 from the viewpoint of expressing reverse wavelength dispersion, preferably k+l=4, and more preferably k=2 and l=2. It is more preferable that k=2 and l=2 because a symmetrical structure is obtained.

E ¹ and E ² are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

Examples of the polymerizable group represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group. group, and oxetanyl group. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferred, and acryloyloxy group is more preferred.

Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and the like, with benzene rings and naphthalene rings being preferred. The aromatic heterocycles include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, and a pyrazole ring. , thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. Among these, it is preferable to have a thiazole ring, benzothiazole ring, or benzofuran ring, and it is more preferable to have a benzothiazole ring. Further, when Ar includes a nitrogen atom, it is preferable that the nitrogen atom has π electrons.

In formula (I), the total number N _π of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and especially Preferably it is 16 or more. Further, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

Examples of the aromatic group represented by Ar include groups of the following formulas (Ar-1) to (Ar-23).

In formulas (Ar-1) to (Ar-23), the mark * represents a connecting part, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 12 carbon atoms. group, cyano group, nitro group, alkylsulfinyl group having 1 to 12 carbon atoms, alkylsulfonyl group having 1 to 12 carbon atoms, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 6 carbon atoms, Alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms, or carbon Represents an N,N-dialkylsulfamoyl group having numbers 2 to 12.

Q ¹ and Q ² each independently represent -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, -CO- or O-, and R ^2' and R ^3' each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group.

W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group, or a halogen atom, and m represents an integer of 0 to 6.

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, and biphenyl group. , naphthyl group is preferred, and phenyl group is more preferred. Examples of the aromatic heterocyclic group include a group having 4 to 20 carbon atoms and containing at least one heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group. Examples include aromatic heterocyclic groups, and furyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups are preferred.

Y ¹ and Y ² may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² are preferably each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

Q ¹ and Q ² are preferably -NH-, -S-, -NR ^2' -, -O-, and R ^2' is preferably a hydrogen atom. Among them, -S-, -O-, and -NH- are particularly preferred.

Among formulas (Ar-1) to (Ar-23), formulas (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

In formulas (Ar-17) to (Ar-23), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Examples of the aromatic heterocyclic group include those mentioned above as aromatic heterocycles that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and an indole ring. ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring, etc. This aromatic heterocyclic group may have a substituent. Further, Y ¹ may be the aforementioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, together with the nitrogen atom to which it is bonded and Z ⁰ . Examples include a benzofuran ring, a benzothiazole ring, a benzoxazole ring, and the like. The compounds represented by the formulas (Ar-1) to (Ar-23) can be produced, for example, according to the method described in JP-A No. 2010-31223.

The content of the polymerizable liquid crystal compound (A) in the polymerizable liquid crystal composition (A) constituting the retardation layer is, for example, 70 to 99 parts by mass based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition (A). .5 parts by weight, preferably 80 to 99 parts by weight, more preferably 90 to 98 parts by weight. When the content is within the above range, the orientation of the retardation plate tends to be high. Here, the solid content refers to the total amount of components excluding volatile components such as solvents from the polymerizable liquid crystal composition (A).

The polymerizable liquid crystal composition (A) may contain a polymerization initiator for starting the polymerization reaction of the polymerizable liquid crystal compound (A). Moreover, the polymerizable liquid crystal composition (A) may contain a photosensitizer, a leveling agent, an additive, etc. as necessary.

The retardation layer is prepared, for example, by adding a solvent to a polymerizable liquid crystal composition (A) containing a polymerizable liquid crystal compound (A) and, if necessary, a polymerization initiator, additives, etc., followed by mixing and stirring. A composition (hereinafter also referred to as "composition for forming a retardation film") is applied onto a base material or an alignment film, the solvent is removed by drying, and the polymerizable liquid crystal compound (A) in the obtained coating film is obtained. can be obtained by curing with heating and/or active energy rays.

The base material is preferably a transparent base material. The alignment film is for aligning the polymerizable liquid crystal compound contained in the composition for forming a retardation film in any direction. The alignment film can be formed from an alignment polymer. Further, the alignment film may be a photo-alignment film.

Examples of oriented polymers include polyamides and gelatins having an amide bond in the molecule, polyimide having an imide bond in the molecule, and polyamic acid, which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, and polyamide. Mention may be made of oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic ester. Among them, polyvinyl alcohol is preferred. The oriented polymers can be used alone or in combination of two or more.

An oriented film containing an oriented polymer is usually produced by applying a composition in which an oriented polymer is dissolved in a solvent (hereinafter sometimes referred to as an "oriented polymer composition") to a base material, and then removing the solvent, or It is obtained by applying an oriented polymer composition to a base material, removing the solvent, and rubbing it (rubbing method). The solvent may be any solvent as long as it can dissolve the components constituting the oriented polymer composition, such as aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as toluene and xylene; ethanol and 1-propanol. , isopropanol, 1-butanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, isobutyl acetate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl Ethers, glycol ethers such as propylene glycol monoethyl ether, and esterified glycol ethers such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate can be used.

The concentration of the oriented polymer in the oriented polymer composition may be within a range that allows the oriented polymer material to be completely dissolved in the solvent, but it is preferably 0.1 to 20% in terms of solid content with respect to the solution. It is more preferably about .1 to 10%.

Commercially available alignment film materials may be used as they are as the alignment polymer composition. Commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), and the like.

Methods for applying the oriented polymer composition to the substrate include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing methods such as flexography. For example, known methods such as

Examples of methods for removing the solvent contained in the oriented polymer composition include natural drying, ventilation drying, heat drying, and reduced pressure drying.

In order to impart an alignment regulating force to the alignment film, rubbing treatment can be performed as necessary (rubbing method).

As a method of imparting an orientation regulating force by a rubbing method, a rubbing cloth is wrapped around a rotating rubbing roll, and an oriented polymer composition is applied to a substrate and annealed to form an oriented polymer composition on the surface of the substrate. Examples include a method of bringing oriented polymer films into contact with each other.

A photo-alignment film is usually produced by coating a base material with a composition containing a polymer or monomer having a photo-reactive group and a solvent (hereinafter also referred to as a "composition for forming a photo-alignment film"), and applying polarized light (preferably, Obtained by irradiating with polarized UV). A photo-alignment film is more preferable in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The photoreactive group refers to a group that produces liquid crystal alignment ability when irradiated with light. Specifically, groups that are involved in molecular alignment induction caused by light irradiation or photoreactions that are the origin of liquid crystal alignment ability, such as isomerization reactions, dimerization reactions, photocrosslinking reactions, or photodecomposition reactions, can be mentioned. Among these, groups that participate in a dimerization reaction or a photocrosslinking reaction are preferable because they have excellent orientation. The photoreactive group is preferably a group having an unsaturated bond, especially a double bond, such as a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), or a nitrogen-nitrogen double bond. Particularly preferred is a group having at least one selected from the group consisting of a double bond (N=N bond) and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group.
Examples of the photoreactive group having a C=N bond include groups having structures such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, or a halogenated alkyl group.

Among these, photoreactive groups that participate in photodimerization reactions are preferred, since the amount of polarized light irradiation required for photoalignment is relatively small, and it is easy to obtain a photoalignment film with excellent thermal stability and stability over time. Cinnamoyl and chalcone groups are preferred. As the polymer having a photoreactive group, one having a cinnamoyl group such that the end of the polymer side chain has a cinnamic acid structure is particularly preferred.

A photo-alignment layer can be formed on a base material by applying the composition for forming a photo-alignment film onto the base material. Examples of the solvent contained in the composition include those similar to those exemplified above as solvents that can be used in the composition for forming an alignment film, and the solvent may be used as appropriate depending on the solubility of the polymer or monomer having a photoreactive group. You can choose.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be adjusted as appropriate depending on the type of polymer or monomer and the desired thickness of the photo-alignment film. The amount is preferably at least 0.2% by weight, more preferably from 0.3 to 10% by weight. The composition for forming a photo-alignment film may contain a polymeric material such as polyvinyl alcohol or polyimide, and a photosensitizer as long as the properties of the photo-alignment film are not significantly impaired.

Examples of the method for applying the composition for forming a photo-alignment film onto the substrate include the same method as the method for applying the alignment composition onto the substrate. Examples of methods for removing the solvent from the applied composition for forming a photoalignment film include natural drying, ventilation drying, heat drying, and reduced pressure drying.

In order to irradiate polarized light, polarized UV can be directly irradiated onto the photo-alignment film forming composition coated on the substrate, from which the solvent has been removed, or the polarized light can be irradiated from the substrate side, allowing the polarized light to pass through. It may also be a form of irradiation. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which a polymer having a photoreactive group or a photoreactive group of a monomer can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferred. Light sources used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. Lamps are more preferred. Among these, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are preferable because they emit a high intensity of ultraviolet light with a wavelength of 313 nm. Polarized UV can be irradiated by passing the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.

Note that by performing masking when performing rubbing or polarized light irradiation, it is also possible to form a plurality of regions (patterns) in which the directions of liquid crystal alignment are different.

A groove alignment film is a film having an uneven pattern or a plurality of grooves on its surface. When a polymerizable liquid crystal compound is applied to a film having a plurality of linear grooves arranged at equal intervals, liquid crystal molecules are aligned in the direction along the grooves.

The groove alignment film can be obtained by exposing the surface of a photosensitive polyimide film to light through an exposure mask having pattern-shaped slits, followed by development and rinsing to form a concavo-convex pattern, and by using a plate with grooves on the surface. A method of forming a layer of uncured UV curable resin on a shaped master, transferring the formed resin layer to a base material, and then curing it; Examples include a method in which a rolled master having a plurality of grooves is pressed against each other to form irregularities, and then hardened.

The thickness of the alignment film (orientation film containing an alignment polymer or photo-alignment film) is usually in the range of 10 to 10,000 nm, preferably in the range of 10 to 1,000 nm, more preferably 500 nm or less, and even more preferably The range is from 10 to 200 nm, particularly preferably from 50 to 150 nm.

Methods for applying the composition for forming a retardation film to a base material include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and flexography. Known methods such as printing methods can be used.

Next, a dry coating film is formed by removing the solvent by drying or the like under conditions in which the polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a retardation film does not polymerize. Examples of the drying method include natural drying, ventilation drying, heating drying, and reduced pressure drying.

Further, in order to cause the polymerizable liquid crystal compound to undergo a phase transition to a liquid phase, the temperature is raised to a temperature above which the polymerizable liquid crystal compound undergoes a phase transition to a liquid phase, and then the temperature is lowered to cause a phase transition of the polymerizable liquid crystal compound to a nematic phase. Such a phase transition may be performed after removing the solvent in the coating film, or may be performed simultaneously with the removal of the solvent.

By polymerizing the polymerizable liquid crystal compound while maintaining the nematic liquid crystal state of the polymerizable liquid crystal compound, a retardation layer that is a cured layer of the polymerizable liquid crystal composition is formed. As the polymerization method, a photopolymerization method is preferred. In photopolymerization, the light irradiated to the dry coating film depends on the type of photopolymerization initiator contained in the dry coating film, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound) and the amount thereof is selected as appropriate. Specific examples include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays, and active electron beams. Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and it is possible to use photopolymerization equipment that is widely used in the field. It is preferable to select the type of polymerizable liquid crystal compound and photopolymerization initiator contained in the polymerizable liquid crystal composition. Moreover, during polymerization, the polymerization temperature can also be controlled by irradiating light while cooling the dried coating film with an appropriate cooling means.
By employing such a cooling means and polymerizing the polymerizable liquid crystal compound at a lower temperature, a polarizing plate can be appropriately formed even if a base material with relatively low heat resistance is used. A patterned retardation plate can also be obtained by performing masking or development during photopolymerization.

Examples of the light source of the active energy ray include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, and a wavelength range. Examples include an LED light source that emits light in the range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The ultraviolet irradiation intensity is usually 10 to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably an intensity in a wavelength range effective for activating the photopolymerization initiator. The light irradiation time is usually 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. When irradiated once or multiple times with such ultraviolet irradiation intensity, the cumulative amount of light is 10 to 3,000 mJ/cm ² , preferably 50 to 2,000 mJ/cm ² , more preferably 100 to 1,000 mJ/cm It is ² .

The thickness of the retardation layer can be appropriately selected depending on the display device to which it is applied, but from the viewpoint of thinning and flexibility, it is preferably 0.1 to 10 μm, more preferably 1 to 5 μm. , more preferably 1 to 3 μm.

<Optical compensation plate>
The organic EL display laminate of the present invention may further be combined with an optical compensator, if necessary. The optical compensator has an optical function of compensating the viewing angle and color of the liquid crystal display device, and is preferably made of oriented liquid crystal material.
The optical compensator is more preferably made of a polymer of a polymerizable liquid crystal compound and satisfies the following formula (5):
-30nm ≦ Rth (550) ≦ -100nm (5)
(Rth(550) represents the in-plane retardation in the film thickness direction when irradiated with a wavelength of 550 nm.)
As a liquid crystal substance preferably used in such an optical compensator, a side chain type liquid crystal polymer compound can be mentioned. Side-chain type liquid crystalline polymer compounds are compounds in which a mesogenic group, which is a core unit that develops a liquid crystal layer, is bonded to a flexible main chain as a side chain via a flexible chain, such as polyacrylate, polymethacrylate, polyester, etc. Examples include those having a main chain skeleton of siloxane or the like, and having a mesogenic group as a side chain, if necessary, via a spacer portion made of a conjugated atomic group or the like. In addition, at the end opposite to the main chain when viewed from the mesogenic group of the side chain, crosslinking of oxetanyl group, epoxy group, vinyl ether group, etc. A polymerizable functional group may be included to control the tensile modulus of the film.

The thickness of the optical compensator is, for example, about 0.1 to 30 μm, preferably about 0.5 to 25 μm, and more preferably about 3 to 20 μm.

<Circular polarizing plate>
The circularly polarizing plate in the present invention includes a polarizing plate and a retardation plate, and the polarizing plate includes a polarizer and a protective film. The polarizing plate has a protective film on the opposite side to the retardation plate.

In the above circularly polarizing plate, the polarizing plate and the retardation plate may be laminated via an adhesive layer, may be laminated via an adhesive layer, or may be laminated via an adhesive layer. It is preferable that That is, the circularly polarizing plate preferably has a structure in which a polarizing plate, an adhesive layer, and a retardation plate are laminated in this order.

As the adhesive layer on which the polarizing plate and the retardation plate are laminated, an adhesive layer having a transmittance of 10% or less at a wavelength of 400 nm (hereinafter sometimes referred to as a near-infrared absorbing adhesive layer) is preferable.

The adhesive composition forming the adhesive layer on which the polarizing plate and the retardation plate are laminated is not particularly limited, and any known adhesive composition can be used.

The adhesive composition forming the near-infrared absorbing adhesive layer is not particularly limited, but examples thereof include the adhesive composition described in JP-A-2017-119700. ) The adhesive composition preferably contains a compound that selectively absorbs light, and more preferably the adhesive composition contains a light selective absorption compound having a merocyanine structure.

The circularly polarizing plate in the present invention has a water vapor transmittance of 100 g/m ² /24 hrs or less and a 380 nm light transmittance of 1% or less. As a result, an organic EL display having excellent display characteristics, flexibility, and resistance to aging can be obtained.

The water vapor transmission rate is measured in accordance with JIS Z 0208 at 40° C. and 90% relative humidity, and is calculated as the amount of water that passes through the film per 1 m ² of film area in 24 hours. When the water vapor transmission rate exceeds 100 g/m ² /24 hrs, the durability of the obtained organic EL display deteriorates. The water vapor permeability is preferably 60 g/m ² /24 hrs or less, more preferably 30 g/m ² /24 hrs or less, even more preferably 10 g/m ² /24 hrs or less, and has a low water vapor permeability below the measurement limit. There may be.

The light transmittance is measured at 380 nm using a spectrophotometer (UV-3150; manufactured by Shimadzu Corporation). It is more preferable to specify the transmittance at both 380 nm and 400 nm. The light transmittance at these wavelengths is preferably 0.5% or less, more preferably 0.3% or less.

In the circularly polarizing plate, the oxygen permeability is preferably 30 cc/atm/m ² /24 hrs or less. The oxygen permeability is measured based on JIS K 7126 using an oxygen permeability measuring device (OX-TRANML, manufactured by MOCON) at 23° C. and 50% relative humidity. The oxygen permeability is more preferably 20 cc/atm/m ² /24 hrs or less, still more preferably 10 cc/atm/m ² /24 hrs or less, from the viewpoint of further improving the durability of the organic EL display.

<Adhesive layer (1)>
In the present invention, the adhesive composition forming the adhesive layer (herein, this adhesive layer may be referred to as "adhesive layer (1)") to be laminated with the circularly polarizing plate is particularly There is no limitation, and suitable adhesives such as acrylic, silicone, polyester, polyurethane, polyamide, polyether, and rubber adhesives can be used. Among these, pressure-sensitive acrylic adhesives are preferred in terms of optical transparency, adhesive properties, weather resistance, and the like. The adhesive layer (1) is usually laminated on a retardation plate of a circularly polarizing plate. Another layer (such as a separate film) may be further laminated on the side of the adhesive layer (1) opposite to the side on which the circularly polarizing plate is laminated.

In addition, the adhesive layer (1) and the adhesive layer used for laminating the polarizing plate and the retardation plate may be dispersed with various diffusing agents to impart diffusivity, or mixed with various conductive substances. Depending on the application, it may be provided with functionality such as imparting antistatic properties.

In the present invention, the thickness of the laminate in which the circularly polarizing plate and the adhesive layer are laminated is preferably 100 μm or less, more preferably 90 μm or less, from the viewpoint of flexibility and visibility of the display device.

<Organic EL display device (organic EL display)>
The present invention includes a display device comprising the organic EL display laminate of the present invention.
Display devices include liquid crystal display devices, organic electroluminescent (EL) display devices, inorganic electroluminescent (EL) display devices, touch panel display devices, electron emission display devices (field emission display devices (FEDs, etc.), surface field emission display devices) (SED)), electronic paper (display device using electronic ink or electrophoretic element), plasma display device, projection type display device (grating light valve (GLV) display device, display device with digital micromirror device (DMD)) etc.) and piezoelectric ceramic displays. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view type liquid crystal display device, a projection type liquid crystal display device, and the like. These display devices may be display devices that display two-dimensional images or stereoscopic display devices that display three-dimensional images. In particular, as the display device of the present invention, an organic EL display device and a touch panel display device are preferable, and an organic EL display device is particularly preferable.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. "%" and "parts" in Examples and Comparative Examples are "% by mass" and "parts by mass" unless otherwise specified.

[Example 1]
<Preparation of polarizing plate>
[Polarizing plate: Production of iodine PVA type polarizing plate]
A polyvinyl alcohol film (PVA: average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) with a thickness of 30 μm was uniaxially stretched to about 5 times by dry stretching, and then stretched at 40°C while maintaining the tension state. It was immersed in pure water for 40 seconds. Thereafter, it was immersed in a dyeing aqueous solution having a mass ratio of iodine/potassium iodide/water of 0.044/5.7/100 at 28° C. for 30 seconds to perform a dyeing treatment. Next, it was immersed in a boric acid aqueous solution having a mass ratio of potassium iodide/boric acid/water of 11.0/6.2/100 at 70° C. for 120 seconds. Subsequently, after washing with pure water at 8°C for 15 seconds, the polyvinyl alcohol film was dried at 60°C for 50 seconds and then at 75°C for 20 seconds while being held under a tension of 300N, so that iodine was adsorbed and oriented in the polyvinyl alcohol film. A polarizer with a thickness of 12 μm was obtained.

A water-based adhesive was injected between the obtained polarizer and a cycloolefin film (ZF14 manufactured by Nippon Zeon Co., Ltd.), and the films were bonded together using nip rolls. While maintaining the tension of the obtained bond at 430 N/m, it was dried at 60° C. for 2 minutes to obtain a polarizing plate I having a cycloolefin film (COP) as a protective film on one side. The above water-based adhesive contains 100 parts of water, 3 parts of carboxyl group-modified polyvinyl alcohol (Kuraray Poval KL318; manufactured by Kuraray Co., Ltd.), and a water-soluble polyamide epoxy resin (Sumirezu Resin 650; manufactured by Sumika Chemtex Co., Ltd.). 1.5 parts of an aqueous solution with a solid content concentration of 30%).

<Preparation of retardation plate>
[Preparation of composition for forming photo-alignment film]
By mixing 5 parts of the following photo-alignable material described in JP-A-2013-033249 with 95 parts of cyclopentanone (solvent) and stirring the resulting mixture at 80° C. for 1 hour, a photo-alignable material for forming a photo-alignment film can be prepared. A composition was obtained.
(Photoalignable material)

[Preparation of polymerizable liquid crystal composition]
Polymerizable liquid crystal compound A-1 (86.0 parts) having the following structure, polymerizable liquid crystal compound A-2 (14.0 parts), and polyacrylate compound (leveling agent/BYK-361N; manufactured by BYK-Chemie) (0.12 parts) and 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (photopolymerization initiator/Irgacure 369; manufactured by Ciba Specialty Chemicals) (3.0 parts). ) to obtain a polymerizable liquid crystal composition (A1) containing polymerizable liquid crystal compound A-1 and polymerizable liquid crystal compound A-2.

Polymerizable liquid crystal compound A-1:

Polymerizable liquid crystal compound A-2:

[Fabrication of retardation plate]
A cycloolefin polymer film (COP; ZF-14; manufactured by Nippon Zeon Co., Ltd.) was treated using a corona treatment device (AGF-B10; manufactured by Kasuga Denki Co., Ltd.) under conditions of an output of 0.3 kW and a processing speed of 3 m/min. Processed twice. The photo-alignment film forming composition was applied to the corona-treated surface using a bar coater, dried at 80°C for 1 minute, and then heated using a polarized UV irradiation device (SPOT CURE SP-7 with polarizer unit; manufactured by Ushio Inc.) ), polarized UV exposure was performed with an integrated light amount of 100 mJ/cm ² to form an alignment film. The thickness of the obtained alignment film was measured with an ellipsometer M-220 (manufactured by JASCO Corporation) and was found to be 100 nm.

Subsequently, the polymerizable liquid crystal composition (A1) containing the previously prepared polymerizable liquid crystal compound was coated onto the alignment film at a speed of 50 mm/sec using a bar coater wire set to #30. Dry at ℃ for 1 minute. Then, using a high-pressure mercury lamp (Unicure VB-15201BY-A; manufactured by Ushio Inc.), ultraviolet rays were irradiated from the side coated with the polymerizable liquid crystal composition (A1) (integrated light intensity at a wavelength of 313 nm in a nitrogen atmosphere). :500 mJ/cm ² ) to form a laminate of the retardation layer and the cycloolefin polymer film. The thickness of the obtained retardation layer was measured using a laser microscope (LEXT; manufactured by Olympus Corporation) and was found to be 2.3 μm.
When the retardation value of the obtained retardation layer at a wavelength of 550 nm was measured, it was found that Re (550) = 140 nm.
Furthermore, when the retardation values of the obtained retardation layer were measured at a wavelength of 450 nm and a wavelength of 650 nm, Re(450)/Re(550)=0.85, Re(650)/Re(550)=1.05 Met.

<Preparation of circularly polarizing plate>
Polarizing plate I and retardation plate B are bonded using adhesive (acrylic adhesive manufactured by Lintec Corporation) so that the angle (θ) between the absorption axis of polarizing plate I and the slow axis of retardation plate B is 45°. (colorless and transparent, non-oriented), and then the cycloolefin polymer film of the retardation plate was peeled off to produce circularly polarizing plate 1.

<Production of laminate for organic EL display>
An acrylic adhesive (manufactured by Lintec, film thickness: 15 μm) was laminated on the retardation plate of the obtained circularly polarizing plate to obtain a laminate for an organic EL display.
The layer structure of the obtained laminate for organic EL display is summarized in Table 1.

<Measurement of water vapor transmission rate>
The obtained circularly polarizing plate was measured according to JIS Z 0208 at 40° C. and relative humidity of 90%, and the amount of water passing through the film per 1 m ² of film area in 24 hours was calculated. The results are shown in Table 2.

<Measurement of oxygen permeability>
The obtained circularly polarizing plate was measured in accordance with JIS K7126 using an oxygen transmittance measuring device (OX-TRANML, manufactured by MOCON) at 23° C. and 50% relative humidity. The results are shown in Table 2.

<Measurement of transmittance>
The transmittance of the obtained circularly polarizing plate at 380 nm and 400 nm was measured using a spectrophotometer (UV-3150; manufactured by Shimadzu Corporation). The results are shown in Table 2.

<Weather resistance test>
The acrylic adhesive of the obtained organic EL display laminate was bonded to a display device obtained by removing the front glass and polarizing plate from "Galaxy S5" manufactured by SAMSUNG. The reflected hue was confirmed when the power of the display device was turned off (when displaying black) and when it was turned on (when displaying white). Table 3 shows the initial appearance and the appearance after the 100-hour accelerated weathering test using a sunshine weather meter (100-hour accelerated weathering test). Note that the frontal reflection hue (in Table 3, "white display" and "black display") is the hue confirmed by visually observing the sample at a distance of 50 cm from the front, and the oblique reflection hue (in Table 3, "oblique display") The hue is observed when visually observed from a distance of 50 cm from a direction with an elevation angle of 60° and an azimuth angle of 0 to 360°.

<Flexibility test>
A glass plate with a thickness of 0.7 mm was placed on the coated side of the circularly polarizing plate obtained, and the laminate was bent 180 degrees so as to lie on the glass plate. Using a 10x magnifying glass, the fluorescent lamp was The bent parts were observed under light to check for wrinkles and cracks. Those with no wrinkles or cracks observed were rated A, those with slight wrinkles were rated B, and those with wrinkles and cracks observed were rated C. The results are shown in Table 3.

[Example 2]
Example 1 except that the adhesive for the polarizing plate and retardation plate in Example 1 was changed to the adhesive (near ultraviolet PSA) described in Example 2 of Japanese Patent Application Publication No. 2017-120430. It was produced in the same manner.

[Example 3]
[Fabrication of retardation plate]
<Preparation of oriented polymer composition (1)>
Water was added to commercially available polyvinyl alcohol (Polyvinyl Alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) and heated at 100° C. for 1 hour to obtain an oriented polymer composition (1). The solid content in the oriented polymer composition (1) was 2% by mass.

<Preparation of composition (B-1)>
Polymerizable liquid crystal compound represented by formula (LC242), polymerization initiator (manufactured by BASF; Irgacure 907), polyacrylate compound (leveling agent/BYK-361N; manufactured by BYK-Chemie), reaction additive (manufactured by BASF) A composition (B-1) was obtained by mixing Laromer (registered trademark) LR-900) and propylene glycol 1-monomethyl ether 2-acetate (PGMEA). The proportions of each compound in composition (B-1) are: 19.2% by mass of the polymerizable liquid crystal compound, 0.5% by mass of the polymerization initiator, 0.1% by mass of the leveling agent, and 1.1% by mass of the reaction additive. % and PGMEA 79.1%.

<Preparation of retardation layer 1>
The oriented polymer composition (1) was applied to a saponified triacetyl cellulose film (hereinafter sometimes referred to as TAC), and after heating and drying, an oriented polymer film with a thickness of 80 nm was obtained. The surface of the obtained oriented polymer film was subjected to a rubbing treatment. Composition (B-1) was applied on top of this using a bar coater, dried at 100°C for 1 minute, and then irradiated with ultraviolet rays using a high-pressure mercury lamp (integrated light intensity at a wavelength of 365 nm in a nitrogen atmosphere). :1200 mJ/cm ² ) to form the retardation layer 1. The thickness of the obtained retardation layer 1 was measured using a laser microscope and was found to be 1.94 μm. When the retardation value of the obtained retardation layer 1 was measured, it was found that Re(550)=269 nm. Further, when the retardation values at a wavelength of 450 nm and a wavelength of 650 nm were measured, Re(450)/Re(550)=1.08 and Re(650)/Re(550)=0.99.

<Preparation of retardation layer 2>
The oriented polymer composition (1) was applied to a saponified triacetyl cellulose film (KC4UY, manufactured by Konica Minolta, Inc.), and after heating and drying, an oriented polymer film with a thickness of 82 nm was obtained. The surface of the obtained oriented polymer film was rubbed at an angle of 15° from the longitudinal direction of the TAC, and the composition (B-1) was applied thereon using a bar coater and heated at 100°C. After drying for 1 minute, a retardation layer 2 was formed by irradiating ultraviolet rays (in a nitrogen atmosphere, cumulative amount of light at a wavelength of 365 nm: 1200 mJ/cm ² ) using a high-pressure mercury lamp. The thickness of the obtained retardation layer 2 was measured using a laser microscope and was found to be 973 nm. When the retardation value of the obtained retardation layer 2 was measured, it was found that Re(550)=135 nm. Further, when the retardation values at a wavelength of 450 nm and a wavelength of 650 nm were measured, Re(450)/Re(550)=1.07 and Re(650)/Re(550)=0.98.

<Lamination of retardation layer 1 and retardation layer 2>
The retardation plate 3 was produced by laminating using a photocurable adhesive so that the angle between the slow axis of the retardation layer 1 obtained above and the slow axis of the retardation layer 2 was 60°. did.

<Preparation of circularly polarizing plate>
The polarizing plate I and the retardation layer 1 side of the retardation plate 3 are arranged so that the angle (θ) between the absorption axis of the polarizing plate I and the slow axis of the retardation layer 1 is 15°, and the absorption axis of the polarizing plate I and the position After bonding using an adhesive so that the angle (θ) formed by the slow axis of the retardation plate 2 was 75°, the cycloolefin polymer film of the retardation plate was peeled off to produce a circularly polarizing plate.

<Production of laminate for organic EL display>
A laminate for an organic EL display was produced in the same manner as in Example 1 except that the retardation plate 3 obtained above was used.

[Example 4]
[Preparation of optical compensation plate]
<Preparation of oriented polymer composition (2)>
An oriented polymer composition (2) was obtained by adding 2-butoxyethanol to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available oriented polymer. Note that the solid content of the oriented polymer composition (2) was 1% by mass.

The surface of the cycloolefin film was treated once using a corona treatment device at an output of 0.3 kW and a treatment speed of 3 m/min. The oriented polymer composition (2) was applied to the corona-treated surface using a bar coater and dried at 90° C. for 1 minute to obtain an oriented film. The thickness of the obtained alignment film was measured using a laser microscope and was found to be 34 nm. Subsequently, composition (B-1) was applied onto the alignment film using a bar coater, dried at 90°C for 1 minute, and then irradiated with ultraviolet rays (under nitrogen atmosphere, wavelength 365 nm) using a high-pressure mercury lamp. An optical compensator plate was obtained by performing an integrated light amount of 1000 mJ/cm ² ). When the film thickness of the obtained optical compensation plate was measured using a laser microscope, the film thickness was 450 nm. Further, when the retardation values of the obtained optical compensator were measured at a wavelength of 550 nm, they were found to be Re (550) = 1 nm and Rth (550) = -70 nm. Note that the retardation value of the cycloolefin film alone at a wavelength of 550 nm was approximately 0.

The circularly polarizing plate produced in Example 1 and the optical compensator obtained above were bonded together using the acrylic adhesive described in Example 1 to obtain a circularly polarizing plate with an optical compensator. An acrylic adhesive was further laminated on the optical compensator of the obtained circularly polarizing plate with an optical compensator to obtain a laminate for an organic EL display.

[Example 5]
A 30 μm polyimide film (PI film) was produced in the same manner as in Example 1 described in International Publication No. 2017/014279.
It was produced in the same manner as in Example 2 except that the polyimide film (PI film) was used as a protective film instead of the cycloolefin polymer film.

[Example 6]
A 30 μm polyimide film (PI film) was produced in the same manner as in Example 1 described in International Publication No. 2017/014279.
A protective film was prepared in the same manner as in Example 3 except that the polyimide film described above was used.

[Example 7]
A 30 μm polyimide film (PI film) was produced in the same manner as in Example 1 described in International Publication No. 2017/014279.
It was prepared in the same manner as in Example 4, except that the polyimide film was used as the protective film and the acrylic adhesive described in Example 1 was used as the adhesive used to laminate the retardation plate and the polarizing plate.

[Comparative example 1]
<Preparation of polarizing plate>
Triacetyl cellulose films (TAC; KC2UA; manufactured by Konica Minolta, Inc.) were placed on both sides of the polarizer, a water-based adhesive was injected between each layer, and the films were bonded together using nip rolls. While maintaining the tension of the obtained bond at 430 N/m, it was dried at 60° C. for 2 minutes to obtain a polarizing plate having triacetylcellulose films as protective films on both sides. The above water-based adhesive contains 100 parts of water, 3 parts of carboxyl group-modified polyvinyl alcohol (Kuraray Poval KL318; manufactured by Kuraray Co., Ltd.), and a water-soluble polyamide epoxy resin (Sumirezu Resin 650; manufactured by Sumika Chemtex Co., Ltd.). 1.5 parts of an aqueous solution with a solid content concentration of 30%).

<Production of laminate for organic EL display>
A laminate for an organic EL display was produced in the same manner as in Example 1 except that a polycarbonate copolymer resin film (WRS-143; manufactured by Teijin Ltd.) was used as the retardation plate.

[Comparative example 2]
A laminate for an organic EL display was produced in the same manner as in Comparative Example 1 except that the retardation plate 2 produced in Example 3 was used.

[Comparative example 3]
A laminate for an organic EL display was produced in the same manner as in Example 1, except that the polarizing plate produced in Comparative Example 1 was used.

なお、表１における「ＣＯＰ」はシクロオレフィンフィルムを表し、「ＰＩ」はポリイミドを表し、「ＴＡＣ」はトリアセチルセルロースフィルムを表し、「ＰＶＡ」はポリビニルアルコールを表し、「ＰＳＡ」はアクリル系粘着剤を表す。また、ＲｅはＲｅ（５５０）を表し、α＝Ｒｅ（４５０）／Ｒｅ（５５０）、β＝Ｒｅ（６５０）／Ｒｅ（５５０）を表し、Ｒｔｈは膜厚方向の面内位相差を表す。

In addition, "COP" in Table 1 represents cycloolefin film, "PI" represents polyimide, "TAC" represents triacetyl cellulose film, "PVA" represents polyvinyl alcohol, and "PSA" represents acrylic adhesive. represents an agent. Further, Re represents Re(550), α=Re(450)/Re(550), β=Re(650)/Re(550), and Rth represents the in-plane retardation in the film thickness direction.

As is clear from the results in Tables 2 and 3 above, in Examples 1 to 7 that satisfy the requirements of the present invention, the appearance after the 100-hour accelerated weathering test was almost unchanged from the initial appearance, and the flexibility has maintained its original performance. In Comparative Examples 1 to 3, the appearance after the 100 hour accelerated weathering test changed from the initial appearance. In particular, the water vapor permeability in all comparative examples was 700 g/m ² /24 hrs, which is significantly different from the standard value of 100 g/m ² /24 hrs, so it is understood that the weather resistance has deteriorated.

Claims (8)

A laminate in which a circularly polarizing plate and an adhesive layer are laminated,
Formula (5):
-30nm ≦ Rth (550) ≦ -100nm (5)
(Rth(550) represents the in-plane retardation in the film thickness direction for light with a wavelength of 550 nm.)
an optical compensator made of a polymer of a polymerizable liquid crystal compound that satisfies the following;
A laminate for an organic EL display, comprising:
The thickness of the laminate in which the circularly polarizing plate and the adhesive layer are laminated is 75 μm or less,
The circularly polarizing plate includes a polarizing plate and a retardation plate,
The polarizing plate includes a polarizer and a protective film, and has the protective film only on the opposite side of the polarizer to the surface on which the retardation plate is laminated,
The protective film has a transmittance of 10% or less at 400 nm,
The water vapor transmission rate of the circularly polarizing plate is 100 g/m ² /24 hrs or less,
A laminate for an organic EL display, wherein the circularly polarizing plate has a transmittance of 1% or less at 380 nm, and the protective film is a polyimide film or a polyamide-imide film. The laminate for an organic EL display according to claim 1, wherein the polarizer is a polarizer formed from a polyvinyl alcohol resin film. The laminate for an organic EL display according to claim 1 or 2, wherein the circularly polarizing plate has a transmittance of 400 nm of 1% or less. Claim: The retardation plate includes only one retardation layer containing a polymer of a polymerizable liquid crystal compound, and satisfies all of the following formulas (1), (2), and (3). 4. The laminate for an organic EL display according to any one of 1 to 3.
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
100nm≦Re(550)≦180nm (3)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.) 5. The laminate for an organic EL display according to claim 4, wherein the angle between the slow axis of the retardation plate and the absorption axis of the polarizing plate is substantially 45 degrees. The retardation plate includes a first retardation layer and a second retardation layer in order from the polarizing plate side,
The first retardation layer and the second retardation layer are each a polymer of a polymerizable liquid crystal compound,
The first retardation layer satisfies the relationship of formula (4) below,
The second retardation layer satisfies the relationship of formula (3),
The laminate for an organic EL display according to any one of claims 1 to 3, wherein the retardation plate satisfies the relationships of formulas (1) and (2).
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)
100nm≦Re(550)≦180nm (3)
200nm≦Re(550)≦300nm (4)
(In the formula, Re(λ) represents the in-plane retardation value for light with a wavelength of λnm.) The laminate for an organic EL display according to any one of claims 1 to 6, wherein the circularly polarizing plate includes an adhesive layer having a transmittance of 10% or less at 400 nm. The circularly polarizing plate is one in which at least a polarizing plate, an adhesive layer, and a retardation plate are laminated in this order,
The polarizing plate includes a polarizer and a protective film, and has the protective film only on the opposite side of the polarizer to the surface on which the retardation plate is laminated,
The protective film has a transmittance of 10% or less at 400 nm,
the retardation plate satisfies the relationships of formulas (1) and (2),
The water vapor transmission rate of the circularly polarizing plate is 100 g/m ² /24 hrs or less,
The laminate for an organic EL display according to claim 1, wherein the circularly polarizing plate has a transmittance of 1% or less at 380 nm, and the protective film is a polyimide film or a polyamide-imide film.
Re(450)/Re(550) ≦ 1.00 (1)
1.00≦Re(650)/Re(550) (2)