TWI882978B - Multilayer body for organic EL display - Google Patents

Abstract

The present invention provides a multilayer body for an organic EL display, which includes a circular polarizer that can protect the organic EL panel even when there is no glass on the outermost surface. Based on this, the purpose of the present invention is to provide an organic EL display device with excellent display characteristics, flexibility and aging degradation, and a circular polarizer used therefor.

The present invention provides a laminate for an organic EL display, which is a laminate formed by laminating a circular polarizing plate and an adhesive layer, and the thickness of the laminate is less than 100 μm, the circular polarizing plate includes a polarizing plate and a phase difference plate, the polarizing plate includes a polarizing element and a protective film, and the protective film is provided only on the side opposite to the surface of the polarizing element on which the phase difference plate is laminated, the water vapor transmittance of the circular polarizing plate is less than 100 g/m ² /24 hrs, and the 380 nm transmittance of the circular polarizing plate is less than 1%.

Description

Multilayer body for organic EL display

The present invention relates to a multilayer structure for an organic EL (Electroluminescence) display, and more particularly to a multilayer structure for an organic EL display having a specific circular polarizer.

In recent years, with the popularity of thin displays, displays equipped with organic EL panels (organic EL display devices) have become popular. Organic EL panels have the following problem: since the metal electrodes inside reflect external light, it is impossible to obtain a clear black display. In response to this problem, by setting a circular polarizing plate on the viewing surface, the reflection of external light can be suppressed. That is, the lamination order from the viewer is protective glass → circular polarizing plate → organic EL panel. Circular polarizing plates can usually be made by laminating polarizing plates and phase difference plates. As a polarizing plate, a transparent protective film is usually laminated on a polarizing element formed by stretching a polyvinyl alcohol (PVA) film and dyeing it with iodine, but as a phase difference plate, a stretched film or a λ/4 plate with liquid crystal molecules aligned is used, among which a λ/4 plate showing a property that the longer the wavelength, the greater the birefringence (inverse wavelength dispersion property) is preferably used. In addition, in order to suppress the change in the reflection color when observing from an oblique direction, Patent Document 1 [Japanese Patent Publication No. 2015-163935] proposes a circular polarizing plate having a vertically aligned liquid crystal cured film formed by polymerizing and curing the rod-like liquid crystal in a vertically aligned state.

[Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2015-163935

Regarding organic EL display devices, their applications in flexible forms have been studied, and studies have been conducted on not using glass on the outermost surface of the device. However, it is known that organic EL panels deteriorate when driven in a state where glass has no barrier properties to water (water vapor) or oxygen. In addition, it is known that in order to obtain good flexibility, the circular polarizer itself also needs to be thinner.

Therefore, the purpose of the present invention is to provide a multilayer body for an organic EL display, which can protect the circular polarizer of the organic EL panel even when there is no glass on the outermost surface, and based on this, to provide an organic EL display device with excellent display characteristics, flexibility and aging degradation, and a circular polarizer used therefor.

The present invention has the following aspects:

[1] A laminate for an organic EL display, comprising a laminate of a circular polarizing plate and an adhesive layer, wherein the laminate has a thickness of 100 μm or less, the circular polarizing plate comprises a polarizing plate and a phase difference plate, the polarizing plate comprises a polarizing element and a protective film, and the protective film is provided only on the side of the polarizing element opposite to the side on which the phase difference plate is laminated, the water vapor transmittance of the circular polarizing plate is 100 g/m ² /24 hrs or less, and the transmittance at 380 nm of the circular polarizing plate is 1% or less.

[2] A multilayer structure for an organic EL display as described in [1], wherein the polarizing element is formed of a polyvinyl alcohol-based resin film.

[3] A multilayer structure for an organic EL display as described in [1] or [2], wherein the 400nm transmittance of the circular polarizer is less than 1%.

[4] A multilayer for an organic EL display as described in any one of [1] to [3], wherein the phase difference plate comprises only one phase difference layer of a polymer containing a polymerizable liquid crystal compound, and satisfies all of the following formulas (1), (2) and (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 phase difference for light with a wavelength of λnm)

[5] A multilayer structure for an organic EL display as in [4], wherein the angle between the phase axis of the phase difference plate and the absorption axis of the polarizing plate is substantially 45 degrees.

[6] A laminate for an organic EL display as described in any one of [1] to [3], wherein the phase difference plate comprises a first phase difference layer and a second phase difference layer in order from the polarizing plate side, and the first phase difference layer and the second phase difference layer are polymers of polymerizable liquid crystal compounds, respectively, the first phase difference layer satisfies the relationship of the following formula (4), the second phase difference layer satisfies the relationship of formula (3), and the phase difference plate satisfies the relationship of formula (1) and formula (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 phase difference for light with a wavelength of λnm)

[7] A multilayer body for an organic EL display as described in any one of [1] to [6], which further comprises an optical compensation plate of a polymer containing a polymerizable liquid crystal compound satisfying the following formula (5).

-30nm≦Rth(550)≦-100nm (5)

(Rth(550) represents the phase difference in the film thickness direction for light with a wavelength of 550nm)

[8] A multilayer body for an organic EL display as described in any one of [1] to [6], wherein the circularly polarizing plate comprises an adhesive layer having a transmittance of 10% or less at 400 nm.

[9] A multilayer body for an organic EL display as described in any one of [1] to [7], wherein the protective film is a cycloolefin film.

[10] A multilayer body for an organic EL display as described in any one of [1] to [7], wherein the protective film is a polyimide film or a polyamide imide film.

[11] A circularly polarizing plate, which is formed by laminating at least a polarizing plate, an adhesive layer and a phase difference plate in that order, wherein the polarizing plate comprises a polarizing element and a protective film, and the protective film is present only on the side of the polarizing element opposite to the side on which the phase difference plate is laminated, the phase difference plate satisfies the relationship of equations (1) and (2), the water vapor transmittance of the circularly polarizing plate is less than 100 g/m ² /24 hrs, and the transmittance at 380 nm of the circularly polarizing plate is less than 1%.

Re(450)/Re(550)≦1.00 (1)

1.00≦Re(650)/Re(550) (2)

[12] A circularly polarizing plate as described in [11], wherein the polarizing element is formed of a polyvinyl alcohol resin film.

[13] A circular polarizing plate as described in [11] or [12], wherein the transmittance at 400nm of the circular polarizing plate is less than 1%.

[14] A circularly polarizing plate as described in any one of [11] to [13], wherein the transmittance of the adhesive layer at 400 nm is less than 10%.

[15] A circularly polarizing plate as described in any one of [11] to [14], wherein the protective film is a cycloolefin film.

[16] A circularly polarizing plate as described in any one of [11] to [15], wherein the protective film is a polyimide film or a polyamide imide film.

The present invention can provide an organic EL display device and a circular polarizing plate used therein that have excellent display characteristics, flexibility, and aging degradation even when there is no glass on the outermost surface of the organic EL display device.

The laminate for organic EL display of the present invention is formed by laminating circular polarizing plates and adhesive layers, and the circular polarizing plates include polarizing plates and phase difference plates, and the polarizing plates include polarizing elements and protective films. The polarizing plates have protective films on the surface of the polarizing elements on the opposite side of the phase difference plates. The phase difference plates may include one phase difference layer or two phase difference layers, and in the case of two layers, they are sometimes referred to as the first phase difference layer and the second phase difference layer to distinguish them. The polarizing plates and phase difference plates are usually joined by adhesive layers to form the laminate for organic EL display of the present invention. The circular polarizing plates can be combined with adhesive layers to form the laminate for organic EL display of the present invention, but optical compensation plates can also be further combined. Therefore, the multilayer body for the organic EL display of the present invention may include a circular polarizing plate and an adhesive layer; and an optical compensation plate may be connected to the circular polarizing plate via another adhesive layer between the circular polarizing plate and the adhesive layer.

<Polarizing plate>

The polarizing plate includes a film having anisotropic light absorption function (hereinafter, sometimes referred to as a polarizing element). The polarizing element may be a stretched film adsorbed with a dichroic pigment.

The stretched film adsorbed with dichroic dye, i.e., polarizing element, is usually manufactured through the following steps: a step of uniaxially stretching the polyvinyl alcohol resin film; a step of dyeing the polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye; a step of treating the polyvinyl alcohol resin film adsorbed with the dichroic dye with a boric acid aqueous solution; and a step of washing with water after the treatment with the boric acid aqueous solution.

Polyvinyl alcohol resins are obtained by saponifying polyvinyl acetate resins. As polyvinyl acetate resins, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith can also 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 polyvinyl alcohol resin is usually about 85~100 mol%, preferably 98 mol% or more. Polyvinyl alcohol resin can be modified, for example, polyvinyl formal or polyvinyl acetaldehyde modified by aldehydes can also be used. The polymerization degree of polyvinyl alcohol resin is usually about 1,000~10,000, preferably in the range of 1,500~5,000.

The film obtained by forming such a polyvinyl alcohol resin can be used as a raw film of a polarizing film. The method of forming a polyvinyl alcohol resin film is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol raw film can be set to about 10~150μm, for example.

The uniaxial stretching of the polyvinyl alcohol resin film can be performed before dyeing with a dichroic dye, at the same time as dyeing, or after dyeing. When the uniaxial stretching is performed after dyeing, the uniaxial stretching can be performed before the boric acid treatment or during the boric acid treatment. In addition, the uniaxial stretching can be performed in multiple stages. During the uniaxial stretching, the uniaxial stretching can be performed between rollers with different peripheral speeds, or the uniaxial stretching can be performed using a hot roller. In addition, the uniaxial stretching can be dry stretching performed in the atmosphere, or wet stretching performed using a solvent to swell the polyvinyl alcohol resin film. The stretching ratio is usually about 3 to 8 times.

The polyvinyl alcohol resin film is dyed with a dichroic dye, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye.

As the dichroic pigment, specifically, iodine or dichroic organic dyes can be used. As dichroic organic dyes, dichroic direct dyes including disazo compounds such as C.I.DIRECT RED 39 and dichroic direct dyes including trisazo, tetrakisazo and other compounds can be listed. The polyvinyl alcohol resin film is preferably immersed in water before dyeing.

When iodine is used as a dichroic pigment, a method of dyeing is usually adopted in which a polyvinyl alcohol resin film is immersed in an aqueous solution containing iodine and potassium iodide.

The iodine content in the aqueous solution is usually about 0.01 to 1 mass part per 100 mass parts of water. Also, the potassium iodide content is usually about 0.5 to 20 mass parts per 100 mass parts of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. Also, the immersion time (dyeing time) in the aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when using dichroic organic dyes as dichroic pigments, a method of dyeing is usually adopted in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing a water-soluble dichroic dye.

The content of the dichroic organic dye in the aqueous solution is usually about 1×10 ^-4 to 10 parts by mass, preferably 1×10 -3 to 1 part by mass, and further preferably 1×10 ^-3 to 1×10 ^-2 parts by mass per ¹⁰⁰ parts by mass of water. The aqueous solution may also contain an inorganic salt such as sodium sulfate as a dyeing auxiliary. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. In addition, the immersion time (dyeing time) in the aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye can usually be performed by immersing the dyed polyvinyl alcohol-based resin film in an aqueous boric acid solution. The content of boric acid in the aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, it is preferred that the aqueous boric acid solution contains potassium iodide, and the content of potassium iodide in this case is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the aqueous boric acid solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and further preferably 200 to 400 seconds. The temperature of boric acid treatment is usually above 50℃, preferably 50~85℃, and more preferably 60~80℃.

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 the polyvinyl alcohol resin film treated with boric acid in water. The temperature of the water in the water washing treatment is usually around 5~40℃.

In addition, the immersion time is usually around 1 to 120 seconds.

After washing, a drying process is performed to obtain a polarizing element. The drying process can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying process is usually about 30 to 100°C, preferably 50 to 80°C. The drying process time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. Through the drying process, the moisture content of the polarizing element is reduced to a practical level. The moisture content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. If the moisture content is lower than 5% by weight, the flexibility of the polarizing element may be lost, and the polarizing element may be damaged or broken after drying. In addition, if the moisture content is higher than 20% by weight, the thermal stability of the polarizing element may deteriorate.

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

The polarizing plate of the present invention is obtained by laminating a protective film through an adhesive layer on only one side of the polarizing element obtained by the above method. The protective film is laminated on the side of the polarizing element opposite to the side on which the phase difference plate is laminated. The adhesive layer is formed using a known adhesive composition.

<Protective film>

烯系聚合物等環烯烴系樹脂；聚乙烯醇；聚對苯二甲酸乙二酯；聚甲基丙烯酸酯；聚丙烯酸酯；三乙醯纖維素、二乙醯纖維素、醋酸丙酸纖維素等纖維素酯；聚萘二甲酸乙二酯；聚碳酸酯；聚碸；聚醚碸；聚醚酮；聚苯硫醚及聚苯醚等。就獲取容易性或透明性之觀點而言，較佳為聚對苯二甲酸乙二酯、聚甲基丙烯酸酯、纖維素酯、環烯烴系樹脂或聚碳酸酯。纖維素酯係纖維素中所含之羥基之一部分或全部經酯化者，且可容易自市場獲取。纖維素酯基材亦可容易自市場獲取。 Protective film refers to a transparent substrate that allows light (especially visible light) to pass through. Transparency refers to the property that the transmittance of light covering a wavelength of 380~780nm is more than 80%. Specific protective films include: polyethylene, polypropylene and other polyolefins;

Cycloolefin resins such as olefin polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide and polyphenylene ether, etc. From the viewpoint of easy availability or transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cycloolefin resin or polycarbonate is preferred. Cellulose ester is a cellulose in which part or all of the hydroxyl groups contained in cellulose are esterified and can be easily obtained from the market. Cellulose ester substrates can also be easily obtained from the market.

Examples of commercially available cellulose ester substrates include: "Fuji-TAC Film" (Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (KONICA MINOLTA OPTO Co., Ltd.), etc.

The properties required of the protective film vary depending on the composition of the polarizing plate, but it is usually preferred to have a film with the smallest possible phase difference. Examples of films with the smallest possible phase difference include: Zero TAC (KONICA MINOLTA OPTO Co., Ltd.), Z-TAC (Fuji Film Co., Ltd.), and other cellulose ester films without phase difference. Unstretched cyclic olefin resin films are also preferred. Other preferred protective films include polyimide films and polyamide imide films. The surface of the protective film without the polarizing plate laminated can also be hard-coated, anti-reflected, and anti-static treated.

唑、聚伸乙基亞胺、聚苯乙烯、聚乙烯吡咯啶酮、聚丙烯酸及聚丙烯酸酯。保護膜較佳為400nm之透過率為10%以下。若400nm之透過率為10%以下，則具有抑制有機EL面板劣化(變色)之效果。 In the present invention, the resin forming the protective film may be, for example, cycloolefin, polyamide or gelatin compound having an amide bond in the molecule, polyimide having an imide bond in the molecule and polyamide acid as its hydrolyzate, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, poly

The protective film preferably has a transmittance of 10% or less at 400nm. If the transmittance at 400nm is 10% or less, it has the effect of inhibiting the degradation (discoloration) of the organic EL panel.

In terms of improving strength and processability, the thickness of the protective film is usually 10~80μm, preferably 20~60μm, and more preferably 20~40μm.

<Phase difference plate>

The phase difference plate can be a stretched film that imparts a phase difference by stretching a polymer, but from the perspective of thinning the layer of the laminate for the organic EL display of the present invention, it is preferably a phase difference layer containing a polymer containing a horizontally aligned or vertically aligned polymerizable liquid crystal compound. When the phase difference plate includes a phase difference layer, it may be only a phase difference layer, or it may include the following alignment film or substrate.

When the phase difference plate only includes one phase difference layer of a polymer containing a polymerizable liquid crystal compound, it is preferred to satisfy all of the following formulas (1), (2) and (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 phase difference for light with a wavelength of λnm)

The phase difference plate satisfying the above formula (1) has the so-called reverse wavelength dispersion and shows excellent polarization performance. The value of Re(450)/Re(550) is preferably less than 0.93, more preferably less than 0.88, and further preferably less than 0.86, and is preferably greater than 0.80, and more preferably greater than 0.82. The above formula (3) is preferably 100nm≦Re(550)≦180nm, and further preferably 120nm≦Re(550)≦160nm.

Furthermore, Re(550) can be measured by the method described in the embodiments.

In the circular polarizing plate of the present invention, the angle between the retardation axis of the phase difference plate and the absorption axis of the polarizing plate is preferably substantially 45°. Furthermore, in the present invention, "substantially 45°" means 45°±5°.

The phase difference plate includes a first phase difference layer and a second phase difference layer. When each phase difference layer is a phase difference layer of a polymer of a polymerizable liquid crystal compound, it is preferred that the first phase difference layer satisfies the relationship of the following formula (4), the second phase difference layer satisfies the relationship of the above formula (3), and the phase difference plate as a whole satisfies the relationship of the above formulas (1) and (2).

200nm≦Re(550)≦300nm (4)

(In the formula, Re(λ) represents the in-plane phase difference for light with a wavelength of λnm)

The polymerizable liquid crystal compound (hereinafter, also referred to as "polymerizable liquid crystal compound (A)") forming the phase difference layer refers to a liquid crystal compound having a polymerizable functional group, especially a photopolymerizable functional group. The photopolymerizable functional group refers to a group that can participate in the polymerization reaction by an active free radical or acid generated from a photopolymerization initiator. Examples of the photopolymerizable functional group include: vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxirane, cyclobutyl, etc. Among them, acryloxy, methacryloxy, vinyloxy, oxirane and cyclobutyl are preferred, and acryloxy is more preferred. The liquid crystal can be a thermotropic liquid crystal or a hydrotropic liquid crystal, and the phase order structure can 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.

As polymerizable liquid crystal compounds (A), from the viewpoint of the ease of film formation and the imparting of phase difference, compounds that satisfy all of the following (1) to (4) can be listed.

(1) Compounds with thermotropic liquid crystal properties;

(2) The polymerizable liquid crystal compound has π electrons in the long axis direction (a).

(3) There are π electrons in the direction intersecting the long axis direction (a) [intersecting direction (b)].

(4) The total number of π electrons in the long axis direction (a) is N(πa), the total number of molecular weights in the long axis direction (a) is N(Aa), and the π electron density in the long axis direction (a) of the polymerizable liquid crystal compound is defined by the following formula (i): D(πa)=N(πa)/N(Aa) (i)

The total number of π electrons in the cross direction (b) is N(πb), the total number of molecular weights in the cross direction (b) is N(Ab), and the π electron density in the cross direction (b) of the polymerizable liquid crystal compound is defined by the following formula (ii): D(πb)=N(πb)/N(Ab) (ii)

The relationship is 0≦[D(πa)/D(πb)]≦1 [that is, the π electron density in the cross direction (b) is greater than the π electron density in the long axis direction (a)].

Furthermore, the polymerizable liquid crystal compound (A) satisfying all of the above (1) to (4) can form a nematic phase by coating on an alignment film formed by rubbing treatment and heating to a temperature above the phase transition temperature. The nematic phase formed by the alignment of the polymerizable liquid crystal compound (A) is usually aligned in such a way that the long axis directions of the polymerizable liquid crystal compound become parallel to each other, and the long axis direction becomes the alignment direction of the nematic phase.

所表示之化合物。上述式(I)所表示之化合物可單獨使用，或組合2種以上使用。 The polymerizable liquid crystal compound (A) having the above-mentioned characteristics is usually mostly one that exhibits reverse wavelength dispersion. As a compound satisfying the above-mentioned characteristics (1) to (4), specifically, for example, the following formula (I) can be cited:

The compound represented by the above 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. Here, the aromatic group refers to a group having a planar cyclic structure, and the number of π electrons possessed by the cyclic structure is [4n+2] according to Huckel's law. Here, n represents an integer. When a cyclic structure is formed by containing heteroatoms such as -N= or -S-, the non-covalent bond electron pairs on the heteroatoms satisfy Huckel's law, thereby also including the case of having aromaticity. In the divalent aromatic group, it is preferred to contain at least one of nitrogen atoms, oxygen atoms, and sulfur atoms.

^G1 and ^G2 each independently represent a divalent aromatic group or a divalent alicyclic alkyl group. Here, the hydrogen atom contained in the divalent aromatic group or the divalent alicyclic alkyl group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic alkyl group may be substituted with an oxygen atom, a sulfur atom or a nitrogen atom.

^L1 and ^L2 are each independently a divalent linking group having an ester structure.

^B1 and ^B2 are independently a single bond or a divalent linking group.

k and l represent integers from 0 to 3 independently and satisfy the relationship 1≦k+1. Here, when 2≦k+1, ^B1 and ^B2 , ^G1 and ^G2 may be the same or different.

^E1 and ^E2 each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and the _-CH2- contained in the alkanediyl group may be substituted with -O-, -S-, -Si-, or -COO-. ^P1 and ^P2 each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

^G1 and ^G2 are each independent and are preferably 1,4-phenylenediyl which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, 1,4-cyclohexanediyl which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably 1,4-phenylenediyl substituted by methyl, unsubstituted 1,4-phenylenediyl, or unsubstituted 1,4-trans-cyclohexanediyl, and particularly preferably unsubstituted 1,4-phenylenediyl or unsubstituted 1,4-trans-cyclohexanediyl. Furthermore, it is preferred that at least one of a plurality of ^G1 and ^G2 is a divalent alicyclic hydrocarbon group, and it is more preferred that at least one of ^G1 and ^G2 bonded to ^L1 or ^L2 is a divalent alicyclic hydrocarbon group.

^L1 and ^L2 are independently preferably ^-Ra1COORa2- ( ^Ra1 and ^Ra2 independently represent ^a single bond or an alkylene group having 1 to 4 carbon atoms), more preferably ^-COORa2-1- ( ^Ra2-1 represents a single bond, _-CH2- , _{or -CH2CH2-} ), and further preferably _-COO- or _-COOCH2CH2- .

^B1 and ^B2 are each independently 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 are each independently a single bond or an alkylene group having 1 to 4 carbon atoms. ^B1 and ^B2 are each independently 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 are each independently a single bond, -CH ₂ -, or -CH ₂ CH ₂ . ^B1 and ^B2 are each independently and preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, -OCO- or OCOCH ₂ CH ₂ -.

From the perspective of anti-wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. If k=2 and l=2, it becomes a symmetric structure, which is further preferred.

^E1 and ^E2 are each independently an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

Examples of the polymerizable group represented by ^P1 or ^P2 include epoxy, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxirane and cyclobutyl. Among them, acryloxy, methacryloxy, vinyloxy, oxirane and cyclobutyl are preferred, and acryloxy is more preferred.

環、嘧啶環、三唑環、三

環、吡咯啉環、咪唑環、吡唑環、噻唑環、苯并噻唑環、噻吩并噻唑環、

唑環、苯并

唑環及啡啉環等。該等之中，較佳為具有噻唑環、苯并噻唑環或苯并呋喃環，進而較佳為具有苯并噻唑環。又，於Ar包含氮原子之情形時，該氮原子較佳為具有π電子。 Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring 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, preferably a benzene ring and a naphthalene ring. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyridine ring, and a pyridine ring.

Ring, pyrimidine ring, triazole ring, tri

ring, pyrroline ring, imidazole ring, pyrazole ring, thiazole ring, benzothiazole ring, thienothiazole ring,

Azole, benzo

Among them, it is preferably a thiazole ring, a benzothiazole ring or a benzofuran ring, and more preferably a benzothiazole ring. In addition, when Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

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

As the aromatic group represented by Ar, for example, the following groups of formula (Ar-1) to formula (Ar-23) can be listed.

In formula (Ar-1) to formula (Ar-23), the symbol * represents a linking portion, and ^Z0 , ^Z1 , and ^Z2 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylaminesulfonyl group having 1 to 12 carbon atoms, or an N,N-dialkylaminesulfonyl group having 2 to 12 carbon atoms.

^Q1 and ^Q2 each independently represent ^-CR2'R3'- , ^-S- , -NH-, ^-NR2'- , -CO- or O-, and R2 ^' and R3 ^' each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

^J1 and ^J2 each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an aromatic alkyl group or an aromatic heterocyclic group which may be substituted.

^W1 and ^W2 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 alkyl group in Y ¹ , Y ² and Y ³ include phenyl, naphthyl, anthracenyl, phenanthrenyl, biphenyl and other aromatic alkyl groups having 6 to 20 carbon atoms, preferably phenyl and naphthyl, and more preferably phenyl. Examples of the aromatic heterocyclic group include furanyl, pyrrolyl, thienyl, pyridyl, thiazolyl, benzothiazolyl and other aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom and the like, preferably furanyl, thienyl, pyridyl, thiazolyl, benzothiazolyl.

^Y1 and ^Y2 may also be independently substituted polycyclic aromatic alkyl groups or polycyclic aromatic heterocyclic groups. Polycyclic aromatic alkyl groups refer to condensed polycyclic aromatic alkyl groups or groups derived from aggregated aromatic rings. Polycyclic aromatic heterocyclic groups refer to condensed polycyclic aromatic heterocyclic groups or groups derived from aggregated aromatic rings.

^Z0 , ^Z1 and ^Z2 are independently preferably 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. ^Z0 is further preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group. ^Z1 and ^Z2 are further preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

^Q1 and ^Q2 are preferably -NH-, -S-, ^-NR2'- , or -O-, and R2 ^' is preferably a hydrogen atom, among which -S-, -O-, or -NH- is particularly preferred.

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

環、嘧啶環、吲哚環、喹啉環、異喹啉環、嘌呤環、吡咯啶環等。該芳香族雜環基亦可具有取代基。又，Y¹亦可與其所鍵結之氮原子及Z⁰一起形成上述可經取代之多環系芳香族烴基或多環系芳香族雜環基。例如可列舉：苯并呋喃環、苯并噻唑環、苯并

唑環等。再者，上述式(Ar-1)~(Ar-23)所表示之化合物例如可依據日本專利特開2010-31223號公報中記載之方法進行製造。 In formula (Ar-17) to (Ar-23), ^Y1 may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and ^Z0 . As the aromatic heterocyclic group, the aromatic heterocyclic rings that Ar may have are listed above, but for example, pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrrolidine ring,

ring, pyrimidine ring, indole ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidinyl ring, etc. The aromatic heterocyclic group may also have a substituent. In addition, ^Y1 may also form the above-mentioned polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group which may be substituted together with the nitrogen atom to which it is bonded and ^Z0 . For example, benzofuran ring, benzothiazole ring, benzo

The compounds represented by the above formulae (Ar-1) to (Ar-23) can be produced, for example, according to the method described in Japanese Patent Application Laid-Open No. 2010-31223.

The content of the polymerizable liquid crystal compound (A) in the polymerizable liquid crystal composition (A) constituting the phase difference layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, and more preferably 90 to 98 parts by mass, relative to 100 parts by mass of the solid content of the polymerizable liquid crystal composition (A). If the content is within the above range, the orientation of the phase difference plate tends to be higher. Here, the solid content refers to the total amount of the components after removing volatile components such as solvents from the polymerizable liquid crystal composition (A).

The polymerizable liquid crystal composition (A) may also contain a polymerization initiator for initiating the polymerization reaction of the polymerizable liquid crystal compound (A). In addition, the polymerizable liquid crystal composition (A) may also contain a photosensitizer, a leveling agent, an additive, etc. as needed.

The phase difference layer can be obtained, for example, by coating a composition (hereinafter also referred to as "phase difference film forming composition") on a substrate or an alignment film, removing the solvent by drying, and curing the polymerizable liquid crystal compound (A) in the obtained coating by heating and/or active energy rays. The above composition is prepared by adding a solvent to a polymerizable liquid crystal composition (A) containing a polymerizable liquid crystal compound (A) and, if necessary, a polymerization initiator, an additive, etc., and mixing and stirring.

The substrate is preferably a transparent substrate. The alignment film is a film that aligns the polymerizable liquid crystal compound contained in the phase difference film forming composition in any direction. The alignment film can be formed by an alignment polymer. In addition, the alignment film can also be a photoalignment film.

唑、聚伸乙基亞胺、聚苯乙烯、聚乙烯吡咯啶酮、聚丙烯酸及聚丙烯酸酯。其中，較佳為聚乙烯醇。配向性聚合物可單獨使用，或組合2種以上使用。 As the alignment polymer, for example, there can be mentioned: polyamides or gelatins having an amide bond in the molecule, polyimide having an imide bond in the molecule and polyamide acid as a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, poly

The aligning polymer may be used alone or in combination of two or more.

An alignment film containing an alignment polymer is usually obtained by applying a composition obtained by dissolving the alignment polymer in a solvent (hereinafter, sometimes referred to as an "alignment polymer composition") on a substrate and removing the solvent; or by applying the alignment polymer composition on a substrate, removing the solvent and rubbing (rubbing method). As a solvent, any solvent that can dissolve the components constituting the oriented polymer composition can be used, for example, aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol, 1-propanol, isopropanol, and 1-butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, and isobutyl acetate; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; esterified glycol ethers such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate can be appropriately selected and used.

Regarding the concentration of the alignment polymer in the alignment polymer composition, it is sufficient as long as the alignment polymer material can be completely dissolved in the solvent, but relative to the solution, it is preferably 0.1~20% in terms of solid content, and more preferably about 0.1~10%.

As the alignment polymer composition, commercially available alignment film materials can also be used directly. Commercially available alignment film materials include: Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), etc.

As methods for coating the oriented polymer composition on the substrate, there can be listed: coating methods such as rotary coating, extrusion, gravure coating, die-mouth coating, rod coating, and dressing; or known methods such as printing methods such as flexographic methods.

As methods for removing the solvent contained in the oriented polymer composition, there are: natural drying method, ventilation drying method, heating drying method and reduced pressure drying method, etc.

In order to impart an orientation-restricting force to the orientation film, a friction treatment (friction method) may be performed as necessary.

As a method of imparting an alignment restricting force by friction, the following method can be cited: a rubbing cloth is rolled up so that the rotating rubbing roller contacts an alignment polymer film formed on the surface of a substrate by coating an alignment polymer composition on the substrate and annealing the coating.

The photo-alignment film is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as a "photo-alignment film forming composition") to a substrate and irradiating it with polarized light (preferably polarized UV (Ultraviolet)). The photo-alignment film can arbitrarily control the direction of the alignment restriction force by selecting the polarization direction of the irradiated polarized light, which is more preferable in this respect.

Photoreactive groups refer to groups that generate liquid crystal alignment ability by light irradiation. Specifically, groups that participate in the photoreactions that are the origin of the liquid crystal alignment ability, such as the alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction of molecules generated by light irradiation can be listed. Among them, groups that participate in dimerization reaction or photocrosslinking reaction are better in terms of excellent alignment. As the photoreactive group, it is preferred to have an unsaturated bond, especially a double bond, and it is particularly preferred to have at least one selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

As photoreactive groups having a C=C bond, there can be listed: vinyl, polyene, isobutylene, styryl, styrylpyridyl, styrylpyridinium, chalcone, and cinnamyl, etc.

As photoreactive groups with C=N bonds, there are groups with structures such as aromatic Schiff bases and aromatic hydrazones. As photoreactive groups with N=N bonds, there are groups such as azophenyl, azonaphthyl, aromatic heterocyclic azo, bisazo, formazan, and groups with an oxidized azobenzene structure. As photoreactive groups with C=O bonds, there are groups such as benzophenone, coumarin, anthraquinone, and cis-butylenediimide. These groups may also have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, and halogenated alkyl.

Among them, the photoreactive groups that participate in the photodimerization reaction are preferred. In terms of the relatively small amount of polarized light irradiation required for photo-alignment and the ease of obtaining a photo-alignment film with excellent thermal stability or stability over time, cinnamyl and chalcone groups are preferred. As a polymer having a photoreactive group, it is particularly preferred that the terminal of the polymer side chain has a cinnamyl group such as a cinnamic acid structure.

By applying the photo-alignment film forming composition on the substrate, a photo-alignment layer can be formed on the substrate. As the solvent contained in the composition, the same solvents as those exemplified above as the solvents that can be used for the alignment film forming composition can be appropriately selected depending on the solubility of the polymer or monomer having a photoreactive group.

The content of the polymer or monomer having a photoreactive group in the photo-alignment film-forming composition can be appropriately adjusted according to the type of polymer or monomer or the thickness of the target photo-alignment film, but it is preferably set to at least 0.2% by mass, and more preferably in the range of 0.3-10% by mass, relative to the mass of the photo-alignment film-forming composition. The photo-alignment film-forming composition may also contain a polymer material or a photosensitizer such as polyvinyl alcohol or polyimide within a range that does not significantly damage the properties of the photo-alignment film.

As a method for applying the photo-alignment film-forming composition to a substrate, the same method as the method for applying the aligning composition to a substrate can be cited. As a method for removing the solvent from the applied photo-alignment film-forming composition, for example, natural drying method, ventilation drying method, heating drying method and reduced pressure drying method can be cited.

When irradiating with polarized light, the composition for forming a photo-alignment film applied on the substrate after removing the solvent can be directly irradiated with polarized UV, or the composition can be irradiated from the substrate side to allow the polarized light to pass through. In addition, it is particularly preferred that the polarized light is substantially parallel light. The wavelength of the irradiated polarized light can be a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength range of 250 to 400 nm is particularly preferred. As the light source used for the polarized light irradiation, there can be listed: xenon lamp, high pressure mercury lamp, ultra high pressure mercury lamp, metal halide lamp, KrF, ArF and other ultraviolet lasers, etc., preferably high pressure mercury lamp, ultra high pressure mercury lamp and metal halide lamp. Among them, high pressure mercury lamp, ultra high pressure mercury lamp and metal halide lamp are more preferred because of the high intensity of ultraviolet light with a wavelength of 313nm. The light from the above light sources is irradiated through an appropriate polarizing element, thereby irradiating polarized UV. As the above-mentioned polarizing element, a polarizing filter or a polarizing prism such as Glenn-Thompson or Glenn-Taylor or a wire-grid type polarizing element can be used.

Furthermore, if shielding is performed during rubbing or polarized light irradiation, multiple regions (patterns) with different liquid crystal alignment directions can also be formed.

A groove alignment film is a film having a concave-convex pattern or multiple grooves on the film surface. When a polymerizable liquid crystal compound is applied to a film having multiple linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction along the grooves.

As methods for obtaining a groove alignment film, there are: a method of forming a concave-convex pattern by exposing a photosensitive polyimide film through an exposure mask having narrow slits in a pattern shape on the surface, and then developing and rinsing; a method of forming a layer of a UV curable resin before curing on a plate-shaped master having grooves on the surface, transferring the formed resin layer to a substrate and curing it; and a method of pressing a roll-shaped master having a plurality of grooves against a film of a UV curable resin before curing formed on a substrate to form concave-convex, and then curing it, etc.

The thickness of the alignment film (including the alignment film of the alignment polymer or the photo-alignment film) is usually in the range of 10 to 10000 nm, preferably in the range of 10 to 1000 nm, more preferably below 500 nm, further preferably in the range of 10 to 200 nm, and particularly preferably in the range of 50 to 150 nm.

As a method for applying the phase difference film forming composition to a substrate, etc., there can be listed: a coating method such as a rotary coating method, an extrusion method, a gravure coating method, a die coating method, a rod coating method, a dressing method, and a printing method such as a flexographic method, and other well-known methods.

Next, under the condition that the polymerizable liquid crystal compound contained in the coating obtained from the phase difference film forming composition does not polymerize, the solvent is removed by drying, thereby forming a dry coating. Examples of drying methods include natural drying, ventilation drying, heating drying, and reduced pressure drying.

Furthermore, in order to make the polymerizable liquid crystal compound phase transition to a liquid phase, the temperature is raised to a temperature above the temperature at which the polymerizable liquid crystal compound will phase transition to a liquid phase and then cooled, so that the polymerizable liquid crystal compound phase transitions to a nematic phase. The above phase transition can be performed after removing the solvent in the above coating, or it can be performed simultaneously with the removal of the solvent.

The phase difference layer as the curing layer of the polymerizable liquid crystal composition is formed by polymerizing the polymerizable liquid crystal compound while maintaining the nematic liquid crystal state of the polymerizable liquid crystal compound. As a polymerization method, photopolymerization is preferred. In photopolymerization, the light irradiated to the dry coating is appropriately selected depending on the type of photopolymerization initiator contained in the dry coating, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound) and its amount. As a specific example, one or more light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α rays, β rays and γ rays or active electron beams can be listed. Among them, ultraviolet light is preferred in terms of easy control of the progress of the polymerization reaction or the ability to be used as a photopolymerization device for a wide range of users in this field. It is preferred to pre-select the type of polymerizable liquid crystal compound or photopolymerization initiator contained in the polymerizable liquid crystal composition so that photopolymerization can be performed by ultraviolet light. In addition, during polymerization, the dried coating can be cooled by an appropriate cooling method, and the polymerization temperature can be controlled by light irradiation.

If the polymerization of the polymerizable liquid crystal compound is carried out at a lower temperature by adopting this cooling method, a polarizing plate can be properly formed even if a substrate with relatively low heat resistance is used. During photopolymerization, a patterned phase difference plate can also be obtained by shielding or developing.

Examples of the light sources of the above-mentioned active energy rays include: low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten filament lamps, gallium lamps, excimer lasers, LED (Luminescent Diode) light sources emitting light in the wavelength range of 380-440nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc.

The intensity of ultraviolet irradiation is usually 10~3,000mW/cm ² . The intensity of ultraviolet irradiation is preferably an intensity in the wavelength region effective for activation of photopolymerization initiators. The irradiation time is usually 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and further preferably 10 seconds to 1 minute. If the ultraviolet irradiation intensity is used once or multiple times, the cumulative light amount is 10~3,000mJ/cm ² , preferably 50~2,000mJ/cm ² , and more preferably 100~1,000mJ/cm ² .

The thickness of the phase difference layer can be appropriately selected depending on the display device used, but from the perspective of thin film and flexibility, it is preferably 0.1~10μm, more preferably 1~5μm, and further preferably 1~3μm.

<Optical compensation plate>

The multilayer body for organic EL display of the present invention can be further combined with an optical compensation plate as needed. The optical compensation plate has the optical function of compensating the viewing angle or color of the liquid crystal display device, and is preferably formed by the alignment of liquid crystal materials.

The optical compensation plate is preferably a polymer containing a polymerizable liquid crystal compound and satisfies the following formula (5): -30nm≦Rth(550)≦-100nm (5)

(Rth(550) represents the phase difference in the film thickness direction when the irradiation wavelength is 550nm)

As a liquid crystal substance preferably used in such an optical compensation plate, a side chain type liquid crystal polymer compound can be listed. A side chain type liquid crystal polymer compound is a compound in which a core unit, i.e., a mesogen, which makes a liquid crystal layer appear, is bonded to a flexible main chain via a flexible chain, for example, a compound having a main chain skeleton of polyacrylate, polymethacrylate, polysiloxane, etc., and optionally having a mesogen as a side chain via a spacer base containing a conjugated atomic group, etc. In addition, in order to control the tensile elastic modulus of the film, the end on the opposite side of the main chain can be observed from the liquid crystal radical of the side chain, and a polymerizable functional group such as cyclobutylene oxide, epoxy group, vinyl ether group, etc. for cross-linking can be optionally provided through a spacer base containing a conjugated atomic group.

The thickness of the optical compensation plate 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 circular polarizing plate in the present invention includes a polarizing plate and a phase difference plate, and the polarizing plate includes a polarizing element and a protective film. The polarizing plate has a protective film on the side opposite to the phase difference plate.

In the circular polarizing plate, the polarizing plate and the phase difference plate may be laminated via a bonding agent layer or an adhesive layer, preferably via an adhesive layer. That is, the circular polarizing plate preferably has a structure in which the polarizing plate, the adhesive layer and the phase difference plate are laminated in order.

As an adhesive layer for laminating the polarizing plate and the phase difference plate, an adhesive layer with a transmittance of 10% or less at a wavelength of 400nm (hereinafter sometimes referred to as a near-infrared absorption adhesive layer) is preferred.

The adhesive composition used to form the adhesive layer for laminating the polarizing plate and the phase difference plate is not particularly limited, and a known adhesive composition can be used.

The adhesive composition forming the near-infrared absorption adhesive layer is not particularly limited. For example, the adhesive composition described in Japanese Patent Publication No. 2017-119700 can be cited. Preferably, it is an adhesive composition comprising a compound that selectively absorbs light with a wavelength of about 400nm (e.g., a wavelength of 385nm to 405nm), and more preferably, it is an adhesive composition comprising a light selectively absorbing compound having a merocyanine structure.

The water vapor transmission rate of the circular polarizing plate of the present invention is less than 100g/ ^m2 /24hrs and the light transmission rate of 380nm is less than 1%. Thus, an organic EL display with excellent display characteristics, flexibility and aging degradation is obtained.

The water vapor permeability is measured at 40°C and 90% relative humidity in accordance with JIS Z 0208, and is calculated as the amount of water that passes through the film per ^1m2 of the film area within 24 hours. If the water vapor permeability exceeds 100g/ ^m2 /24hrs, the durability of the obtained organic EL display deteriorates. The water vapor permeability is preferably 60g/ ^m2 /24hrs or less, more preferably 30g/ ^m2 /24hrs or less, and further preferably 10g/ ^m2 /24hrs or less. It may also be a lower water vapor permeability below the measurement limit.

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

In the circularly polarizing plate, the oxygen permeability is preferably 30cc/atm/ ^m2 /24hrs or less. The oxygen permeability is measured at 23°C and relative humidity 50% using an oxygen permeability measuring device (OX-TRANML, manufactured by MOCON) based on JIS K 7126. In order to further improve the durability of the organic EL display, the oxygen permeability is more preferably 20cc/atm/ ^m2 /24hrs or less, and further preferably 10cc/atm/ ^m2 /24hrs or less.

<Adhesive layer (1)>

In the present invention, the adhesive composition used to form the adhesive layer laminated with the circular polarizing plate (in this specification, the adhesive layer is sometimes referred to as "adhesive layer (1)") is not particularly limited, and for example, an appropriate adhesive such as an acrylic adhesive, a polysilicone adhesive, a polyester adhesive, a polyurethane adhesive, a polyamide adhesive, a polyether adhesive, or a rubber adhesive can be used. Among them, in terms of optical transparency or adhesive properties, weather resistance, etc., a pressure-sensitive acrylic adhesive is preferred. The adhesive layer (1) is usually laminated on the phase difference plate of the circular polarizing plate. Another layer (separation film, etc.) may also be deposited on the opposite side of the adhesive layer (1) where the circular polarizer is deposited.

Furthermore, for the adhesive layer (1) and the adhesive layer used for laminating the polarizing plate and the phase difference plate, various diffusants can be dispersed to give diffusibility, or various conductive substances can be mixed to give anti-static properties, etc., so as to make it functional according to its use.

From the perspective of the flexibility or visibility of the display device, the thickness of the laminate formed by laminating the circular polarizing plate and the adhesive layer in the present invention is preferably less than 100μm, and more preferably less than 90μm.

<Organic EL display device (organic EL display)>

The present invention includes a display device comprising a multilayer body for an organic EL display of the present invention.

Examples of display devices include liquid crystal display devices, organic electroluminescent (EL) display devices, inorganic electroluminescent (EL) display devices, touch panel display devices, electroluminescent display devices (field emission display devices (FED), surface field emission display devices (SED)), electronic paper (display devices using electronic ink or electrophoretic elements), plasma display devices, projection display devices (grating valve imaging system (GLV) display devices, display devices with digital micromirror devices (DMD), etc.), and piezoelectric ceramic displays. Liquid crystal display devices also include any of transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices, and projection liquid crystal display devices. The display devices may be display devices for displaying two-dimensional images or three-dimensional display devices for displaying three-dimensional images. In particular, the display device of the present invention is preferably an organic EL display device and a touch panel display device, and is particularly preferably an organic EL display device.

[Implementation example]

The present invention is further described below with reference to the Examples and Comparative Examples. Unless otherwise specified, "%" and "parts" in the Examples and Comparative Examples represent "% by mass" and "parts by mass".

[Implementation Example 1] <Production of polarizing plate> [Polarizing plate: Manufacturing of iodine PVA type polarizing plate]

A 30 μm thick polyvinyl alcohol film (PVA: average degree of polymerization of about 2400, saponification degree of 99.9 mol% or more) was uniaxially stretched to about 5 times by dry stretching, and then immersed in pure water at 40°C for 40 seconds while maintaining the stretched state. Thereafter, it was dyed by immersing in a dyeing aqueous solution at a mass ratio of iodine/potassium iodide/water of 0.044/5.7/100 at 28°C for 30 seconds. Next, it was immersed in a boric acid aqueous solution at a mass ratio of potassium iodide/boric acid/water of 11.0/6.2/100 at 70°C for 120 seconds. Then, after washing with pure water at 8°C for 15 seconds, it was dried at 60°C for 50 seconds while being maintained at a tension of 300N, and then dried at 75°C for 20 seconds, to obtain a polarizing element with a thickness of 12μm in which iodine was adsorbed and aligned on a polyvinyl alcohol film.

A water-based adhesive was injected between the obtained polarizing element and the cycloolefin film (ZF14 manufactured by Nippon Zeon Co., Ltd.), and the laminate was performed by roller bonding. The obtained laminate was dried at 60°C for 2 minutes while the tension was maintained at 430 N/m, and a polarizing plate I having a cycloolefin film (COP) as a protective film on one side was obtained. Furthermore, the above-mentioned water-based adhesive was prepared by adding 3 parts of carboxyl-modified polyvinyl alcohol (KURARAY-POVAL KL318; manufactured by Kuraray Co., Ltd.) and 1.5 parts of water-soluble polyamide epoxy resin (Sumirez Resin650; manufactured by Sumika Chemtex Co., Ltd., an aqueous solution with a solid content concentration of 30%) to 100 parts of water.

<Production of phase difference plate> [Preparation of a composition for forming a photo-alignment film]

5 parts of the following photo-alignment material described in Japanese Patent Publication No. 2013-033249 and 95 parts of cyclopentanone (solvent) were mixed, and the obtained mixture was stirred at 80°C for 1 hour to obtain a composition for forming a photo-alignment film.

(Photo-aligned materials)

[Preparation of polymerizable liquid crystal compositions]

啉基苯基)丁烷-1-酮(光聚合起始劑/Irgacure369；Ciba Specialty Chemicals公司製造)(3.0份)加以混合，獲得包含聚合性液晶化合物A-1及聚合性液晶化合物A-2之聚合性液晶組合物(A1)。 The polymerizable liquid crystal compound A-1 (86.0 parts), polymerizable liquid crystal compound A-2 (14.0 parts), polyacrylate compound (leveling agent/BYK-361N; manufactured by BYK-Chemie) (0.12 parts) and 2-dimethylamino-2-benzyl-1-(4-

The resulting mixture was mixed with 1-butylene glycol (2-[4-[(2 ...

Polymerizable liquid crystal compound A-1:

Polymerizable liquid crystal compound A-2:

[Production of phase difference plate]

A cycloolefin polymer film (COP; ZF-14; manufactured by Nippon Zeon Co., Ltd.) was treated once using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.) at an output of 0.3 kW and a treatment speed of 3 m/min. The above-mentioned photo-alignment film-forming composition was coated on the surface subjected to the corona treatment by a rod type, dried at 80°C for 1 minute, and polarized UV exposure was performed using a polarized UV irradiation device (SPOT CURE SP-7 with a polarizing element unit; manufactured by Ushio Co., Ltd.) at a cumulative light amount of 100 mJ/ ^cm2 to form an alignment film. The thickness of the obtained alignment film was measured by Ellipsometer M-220 (manufactured by JASCO Corporation) and the result was 100 nm.

Next, the wire of the bar coater was set to #30, and the previously prepared polymerizable liquid crystal composition (A1) containing a polymerizable liquid crystal compound was coated on the alignment film at a speed of 50 mm/sec, and dried at 120°C for 1 minute. Thereafter, a high-pressure mercury lamp (UNICURE VB-15201BY-A; manufactured by Ushio Co., Ltd.) was used to irradiate ultraviolet rays (in nitrogen atmosphere, cumulative light quantity at a wavelength of 313 nm: 500 mJ/cm ² ) from the side coated with the polymerizable liquid crystal composition (A1), thereby forming a laminate of a phase difference layer and a cycloolefin polymer film. The thickness of the phase difference layer was measured using a laser microscope (LEXT; manufactured by Olympus Corporation) and the result was 2.3 μm.

The phase difference value of the phase difference layer obtained at a wavelength of 550nm was measured, and the result was Re(550)=140nm.

In addition, the phase difference values of the obtained phase difference layer at wavelengths of 450nm and 650nm were measured, and the results were Re(450)/Re(550)=0.85 and Re(650)/Re(550)=1.05.

<Production of circular polarizing plates>

Polarizing plate I and phase difference plate B are bonded together using an adhesive (manufactured by LINTEC Co., Ltd., acrylic adhesive (colorless, transparent, non-aligned) in such a way that the angle (θ) between the absorption axis of polarizing plate I and the retardation axis of phase difference plate B is 45°, and then the cycloolefin polymer film of the phase difference plate is peeled off to produce circular polarizing plate 1.

<Manufacturing of multilayer bodies for organic EL displays>

An organic EL display laminate was obtained by laminating the phase difference plate of the circular polarizing plate with an acrylic adhesive (manufactured by LINTEC, film thickness 15μm).

The layer structure of the obtained multilayer body for organic EL display is summarized in Table 1.

<Determination of water vapor transmission rate>

The obtained circular polarizing plate was measured at 40°C and relative humidity 90% according to JIS Z 0208, and the amount of water passing through the film per ^1m2 of the film within 24 hours was calculated. The results are shown in Table 2.

<Determination of oxygen permeability>

The obtained circular polarizing plate was measured based on JIS K7126 using an oxygen transmission rate measuring device (OX-TRANML, manufactured by MOCON) at 23°C and a relative humidity of 50%. The results are shown in Table 2.

<Determination of transmittance>

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

<Weather resistance test>

The obtained organic EL display laminated body was bonded to a display device obtained by removing the front glass and polarizing plate of the "Galaxy S5" manufactured by SAMSUNG. The reflected hue was confirmed when the power of the display device was set to OFF (black display) and ON (white display). The results of the initial appearance and the appearance after 100-hour accelerated weathering test using a sunlight weathering machine (100-hour accelerated weathering test) are shown in Table 3. Furthermore, the front reflection hue ("white display" and "black display" in Table 3) is the hue obtained by visually observing the sample at a distance of 50 cm from the front, and the oblique reflection hue ("oblique black display" in Table 3) is the hue obtained by visually observing the sample at a distance of 50 cm from an elevation angle of 60° and an azimuth angle of 0~360°.

<Flexibility test>

A 0.7 mm thick glass plate was placed on the coated surface of the obtained circular polarizing plate and attached to the glass plate. After the laminate was bent 180 degrees, a 10x magnifying glass was used to pass the light of a fluorescent lamp through the laminate, and the flexible part was observed to confirm whether there were wrinkles or cracks. The one with no wrinkles or cracks was set as A, the one with slight wrinkles was set as B, and the one with wrinkles and cracks was set as C. The results are shown in Table 3.

[Example 2]

The adhesive for the polarizing plate and the phase difference plate in Example 1 was changed to the adhesive described in Example 2 of Japanese Patent Application Publication, Japanese Patent Laid-Open No. 2017-120430 (near-ultraviolet PSA (Polymer sustained alignment)), and the preparation was carried out in the same manner as in Example 1.

[Implementation Example 3] [Production of phase difference 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 alignment polymer composition (1). The solid content of the alignment polymer composition (1) was 2% by mass.

<Preparation of Composition (B-1)>

The polymerizable liquid crystal compound represented by formula (LC242), a polymerization initiator (manufactured by BASF; Irgacure907), a polyacrylate compound (leveling agent/BYK-361N; manufactured by BYK-Chemie), a reaction additive (Laromer (registered trademark) LR-900 manufactured by BASF) and propylene glycol 1-monomethyl ether 2-acetate (PGMEA) were mixed to obtain a composition (B-1). The ratio of each compound in the composition (B-1) was 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, 1.1% by mass of the reaction additive and 79.1% by mass of PGMEA.

<Production of phase difference layer 1>

The alignment polymer composition (1) was applied to a saponified triacetyl cellulose film (hereinafter, sometimes referred to as TAC) and heated and dried to obtain an alignment polymer film with a thickness of 80 nm. The surface of the obtained alignment polymer film was subjected to a rubbing treatment. Then, the composition (B-1) was applied using a rod coater, dried at 100°C for 1 minute, and then irradiated with ultraviolet light (cumulative light quantity at a wavelength of 365 nm in a nitrogen atmosphere: 1200 mJ/ ^cm2 ) using a high-pressure mercury lamp to form a phase difference layer 1. The film thickness of the obtained phase difference layer 1 was measured using a laser microscope and the film thickness was 1.94 μm. The phase difference value of the phase difference layer 1 was measured and the result was Re(550) = 269nm. In addition, the phase difference values at a wavelength of 450nm and a wavelength of 650nm were measured and the results were Re(450)/Re(550) = 1.08 and Re(650)/Re(550) = 0.99.

<Production of phase difference layer 2>

The alignment polymer composition (1) was coated on a saponified triacetyl cellulose film (KC4UY manufactured by Konica Minolta Co., Ltd.), and after heating and drying, an alignment polymer film with a thickness of 82 nm was obtained. The surface of the obtained alignment polymer film was subjected to a rubbing treatment at an angle of 15° to the longitudinal direction of TAC, and then the composition (B-1) was coated using a rod coater, and after drying at 100°C for 1 minute, it was irradiated with ultraviolet rays (accumulated light quantity at a wavelength of 365 nm in a nitrogen atmosphere: 1200 mJ/ ^cm2 ) using a high-pressure mercury lamp to form a phase difference layer 2. The film thickness of the obtained phase difference layer 2 was measured by a laser microscope, and the film thickness was 973 nm. The phase difference value of the phase difference layer 2 was measured and the result was Re(550) = 135nm. In addition, the phase difference values at wavelengths of 450nm and 650nm were measured and the results were Re(450)/Re(550) = 1.07 and Re(650)/Re(550) = 0.98.

<Lamination of phase difference layer 1 and phase difference layer 2>

The phase difference plate 3 is manufactured by bonding the phase difference layer 1 obtained in the above to the phase difference layer 2 with the phase difference axis at an angle of 60° using a photocurable adhesive.

<Production of circular polarizing plates>

The phase difference layer 1 side of the phase difference plate 3 is bonded to the polarizing plate 1 in such a way that the angle (θ) formed by the absorption axis of the polarizing plate 1 and the phase difference layer 1 is 15° and the angle (θ) formed by the absorption axis of the polarizing plate 1 and the phase difference layer 2 is 75°. Then, the cycloolefin polymer film of the phase difference plate is peeled off to make a circular polarizing plate.

<Manufacturing of multilayer bodies for organic EL displays>

Using the phase difference plate 3 obtained above, a multilayer body for an organic EL display is prepared in the same manner as in Example 1 except for the above.

[Implementation Example 4] [Production of optical compensation plates] <Preparation of oriented polymer composition (2)>

2-Butoxyethanol was added to the commercially available aligning polymer Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.) to obtain an aligning polymer composition (2). The solid content of the aligning 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 aligning polymer composition (2) was coated on the surface treated with corona treatment using a rod coater and dried at 90°C for 1 minute to obtain an aligning film. The film thickness of the aligning film obtained was measured by a laser microscope and the result was 34 nm. Next, the composition (B-1) was coated on the alignment film using a bar coater, dried at 90°C for 1 minute, and then irradiated with ultraviolet light (accumulated light quantity at a wavelength of 365nm in a nitrogen atmosphere: 1000mJ/ ^cm2 ) using a high-pressure mercury lamp to obtain an optical compensation plate. The film thickness of the obtained optical compensation plate was measured using a laser microscope, and the result was that the film thickness was 450nm. In addition, the phase difference value of the obtained optical compensation plate at a wavelength of 550nm was measured, and the result was Re(550)=1nm, Rth(550)=-70nm. Furthermore, the phase difference value of the cycloolefin film alone at a wavelength of 550nm is approximately 0.

The circular polarizing plate prepared in Example 1 and the optical compensation plate obtained above are bonded together using the acrylic adhesive described in Example 1 to obtain a circular polarizing plate with an optical compensation plate. The optical compensation plate of the circular polarizing plate with an optical compensation plate is further laminated with acrylic adhesive to obtain a laminate for an organic EL display.

[Implementation Example 5]

A 30 μm polyimide film (PI film) was prepared by the same method as Example 1 described in International Publication No. 2017/014279.

The above-mentioned polyimide film (PI film) was used as a protective film instead of the cycloolefin polymer film, and the preparation was carried out in the same manner as in Example 2.

[Implementation Example 6]

A 30 μm polyimide film (PI film) was prepared by the same method as Example 1 described in International Publication No. 2017/014279.

The above-mentioned polyimide film is used as a protective film, and the preparation is the same as Example 3 except that.

[Implementation Example 7]

A 30 μm polyimide film (PI film) was prepared by the same method as Example 1 described in International Publication No. 2017/014279.

The above-mentioned polyimide film is used as a protective film, and the adhesive used for laminating the phase difference plate and the polarizing plate is set to the acrylic adhesive described in Example 1. The preparation is carried out in the same manner as Example 4, except that the adhesive is set to the acrylic adhesive described in Example 1.

[Comparative example 1] <Production of polarizing plate>

A triacetyl cellulose film (TAC; KC2UA; manufactured by Konica Minolta Co., Ltd.) was placed on both sides of the polarizing element, and a water-based adhesive was injected between the layers, and the layers were bonded using rollers. The obtained bond was dried at 60°C for 2 minutes while the tension of the bond was maintained at 430 N/m, to obtain a polarizing plate with triacetyl cellulose films as protective films on both sides. The water-based adhesive was prepared by adding 3 parts of carboxyl-modified polyvinyl alcohol (KURARAY-POVAL KL318; manufactured by Kuraray Co., Ltd.) and 1.5 parts of a water-soluble polyamide epoxy resin (Sumirez Resin650; manufactured by Sumika Chemtex Co., Ltd., an aqueous solution with a solid content concentration of 30%) to 100 parts of water.

<Manufacturing of multilayer bodies for organic EL displays>

A multilayer body for an organic EL display was prepared in the same manner as in Example 1 except that a polycarbonate copolymer resin film (WRS-143; manufactured by Teijin Co., Ltd.) was used as a phase difference plate.

[Comparative example 2]

The phase difference plate 2 prepared in Example 3 is used, and the multilayer body for an organic EL display is prepared in the same manner as in Comparative Example 1 except for the above.

[Comparative example 3]

The multilayer body for an organic EL display is prepared in the same manner as in Example 1 except that the polarizing plate prepared in Comparative Example 1 is used.

In Table 1, "COP" indicates cycloolefin film, "PI" indicates polyimide, "TAC" indicates triacetyl cellulose film, "PVA" indicates polyvinyl alcohol, and "PSA" indicates acrylic adhesive. In addition, Re indicates Re(550), α=Re(450)/Re(550), β=Re(650)/Re(550), and Rth indicates the phase difference in the film thickness direction.

From the results of Table 2 and Table 3, it can be seen that in Examples 1 to 7 that meet the requirements of the present invention, the appearance after the 100-hour accelerated weathering test is almost unchanged from the initial appearance, and the flexibility also maintains the original performance. In Comparative Examples 1 to 3, the appearance after the 100-hour accelerated weathering test is different from the initial appearance. In particular, the water vapor transmission rate in the comparative examples is 700g/ ^m2 /24hrs, which is greatly deviated from the standard value of 100g/ ^m2 /24hrs, so it is understood that the weather resistance is deteriorated.

Claims (8)

A laminate for an organic EL display, which is a laminate formed by laminating a circular polarizing plate and an adhesive layer, and the thickness of the laminate is less than 100 μm, the circular polarizing plate includes a polarizing plate and a phase difference plate, the polarizing plate includes a polarizing element and a protective film, and the protective film is provided only on the side opposite to the surface of the polarizing element on which the phase difference plate is laminated, the protective film is a polyimide film or a polyamide imide film, and the transmittance of the protective film at 400 nm is less than 10%, the water vapor transmittance of the circular polarizing plate is less than 100 g/m ² /24 hrs, and the transmittance of the circular polarizing plate at 380 nm is less than 1%. As in claim 1, the multilayer body for an organic EL display, wherein the polarizing element is formed by a polyvinyl alcohol-based resin film. For a multilayer body for an organic EL display as claimed in claim 1 or 2, the 400nm transmittance of the circular polarizer is less than 1%. The multilayer body for an organic EL display as claimed in claim 1 or 2, wherein the phase difference plate comprises only one phase difference layer of a polymer comprising a polymerizable liquid crystal compound and satisfies all of the following formulas (1), (2) and (3); Re(450)/Re(550)≦1.00 (1) 1.00≦Re(650)/Re(550) (2) 100nm≦Re(550)≦180nm (3) (wherein Re(λ) represents the in-plane phase difference value for light of wavelength λnm). For example, in the multilayer body for organic EL display of claim 4, the angle between the phase axis of the above-mentioned phase difference plate and the absorption axis of the polarizing plate is substantially 45 degrees. A multilayer body for an organic EL display as claimed in claim 1 or 2, wherein the phase difference plate comprises a first phase difference layer and a second phase difference layer in order from the polarizing plate side, and the first phase difference layer and the second phase difference layer are polymers of polymerizable liquid crystal compounds, respectively, the first phase difference layer satisfies the relationship of the following formula (4), the second phase difference layer satisfies the relationship of formula (3), and the phase difference plate satisfies the relationship of formula (1) and formula (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 phase difference value for light with a wavelength of λnm). The multilayer body for an organic EL display as claimed in claim 1 or 2 further comprises an optical compensation plate of a polymer containing a polymerizable liquid crystal compound satisfying the following formula (5); -30nm≦Rth(550)≦-100nm (5) (Rth(550) represents the phase difference in the film thickness direction for light of a wavelength of 550nm). The multilayer body for an organic EL display as claimed in claim 1 or 2, wherein the circular polarizing plate comprises an adhesive layer having a transmittance of less than 10% at 400nm.