WO2017043438A1

WO2017043438A1 - Polymerizable liquid crystal composition, retardation film, polarizing plate, liquid crystal display device and organic electroluminescent device

Info

Publication number: WO2017043438A1
Application number: PCT/JP2016/075969
Authority: WO
Inventors: 直澄白岩; 慶太高橋; 森嶌　慎一
Original assignee: 富士フイルム株式会社
Priority date: 2015-09-07
Filing date: 2016-09-05
Publication date: 2017-03-16
Also published as: JP6626896B2; JPWO2017043438A1

Abstract

The objective of the present invention is to provide: a polymerizable liquid crystal composition which is capable of forming a retardation film having excellent wet heat durability; a retardation film which is obtained using this polymerizable liquid crystal composition; a polarizing plate; a liquid crystal display device; and an organic electroluminescent device. A polymerizable liquid crystal composition according to the present invention contains an organic oxidant represented by general formula (A) and a polymerizable liquid crystal compound having reverse wavelength dispersion properties. In general formula (A), each of X¹ and X² independently represents an oxygen atom, a sulfur atom, an =NR¹ group or a =CR²R³ group; each of m and n independently represents an integer of 0-3, provided that the sum of m and n is 2 or more; each of R¹, R² and R³ independently represents a hydrogen atom or a substituent; and each of L¹ and L² independently represents a divalent linking group.

Description

Polymerizable liquid crystal composition, retardation film, polarizing plate, liquid crystal display device and organic electroluminescent device

The present invention relates to a polymerizable liquid crystal composition, a retardation film, a polarizing plate, a liquid crystal display device and an organic electroluminescence device.

Conventionally, a polarizing plate having a retardation film and a polarizer has been used in liquid crystal display devices, organic electroluminescent devices, and the like for the purpose of optical compensation and antireflection.
In recent years, the development of a polarizing plate (so-called broadband polarizing plate) that can give the same effect to white light, which is a composite wave in which light in the visible light range is mixed, corresponding to light of all wavelengths. In particular, the retardation film contained in the polarizing plate is also required to be thin from the demand for thinning the device to which the polarizing plate is applied.
In response to the above requirements, for example, Patent Documents 1 and 2 propose the use of a reverse wavelength dispersible polymerizable liquid crystal compound as a polymerizable compound used for forming a retardation film.

International Publication No. 2014/010325 JP 2011-207765 A

However, a polarizing plate having a retardation film formed using a reverse wavelength-dispersible polymerizable liquid crystal (polymerizable compound) described in Patent Documents 1 and 2 is prepared, and the polarizing plate is subjected to high temperature and high humidity. When exposed to the above conditions for a long time, the fluctuation value of the in-plane retardation (Re) becomes too large (that is, a decrease in wet heat durability), and the desired optical performance cannot be obtained. It became clear.

Therefore, the present invention relates to a polymerizable liquid crystal composition capable of producing a retardation film excellent in wet heat durability, a retardation film obtained using the same, a polarizing plate, a liquid crystal display device, and an organic electroluminescence device.

As a result of intensive studies on the above problems, the present inventor has found that a retardation film excellent in wet heat durability can be produced by using a polymerizable liquid crystal composition containing a predetermined organic oxidant, leading to the present invention. It was.
That is, the present inventor has found that the above problem can be solved by the following configuration.

[1]
A polymerizable liquid crystal composition comprising an organic oxidant represented by the general formula (A) described later and a reverse wavelength dispersible polymerizable liquid crystal compound.
[2]
The polymerizable liquid crystal composition according to the above [1], wherein the polymerizable liquid crystal compound is a liquid crystal compound represented by the general formula (II) described later.
[3]
The polymerizable liquid crystal composition according to the above [1] or [2], wherein the reduction potential of the organic oxidant is nobler than 0 volt.
[4]
A retardation film formed using the polymerizable liquid crystal composition according to any one of the above [1] to [3],
Re (450) which is an in-plane retardation value measured at a wavelength of 450 nm, Re (550) which is an in-plane retardation value measured at a wavelength of 550 nm, and Re which is an in-plane retardation value measured at a wavelength of 650 nm (650) is a retardation film having a relationship of Re (450) ≦ Re (550) ≦ Re (650).
[5]
The retardation film according to [4], wherein the retardation film is a positive A plate.
[6]
The retardation film according to [5], wherein the positive A plate is a λ / 4 plate.
[7]
A polarizing plate comprising the retardation film according to any one of [4] to [6] above and a polarizer.
[8]
A liquid crystal display device comprising the polarizing plate according to the above [7].
[9]
The organic electroluminescent apparatus which has the polarizing plate as described in said [7].

As shown below, according to the present invention, a polymerizable liquid crystal composition capable of producing a retardation film excellent in wet heat durability, a retardation film obtained using the same, a polarizing plate, a liquid crystal display device, and organic electroluminescence An apparatus can be provided.

Hereinafter, the polymerizable liquid crystal composition, the retardation film, the polarizing plate, the liquid crystal display device and the organic electroluminescent device of the present invention will be described.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In addition, “orthogonal” and “parallel” with respect to an angle mean an exact range of ± 10 °, and “identical” and “different” with respect to an angle indicate whether or not the difference is less than 5 °. Can be judged on the basis of.
In the present specification, “visible light” means 380 to 780 nm. Moreover, in this specification, when there is no special mention about a measurement wavelength, a measurement wavelength is 550 nm.
Next, terms used in this specification will be described.

<Slow axis>
In this specification, the “slow axis” means a direction in which the refractive index becomes maximum in the plane. In addition, when referring to the slow axis of the retardation film, the slow axis of the entire retardation film is intended.

<Inclination angle>
In this specification, “tilt angle” (also referred to as tilt angle) means an angle formed by a tilted liquid crystal compound with a layer plane, and the direction of the maximum refractive index in the refractive index ellipsoid of the liquid crystal compound is the layer plane. It means the maximum angle among the angles formed. Therefore, in the rod-like liquid crystal compound having positive optical anisotropy, the tilt angle means an angle formed by the major axis direction of the rod-like liquid crystal compound, that is, the director direction and the layer plane. In the present invention, the “average tilt angle” means an average value of the angle of inclination from the tilt angle at the upper interface of the retardation film to the lower interface.

<Re (λ), Rth (λ)>
In the present specification, “Re (λ)” and “Rth (λ)” represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively.
Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or KOBRA WR (both manufactured by Oji Scientific Instruments). In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like.

Here, when the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ) with the in-plane slow axis (determined by KOBRA 21ADH or KOBRA WR) as the tilt axis (rotation axis) (in the absence of the slow axis, With respect to the film normal direction (with an arbitrary direction as the rotation axis), the light of wavelength λ nm is incident from each inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side, and a total of 6 points are measured. The KOBRA 21ADH or KOBRA WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated in KOBRA 21ADH or KOBRA WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following formulas (1) and (2).

In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. Further, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. d represents the film thickness of the film.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis (OPTIC AXIS), Rth (λ) is calculated by the following method.
Rth (λ) is -50 ° to + 50 ° with respect to the film normal direction with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or KOBRA WR) as the tilt axis (rotation axis) 11 points of light having a wavelength of λ nm are incident from each inclined direction in 10 degree steps until KOBRA 21ADH is measured based on the measured retardation value, assumed average refractive index, and input film thickness value. Or it is calculated by KOBRA WR.

In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting the assumed value of the average refractive index and the film thickness, nx, ny, and nz are calculated in KOBRA 21ADH or KOBRA WR. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

[Polymerizable liquid crystal composition]
The polymerizable liquid crystal composition of the present invention comprises an organic oxidant represented by the general formula (A) described later (hereinafter also simply referred to as “specific organic oxidant”) and a polymerizable liquid crystal compound having a reverse wavelength dispersion ( Hereinafter, it is also simply referred to as “specific liquid crystal compound”.
According to the polymerizable liquid crystal composition of the present invention, a retardation film excellent in wet heat durability can be produced. Although the details of this reason have not yet been clarified, it is assumed that the reason is as follows.

The polymerizable liquid crystal compound is susceptible to hydrolysis by water, and this problem tends to become prominent when a polymerizable liquid crystal compound having a reverse wavelength dispersion (specific liquid crystal compound) is used among the polymerizable liquid crystal compounds.
Specifically, when the retardation film produced using the specific liquid crystal compound is exposed to a high temperature and high humidity condition, the inventors of the specific liquid crystal compound contained in the retardation film undergo a certain induction period. It is known that the decomposition occurs rapidly and the fluctuation of the in-plane retardation value increases. This reason is presumed to be due to the following phenomenon.
That is, one method for making a polymerizable liquid crystal compound have reverse wavelength dispersion is to have an electron-withdrawing property, which causes positive polarization of carbon atoms constituting the polymerizable liquid crystal compound. Becomes larger and more susceptible to nucleophilic attacks. As a result, a decomposition product derived from the decomposed polymerizable liquid crystal compound (for example, in the case of using the general formula (II) described later, a divalent aromatic ring derived from Ar) serves as a catalyst, and is unreacted. It is presumed to further promote the hydrolysis of the polymerizable liquid crystal compound.

As a result of further investigations by the inventors, it was found that the wet heat durability of the retardation film can be improved by using a specific organic oxidant. This is presumably because the specific organic oxidant decomposes the decomposition product derived from the specific liquid crystal compound oxidatively by an electron transfer reaction and suppresses the above-described catalytic reaction of the decomposition product. .

<Organic Oxidant Represented by General Formula (A) (Specific Organic Oxidant)>
The polymerizable liquid crystal composition of the present invention contains an organic oxidizing agent (specific organic oxidizing agent) represented by the following general formula (A).

In the general formula (A), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, a ═NR ¹ group, or a ═CR ² R ³ group. When a plurality of X ¹ and X ² are present, the plurality of X ¹ and the plurality of X ² may be the same as or different from each other.
X ¹ and X ² can increase the reduction potential (can increase the oxidizing power) from the viewpoint of improving the effect of oxidatively decomposing and removing the decomposition product derived from the specific liquid crystal compound among the above, An atom or a = CR ² R ³ group is preferred, and a = CR ² R ³ group is more preferred.

M and n each independently represents an integer of 0 to 3, preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 1. However, the total of m and n is 2 or more, preferably 2 to 6, more preferably 2 to 4, and still more preferably 2.

R ¹ , R ² and R ³ each independently represents a hydrogen atom or a substituent. When each of R ^1, ^{R 2} and ^{R 3} there are a plurality, the plurality of ^{R 1,} a plurality of ^{R 2} and a plurality of ^{R 3} may be the same or different from each other.
L ¹ and L ² each independently represents a divalent linking group.

The substituent represented by R ¹ , R ² and R ³ is a halogen atom or a substituent bonded with a carbon atom, an oxygen atom, a nitrogen atom or a sulfur atom, specifically, an alkyl group or an alkenyl group. Aralkyl group, aryl group, heterocyclic group, halogen atom, cyano group, nitro group, mercapto group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyloxy group, amino group, alkylamino group, carvone Amido group, sulfonamido group, sulfamoylamino group, oxycarbonylamino group, oxysulfonylamino group, ureido group, thioureido group, acyl group, oxycarbonyl group, carbamoyl group, sulfonyl group, sulfinyl group, sulfamoyl group, carboxyl group (Including salt) and sulfo group (salt) Can be included). These may be further substituted with these substituents. Among these, from the viewpoint of improving the effect of oxidatively decomposing and removing decomposition products derived from a specific liquid crystal compound, the reduction potential can be increased (oxidizing power can be increased), a cyano group, an acyl group, or It is preferably an oxycarbonyl group, more preferably a cyano group or an oxycarbonyl group, and even more preferably a cyano group.

Examples of substituents represented by R ¹ , R ² and R ³ are shown in more detail. The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms), such as methyl, ethyl, propyl, isopropyl, t-butyl, Cyclopentyl, cyclohexyl, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 3-methoxypropyl, 2-aminoethyl, acetamidomethyl, 2-acetamidoethyl, carboxymethyl, 2-carboxyethyl, 2-sulfoethyl, ureido Mention may be made of methyl, 2-ureidoethyl, carbamoylmethyl, 2-carbamoylethyl, 3-carbamoylpropyl, pentyl, hexyl, octyl, decyl, undecyl, dodecyl, hexadecyl and octadecyl.
The alkenyl group is preferably a linear, branched or cyclic alkenyl group having 2 to 18 carbon atoms (more preferably 6 to 18 carbon atoms), such as vinyl, allyl, 1-propenyl, 2-pentenyl, Examples include 1,3-butadienyl, 2-octenyl, and 3-dodecenyl.

The aralkyl group is preferably an aralkyl group having 7 to 10 carbon atoms, and examples thereof include benzyl.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include phenyl, naphthyl, p-dibutylaminophenyl, and p-methoxyphenyl.
The heterocyclic group is preferably a 5- or 6-membered saturated or unsaturated heterocyclic group composed of a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom. The number of heteroatoms constituting the ring and the number of element types may be one or more. For example, furyl, benzofuryl, pyranyl, pyrrolyl, imidazolyl, isoxazolyl, pyrazolyl, benzotriazolyl, pyridyl, pyrimidyl, pyridazinyl, Examples include thienyl, indolyl, quinolyl, phthalazinyl, quinoxalinyl, pyrrolidinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, piperidyl, piperazinyl, indolinyl, morpholinyl and the like.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, etc. are mentioned, for example.
The alkoxy group is preferably an alkoxy group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms). For example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, 2-methoxyethoxy, 2-methanesulfonyl Examples thereof include ethoxy, pentyloxy, hexyloxy, octyloxy, undecyloxy, dodecyloxy, hexadecyloxy, and octadecyloxy.
The aryloxy group is preferably an aryloxy group having 6 to 10 carbon atoms, and examples thereof include phenoxy and p-methoxyphenoxy.
The alkylthio group is preferably an alkylthio group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms), such as methylthio, ethylthio, octylthio, undecylthio, dodecylthio, hexadecylthio, and octadecylthio. It is done.
The arylthio group is preferably an arylthio group having 6 to 10 carbon atoms, and examples thereof include phenylthio and 4-methoxyphenylthio.
The acyloxy group is preferably an acyloxy group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms), such as acetoxy, propanoyloxy, pentanoyloxy, octanoyloxy, dodecanoyloxy, and Examples include octadecanoyloxy.

The alkylamino group is preferably an alkylamino group having 1 to 18 carbon atoms (more preferably an alkylamino group having 6 to 18 carbon atoms), for example, methylamino, dimethylamino, diethylamino, dibutylamino, octylamino, dioctylamino, and , Undecylamino and the like. The carbonamido group is preferably a carbonamido group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms). For example, acetamido, acetylmethylamino, acetyloctylamino, acetyldecylamino, acetylundecylamino Acetyloctadecylamino, propanoylamino, pentanoylamino, octanoylamino, octanoylmethylamino, dodecanoylamino, dodecanoylmethylamino, octadecanoylamino and the like.
The sulfonamide group is preferably a sulfonamide group having 1 to 18 carbon atoms (more preferably 6 to 18 carbon atoms), such as methanesulfonamide, ethanesulfonamide, propylsulfonamide, 2-methoxyethylsulfonamide. , 3-aminopropylsulfonamide, 2-acetamidoethylsulfonamide, octylsulfonamide, and undecylsulfonamide.
The oxycarbonylamino group is preferably an oxycarbonylamino group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as methoxycarbonylamino, ethoxycarbonylamino, octyloxycarbonylamino, and unoxy Examples include decyloxycarbonylamino.
The oxysulfonylamino group is preferably an oxysulfonylamino group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as methoxysulfonylamino, ethoxysulfonylamino, octyloxysulfonylamino, and unoxy Examples include decyloxysulfonylamino.
The sulfamoylamino group is preferably a sulfamoylamino group having 0 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as methylsulfamoylamino, dimethylsulfamoylamino, ethylsulfamoyl. Examples include amino, propylsulfamoylamino, octylsulfamoylamino, and undecylsulfamoylamino.
The ureido group is preferably a ureido group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as ureido, methylureido, N, N-dimethylureido, octylureido, and undecylureido. Etc.
The thioureido group is preferably a thioureido group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as thioureido, methylthioureido, N, N-dimethylthioureido, octylthioureido, and Examples include decylthioureido.
The acyl group is preferably an acyl group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), and examples thereof include acetyl, benzoyl, octanoyl, decanoyl, undecanoyl, and octadecanoyl.
The oxycarbonyl group is preferably an oxycarbonyl group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, octyloxycarbonyl, and undecyloxycarbonyl). It is done.
The carbamoyl group is preferably a carbamoyl group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as carbamoyl, N, N-dimethylcarbamoyl, N-ethylcarbamoyl, N-octylcarbamoyl, N , N-dioctylcarbamoyl, N-undecylcarbamoyl and the like.
The sulfonyl group is preferably a sulfonyl group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), such as methanesulfonyl, ethanesulfonyl, 2-chloroethanesulfonyl, octanesulfonyl, and undecanesulfonyl. Can be mentioned.
The sulfinyl group is preferably a sulfinyl group having 1 to 18 carbon atoms (more preferably 8 to 18 carbon atoms), and examples thereof include methanesulfinyl, ethanesulfinyl, and octanesulfinyl.
The sulfamoyl group is preferably a sulfamoyl group having 0 to 18 carbon atoms (more preferably 8 to 18 carbon atoms, such as sulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, octylsulfamoyl, dioctylsulfamoyl). And undecylsulfamoyl.

L ¹ and L ² each independently represents a divalent linking group.
Here, the divalent linking group is composed of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and forms a 4- to 8-membered ring together with the carbon atom substituted by X ¹ and X ² . Specific examples of L ¹ and L ² include —C (R ⁴ ) (R ⁵ ) —, —C (R ⁶ ) =, —N (R ⁷ ) —, —N═, —O—, and —S. It is configured by combining-. Here, R ⁴ , R ⁵ , R ⁶ and R ⁷ represent a hydrogen atom or a substituent, and the details thereof are the same as those described for R ¹ , R ² and R ³ .
The 4- to 8-membered ring may form a saturated or unsaturated condensed ring, and examples of the condensed ring include a cycloalkyl ring, an aryl ring, and a heterocyclic ring. , R ¹ , R ² and R ³ are the same as those described above.
Further, examples of the 4- to 8-membered ring include cyclobutanedione, cyclobutenedione, and benzocyclobutenequinone as examples of the 4-membered ring. Examples of the 5-membered ring include cyclopentanedione, cyclopentenedione, and cyclopentane. Trione, cyclopentenetrione, indanedione, indanetrione, tetrahydrofurandione, tetrahydrofurantrione, tetrahydropyrroledione, tetrahydropyrroletrione, tetrahydrothiophenedione, tetrahydrothiophenedione, and the like are benzoquinone, quinomethane, quinodimethane, Quinoneimine, quinonediimine, thiobenzoquinone, dithiobenzoquinone, naphthoquinone, anthraquinone, dihydrochromementurion, dihydropyridinedione Dihydropyrazinedione, dihydropyrimidinedione, dihydropyridazinedione, dihydrophthalazinedione, dihydroisoquinolinedione, and tetrahydroquinolinetrione are examples of seven-membered rings such as cycloheptanedione, cycloheptanetrione, azacycloheptanetrione, dia Examples of 8-membered rings such as zacycloheptanetrione, oxocycloheptanetrione, dioxocycloheptanetrione, and oxoazacycloheptanetrione are cyclooctanedione, cyclooctanetrione, azacyclooctanetrione, diazacyclooctane Trione, oxocyclooctanetrione, dioxocyclooctanetrione, oxoazacyclooctanetrione, cyclooctenedione, cyclooctadiene On, and the like can be given dibenzo cyclooctene dione. L ¹ and L ^2, Examples of the ring X ^1, X ² constitute jointly with the carbon atom to which they are substituted, preferably 6-membered ring.

Among the compounds represented by the general formula (A), compounds represented by the following general formula (AI) are preferable.

In general formula (AI), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent. The definition of the substituent is as described above.
When R ¹⁰ and R ¹¹ , or R ¹² and R ¹³ simultaneously become a substituent, they may be linked together to form an unsaturated condensed ring. This unsaturated condensed ring may have a substituent, and examples of the substituent include the same as those described for R ¹ to R ³ . X ¹¹ and ^{X 22} may be the same or different, have the same meanings as ^{X 1} and ^{X 2,} respectively, preferred embodiments thereof are also the same.

X ¹¹ and X ^{22 in} formula (AI) are preferably an oxygen atom or a ═C (R ¹⁴ ) (R ¹⁵ ) group, and at the same time, an oxygen atom or a ═C (R ¹⁴ ) (R ¹⁵ ) group More preferably. Here, R ¹⁴ and R ¹⁵ each independently represent a halogen atom, a cyano group, an acyl group, an oxycarbonyl group or a sulfonyl group.
When X ¹¹ and X ²² in the general formula (AI) are simultaneously oxygen atoms, it is more preferable that at least two of R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are electron-withdrawing groups, Here, the electron withdrawing group refers to a substituent having a positive Hammett σp value, specifically, a halogen atom, a cyano group, a nitro group, an acyl group, an oxycarbonyl group, a carbamoyl group, a sulfonyl group, and Such as a sulfinyl group.
Particularly preferred combinations in the case where X ¹¹ and ^{X 22} is simultaneously oxygen ^{^{^{atom, R 10, R 11, R}}} 12 and ^{R 13} are a hydrogen atom, an alkyl group, a halogen atom, a cyano group, a nitro group, an alkoxy group, an alkylthio Group, amino group, alkylamino group, carbonamido group, sulfonamido group, sulfamoylamino group, oxycarbonylamino group, oxysulfonylamino group, ureido group, thioureido group, acyl group, oxycarbonyl group, carbamoyl group, sulfonyl group, a sulfinyl group, or a sulfamoyl group, of at least two or more electron-withdrawing groups, and most preferred is a ^{^{^{combination, R 10, R 11, R}}} 12 and ^{R 13} are a hydrogen atom, 8 carbon atoms 18 alkyl groups, halogen atoms, cyano groups, carbon number An alkoxy group having 18 to 18 carbon atoms, an alkylthio group having 8 to 18 carbon atoms, a carbonamido group having 8 to 18 carbon atoms, a sulfonamide group having 8 to 18 carbon atoms, a ureido group having 8 to 18 carbon atoms, and an 8 to 18 carbon atom. An acyl group, an oxycarbonyl group having 8 to 18 carbon atoms, a carbamoyl group having 8 to 18 carbon atoms, a sulfonyl group having 8 to 18 carbon atoms, or a sulfinyl group having 8 to 18 carbon atoms, and at least two of them are A halogen atom, a cyano group, a sulfonyl group or a sulfinyl group;

Among the compounds represented by the above general formula (AI), compounds represented by the following general formula (A-II) are preferable.

In general formula (A-II), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ may be the same or different and have the same meanings as described for R ¹⁰ to R ¹³ .

Among the compounds represented by the general formula (A-II), compounds represented by the following general formula (A-III) or general formula (A-IV) are preferable.

In the general formula (A-III), R ³¹ represents a halogen atom, a cyano group, an alkoxy group, an alkylthio group, a carbonamido group, a sulfonamido group, a ureido group, an acyl group, or an oxycarbonyl group, and R ⁰³¹ represents R Examples thereof are the same as those described in ¹ to R ³ . m ⁴ represents an integer of 1 to 4, and when m ⁴ or 4-m ⁴ represents an integer of 2 or more, the plurality of R ³¹ and the plurality of R ⁰³¹ may be the same or different from each other.

Preferred combinations of R ³¹ and R ^{031 in} formula (A-III) are described below.
R ³¹ is a halogen atom, a cyano group, an alkoxy group having 8 to 18 carbon atoms, an acyl group having 8 to 18 carbon atoms or an oxycarbonyl group having 8 to 18 carbon atoms, and R ⁰³¹ is a hydrogen atom or 8 carbon atoms. Preferred is a combination in which the alkyl group of ^˜18 or “4-m ⁴ ” representing the number of R ⁰³¹ is 0 (that is, when it is not substituted with R ⁰³¹ ).
More preferably, the combination is a combination in which R ³¹ is an alkoxy group having 8 to 18 carbon atoms or a halogen atom, and R ⁰³¹ is a hydrogen atom or “4-m ⁴ ” representing the number of R ⁰³¹ is 0. .

In the general formula (A-IV), R ³² represents a hydrogen atom or a substituent. Here, examples of the substituent include the same as those described for R ¹ to R ³ . m ⁵ represents an integer of 0 to 6, and when m ⁵ represents an integer of 2 or more, the plurality of R ³² may be the same as or different from each other.

R ³² in formula (A-IV) is, preferably a hydrogen atom, alkyl groups, halogen atom, a cyano, alkoxy, alkylthio, carbonamido, sulfonamido, ureido group, or an acyl group More preferably, a hydrogen atom, an alkyl group having 8 to 18 carbon atoms, a halogen atom, a cyano group, an alkoxy group having 8 to 18 carbon atoms, an alkylthio group having 8 to 18 carbon atoms, or a carbonamido group having 8 to 18 carbon atoms. , A sulfonamide group having 8 to 18 carbon atoms, a ureido group having 8 to 18 carbon atoms, or an acyl group having 8 to 18 carbon atoms, and more preferably a hydrogen atom, an alkyl group having 8 to 18 carbon atoms, fluorine An atom, a chlorine atom, a bromine atom, a cyano group, or an alkoxy group having 8 to 18 carbon atoms, particularly preferably a hydrogen atom.

Examples of specific compounds of the organic oxidant of the present invention are given below, but the organic oxidant of the present invention is not limited to these.

Specific organic oxidizers may be used alone or in combination of two or more.

The specific organic oxidant is preferably an oxidant having high oxidizing power (that is, the reduction potential is noble) from the viewpoint of further improving the function of oxidatively decomposing and removing the decomposition product derived from the specific liquid crystal compound.
Specifically, the reduction potential (Ered) of the specific organic oxidant is preferably noble (over 0 volt) from 0 volt, more preferably noble (over 0.1 volt) from 0.1 volt. Preferably, it is more noble (over 0.3 volts) than 0.3 volts, and more preferably noble (above 0.5 volts) than 0.5 volts. By being nobler than 0 volts, the above functions are further exhibited.
The upper limit of the reduction potential (Ered) of the organic oxidant is preferably base (less than 2 volts), more preferably 2 volts, and more preferably base (less than 1 volt) than 1 volt. By being less than 1 volt, there is an advantage that the specific organic oxidant can be prevented from decomposing the specific liquid crystal compound itself.
Here, the value of the reduction potential Ered means a potential at which the organic oxidant is reduced by receiving electron injection at the cathode in voltammetry, and the value of Ered can be accurately measured by this voltammetry. That is, a voltammogram of an organic oxidant 1 × 10 ⁻³ M is measured in acetonitrile containing 0.1 M of tetra-n-ethylammonium perchlorate as a supporting electrolyte, and a half-wave potential obtained therefrom can be obtained. it can. More specifically, platinum is used for the working electrode, a saturated calomel electrode (SCE) is used for the reference electrode, and the measurement is performed at 25 ° C.

The content of the specific organic oxidant is preferably 0.1 to 25 parts by mass, and preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the specific liquid crystal compound contained in the polymerizable liquid crystal composition. Is more preferably 1 to 20 parts by mass, further preferably 1 to 10 parts by mass, particularly preferably 1 to 8 parts by mass, and preferably 1 to 5 parts by mass. Most preferred. When the content of the specific organic oxidant is 0.1 parts by mass or more, the effect of oxidatively decomposing a decomposition product derived from the specific liquid crystal compound is further improved. In particular, when the content of the specific organic oxidant is 20 parts by mass or less, there is an effect that the specific organic oxidant can be prevented from decomposing the specific liquid crystal compound itself.

<Reverse wavelength dispersible polymerizable liquid crystal compound (specific liquid crystal compound)>
The polymerizable liquid crystal composition of the present invention contains a polymerizable liquid crystal compound having a reverse wavelength dispersion (specific liquid crystal compound).
Here, in the present specification, the “reverse wavelength dispersion” polymerizable liquid crystal compound means an in-plane retardation (Re) value at a specific wavelength (visible light range) of a retardation film produced using the same. When the measurement is performed, the Re value becomes the same or higher as the measurement wavelength is increased, and the Re satisfies the relationship of Re (450) ≦ Re (550) ≦ Re (650) as described later.

In addition, the polymerizable liquid crystal compound in the present specification refers to a liquid crystal compound having a polymerizable group.
The kind of the polymerizable group of the specific polymerizable liquid crystal compound of the present invention is not particularly limited, and examples thereof include an acryloyl group, a methacryloyl group, a vinyl group, a styryl group, and an allyl group.

The type of the specific liquid crystal compound is not particularly limited, but can be classified into a rod-shaped type (bar-shaped liquid crystal compound) and a disk-shaped type (disc-shaped liquid crystal compound. Discotic liquid crystal compound) based on the shape. Furthermore, there are a low molecular type and a high molecular type, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used. Two or more rod-like liquid crystal compounds, two or more disc-like liquid crystal compounds, or a mixture of a rod-like liquid crystal compound and a disc-like liquid crystal compound may be used.
Among these, it is preferable to use a rod-like liquid crystal compound. This is because by aligning the rod-shaped liquid crystal compound homogeneously (horizontal), it is easy to make the formed retardation film function as a positive A plate.

The specific liquid crystal compound of the present invention is not particularly limited as long as it can form a reverse wavelength dispersive film as described above. For example, the specific liquid crystal compound is represented by the general formula (I) described in JP-A-2008-297210. Compounds (especially compounds described in paragraph numbers [0034] to [0039]), compounds represented by general formula (1) described in JP 2010-84032 A (in particular, paragraph numbers [0067] to [ And the liquid crystal compound represented by the general formula (II) described later can be used.

The above-mentioned specific liquid crystal compound preferably contains a liquid crystal compound represented by the following general formula (II) from the viewpoint of being excellent in reverse wavelength dispersion.

L ₁ -G ₁ -D ₁ -Ar-D ₂ -G ₂ -L ₂ (II)

In the general formula (II), D ₁ and D ₂ are each independently a single bond, —CO—O—, —C (═S) O—, —CR ¹ R ² —, —CR ¹ R ² —CR. ³ R ⁴ —, —O—CR ¹ R ² —, —CR ¹ R ² —O—CR ³ R ⁴ —, —CO—O—CR ¹ R ² —, —O—CO—CR ¹ R ² —, ^{^{^{^{-CR 1 R 2 -O-CO-}}}} CR 3 R 4 -, - CR 1 R 2 -CO-O-CR 3 R 4 -, - NR 1 -CR 2 R 3 - or -CO-NR ¹ - represents a .
R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms. When there are a plurality of each of R ¹ , R ² , R ³ and R ⁴ , the plurality of R ¹ , the plurality of R ² , the plurality of R ³ and the plurality of R ⁴ may be the same as or different from each other. Good.
G ₁ and G ₂ each independently represents a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group includes —O—, —S—, Alternatively, it may be substituted with -NH-.
L ₁ and L ₂ each independently represent a monovalent organic group, and at least one selected from the group consisting of L ₁ and L ₂ represents a monovalent group having a polymerizable group.
Ar represents a divalent aromatic ring group represented by the following general formula (II-1), (II-2), (II-3) or (II-4).

In the general formulas (II-1) to (II-4), Q ₁ represents —CH— or —N—,
Q ₂ is, -S -, - O-, or ^{-NR 11} - it represents,
R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
Y ₁ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms or an aromatic heterocyclic group having 3 to 12 carbon atoms (in addition, the aromatic hydrocarbon group and the aromatic heterocyclic group are substituents) May have)
The Z _1, _{Z 2} and _{Z 3} are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, alicyclic hydrocarbon group having 3 to 20 carbon atoms, monovalent number of 6 to 20 carbon atoms in the Represents an aromatic hydrocarbon group, a halogen atom, a cyano group, a nitro group, —NR ¹² R ¹³ or —SR ¹² ;
Z ₁ and Z ₂ may combine with each other to form an aromatic ring or an aromatic heterocyclic ring, and R ¹² and R ¹³ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
A ₁ and A ₂ are each independently a group selected from the group consisting of —O—, —NR ²¹ —, —S— and —CO—, wherein R ²¹ represents a hydrogen atom or a substituent; Is a nonmetallic atom of group 14 to group 16 to which a hydrogen atom or a substituent may be bonded (preferably ═O, ═S, ═NR ′, and ═C (R ′) R ′ (Wherein R ′ represents a substituent)),
Ax represents an organic group having 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, preferably an aromatic hydrocarbon ring group; A heterocyclic group; an alkyl group having 3 to 20 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring; a group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring An alkenyl group having 3 to 20 carbon atoms having at least one aromatic ring selected from the group consisting of: 3 to 20 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring An alkenyl group,
Ay is a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or a carbon having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Represents an organic group having a number of 2 to 30, and a preferred embodiment of this organic group is the same as the preferred embodiment of the organic group of Ax,
Each of the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring,
Q ₃ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.
Examples of the substituent include a halogen atom, alkyl group, halogenated alkyl group, alkenyl group, aryl group, cyano group, amino group, nitro group, nitroso group, carboxy group, alkylsulfinyl group having 1 to 6 carbon atoms, carbon An alkylsulfonyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylsulfanyl group having 1 to 6 carbon atoms, an N-alkylamino group having 1 to 6 carbon atoms, N, N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 6 carbon atoms, N, N-dialkylsulfamoyl group having 2 to 12 carbon atoms, or a combination thereof Etc.

For definitions and preferred ranges of the substituents of the liquid crystal compound represented by the general formula (II), D ¹ , D ² , G ¹ , G ² , and the like relating to the compound (A) described in JP2012-21068A are described. Descriptions of L ¹ , L ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , X ¹ , Y ¹ , Q ¹ , and Q ² are respectively D ₁ , D ₂ , G ₁ , G ₂ , L ₁ , L ₂ , R ¹ , R ² , R ³ , R ⁴ , Q ₂ , Y ₁ , Z ₁ , and Z ₂ can be referred to, and compounds represented by the general formula (I) described in JP-A-2008-107767 _a 1 for, _{a 2,} and _a 1 a description of X respectively, _{a 2,} and X can refer for, Ax of the compound represented by the general formula described in WO 2013/018526 (I), Ay, and with respect to ^{Q 1} serial The possible reference Ax, Ay, and the _{Q 3,} respectively. Regarding Z ₃ , the description of Q ¹ relating to the compound (A) described in JP2012-21068A can be referred to.

In particular, the organic group represented by _{L 1} and _{L 2,} respectively, in _particular, is preferably a group represented by _{_{-D 3 -G 3 -Sp-P 3}} .
D ₃ has the same meaning as _{D 1.}
G ₃ represents a single bond, a divalent aromatic or heterocyclic group having 6 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the above alicyclic hydrocarbon group The methylene group contained in may be substituted with —O—, —S—, or —NR ⁷ —, wherein R ⁷ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Sp is a single bond, — (CH ₂ ) _n —, — (CH ₂ ) _n —O—, — (CH ₂ —O—) _n —, — (CH ₂ CH ₂ —O—) _m , —O— (CH ₂ ) _n —, —O— (CH ₂ ) _n —O—, —O— (CH ₂ —O—) _n —, —O— (CH ₂ CH ₂ —O—) _m , —C (= O) —O— (CH ₂ ) _n —, —C (═O) —O— (CH ₂ ) _n —O—, —C (═O) —O— (CH ₂ —O—) _n —, — C (═O) —O— (CH ₂ CH ₂ —O—) _m , —C (═O) —N (R ⁸ ) — (CH ₂ ) _n —, —C (═O) —N (R ⁸ ) — (CH ₂ ) _n —O—, —C (═O) —N (R ⁸ ) — (CH ₂ —O—) _n —, —C (═O) —N (R ⁸ ) — (CH ₂ CH ₂ _{-O-) m} _{_{or,, - (CH 2) n}} -O- (C = O) - (CH 2 It represents a represented by a spacer group _{- n -C (= O) -O-} (CH 2) n. Here, n represents an integer of 2 to 12, m represents an integer of 2 to 6, and R ⁸ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. In addition, the —CH ₂ — hydrogen atom in each of the above groups may be substituted with a methyl group.
P ₃ represents a polymerizable group.

The polymerizable group is not particularly limited, but a polymerizable group capable of radical polymerization or cationic polymerization is preferable.
As the radical polymerizable group, a generally known radical polymerizable group can be used, and preferable examples include an acryloyl group or a methacryloyl group. In this case, it is known that the acryloyl group is generally fast in the polymerization rate, and the acryloyl group is preferable from the viewpoint of productivity improvement. However, the methacryloyl group is also used as the polymerizable group of the highly birefringent liquid crystal. Can do.
As the cationic polymerizable group, generally known cationic polymerizable can be used, and specifically, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and And vinyloxy groups. Among these, an alicyclic ether group or a vinyloxy group is preferable, and an epoxy group, an oxetanyl group, or a vinyloxy group is particularly preferable.
Examples of particularly preferred polymerizable groups include the following.

In the present specification, the “alkyl group” may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, 1,1-dimethylpropyl group, n-hexyl group, isohexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, And a cyclohexyl group etc. are mentioned.

Preferred examples of the liquid crystal compound represented by the general formula (II) are shown below, but are not limited to these liquid crystal compounds. Note that all 1,4-cyclohexylene groups in the following formulas are trans-1,4-cyclohexylene groups.

In the above formula, “*” represents a bonding position.

When the liquid crystal compound represented by the general formula (II) is used, the content of the liquid crystal compound represented by the general formula (II) in the specific liquid crystal compound is preferably 60 to 100% by mass, It is more preferably from 100 to 100% by mass, and further preferably from 70 to 90% by mass. By being 70 mass% or more, it is more excellent in reverse wavelength dispersion.

<Polymerization initiator>
The polymerizable liquid crystal compound of the present invention preferably contains a polymerization initiator.
The polymerization initiator to be used is preferably a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation.
Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics, and the like. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US patent) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850), oxadiazole compounds (described in U.S. Pat. No. 4,221,970), and acyl Phosphine oxide compound No. 63-40799, JP-B-5-29234, JP-A-10-95788, JP-A-10-29997) and the like.

Specific examples of the photopolymerization initiator include Irgacure series (for example, Irgacure 651, Irgacure 754, Irgacure 184, Irgacure 2959, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, commercially available from BASF. , And Irgacure OXE-01), Darocure series (eg, Darocur TPO and Darocur 1173, etc.), Quantacure PDO, Ezacure commercially available from Lamberti Series (for example, Ezacure TZM, Ezacure TZT, Ezacure KTO46, etc.) and the like.

In the case of containing a polymerization initiator, the content of the polymerization initiator is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the specific liquid crystal compound contained in the polymerizable liquid crystal composition of the present invention. It is more preferably 1 to 10 parts by mass.

<Polymerizable compound>
The polymerizable liquid crystal composition of the present invention may contain a polymerizable compound other than the specific liquid crystal compound.
Here, the polymerizable group that the polymerizable compound has is not particularly limited, and examples thereof include a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Of these, a (meth) acryloyl group is preferable.

In the present invention, a polymerizable compound having 2 to 4 polymerizable groups is preferable because the durability of the retardation film is improved, and a polymerizable compound having 2 polymerizable groups is preferable. More preferred.

As such a polymerizable compound, for example, a compound represented by the formula (M1), (M2), or (M3) described in paragraphs [0030] to [0033] of JP2014-077068A More specifically, specific examples described in paragraphs [0046] to [0055] of the same publication can be given.
A polymeric compound may be used individually by 1 type, and may be used together 2 or more types.

In the present invention, the content when the polymerizable compound is contained is not particularly limited, but it is preferably 1 to 40 parts by mass in a total of 100 parts by mass of the specific liquid crystal compound and the polymerizable compound described above. More preferably, it is 5 to 30 parts by mass.

<Solvent>
The polymerizable liquid crystal composition of the present invention preferably contains an organic solvent from the viewpoint of workability and the like for forming a retardation film.
Specific examples of the organic solvent include ketones (for example, acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone), ethers (for example, dioxane and tetrahydrofuran), Aliphatic hydrocarbons (eg, hexane), alicyclic hydrocarbons (eg, cyclohexane), aromatic hydrocarbons (eg, toluene, xylene, and trimethylbenzene), halogenated carbons (eg, , Dichloromethane, dichloroethane, dichlorobenzene, and chlorotoluene), esters (eg, methyl acetate, ethyl acetate, and butyl acetate), water, alcohols (eg, ethanol, isopropanol, butanol, and cyclohexanol) Such) Cellosolves (for example, methyl cellosolve and ethyl cellosolve), cellosolve acetates, sulfoxides (for example, dimethylsulfoxide, etc.), amides (for example, dimethylformamide, dimethylacetamide, etc.), etc. These may be used alone or in combination of two or more.

<Other ingredients>
The polymerizable liquid crystal composition of the present invention may contain components other than those described above, for example, liquid crystal compounds other than those described above, leveling agents, surfactants, tilt angle control agents, alignment aids, plasticizers, And a crosslinking agent etc. are mentioned.

[Phase difference film]
The retardation film of the present invention is formed using the polymerizable liquid crystal composition. Specifically, the retardation film of the present invention preferably has an optically anisotropic layer formed using the polymerizable liquid crystal composition.
The retardation film of the present invention is preferably a film formed by fixing a specific liquid crystal compound contained in the polymerizable liquid crystal composition by polymerization. In this case, the film no longer exhibits liquid crystallinity after becoming a film. There is no need.
In the present specification, the retardation film can be used for optical members such as various display devices, light emitting devices, and various optical elements such as polarizing plates.

The thickness of the retardation film is preferably 100 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less from the viewpoint of reducing the thickness of the member. Further, from the viewpoint of production suitability, it is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. In addition, when the retardation film has a plurality of layers, the film thickness of the retardation film refers to the entire film thickness including the layers.
When the retardation film has the optically anisotropic layer, the thickness of the optically anisotropic layer is preferably 1 to 5 μm, more preferably 1 to 4 μm, and more preferably 1 to 3 μm. Is more preferable.

<Support layer>
The retardation film may have a support layer for supporting the optically anisotropic layer. In this case, the retardation film includes a support layer and an optically anisotropic layer formed on one surface of the support layer.
Such a support layer is preferably transparent, and specifically has a light transmittance of 80% or more. Examples of such a support include a glass substrate and a polymer film.
Moreover, the aspect which the polarizer mentioned later may serve as such a support body layer may be sufficient, and in this case, in this invention, the retardation film and the polarizing plate containing a polarizer are meant.
In the present invention, the thickness of the support layer is not particularly limited, but is preferably 5 to 80 μm, and more preferably 10 to 40 μm.

<Alignment film>
The retardation film of the present invention may include an alignment film (alignment layer) having a function of defining the alignment direction of the specific liquid crystal compound. Thereby, it becomes easy to make the said retardation film into a positive A plate.
The alignment film is a film (layer) provided on one surface of the optically anisotropic layer. When the retardation film includes the support layer, the support layer, the optically anisotropic layer, Located between.

In order to form a positive A plate, which will be described later, which is an embodiment of a retardation film, a technique for bringing liquid crystal compound molecules into a desired alignment state is used. For example, a liquid crystal compound is formed using an alignment film. A technique for aligning in a desired direction is common.
Examples of the alignment film include a rubbing treatment film of a layer containing an organic compound such as a polymer, an oblique deposition film of an inorganic compound, a film having a microgroove, or ω-tricosanoic acid, dioctadecylmethylammonium chloride, or methyl stearylate. Examples thereof include films obtained by accumulating LB (Langmuir-Blodgett) films of organic compounds by the Langmuir-Blodgett method. Further examples include an alignment film in which an alignment function is generated by light irradiation.
As the alignment film, a film formed by rubbing the surface of a layer (polymer layer) containing an organic compound such as a polymer can be preferably used. The rubbing treatment is carried out by rubbing the surface of the polymer layer several times with paper or cloth in a certain direction (preferably in the longitudinal direction of the support). Examples of the polymer used for forming the alignment film include polyimide, polyvinyl alcohol, modified polyvinyl alcohol described in paragraph Nos. [0071] to [0095] of Japanese Patent No. 3907735, or JP-A-9-152509. It is preferable to use a polymer having a polymerizable group.
The thickness of the alignment film is not particularly limited as long as it can exert an alignment function, but is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.

As the alignment film, it is also a preferable aspect to use a so-called photo-alignment film (photo-alignment layer) which is an alignment layer by irradiating a photo-alignment material with polarized light or non-polarized light. It is preferable to apply an alignment regulating force to the photo-alignment film by a step of irradiating polarized light from the vertical direction or oblique direction or a step of irradiating non-polarized light from the oblique direction.
By using the photo-alignment film, the specific liquid crystal compound can be horizontally aligned with excellent symmetry. Therefore, the positive A plate formed using the photo-alignment film is particularly useful for optical compensation in a liquid crystal display device that does not require a pre-tilt angle of the driving liquid crystal, such as an IPS (In-Place-Switching) mode liquid crystal display device. It is.

Examples of the photo-alignment material used for the photo-alignment film include, for example, JP-A-2006-285197, JP-A-2007-76839, JP-A-2007-138138, JP-A-2007-94071, JP-A-2007-. No. 121721, JP 2007-140465, JP 2007-156439, JP 2007-133184, JP 2009-109831, JP 3883848, and JP 4151746 Azo compounds, aromatic ester compounds described in JP-A No. 2002-229039, maleimide and / or alkenyl substitution having photo-alignment units described in JP-A No. 2002-265541 and JP-A No. 2002-317013 Nadiimide compound, patent 4205195 And photocrosslinkable silane derivatives described in Japanese Patent No. 4205198, photocrosslinkable polyimides, polyamides or esters described in Japanese Patent Publication No. 2003-520878, Japanese Patent Publication No. 2004-529220, and Japanese Patent No. 4162850 And JP-A-9-118717, JP-A-10-506420, JP-A-2003-505561, International Publication No. 2010/150748, JP-A-2013-177561, and JP-A-2014- Examples thereof include compounds capable of photodimerization described in Japanese Patent No. 12823, particularly cinnamate compounds, chalcone compounds, and coumarin compounds. Particularly preferred examples include azo compounds, photocrosslinkable polyimides, polyamides, esters, cinnamate compounds, and chalcone compounds.

The support layer and the alignment film may be provided separately as layers that perform the respective functions, or may have both functions as a single layer.
Moreover, when producing the polarizing plate containing the retardation film of this invention and the polarizer mentioned later, the said orientation film is not contained in retardation film, but is formed in the surface of a polarizer (polarizer layer). (Polarizer with alignment film). In this case, the alignment film is preferably arranged between the retardation film and the polarizer.

The retardation film of the present invention has an in-plane retardation value Re (450) measured at a wavelength of 450 nm, an in-plane retardation value Re (550) measured at a wavelength of 550 nm, and a surface measured at a wavelength of 650 nm. It is preferable that Re (650), which is the value of the inner retardation, has a relationship of Re (450) ≦ Re (550) ≦ Re (650). That is, this relationship can be said to represent the above-described inverse wavelength dispersion.
The method for measuring the in-plane retardation value at each wavelength is as described above.

<Positive A plate>
The retardation film of the present invention is preferably a positive A plate.
In this specification, the positive A plate is defined as follows. In the positive A plate (positive A plate), the refractive index in the slow axis direction in the film plane (direction in which the refractive index in the plane becomes maximum) is nx, and the slow axis in the plane is orthogonal to the in-plane plane. When the refractive index in the direction is ny and the refractive index in the thickness direction is nz, the relationship of the formula (A1) is satisfied. The positive A plate shows a positive value for Rth.
Formula (A1) nx> ny≈nz
The above “≈” includes not only the case where both are completely the same, but also the case where both are substantially the same. “Substantially the same” means, for example, that (ny−nz) × d (where d is the film thickness) is −10 to 10 nm, preferably −5 to 5 nm, “ny≈nz”. include.

For details of the method for producing the positive A plate, for example, descriptions in JP-A-2008-225281 and JP-A-2008-026730 can be referred to.

<Λ / 4 plate>
The positive A plate preferably functions as a λ / 4 plate.
The λ / 4 plate is a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light), and has an in-plane retardation Re (λ) at a specific wavelength λnm. A plate (retardation film) satisfying Re (λ) = λ / 4.
This expression only needs to be achieved at any wavelength in the visible light region (for example, 550 nm), but the in-plane retardation Re (550) at a wavelength of 550 nm has a relationship of 110 nm ≦ Re (550) ≦ 160 nm. It is preferable to satisfy | fill, and it is more preferable to satisfy | fill 110nm <= Re (550) <= 150nm.

(Method for producing retardation film)
The formation method in particular of a phase difference film is not restrict | limited, A well-known method is mentioned.
For example, the polymerizable liquid crystal composition is applied to a predetermined substrate (for example, a support layer to be described later) to form a coating film, and the resulting coating film is cured (irradiated with active energy rays (light irradiation). By performing the treatment) and / or heat treatment), a retardation film including a cured coating film (optically anisotropic layer) can be produced. In addition, you may use the orientation layer mentioned later as needed.
The polymerizable liquid crystal composition can be applied by a known method (for example, a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, or a die coating method).

In the method for forming the retardation film, it is preferable to perform an alignment treatment of the specific liquid crystal compound contained in the coating film before performing the curing treatment on the coating film. Thereby, it becomes easy to make the obtained retardation film into a positive A plate described later.
The alignment treatment can be performed by drying at room temperature (for example, 20 to 25 ° C.) or by heating. In the case of a thermotropic liquid crystal compound, the liquid crystal phase formed by the alignment treatment can generally be transferred by a change in temperature or pressure. In the case of a liquid crystal compound having lyotropic properties, it can be transferred also by a composition ratio such as the amount of solvent.
For example, when the rod-like liquid crystal compound develops a smectic phase, the temperature region in which the nematic phase develops is generally higher than the temperature region in which the rod-like liquid crystal compound develops a smectic phase. Therefore, when the specific liquid crystal compound of the present invention is a rod-like liquid crystal, the specific liquid crystal compound is heated to a temperature range where a nematic phase appears, and then the heating temperature is increased to a temperature range where the specific liquid crystal compound develops a smectic phase. By lowering, the specific liquid crystal compound can be transferred from the nematic phase to the smectic phase. By such a method, a positive A plate in which a specific liquid crystal compound is aligned with a high degree of order can be obtained.
In the case where the specific liquid crystal compound is a rod-like liquid crystal, it is necessary to heat for a certain period of time until the specific liquid crystal compound forms a monodomain in a temperature range where the specific liquid crystal compound develops a nematic phase. The heating time (heating aging time) is preferably 10 seconds to 5 minutes, more preferably 10 seconds to 3 minutes, and most preferably 10 seconds to 2 minutes.
When the specific liquid crystal compound is a rod-like liquid crystal, it is necessary to heat for a certain period of time until the rod-like liquid crystal compound develops a smectic phase in a temperature range where the specific liquid crystal compound develops a smectic phase. The heating time is preferably 10 seconds to 5 minutes, more preferably 10 seconds to 3 minutes, and most preferably 10 seconds to 2 minutes.

The above-described curing treatment (irradiation with active energy rays (light irradiation treatment) and / or heat treatment) on the coating film can also be referred to as an immobilization treatment for fixing the orientation of the specific liquid crystal compound.
The immobilization treatment is preferably performed by irradiation with active energy rays (preferably ultraviolet rays), and the liquid crystal is immobilized by polymerization of a specific liquid crystal compound.

[Polarizer]
The polarizing plate of this invention has the said retardation film and a polarizer. Description of the retardation film is omitted because it is as described above.

<Polarizer>
The polarizer (polarizing film) may be a so-called linear polarizer having a function of converting light into specific linearly polarized light. The polarizer is not particularly limited, but an absorptive polarizer can be used.
The type of the polarizer is not particularly limited, and a commonly used polarizer can be used. For example, an iodine polarizer, a dye polarizer using a dichroic dye, a polyene polarizer, and Any polarizer using a wire grid can be used. In general, iodine-based polarizers and dye-based polarizers are produced by adsorbing iodine or dichroic dyes to polyvinyl alcohol and stretching them.
Further, as the polarizer, a thermotropic liquid crystalline dichroic dye (for example, a thermotropic liquid crystalline dichroic dye used in a light-absorbing anisotropic film described in JP2011-237513A) is used for coating. It is also preferable to use a coating type polarizer produced by the above method. By using a coating type polarizer, it is possible to further reduce the thickness of the polarizer obtained by stretching polyvinyl alcohol. Further, even when an external force such as bending is applied, a polarizing plate with little change in optical characteristics can be provided.
The thickness of the polarizer is not particularly limited, but is preferably 5 to 40 μm, more preferably 5 to 30 μm, and even more preferably 5 to 20 μm. If it is the said thickness, it will respond | correspond to thickness reduction of a display apparatus.

<Other layers>
(Polarizer protective film)
A polarizer protective film may be disposed on the surface of the polarizer. The polarizer protective film may be disposed only on one side of the polarizer (on the surface opposite to the retardation film side), or may be disposed on both sides of the polarizer.
The configuration of the polarizer protective film is not particularly limited, and may be, for example, a so-called transparent support or hard coat layer, or a laminate of the transparent support and the hard coat layer.
As the hard coat layer, a known layer can be used. For example, a layer obtained by polymerizing and curing a polyfunctional monomer may be used.
Moreover, as a transparent support body, a well-known transparent support body can be used, for example, as a material which forms a transparent support body, a cellulose polymer (henceforth cellulose acylate typified by triacetylcellulose) is represented. ), Thermoplastic norbornene resins (ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Co., Ltd.), acrylic resins, and polyester resins can be used.
The thickness of the polarizer protective film is not particularly limited, but is preferably 40 μm or less, and more preferably 25 μm or less, for the reason that the thickness of the polarizing plate can be reduced.

¡In order to ensure adhesion between the layers, an adhesive layer or an adhesive layer may be disposed between the layers. Furthermore, you may arrange | position a transparent support body between each layer.

[Liquid crystal display device and organic electroluminescence device]
The polarizing plate can be preferably used for an organic electroluminescence device (preferably, an organic EL (electroluminescence) display device), a liquid crystal display device, and the like.

<Liquid crystal display device>
The liquid crystal display device of the present invention is an example of an image display device, and includes the above-described polarizing plate of the present invention and a liquid crystal cell.
In the present invention, among the polarizing plates provided on both sides of the liquid crystal cell, the polarizing plate of the present invention is preferably used as the polarizing plate on the front side, and the polarizing plate of the present invention is used as the polarizing plate on the front side and the rear side. Is more preferable. Moreover, it is preferable that the said retardation film contained in a polarizing plate is arrange | positioned at the liquid crystal cell side.
That is, the retardation film of the present invention can be suitably used as an optical compensation film.
Below, the liquid crystal cell which comprises a liquid crystal display device is explained in full detail.

(Liquid crystal cell)
The liquid crystal cell used in the liquid crystal display device is preferably in a VA (Virtual Alignment Bend) mode, an OCB (Optical Compensated Bend) mode, an IPS (In-Placed Switching) mode, or a TN (Twisted Nematic). It is not limited to.
In a TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes: (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) A liquid crystal cell (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Further, any of a PVA (Patterned Vertical Alignment) type, a photo-alignment type (Optical Alignment), and a PSA (Polymer-Stained Alignment) may be used. Details of these modes are described in JP-A-2006-215326 and JP-T 2008-538819.
In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. The IPS mode displays black when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, and JP-A-10-54923 disclose methods for reducing leakage light during black display in an oblique direction and improving the viewing angle using an optical compensation sheet (optical compensation film). These are disclosed in JP-A-9-292522, JP-A-11-133408, JP-A-11-305217, JP-A-10-307291, and the like.

<Organic EL display device>
As an organic electroluminescence display which is an example of the organic electroluminescent apparatus of this invention, the aspect which has the polarizing plate of this invention and the organic electroluminescence display panel in this order from a visual recognition side is mentioned suitably, for example. The retardation film contained in the polarizing plate is preferably disposed on the organic EL display panel side.
That is, the retardation film of the present invention is used as a so-called antireflection film.
The organic EL display panel is a display panel configured using an organic EL element in which an organic light emitting layer (organic electroluminescence layer) is sandwiched between electrodes (between a cathode and an anode). The configuration of the organic EL display panel is not particularly limited, and a known configuration is adopted.

Hereinafter, the present invention will be described in more detail using examples. However, the present invention is not limited to this.

[Preparation of polarizing plate]
The polarizing plate of the Example and comparative example which are used for evaluation of wet heat durability was produced as follows.

<Example 1>
(Preparation of polarizer 1 with photo-alignment film 1)
The support surface of the cellulose triacetate film TD80UL (manufactured by Fujifilm) was subjected to alkali saponification treatment. Specifically, after immersing the support in an aqueous 1.5N sodium hydroxide solution at 55 ° C for 2 minutes, the substrate was washed in a water bath at room temperature and neutralized using 0.1N sulfuric acid at 30 ° C. did. After neutralization, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C.
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an MD (Machine Direction) direction in an aqueous iodine solution and dried to obtain a polarizer (polarizing film) having a thickness of 20 μm. A polarizer in which a cellulose triacetate film TD80UL was bonded to one surface of the polarizer as a polarizer protective film subjected to alkali saponification as described above was produced.
Furthermore, with reference to the description of JP 2012-155308 A and Example 3, a coating liquid 1 for a photo-alignment film was prepared and applied to the other surface of the polarizer with a wire bar. The film was dried with warm air of 60 ° C. for 60 seconds to produce a polarizer 1 with a photo-alignment film 1.

(Preparation of polarizing plate 1)
Subsequently, the following coating liquid A-1 for forming a positive A plate A-1 was prepared.
――――――――――――――――――――――――――――――――――
Composition of coating liquid A-1 for forming positive A plate A-1 ――――――――――――――――――――――――――――――――――
The following polymerizable compound X-1 20.00 parts by mass The following specific liquid crystal compound L-1 40.00 parts by mass The following specific liquid crystal compound L-2 40.00 parts by mass Polymerization initiator (IRGACURE 184, manufactured by BASF)
3.00 parts by mass polymerization initiator (IRGACURE OXE-01, manufactured by BASF)
3.00 parts by mass The following organic oxidant A-1 1.00 parts by mass Leveling agent (compound T-1 below) 0.20 parts by mass Cyclopentanone (solvent) 423.11 parts by mass ――――――――――――――――――――――――――

The produced polarizer 1 with the photo-alignment film 1 was irradiated with ultraviolet rays using an ultrahigh pressure mercury lamp in the atmosphere. At this time, a wire grid polarizer (manufactured by Moxtek, ProFlux PPL02) was set to be parallel to the surface of the photo-alignment film 1 and exposed to perform photo-alignment treatment. The illuminance of the ultraviolet rays used at this time was 100 mJ / cm ^{2 in the} UV-A region (ultraviolet A wave, wavelength 380 nm to 320 nm integrated).

Next, the coating liquid A-1 for forming a positive A plate A-1 was applied onto the photo-alignment treated surface using a bar coater. After aging for 20 seconds at a film surface temperature of 80 ° C. and cooling to 55 ° C., the sample was irradiated with 1000 mJ / cm ² of ultraviolet rays using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under air. The polarizing plate 1 was formed by fixing the alignment state. That is, the obtained polarizing plate 1 has a positive A plate A-1 as a retardation film, a photo-alignment film 1, a polarizer 1, and a polarizer protective film arranged in this order.
The formed positive A plate A-1 had a slow axis direction perpendicular to the absorption axis of the polarizing plate (that is, the specific liquid crystal compound was aligned perpendicular to the absorption axis of the polarizing plate). The positive A plate A-1 was measured for the light incident angle dependency of Re and the tilt angle of the optical axis using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). At 550 nm, Re is 145 nm, Rth is 73 nm, Re (550) / Re (450) is 1.11, Re (650) / Re (550) is 1.01, and the tilt angle of the optical axis is 0 °. The liquid crystal compound was homogeneously aligned.

<Example 2>
In Example 1, the polarizing plate 2 (retardation film) of Example 2 was prepared in the same manner as in Example 1 except that 0.5 part by mass of organic oxidant A-1 was used instead of 1 part by mass. As a positive A plate A-2).
When the optical properties of the positive A plate A-2 were measured, Re was 145 nm, Rth was 73 nm, Re (550) / Re (450) was 1.11 and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 3>
In Example 1, the polarizing plate 3 of Example 3 (positive as a retardation film) was prepared in the same manner as in Example 1, except that 20 parts by mass of organic oxidant A-1 was used instead of 1 part by mass. With A plate A-3).
When the optical properties of the positive A plate A-3 were measured, Re (550) / Re (450) was 1.11 and Re (650) / Re (550) was 1.01, and the tilt angle of the optical axis was 0 °. The specific liquid crystal compound had homogeneous alignment, but Re at a wavelength of 550 nm was 120 nm and Rth was 60 nm, which were lower than those of the positive A plate A-1 of Example 1. This is considered that the specific liquid crystal compound itself was oxidatively decomposed by the excess organic oxidant A-1.

<Example 4>
In Example 1, the polarizing plate 4 of Example 4 was prepared in the same manner as in Example 1 except that 3.0 parts by mass of the following organic oxidant A-2 was used instead of the organic oxidant A-1. A positive A plate A-4) was formed as a retardation film.
When the optical properties of the positive A plate A-4 were measured, Re was 145 nm, Rth was 73 nm, Re (550) / Re (450) was 1.11 and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 5>
In Example 1, in place of the organic oxidant A-1, 10 parts by mass of the following organic oxidant A-3 was used. With positive A plate A-5 as a film.
When the optical properties of the positive A plate A-5 were measured, Re was 137 nm, Rth was 69 nm, Re (550) / Re (450) was 1.11 and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 6>
In Example 1, in place of the organic oxidant A-1, 10 parts by mass of the following organic oxidant A-4 was used. With positive A plate A-6 as a film.
When the optical properties of the positive A plate A-6 were measured, Re was 137 nm, Rth was 69 nm, Re (550) / Re (450) was 1.11 and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 7>
In Example 1, Example 100 was used except that 100 parts by mass of the following specific liquid crystal compound L-5 was used instead of the polymerizable compound X-1, the specific liquid crystal compound L-1, and the specific liquid crystal compound L-2. A polarizing plate 7 of Example 7 (having positive A plate A-7 as a retardation film) was formed in the same manner.
When the optical properties of the positive A plate A-7 were measured, Re was 130 nm, Rth was 65 nm, Re (550) / Re (450) was 1.19, and Re (650) / Re (550) was 1 at a wavelength of 550 nm. 0.02, the tilt angle of the optical axis was 0.4 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 8>
In Example 1, Example 100 was used except that 100 parts by mass of the following specific liquid crystal compound L-6 was used instead of the polymerizable compound X-1, the specific liquid crystal compound L-1, and the specific liquid crystal compound L-2. A polarizing plate 8 of Example 8 (having positive A plate A-8 as a retardation film) was formed in the same manner.
When the optical properties of the positive A plate A-8 were measured, Re was 130 nm, Rth was 65 nm, Re (550) / Re (450) was 1.18, and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 9>
Example 1 is the same as Example 1 except that 100 parts by mass of the following specific liquid crystal compound L-7 is used instead of the polymerizable compound X-1, the specific liquid crystal compound L-1, and the specific liquid crystal compound L-2. A polarizing plate 9 of Example 9 (having positive A plate A-9 as a retardation film) was formed in the same manner.
When the optical properties of the positive A plate A-9 were measured, Re was 130 nm, Rth was 65 nm, Re (550) / Re (450) was 1.20, and Re (650) / Re (550) was 1 at a wavelength of 550 nm. .05, the tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Example 10>
Example 1 is the same as Example 1 except that 100 parts by mass of the following specific liquid crystal compound L-8 was used instead of the polymerizable compound X-1, the specific liquid crystal compound L-1, and the specific liquid crystal compound L-2. A polarizing plate 10 of Example 10 (having positive A plate A-10 as a retardation film) was formed in the same manner.
When the optical properties of the positive A plate A-10 were measured, Re was 130 nm, Rth was 65 nm, Re (550) / Re (450) was 1.14, and Re (650) / Re (550) was 1 at a wavelength of 550 nm. The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Comparative Examples 1 to 5>
A polarizing plate B1 of Comparative Example 1 (having a positive A plate B1 as a retardation film) was formed in the same manner as in Examples 1, 4 to 6 except that no organic oxidizing agent was used.
Forming polarizing plates B2 to B5 of Comparative Examples 2 to 5 (each having positive A plates B2 to B5 as retardation films) in the same manner as in Examples 7 to 10 except that no organic oxidizing agent is used did.
For positive A plates B1 to B5, Re and Rth, Re (550) / Re (450), Re (650) / Re (550) at a wavelength of 550 nm were measured in the same manner as in Example 1. The results are shown in Table 1 below.
The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

<Comparative Example 6>
In Example 1, in place of the organic oxidant A-1, 1.0 parts by mass of the following nitroso compound N-1 was used in the same manner as in Example 1, except that the polarizing plate B6 of Comparative Example 6 (position) A positive A plate B6) was formed as a phase difference film.
For the positive A plate B6, Re and Rth, Re (550) / Re (450), Re (650) / Re (550) at a wavelength of 550 nm were measured in the same manner as in Example 1. The results are shown in Table 1 below.
The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

In the formula representing the nitro compound N-1, “Ph” represents “phenyl group”.

<Comparative Example 7>
In Example 1, Polarizer B7 of Comparative Example 7 (in the same manner as in Example 1 except that 1.0 part by mass of organic peroxide N-2 was used instead of organic oxidant A-1). A positive A plate B7) was formed as a retardation film.
For the positive A plate B7, Re and Rth, Re (550) / Re (450), Re (650) / Re (550) at a wavelength of 550 nm were measured in the same manner as in Example 1. The results are shown in Table 1 below.
The tilt angle of the optical axis was 0 °, and the specific liquid crystal compound was homogeneously aligned.

[Evaluation test]
<Damp heat durability test>
About the polarizing plate produced by each Example and comparative example mentioned above, the positive A plate was made the glass side on the glass plate, and it bonded together through the adhesive (brand name "SK2057", the Soken Chemical Co., Ltd. make).
Using Axo Scan (0 PMF-1, manufactured by Axometrics), the wet heat durability of the retardation value (Re) at a wavelength of 550 nm was evaluated according to the following index. The results are shown in Table 1 below.
The wet heat endurance test condition was a test that was allowed to stand for 120 hours in an environment of 85 ° C. and a relative humidity of 85% RH. If it is evaluated as “A” or more, it can be determined that the durability is good.
AAA: Change amount of Re value after test with respect to initial Re value is less than 0.5% of initial value AA: Change amount of Re value after test with respect to initial Re value is 0.5% or more of initial value Less than 1% A: The amount of change in the Re value after the test with respect to the initial Re value is 1% or more and less than 2% of the initial value B: The amount of change in the Re value after the test with respect to the initial Re value is 2 of the initial value % To less than 10% C: The amount of change in the Re value after the test with respect to the initial Re value is 10% or more of the initial value

<Reduction potential>
About each oxidizing agent used by said Example and comparative example, the reduction potential (Ered) was measured as follows.
Specifically, a voltammogram of an oxidizing agent 1 × 10 ⁻³ M is measured in acetonitrile containing 0.1 M tetra-n-ethylammonium perchlorate as a supporting electrolyte, and a half-wave potential obtained therefrom is obtained. It was. Platinum was used for the working electrode, a saturated calomel electrode (SCE) was used for the reference electrode, and the measurement was performed at 25 ° C.

<Evaluation results>
The results of the above evaluation tests are shown in Table 1.

From the results shown in Table 1, when a polarizing plate containing a polymerizable liquid crystal composition containing no organic oxidant of the present invention was prepared, the Re value decreased by 2% or more when a wet heat durability test was performed, It was found that the durability was poor (Comparative Examples 1 to 7).
On the other hand, when producing a polarizing plate containing a polymerizable liquid crystal composition containing the organic oxidant of the present invention, it was found that the Re value change of less than 2% can be maintained, and the wet heat durability is excellent ( Examples 1 to 10).
From the comparison of Examples 1 to 3, when the content of the organic oxidizing agent of the present invention is in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the specific liquid crystal compound (Example 1), the wet heat durability is improved. I found it better.
The comparison between Examples 1 and 4 to 6 showed that wet heat durability was further improved by using an organic oxidizing agent having a reduction potential of 0.1 volts or more (Examples 1, 4, and 5).
From the evaluation results of Examples 7 to 10, it was shown that when the organic oxidizing agent of the present invention was contained, the wet liquid heat resistance was excellent even if the structures of the polymerizable liquid crystal compounds were different.

Claims

A polymerizable liquid crystal composition comprising an organic oxidant represented by the following general formula (A) and a polymerizable liquid crystal compound having reverse wavelength dispersion.

In the general formula (A), X 1 and X 2 each independently represent an oxygen atom, a sulfur atom, a ═NR 1 group, or a ═CR 2 R 3 group. When a plurality of X 1 and X 2 are present, the plurality of X 1 and the plurality of X 2 may be the same as or different from each other.
m and n each independently represents an integer of 0 to 3. However, the sum of m and n is 2 or more.
R 1 , R 2 and R 3 each independently represents a hydrogen atom or a substituent. When each of R 1, R 2 and R 3 there are a plurality, the plurality of R 1, a plurality of R 2 and a plurality of R 3 may be the same or different from each other.
L 1 and L 2 each independently represents a divalent linking group.
The polymerizable liquid crystal composition according to claim 1, wherein the polymerizable liquid crystal compound is a liquid crystal compound represented by the following general formula (II).
L 1 -G 1 -D 1 -Ar-D 2 -G 2 -L 2 (II)
In the general formula (II), D 1 and D 2 are each independently a single bond, —CO—O—, —C (═S) O—, —CR 1 R 2 —, —CR 1 R 2 —CR. 3 R 4 —, —O—CR 1 R 2 —, —CR 1 R 2 —O—CR 3 R 4 —, —CO—O—CR 1 R 2 —, —O—CO—CR 1 R 2 —, —CR 1 R 2 —O—CO—CR 3 R 4 —, —CR 1 R 2 —CO—O—CR 3 R 4 —, —NR 1 —CR 2 R 3 — or —CO—NR 1 — is represented. .
R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.
G 1 and G 2 each independently represents a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group includes —O—, —S—, It may be substituted with —NH—.
L 1 and L 2 each independently represent a monovalent organic group, and at least one selected from the group consisting of L 1 and L 2 represents a monovalent group having a polymerizable group.
Ar represents a divalent aromatic ring group represented by the following general formula (II-1), (II-2), (II-3) or (II-4).

In the general formulas (II-1) to (II-4), Q 1 represents —CH— or —N—, Q 2 represents —S—, —O—, or —NR 11 —, R 11 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Y 1 represents an aromatic hydrocarbon group having 6 to 12 carbon atoms, or an aromatic heterocyclic group having 3 to 12 carbon atoms, Z 1 , Z 2 and Z 3 are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a monovalent carbon atom having 6 to 20 carbon atoms. Represents an aromatic hydrocarbon group, a halogen atom, a cyano group, a nitro group, —NR 12 R 13 or —SR 12 , and Z 1 and Z 2 may be bonded to each other to form an aromatic ring or an aromatic heterocyclic ring. well, R 12 and R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms Each A 1 and A 2 are independently, -O -, - NR 21 - , - a group selected from the group consisting of S- and CO-, R 21 represents a hydrogen atom or a substituent, X is Represents a hydrogen atom or a non-metal atom of group 14 to group 16 to which a substituent may be bonded, and Ax represents at least one aromatic selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle Represents an organic group having 2 to 30 carbon atoms having a ring, and Ay represents a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an aromatic hydrocarbon ring and aromatic heterocycle. Represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of rings, and each of the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay are bonded to each other. Te, may form a ring, Q Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.
The polymerizable liquid crystal composition according to claim 1 or 2, wherein the reduction potential of the organic oxidant is nobler than 0 volt.
A retardation film formed using the polymerizable liquid crystal composition according to any one of claims 1 to 3,
Re (450) which is an in-plane retardation value measured at a wavelength of 450 nm, Re (550) which is an in-plane retardation value measured at a wavelength of 550 nm, and Re which is an in-plane retardation value measured at a wavelength of 650 nm (650) is a retardation film having a relationship of Re (450) ≦ Re (550) ≦ Re (650).
The retardation film according to claim 4, wherein the retardation film is a positive A plate.
The retardation film according to claim 5, wherein the positive A plate is a λ / 4 plate.
A polarizing plate comprising the retardation film according to any one of claims 4 to 6 and a polarizer.
A liquid crystal display device comprising the polarizing plate according to claim 7.
An organic electroluminescent device comprising the polarizing plate according to claim 7.