WO2020149205A1

WO2020149205A1 - Polymerizable liquid crystal composition, retardation plate, elliptically polarizing plate and organic el display device

Info

Publication number: WO2020149205A1
Application number: PCT/JP2020/000431
Authority: WO
Inventors: 由紀西上; 伸行幡中; 慶史小松; 鈴鹿住吉
Original assignee: 住友化学株式会社
Priority date: 2019-01-17
Filing date: 2020-01-09
Publication date: 2020-07-23

Abstract

A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound, at least one kind of primary antioxidant, at least one kind of secondary antioxidant and a photo-radical polymerization initiator, wherein the polymerizable liquid crystal compound has an ester structure and a (meth)acryloyl group and shows maximum absorption at a wavelength of 300-400 nm.

Description

Polymerizable liquid crystal composition, retardation plate, elliptically polarizing plate and organic EL display device

The present invention relates to a polymerizable liquid crystal composition, a retardation plate including a liquid crystal cured film which is a cured product of the polymerizable liquid crystal composition, an elliptically polarizing plate including the retardation plate, and an organic EL display device.

As a retardation plate used for a flat panel display, a retardation plate showing reverse wavelength dispersion is known (Patent Document 1). Particularly in recent years, there has been a demand for a thinner flat panel display, and a retardation plate including a liquid crystal cured layer formed by curing a polymerizable liquid crystal compound in an aligned state by irradiation with ultraviolet rays has been developed (Patent Document 2). ).

JP 2012-214801 A JP, 2005-163935, A

In recent years, flat panel displays are being used for a wider range of applications, including being used as in-vehicle image display devices such as car navigation systems and back monitors. Along with this, there is a demand for a retardation plate having excellent durability that is unlikely to change in performance even under severe conditions. In order to obtain a retardation plate in which such a performance change is unlikely to occur, it is necessary to sufficiently cure the polymerizable liquid crystal compound, and it is desirable to cure the polymerizable liquid crystal compound by irradiating sufficient ultraviolet rays.

However, a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound is generally low in stability and may cause gelation of the polymerizable liquid crystal compound during storage. In order to prevent such gelation, polymerization is prohibited. When the agent is blended, there is a problem that the polymerization inhibitor inhibits the curing of the polymerizable liquid crystal compound and the polymerization rate of the obtained retardation plate is lowered. In addition, a polymerizable liquid crystal compound exhibiting reverse wavelength dispersibility generally has maximum absorption in the ultraviolet region, and when irradiated with high-intensity ultraviolet light to increase the polymerization rate of the polymerizable liquid crystal compound, its optical The characteristics may be deteriorated, and the optical performance of the obtained retardation plate may not always be sufficiently satisfied.

An object of the present invention is to provide a polymerizable liquid crystal composition that has high stability during storage and can be polymerized at a high polymerization rate.

The present invention provides the following preferred embodiments.
[1] A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound, at least one primary antioxidant, at least one secondary antioxidant and a photoradical polymerization initiator, wherein the polymerizable liquid crystal compound is an ester. A polymerizable liquid crystal composition having a structure and a (meth)acryloyl group and exhibiting maximum absorption at a wavelength of 300 to 400 nm.
[2] The polymerizable liquid crystal composition according to the above [1], wherein the content of the primary antioxidant is 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound.
[3] The polymerizable liquid crystal composition according to the above [1] or [2], wherein the primary antioxidant is a phenol compound.
[4] The polymerizable liquid crystal composition according to any one of the above [1] to [3], wherein the molecular weight of the primary antioxidant is 400 g/mol or less.
[5] The polymerizable liquid crystal according to any one of the above [1] to [4], wherein the content of the secondary antioxidant is 0.1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. Composition.
[6] The polymerizable liquid crystal composition according to any one of the above [1] to [5], wherein the secondary antioxidant is a phosphite compound.
[7] The polymerizable liquid crystal composition according to any one of the above [1] to [6], wherein the secondary antioxidant has a molecular weight of 200 g/mol or more.
[8] The polymerizable liquid crystal composition according to any one of the above [1] to [7], wherein the radical photopolymerization initiator is an oxime photopolymerization initiator.
[9] The polymerizable liquid crystal composition according to any one of the above [1] to [8], which contains a polymerizable liquid crystal compound having a birefringence of a homopolymer exhibiting reverse wavelength dispersion.
[10] A cured product of the polymerizable liquid crystal composition according to any one of [1] to [9], which is a cured liquid crystal film in which the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is aligned. Retardation plate including.
[11] The retardation plate according to the above [10], wherein the content of the primary antioxidant in the liquid crystal cured film is 0.001 part by mass or less based on 100 parts by mass of the polymer of the polymerizable liquid crystal compound.
[12] In the above [10] or [11], the content of the secondary antioxidant in the cured liquid crystal film is 0.05 to 15 parts by mass with respect to 100 parts by mass of the polymer of the polymerizable liquid crystal compound. The retardation plate described.
[13] The liquid crystal cured film has the following formulas (I), (II) and (III):
Re(450)/Re(550)≦1.00 (I)
1.00≦Re(650)/Re(550) (II)
100 nm≦Re(550)≦180 nm (III)
[Wherein Re(λ) represents an in-plane retardation value at a wavelength λnm of the liquid crystal cured film, and Re=(nx(λ)−ny(λ))×d (d is the thickness of the liquid crystal cured film). In the refractive index ellipsoid formed by the liquid crystal cured film, nx represents the main refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film, and ny represents the refractive index ellipsoid formed by the liquid crystal cured film. , Represents the refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film and orthogonal to the nx direction)).
The retardation plate according to any one of [10] to [12], which has optical characteristics represented by
[14] The cured liquid crystal film has the following formulas (IV), (V) and (VI):
Rth(450)/Rth(550)≦1.00 (IV)
1.00≦Rth(650)/Rth(550) (V)
-100 nm ≤ Rth(550) ≤ -40 nm (VI)
[In the formula, Rth(λ) represents a retardation value in the thickness direction of the liquid crystal cured film at a wavelength of λ nm, and Rth=((nx(λ)+ny(λ))/2−nz)×d (d is Nx represents the thickness of the liquid crystal cured film, nx represents the main refractive index at a wavelength λnm in the direction parallel to the plane of the liquid crystal cured film in the refractive index ellipsoid formed by the liquid crystal cured film, and ny represents the liquid crystal cured film formed. In the refractive index ellipsoid, the refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film and orthogonal to the direction of nx is represented, and nz is the refraction formed by the liquid crystal cured film. In the index ellipsoid, the refractive index at the wavelength λnm in the direction perpendicular to the plane of the liquid crystal cured film is represented)], and the unit according to any one of the above [10] to [12]. Phase difference plate.
[15] The method for manufacturing a retardation plate according to any one of [10] to [14],
Forming a coating film of the polymerizable liquid crystal composition, drying the coating film to remove the primary antioxidant, and aligning the polymerizable liquid crystal compound in the polymerizable liquid crystal composition,
A method for manufacturing, comprising a step of polymerizing a polymerizable liquid crystal compound by light irradiation while maintaining an alignment state to form a liquid crystal cured film.
[16] An elliptically polarizing plate including the retardation plate according to any one of [10] to [14] and a polarizing film.
[17] An organic EL display device including the elliptically polarizing plate according to the above [16].

According to the present invention, it is possible to provide a polymerizable liquid crystal composition having high stability during storage and capable of being polymerized at a high polymerization rate.

Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

<Polymerizable liquid crystal composition>
The polymerizable liquid crystal composition of the present invention contains a polymerizable liquid crystal compound, at least one primary antioxidant, at least one secondary antioxidant, and a photoradical polymerization initiator. The polymerizable liquid crystal composition of the present invention contains a combination of a primary antioxidant and a secondary antioxidant, thereby suppressing deterioration of the polymerizable liquid crystal compound when stored for a long period of time as a polymerizable liquid crystal composition, and stable. It is possible to improve the sex. Furthermore, since the polymerizable liquid crystal composition can sufficiently cure the polymerizable liquid crystal compound while suppressing damage due to high-intensity ultraviolet rays, etc., the polymerizable liquid crystal composition has a liquid crystal cured film excellent in optical properties. Can be obtained. Therefore, it is considered that it is possible to obtain a retardation plate including a liquid crystal cured film that is unlikely to change in performance even under a harsh environment.

The polymerizable liquid crystal composition of the present invention comprises a polymerizable liquid crystal compound having an ester structure and a (meth)acryloyl group and exhibiting maximum absorption at a wavelength of 300 to 400 nm (hereinafter referred to as “polymerizable liquid crystal compound (A)”). (Also referred to as).
A polymerizable liquid crystal compound having an ester structure in its molecular structure is likely to be decomposed and deteriorated at the ester structure portion when exposed to light such as ultraviolet rays. For this reason, for example, by irradiating with high-intensity ultraviolet light during curing, the optical characteristics of the liquid crystal cured film formed from the polymerizable liquid crystal compound tends to deteriorate. Since the polymerizable liquid crystal composition of the present invention is excellent in the effect of suppressing photodegradation of the polymerizable liquid crystal compound, the effect of the present invention can be particularly remarkably exhibited when a polymerizable liquid crystal compound having an ester structure that easily causes photodegradation is used. ..

On the other hand, in a polymerizable liquid crystal composition containing a photopolymerization initiator, a polymerization reaction or gelation of the polymerizable liquid crystal compound may proceed during long-term storage, but the polymerizable liquid crystal compound showing maximum absorption at a wavelength of 300 to 400 nm. By containing, even when exposed to ultraviolet light during storage, it is possible to effectively suppress the generation of reaction active species from the photopolymerization initiator and the progress of the polymerization reaction and gelation of the polymerizable liquid crystal compound by the reaction active species. .. Therefore, in the polymerizable liquid crystal composition of the present invention containing a photo-radical polymerization initiator, the polymerizable liquid crystal compound exhibiting the maximum absorption at a wavelength of 300 to 400 nm is contained, whereby the long-term stability of the polymerizable liquid crystal composition is improved. This is advantageous, and the orientation and film thickness uniformity of the resulting liquid crystal cured film can be improved. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent capable of dissolving the polymerizable liquid crystal compound, and examples thereof include chloroform.

In the present invention, the polymerizable liquid crystal compound (A) means a liquid crystal compound having a photopolymerizable group, a polymerizable liquid crystal compound having an ester structure and a (meth)acryloyl group, and having a maximum absorption at a wavelength of 300 to 400 nm. There is no particular limitation as long as it is a liquid crystal compound, and for example, a polymerizable liquid crystal compound known in the art in the field of retardation plates can be used.

In the present invention, the photopolymerizable group is a polymerizable group and refers to a reactive active species generated from a photopolymerization initiator, for example, a group capable of participating in a polymerization reaction by an active radical or an acid, such as vinyl. Group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyl group, methacryloyl group, oxiranyl group and oxetanyl group. When the polymerizable liquid crystal compound (A) is a liquid crystal compound having one photopolymerizable group, the photopolymerizable group is a (meth)acryloyl group. When the polymerizable liquid crystal compound (A) has two or more photopolymerizable groups, at least one of them is a (meth)acryloyl group, and all the photopolymerizable groups contained in the polymerizable liquid crystal compound (A). Is preferably a (meth)acryloyl group. In addition, in this specification, (meth)acryloyl means an acryloyl group or a methacryloyl group.

In the present invention, the liquid crystallinity exhibited by the polymerizable liquid crystal compound (A) may be a thermotropic liquid crystal or a lyotropic liquid crystal, but the thermotropic property is that the film thickness can be precisely controlled. Liquid crystals are preferred. The phase ordered structure in the thermotropic liquid crystal may be nematic liquid crystal or smectic liquid crystal. As the polymerizable liquid crystal compound (A), only one kind may be used, or two or more kinds may be used in combination.

Examples of the polymerizable liquid crystal compound (A) include compounds having the following characteristics (a) to (d).
(A) A compound capable of forming a nematic phase or a smectic phase.
(A) Having π electrons in the major axis direction (a) of the polymerizable liquid crystal compound.
(C) π electrons are present in a direction [intersection direction (b)] intersecting with the major axis direction (a).
(D) A polymerizable liquid crystal compound defined by the following formula (i), where N(πa) is the total of π electrons existing in the major axis direction (a) and N(Aa) is the total of molecular weights present in the major axis direction. Π electron density in the major axis direction (a) of:
D(πa)=N(πa)/N(Aa) (i)
And a total of π electrons existing in the cross direction (b) is N(πb), and a total of molecular weights existing in the cross direction (b) is N(Ab), and the polymerizable liquid crystal compound is defined by the following formula (ii). Π electron density in the cross direction (b) of:
D(πb)=N(πb)/N(Ab) (ii)
And are expressions (iii)
0≦[D(πa)/D(πb)]<1 (iii)
(That is, the π electron density in the cross direction (b) is higher than the π electron density in the major axis direction (a)). Further, as described above, a polymerizable liquid crystal compound having π electrons in the major axis and in a direction intersecting with the major axis is generally likely to have a T-shaped structure.

In the above features (a) to (d), the major axis direction (a) and the π electron number N are defined as follows.
The major axis direction (a) is, for example, a rod-shaped major axis direction in the case of a compound having a rod-shaped structure.
The number of π electrons N (πa) existing in the major axis direction (a) does not include π electrons that disappear due to the polymerization reaction.
-The number of π electrons existing in the major axis direction (a) is the total number of π electrons on the major axis and π electrons conjugated with this, and exists in the major axis direction (a), for example. The number of π electrons existing in a ring that satisfies Huckel's rule is included.
The number of π electrons N (πb) existing in the cross direction (b) does not include π electrons that disappear due to the polymerization reaction.
The polymerizable liquid crystal compound satisfying the above has a mesogenic structure in the major axis direction. A liquid crystal phase (nematic phase, smectic phase) is developed by this mesogenic structure.

The polymerizable liquid crystal compound satisfying the above (a) to (d) can be applied on the substrate or the alignment film and heated to the phase transition temperature or higher to form a nematic phase or a smectic phase. In the nematic phase or smectic phase formed by aligning the polymerizable liquid crystal compound, the polymerizable liquid crystal compounds are usually aligned such that the major axis directions thereof are parallel to each other, and the major axis direction is the alignment direction of the nematic phase. Becomes When such a polymerizable liquid crystal compound is formed into a film and polymerized in a state of a nematic phase or a smectic phase, a polymer film composed of a polymer polymerized in a state of being aligned in the major axis direction (a) can be formed. .. This polymer film absorbs ultraviolet rays by π electrons in the major axis direction (a) and π electrons in the cross direction (b). Here, the maximum absorption wavelength of ultraviolet rays absorbed by π electrons in the crossing direction (b) is λbmax. λbmax is usually 300 nm to 400 nm. The density of π electrons satisfies the above formula (iii), and the π electron density in the crossing direction (b) is higher than the π electron density in the major axis direction (a). The absorption of the linearly polarized ultraviolet light having a wavelength of λbmax is larger than that of the linearly polarized ultraviolet light having a vibration plane in the major axis direction (a) (the wavelength is λbmax). The ratio (the ratio of the absorbance in the crossing direction (b) of the linearly polarized ultraviolet light/the absorbance in the major axis direction (a)) is, for example, more than 1.0, preferably 1.2 or more and usually 30 or less, for example 10 or less. Is.

In general, the polymerizable liquid crystal compound having the above-mentioned characteristics is often one in which the birefringence of the homopolymer in the aligned state exhibits reverse wavelength dispersion. From the viewpoint of easily obtaining a liquid crystal cured film having more excellent optical properties, it is preferable that the polymerizable compound (A) contained in the polymerizable liquid crystal composition of the present invention is a homopolymer thereof having reverse wavelength dispersion.

As the polymerizable liquid crystal compound (A), specifically, for example, the following formula (A1):

The compound represented by

In formula (A1), Ar represents a divalent group having an aromatic group which may have a substituent. The term “aromatic group” as used herein refers to an aromatic group having a number of π electrons of [4n+2] according to Huckel's rule, and is exemplified by (Ar-1) to (Ar-23) described later. You may have two or more such Ar groups through the bivalent coupling group. Here, n represents an integer. In the case where a ring structure is formed by containing a hetero atom such as -N= or -S-, the case where the Hückel rule is satisfied including the non-covalent bond electron pair on these hetero atoms and the aromatic structure is also included. It is preferable that the aromatic group contains at least one of a nitrogen atom, an oxygen atom and a sulfur atom. The divalent group Ar may contain one aromatic group or two or more aromatic groups. When there is one aromatic group, the divalent group Ar may be a divalent aromatic group which may have a substituent. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups are bonded to each other by a single bond or a divalent bonding group such as —CO—O— or —O—. May be.
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a carbon atom. The carbon atom which may be substituted with an alkoxy group, a cyano group or a nitro group of the formulas 1 to 4 and which constitutes the divalent aromatic group or divalent alicyclic hydrocarbon group is an oxygen atom or a sulfur atom. Alternatively, it may be substituted with a nitrogen atom.
L ¹ and L ² are each independently a divalent linking group having an ester structure.
B ¹ and B ² are each independently a single bond or a divalent linking group.
k and l each independently represent an integer of 0 to 3 and satisfy the relationship of 1≦k+l. Here, when 2≦k+1, B ¹ and B ² , and G ¹ and G ² may be the same as or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, and an alkanediyl group having 4 to 12 carbon atoms is more preferable. Further, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and —CH ₂ — contained in the alkanediyl group is —O—, —S—, —SiH ₂ —, —C. It may be substituted with (=O)-.
P ¹ and P ² each independently represent a photopolymerizable group or a hydrogen atom, and at least one is a (meth)acryloyl group.

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

L ¹ and L ² are each independently preferably —R ^a1 COOR ^a2 — (R ^a1 and R ^a2 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms), and more preferably — COOR ^a2-1 - a ^{(R a2-1} is a single _{_{bond, -CH 2 -, - - CH}} 2 CH 2 of representing any), more preferably -COO- or -COOCH ₂ CH ₂ - is.

B ¹ and B ² are preferably each independently a single bond, an alkylene group having 1 to 4 carbon atoms, —O—, —S—, —R ^a3 OR ^a4 —, —R ^a5 COOR ^a6 —, —R. ^a7 OCOR ^a8 −, or —R ^a9 OC═OOR ^a10 −. Here, R ^a3 to R ^a10 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently, more preferably a single bond, —OR ^a4-1 —, —CH ₂ —, —CH ₂ CH ₂ —, ^{—COOR a6-1} —, or —OCOR ^a8-1 —. is there. Here, R ^a4-1 , R ^a6-1 and R ^a8-1 each independently represent a single bond, —CH ₂ — or —CH ₂ CH ₂ —. B ¹ and ^{B 2} are each independently more preferably a single _{_{bond, -O -, - CH 2 CH}} 2 -, - COO -, - COOCH 2 CH 2 -, - OCO- or -OCOCH ₂ CH ₂ - is ..

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

Examples of the photopolymerizable group represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyl group, methacryloyl group, oxiranyl group, And oxetanyl group and the like. Of P ¹ or P ^2, at least one acryloyl group or a methacryloyl group, P ¹ and P ² are both an acryloyl group or a methacryloyl group is preferable, an acryloyl group is more preferable.

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

In formula (A1), the total number N _π of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, further preferably 14 or more, and particularly It is preferably 16 or more. Further, it is preferably 30 or less, more preferably 26 or less, and further preferably 24 or less.

Examples of the aromatic group represented by Ar include the following groups.

In formulas (Ar-1) to (Ar-23), * indicates a connecting part, and Z ⁰ , Z ¹ and Z ² are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 12 carbon atoms. Group, cyano group, nitro group, alkylsulfinyl group having 1 to 12 carbon atoms, alkylsulfonyl group having 1 to 12 carbon atoms, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, Alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms or carbon It represents an N,N-dialkylsulfamoyl group of the number 2 to 12. Further, Z ⁰ , Z ¹ and Z ² may include a polymerizable group.

Q ¹ and Q ² each independently represent —CR ^1′ R ^2′ —, —S—, —NH—, —NR ^1′ —, —CO— or —O—, and R ^1′ and R ^{2 '} Independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

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

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

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

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group, and phenyl group. , A naphthyl group is preferable, and a phenyl group is more preferable. The aromatic heterocyclic group includes a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, a benzothiazolyl group and the like, a nitrogen atom, an oxygen atom, a sulfur atom and the like, which has at least one hetero atom and has 4 to 20 carbon atoms. Examples of the aromatic heterocyclic group include furyl group, thienyl group, pyridinyl group, thiazolyl group and benzothiazolyl group.

Y ¹ , Y ² and Y ³ may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group means a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group means a condensed polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

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

Q ¹ and Q ² are preferably —NH—, —S—, —NR ^1′ — and —O—, and R ^1′ is preferably a hydrogen atom. Of these, —S—, —O—, and —NH— are particularly preferable.

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

In formulas (Ar-16) to (Ar-23), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Examples of the aromatic heterocyclic group include those described above as the aromatic heterocyclic ring which Ar may have, and examples thereof include a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring and an indole. Ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring and the like. This aromatic heterocyclic group may have a substituent. Y ¹ may be the above-mentioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Examples thereof include a benzofuran ring, a benzothiazole ring, a benzoxazole ring and the like.

The polymerizable liquid crystal composition of the present invention may contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (A) as long as it does not affect the effects of the present invention. Examples of such a polymerizable liquid crystal compound include polymerization as described in JP 2010-31223 A, JP 2010-270108 A, JP 2011-6360 A and JP 2011-207765 A. Liquid crystal compounds, polymerizable liquid crystal compounds exhibiting positive wavelength dispersion, and the like.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition. %, more preferably 85 to 98 parts by mass, still more preferably 90 to 95 parts by mass. When the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the resulting liquid crystal cured film. In addition, in the present specification, the solid content of the polymerizable liquid crystal composition means all components excluding volatile components such as an organic solvent from the polymerizable liquid crystal composition.

The polymerizable liquid crystal composition of the present invention contains a primary antioxidant. By containing the primary antioxidant, gelation of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition is suppressed, and the storage stability of the polymerizable liquid crystal composition can be enhanced. Examples of primary antioxidants include phenolic antioxidants and amine antioxidants that have a function of trapping generated radicals. As the primary antioxidant, only one kind may be used, or two or more kinds may be used in combination.

Examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,6-dicyclohexyl-4-methylphenol. 2,6-di-tert-amyl-4-methylphenol, 2,6-di-tert-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4 -Methyl-6-tert-butylphenol, 2-tert-butyl-2-ethyl-6-tert-octylphenol, 2-isobutyl-4-ethyl-6-tert-hexylphenol, 2-cyclohexyl-4-n-butyl- 6-isopropylphenol, dl-α-tocopherol, tert-butylhydroquinone, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol) ), 4,4′-thiobis(3-methyl-6-tert-butylphenol), 2,2′-thiobis(4-methyl-6-tert-butylphenol), 4,4′-methylenebis(2,6-di) -Tert-butylphenol), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2' -Butylidene bis(2-tert-butyl-4-methylphenol), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1 -(2-Hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 1,1,3-tris(2-methyl-4-hydroxy-5- tert-butylphenyl)butane, triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol bis[3-(3,5-di- tert-Butyl-4-hydroxyphenyl)propionate], 2,2-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N′-hexamethylenebis( 3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-te rt-Butyl-4-hydroxybenzylphosphonate diethyl ester, tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, tris(3,5-di-tert-butyl-4-hydroxybenzyl) ) Isocyanurate, tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, tris(4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate , 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, tetrakis[methylene-3-(3,5-di -Tert-butyl-4-hydroxyphenyl)propionate]methane, 2,2'-methylenebis(4-methyl-6-tert-butylphenol)terephthalate, 1,3,5-trimethyl-2,4,6-tris(3 ,5-Di-tert-butyl-4-hydroxybenzyl)benzene, 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyl Oxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, 2,2-bis[4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinna Moyloxy))ethoxyphenyl]propane, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid stearyl ester and the like.

Commercially available products may be used as the phenolic antioxidant. Examples of commercially available phenolic antioxidants include Sumilizer (registered trademark) BHT (2,6-di-t-butyl-4-methylphenol) and Sumilizer GM (2-tert-butyl-6-(3 -Tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate), Sumilizer GS(F)(2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl ]-4,6-Di-tert-pentylphenyl acrylate), Sumilizer GA-80 (3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]] -1,1-Dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane), Sumilizer MDP-S (2,2'-methylenebis(6-tert-butyl-4-methylphenol) )), Sumilizer BBM-S (4,4′-butylidene bis(6-tert-butyl-3-methylphenol)), Sumilizer WX-R (4,4′-thiobis(6-tert-butyl-3-methylphenol) )), Sumilizer L(S) (all manufactured by Sumitomo Chemical Co., Ltd.), Irganox (registered trademark) 1010 (tetrakis[methylene-3-(3′,5′-di-tert-butyl-) 4'-hydroxyphenyl)propionate]methane), Irganox 1035 (2,2-thio[diethylbis-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), Irganox 1076 (β- (3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid stearyl ester), Irganox 1098 (N,N′-(1,6-hexanediyl)bis[3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionamide]), Irganox 1135 (3-(4-hydroxy-3,5-diisopropylphenyl)octyl propionate), Irganox 1330 (1,3,5-trimethyl-2) , 4,6-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene), Irganox 1726 (2,4-bis(dodecylthiomethyl)-6-methylphenol), Irganox 1425WL, Irganox 1520L (2,4-bis(octylthiomethyl)-6-methylphenol), Irganox 245 (3,6-dioxaoctane-1,8-diolbis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propanoate]), Irganox 259 (1,6-hexanediolbis[3 -(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), Irganox 3114 (tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate), Irganox 565 ( 6-(4-hydroxy-3,5-di-tert-butylanilino)-2,4-bis(octylthio)-1,3,5-triazine), Irganox 295, Irganox 3125 (Tris[(3,5 -Di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate) (all manufactured by BASF Japan Ltd.), Cyanox 1790 (tris(2,6-dimethyl-3-hydroxy-4-t-). Butylbenzyl) isocyanurate) (Cyanox 1790, manufactured by Cytec), vitamin E (dl-α-tocopherol) (manufactured by Eisai) and the like. The phenolic antioxidants may be used alone or in combination of two or more.

Examples of amine-based antioxidants include N,N′-di-sec-butyl-p-phenylenediamine, N,N′-di-isopropyl-p-phenylenediamine, N,N′-bis(1,4) -Dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N'-phenyl- p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N '-Phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'-di-tert-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine , Alkylated diphenylamine and the like.

A commercially available product may be used as the amine antioxidant. Examples of commercially available amine-based antioxidants include Sumilizer BPA (N,N′-di-sec-butyl-p-phenylenediamine), Sumilizer BPA-M1, Sumilizer 4ML (p-phenylenediamine derivative), Sumilizer 9A (alkalinized difinylamine) and the like.
The amine antioxidant may be used alone or in combination of two or more kinds.

From the viewpoint of effectively suppressing gelation of the polymerizable liquid crystal composition and obtaining high storage stability, the polymerizable liquid crystal composition of the present invention preferably contains a phenol compound as a primary antioxidant.

The molecular weight of the primary antioxidant is preferably 400 g/mol or less, more preferably 350 g/mol or less, further preferably 300 g/mol or less, and particularly preferably 250 g/mol or less. When the molecular weight of the primary antioxidant is not more than the above upper limit, the radical scavenging function is sufficiently exhibited in the polymerizable liquid crystal composition, and gelation of the polymerizable liquid crystal compound when the polymerizable liquid crystal composition is stored for a long time is suppressed. In addition, when producing a liquid crystal cured film from a polymerizable liquid crystal composition, the primary antioxidant is easily vaporized in a drying step or the like, and the polymerization rate of the polymerizable liquid crystal compound is suppressed by suppressing the influence on the polymerization. Can be realized. The lower limit of the molecular weight of the primary antioxidant is not particularly limited, and may be 90 g/mol or more, for example.

The content of the primary antioxidant in the polymerizable liquid crystal composition of the present invention is preferably 0.1 to 5 parts by mass, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the polymerizable liquid crystal compound. , And more preferably 3 parts by mass or less. When the content of the primary antioxidant is at least the above lower limit, the polymerizable liquid crystal composition can sufficiently function as a radical scavenger, and when the content is at most the above upper limit, the influence on the polymerization of the polymerizable liquid crystal compound is exerted. Can be suppressed and a high polymerization rate can be realized.

The polymerizable liquid crystal composition of the present invention contains a secondary antioxidant. By containing a secondary antioxidant, it is possible to suppress damage to the polymerizable liquid crystal compound when the polymerizable liquid crystal composition is irradiated with ultraviolet rays or the like to form a liquid crystal cured film, and thus the liquid crystal is cured with excellent optical properties. A membrane can be obtained.
Further, when the polymerizable liquid crystal compound is cured, it is possible to irradiate ultraviolet rays with higher intensity while suppressing damage to the polymerizable liquid crystal compound, and thus the polymerizable liquid crystal compound can be sufficiently cured. Therefore, it is considered that the polymerizable liquid crystal composition can be used to prepare a liquid crystal cured film having high durability in which change in optical performance hardly occurs even in a severe environment such as a high temperature environment.
Examples of secondary antioxidants include phosphorus-based antioxidants and sulfur-based antioxidants that have the function of decomposing peroxides generated from radicals. As the secondary antioxidant, only one kind may be used, or two or more kinds may be used in combination.

Examples of phosphorus-based antioxidants include trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, (octyl)diphenyl phosphite, tris(2,4-di-tert-butylphenyl)phosphite, triphenyl Phosphite, tris(butoxyethyl)phosphite, tris(nonylphenyl)phosphite, distearyl pentaerythritol diphosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-) 4-hydroxyphenyl)butanediphosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidenediphenyldiphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert) -Butylphenol) diphosphite, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, tris(mono/di mixed nonylphenyl)phosphite, hydrogenated-4,4'-isopropylidenediphenol poly Phosphite, bis(octylphenyl)bis[4,4'-butylidenebis(3-methyl-6-tert-butylphenol)]-1,6-hexanediol diphosphite, phenyl(4,4'-isopropylidenediphenol) ) Pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris[4,4'-isopropylidene bis(2-tert-butylphenol)] phosphite, di(isodecyl)phenyl phosphite, 4,4'-isopropyi Ridene bis(2-tert-butylphenol)bis(nonylphenyl)phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, bis(2,4-di-tert-butyl) -6-Methylphenyl)ethyl phosphite, 2-[{2,4,8,10-tetra-tert-butyldibenz[d,f][1.3.2]-dioxaphosphepin-6-yl} Oxy]-N,N-bis[2-[{2,4,8,10-tetra-tert-butyldibenz[d,f][1.3.2]-dioxaphosphepin-6-yl}oxy ] Ethyl]ethanamine, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenz[d,f][1. 3.2]-dioxaphosphepine Can be mentioned.

A commercially available product may be used as the phosphorus antioxidant. Examples of commercially available phosphorus antioxidants include Sumilizer GP (6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra -Tert-butyl-dibenzo[d,f][1,3,2]dioxaphosphepine) (manufactured by Sumitomo Chemical Co., Ltd.), Irgafos (registered trademark) 168 (tris(2,4-di -Tert-butylphenyl)phosphite), Irgafos 12 (2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphos) Fepin 6-yl]oxy]-N,N-bis[2-[[2,4,8,10-tetrakis(1,1dimethylethyl)dibenzo[d,f][1,3,2]di] Oxaphosfepin-6-yl]oxy]-ethyl]ethanamine), Irgafos 38 (all manufactured by BASF Japan Ltd.), Adekastab TTP (triphenylphosphite), Adekastab 329K, Adekastab PEP36 (cyclic neopentane) Tetrayl bis(2,6-di-t-butyl-4-methylphenyl) phosphite), ADEKA STAB PEP-8 (distearyl pentaerythritol diphosphite) (all from ADEKA), Sandstab P-EPQ (Clariant) Manufactured by GE), Weston 618, Weston 619G, Ultra Knox 626 (all manufactured by GE) and the like. The phosphorus-based antioxidants may be used alone or in combination of two or more.

Examples of sulfur-based antioxidants include dialkylthiodipropionates such as dilaurylthiodipropionate, dimyristylthiodipropionate and distearylthiodipropionate; polyhydric alcohol esters of butylthiopropionic acid, octylthiopropionate. Propionic acid polyhydric alcohol ester, lauryl thiopropionic acid polyhydric alcohol ester, stearyl thiopropionic acid polyhydric alcohol ester (as the polyhydric alcohol, for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol , Trishydroxyethyl isocyanurate, etc.) and polyhydric alcohol esters of alkylthiopropionic acid such as pentaerythryltetrakis-3-laurylthiopropionate.

A commercially available product may be used as the sulfur antioxidant. Examples of commercially available sulfur antioxidants include Sumilizer TPL-R (dilauryl-3,3′-thiodipropionate), Sumilizer TPM (dimyristyl-3,3′-thiodipropionate), Sumilizer TPS. (Distearyl-3,3'-thiodipropionate), Sumilizer TP-D (pentaerythrityl tetrakis (3-lauryl thiopropionate), Sumilizer MB (2-mercaptobenzimidazole) (above, all Sumitomo Chemical ( Co., Ltd.), DTDPA (dithiopropionic acid) (manufactured by SC Organic Chemical Co., Ltd.), etc. The sulfur antioxidants may be used alone or in combination of two or more kinds.

The polymerizable liquid crystal composition of the present invention preferably contains a phosphite compound as a secondary antioxidant from the viewpoint of effectively suppressing deterioration of the liquid crystal upon light irradiation.

The molecular weight of the secondary antioxidant is preferably 200 g/mol or more, more preferably 250 g/mol or more, even more preferably 280 g/mol or more. When the molecular weight of the secondary antioxidant is at least the above lower limit, the secondary antioxidant is less likely to disappear in the process of forming a liquid crystal cured film from the polymerizable liquid crystal composition, and the polymerizable liquid crystal compound when irradiated with ultraviolet rays or the like. It is possible to suppress damage to the liquid crystal and obtain a liquid crystal cured film having excellent optical characteristics. Further, it becomes possible to irradiate the ultraviolet ray with higher intensity, and thereby the polymerizable liquid crystal compound can be sufficiently cured. Therefore, it is considered possible to produce a liquid crystal cured film having high durability in which the optical performance is unlikely to change even under a severe environment such as a high temperature environment. On the other hand, when the molecular weight of the secondary antioxidant is too large, alignment defects of the polymerizable liquid crystal compound due to the secondary antioxidant are likely to occur. Therefore, the molecular weight of the secondary antioxidant is preferably 1500 g/mol or less, It is preferably 1000 g/mol or less.

The molecular weight of the secondary antioxidant in the polymerizable liquid crystal composition of the present invention is preferably larger than the molecular weight of the primary antioxidant, preferably within the above upper and lower limits. When the molecular weight of the secondary antioxidant is larger than that of the primary antioxidant, high storage stability can be achieved, while a liquid crystal cured film having high durability can be obtained while suppressing a decrease in the polymerization rate. it can.

The content of the secondary antioxidant in the polymerizable liquid crystal composition of the present invention is preferably 0.1 to 15 parts by mass, more preferably 0.5 part by mass, based on 100 parts by mass of the polymerizable liquid crystal compound. The amount is more preferably 1 part by mass or more, particularly preferably 2 parts by mass or more, more preferably 14 parts by mass or less, and further preferably 12 parts by mass or less. When the content of the secondary antioxidant is at least the above lower limit value, the function as a decomposer of the peroxide generated from radicals can be sufficiently fulfilled, and when it is at most the above upper limit value, the polymerizable liquid crystal compound is aligned. It is possible to obtain a liquid crystal cured film that hardly affects and has few alignment defects.

The content of the secondary antioxidant in the polymerizable liquid crystal composition of the present invention is preferably larger than the content of the primary antioxidant. When the content of the secondary antioxidant is higher than that of the primary antioxidant, the intermolecular interaction with other components of the primary antioxidant in the polymerizable liquid crystal composition is affected, and the primary oxidation occurs in the drying process. The inhibitor may be easily vaporized. For example, the content of the secondary antioxidant and the primary antioxidant (mass ratio secondary antioxidant:primary antioxidant) is preferably 2:1 to 150:1, more preferably 5:1 to 100: It is 1.

The polymerizable liquid crystal composition of the present invention contains a photo radical polymerization initiator. Examples of the photoradical polymerization initiator include benzoin compounds, benzophenone compounds, benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, oxime compounds, triazine compounds, iodonium salts and sulfonium salts. As the photo-radical polymerization initiator, only one kind may be used, or two or more kinds may be used in combination.

A commercially available product may be used as the photoradical polymerization initiator. As such commercial products, specifically, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369, Irgacure 379, Irgacure 127, Irgacure 2959, Irgacure 754, Irgacure 379EG. (Above, manufactured by BASF Japan Ltd.), SEQUOL BZ, SEQUOL Z, SEQUOL BEE (above, manufactured by Seiko Chemical Co., Ltd.), kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow). ), Adeka Optimer SP-152, Adeka Optimer SP-170, Adeka Optimer N-1717, Adeka Optimer N-1919, Adeka Arcules NCI-831, Adeka Arcules NCI-930 (above, manufactured by ADEKA Corporation) ), TAZ-A, TAZ-PP (above, manufactured by Nihon Siber Hegner) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).

The photoradical polymerization initiator is capable of fully utilizing the energy emitted from the light source and is excellent in productivity. Therefore, the maximum absorption wavelength thereof is preferably 300 nm to 400 nm, more preferably 300 nm to 380 nm, and particularly α-acetophenone. A system polymerization initiator and an oxime system photopolymerization initiator are preferred.

Examples of the α-acetophenone compound include 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one and 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutane-1. -One and 2-dimethylamino-1-(4-morpholinophenyl)-2-(4-methylphenylmethyl)butan-1-one and the like, and more preferably 2-methyl-2-morpholino-1-( 4-Methylsulfanylphenyl)propan-1-one and 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one. Examples of commercially available α-acetophenone compounds include Irgacure 369, 379EG, 907 (all manufactured by BASF Japan Ltd.) and Sequol BEE (manufactured by Seiko Chemical Co., Ltd.).

Oxime-based photopolymerization initiators generate radicals such as phenyl radicals and methyl radicals when irradiated with light. Polymerization of the polymerizable liquid crystal compound suitably proceeds with this radical, but among them, an oxime-based photopolymerization initiator that generates a methyl radical is preferable because the initiation efficiency of the polymerization reaction is high. Further, from the viewpoint of more efficiently proceeding the polymerization reaction, it is preferable to use a photopolymerization initiator capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more. As the photoradical polymerization initiator that can efficiently use ultraviolet rays having a wavelength of 350 nm or more, a triazine compound or a carbazole compound having an oxime structure is preferable, and a carbazole compound having an oxime ester structure is more preferable from the viewpoint of sensitivity. In addition, an oxime ester compound having a thioether structure is also preferable in that a liquid crystal cured film having good optical characteristics can be easily obtained. The carbazole compound containing an oxime structure includes 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methyl Examples thereof include benzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime). Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (above, manufactured by BASF Japan Ltd.), Adeka Optimer N-1919, and Adeka Arcules NCI-831. (Above, manufactured by ADEKA Co., Ltd.) and the like.

The content of the photoradical polymerization initiator is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is a department. Within the above range, the reaction of the polymerizable group sufficiently proceeds, and it is difficult to disturb the alignment of the polymerizable liquid crystal compound.
When the polymerizable liquid crystal composition of the invention contains two or more photo radical polymerization initiators, the total content of the photo radical polymerization initiators is preferably within the above range.

The polymerizable liquid crystal composition of the present invention preferably contains at least one oxime photopolymerization initiator, and more preferably contains an oxime ester compound having a thioether structure.
When the polymerizable liquid crystal composition of the invention contains two or more photo-radical polymerization initiators, it preferably contains an oxime-based photopolymerization initiator and an α-acetophenone-based polymerization initiator. As the α-acetophenone-based polymerization initiator, an alkylphenone-based polymerization initiator is preferable, and an α-aminoalkylphenone-based polymerization initiator is more preferable.

The polymerizable liquid crystal composition of the present invention further comprises a polymerizable liquid crystal compound, a primary antioxidant, a secondary antioxidant and a photoradical polymerization initiator, as well as a solvent, a leveling agent, a photosensitizer and other additives. May be included. Each of these components may be used alone or in combination of two or more.

Since the polymerizable liquid crystal composition is usually applied to a substrate or the like in a state of being dissolved in a solvent, it is preferable to include the solvent. As the solvent, a solvent capable of dissolving the polymerizable liquid crystal compound is preferable, and a solvent inert to the polymerization reaction of the polymerizable liquid crystal compound is preferable. Examples of the solvent include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, propylene glycol monomethyl ether, and the like. Solvents; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone Ketone solvent; Aliphatic hydrocarbon solvent such as pentane, hexane and heptane; Alicyclic hydrocarbon solvent such as ethylcyclohexane; Aromatic hydrocarbon solvent such as toluene and xylene; Nitrile solvent such as acetonitrile; Tetrahydrofuran and dimethoxyethane etc. Ether solvents; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone (NMP), and 1,3-dimethyl-2-imidazolidinone. To be These solvents can be used alone or in combination of two or more. Among these, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents and aromatic hydrocarbon solvents are preferable.

The content of the solvent in the polymerizable liquid crystal composition is preferably 50 to 98 parts by weight, more preferably 70 to 95 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal composition. Therefore, the solid content in 100 parts by mass of the polymerizable liquid crystal composition is preferably 2 to 50 parts by mass. When the solid content is 50 parts by mass or less, the viscosity of the polymerizable liquid crystal composition becomes low, so that the thickness of the film becomes substantially uniform and unevenness tends not to occur easily. The solid content can be appropriately determined in consideration of the thickness of the liquid crystal cured film to be produced.

The leveling agent is an additive having a function of adjusting the fluidity of the polymerizable liquid crystal composition and making the coating film obtained by applying the composition more flat. Fluoroalkyl-based leveling agents may be mentioned. A commercially available product may be used as the leveling agent, and specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Toray Dow Corning Co., Ltd.) , KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4452, TSF4452. (These are all manufactured by Momentive Performance Materials Japan LLC), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Limited) ), Megafac (registered trademark) R-08, same R-30, same R-90, same F-410, same F-411, same F-443, same F-445, same F-470, same F- 477, F-479, F-482, F-483, F-556 (all manufactured by DIC Corporation), Ftop (trade name) EF301, EF303, EF351, EF352 ( As above, Mitsubishi Materials Denshi Kasei Co., Ltd., Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40 , SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratories, Inc.), BM-1000, BM-1100, BYK-352, BYK-353, and BYK-361N (both are trade names: BM Chemie). The leveling agents can be used alone or in combination of two or more.

The content of the leveling agent is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is easy to align the polymerizable liquid crystal compound, and the obtained liquid crystal cured film tends to be smoother, which is preferable.

Also, by using a photosensitizer, the photoradical polymerization initiator can be made highly sensitive. Examples of the photosensitizer include xanthones such as xanthone and thioxanthone; anthracenes having a substituent such as anthracene and alkyl ether; phenothiazine; rubrene. The photosensitizer can be used alone or in combination of two or more kinds. The content of the photosensitizer is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. 3 parts by mass.

The polymerizable liquid crystal composition of the present invention comprises a polymerizable liquid crystal compound, a primary antioxidant, a secondary antioxidant and a radical photopolymerization initiator, and optionally a polymerizable liquid crystal compound such as a solvent or an additive, an antioxidant. It can be obtained by stirring the agent and components other than the photo-radical polymerization initiator at a predetermined temperature.

<Phase plate>
The polymerizable liquid crystal composition of the present invention is capable of being highly polymerized by high-intensity ultraviolet light or the like while suppressing damage to the polymerizable liquid crystal compound, and thus has excellent optical properties and is capable of being used under high temperature environments. It can be suitably used to prepare a liquid crystal cured film that exhibits high durability that is unlikely to cause changes in optical performance even in a harsh environment. The resulting liquid crystal cured film is suitable for optical applications such as retardation plates. Is. Therefore, the present invention is a cured product of the polymerizable liquid crystal composition of the present invention, and is intended for a retardation plate including a liquid crystal cured film cured in a state in which the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is aligned. To do.

In the present invention, the content of the primary antioxidant contained in the liquid crystal cured film forming the retardation plate is preferably 0.001 part by mass or less based on 100 parts by mass of the polymer of the polymerizable liquid crystal compound. It is more preferably 0.8×10 ⁻³ parts by mass or less, further preferably 0.5×10 ⁻³ parts by mass or less, and usually 0.1×10 ⁻³ parts by mass or more.

The content of the secondary antioxidant contained in the liquid crystal cured film forming the retardation plate is preferably 0.05 to 15 parts by mass with respect to 100 parts by mass of the polymer of the polymerizable liquid crystal compound. , 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass.

In one embodiment of the present invention, the retardation plate of the present invention is a cured product of the polymerizable liquid crystal composition of the present invention and has optical characteristics represented by the following formulas (I), (II) and (III). Includes a liquid crystal cured film. The liquid crystal cured film is usually a cured product obtained by curing a polymerizable liquid crystal compound in a state of being aligned in the horizontal direction with respect to the plane of the liquid crystal cured film (hereinafter, also referred to as “horizontal alignment liquid crystal cured film”).
Re(450)/Re(550)≦1.00 (I)
1.00≦Re(650)/Re(550) (II)
100 nm≦Re(550)≦180 nm (III)
[Wherein Re(λ) represents an in-plane retardation value at a wavelength λnm of the liquid crystal cured film, and Re=(nx(λ)−ny(λ))×d (d is the thickness of the liquid crystal cured film). In the refractive index ellipsoid formed by the liquid crystal cured film, nx represents the main refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film, and ny represents the refractive index ellipsoid formed by the liquid crystal cured film. , And the refractive index at a wavelength λ nm in a direction parallel to the plane of the liquid crystal cured film and orthogonal to the nx direction). ]

When the horizontal alignment liquid crystal cured film satisfies the formulas (I) and (II), the horizontal alignment liquid crystal cured film has an in-plane retardation value at a short wavelength smaller than an in-plane retardation value at a long wavelength. It exhibits so-called reverse wavelength dispersion. Re(450)/Re(550) is preferably 0.70 or more, more preferably 0.78 or more, since the reverse wavelength dispersibility is improved and the optical characteristics of the retardation plate are further improved. It is preferably 0.92 or less, more preferably 0.90 or less, still more preferably 0.87 or less, particularly preferably 0.86 or less, and particularly preferably 0.85 or less. Further, Re(650)/Re(550) is preferably 1.0 or more, more preferably 1.01 or more, and further preferably 1.02 or more.

The above-mentioned in-plane retardation value can be adjusted by the thickness d of the horizontally aligned liquid crystal cured film. Since the in-plane retardation value is determined by the above formula Re(λ)=(nx(λ)−ny(λ))×d, the desired in-plane retardation value (Re(λ): wavelength λ( In order to obtain the in-plane retardation value of the horizontally aligned liquid crystal cured film), the three-dimensional refractive index and the film thickness d may be adjusted.

Further, in the case where the horizontally aligned liquid crystal cured film satisfies the formula (III), the effect of improving the front reflection hue (coloring when an elliptically polarizing plate having a retardation plate including the horizontally aligned liquid crystal cured film is applied to an organic EL display device (coloring) The effect of suppressing) is excellent. A more preferable range of the in-plane retardation value is 120 nm≦Re(550)≦170 nm, and a further preferable range is 130 nm≦Re(550)≦150 nm.

In one embodiment of the present invention, the retardation plate of the present invention is a cured product of the polymerizable liquid crystal composition of the present invention and has optical characteristics represented by the following formulas (IV), (V) and (VI). Includes a liquid crystal cured film. The liquid crystal cured film is usually a cured product (hereinafter, also referred to as “vertically aligned liquid crystal cured film”) obtained by curing a polymerizable liquid crystal compound in a state of being aligned in a direction perpendicular to the plane of the liquid crystal cured film.
Rth(450)/Rth(550)≦1.00 (IV)
1.00≦Rth(650)/Rth(550) (V)
-100 nm ≤ Rth(550) ≤ -40 nm (VI)
[In the formula, Rth(λ) represents a retardation value in the thickness direction of the liquid crystal cured film at a wavelength of λ nm, and Rth=((nx(λ)+ny(λ))/2−nz)×d (d is Nx represents the thickness of the liquid crystal cured film, nx represents the main refractive index at a wavelength λnm in the direction parallel to the plane of the liquid crystal cured film in the refractive index ellipsoid formed by the liquid crystal cured film, and ny represents the liquid crystal cured film formed. In the refractive index ellipsoid, the refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film and orthogonal to the direction of nx is represented, and nz is the refraction formed by the liquid crystal cured film. In the index ellipsoid, represents the refractive index at a wavelength λ nm in the direction perpendicular to the plane of the liquid crystal cured film).
]

When the vertically aligned liquid crystal cured film satisfies the formulas (IV) and (V), it is possible to suppress the reduction of the ellipticity on the short wavelength side in the elliptically polarizing plate including the retardation plate including the vertically aligned liquid crystal cured film. It is possible to improve the oblique reflection hue. The value of Rth(450)/Rth(550) in the vertically aligned liquid crystal cured film is preferably 0.70 or more, more preferably 0.78 or more, and preferably 0.92 or less, more preferably 0. It is 90 or less, more preferably 0.87 or less, particularly preferably 0.86 or less, more preferably 0.85 or less. Further, Rth(650)/Rth(550) is preferably 1.0 or more, more preferably 1.01 or more, and further preferably 1.02 or more.

In addition, when the vertically aligned liquid crystal cured film satisfies the formula (VI), it is possible to improve the oblique reflection hue when an elliptically polarizing plate having a retardation plate including the vertically aligned liquid crystal cured film is applied to an organic EL display device. You can The retardation value Rth(550) in the film thickness direction of the vertically aligned liquid crystal cured film is more preferably −90 nm or more, further preferably −80 nm or more, and more preferably −50 nm or less.

The retardation plate of the present invention is, for example,
A step of forming a coating film of the polymerizable liquid crystal composition of the present invention, drying the coating film to remove the primary antioxidant, and aligning the polymerizable liquid crystal compound in the polymerizable liquid crystal composition; and ,
It can be produced by a method including a step of polymerizing a polymerizable liquid crystal compound by light irradiation while maintaining the alignment state to form a liquid crystal cured film.

The coating film of the polymerizable liquid crystal composition can be formed by applying the polymerizable liquid crystal composition on a substrate or an alignment film described later.
Examples of the base material include a glass base material and a film base material, and a resin film base material is preferable from the viewpoint of processability. Examples of the resin that constitutes the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; triacetyl cellulose, Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonates; polysulfones; polyether sulfones; polyether ketones; plastics such as polyphenylene sulfide and polyphenylene oxide. Such a resin can be formed into a film as a substrate by a known means such as a solvent casting method or a melt extrusion method. The surface of the base material may have a protective layer formed of an acrylic resin, a methacrylic resin, an epoxy resin, an oxetane resin, a urethane resin, a melamine resin, or the like, a release treatment such as a silicone treatment, a corona treatment, Surface treatment such as plasma treatment may be applied.

Commercially available products may be used as the base material. As a commercially available cellulose ester base material, for example, a cellulose ester base material manufactured by Fuji Photo Film Co., Ltd. such as Fujitac Film; manufactured by Konica Minolta Opto Co., Ltd. such as “KC8UX2M”, “KC8UY”, and “KC4UY” Cellulose ester base materials and the like. Examples of commercially available cyclic olefin-based resins include cyclic olefin-based resins manufactured by Ticona (Germany) such as "Topas (registered trademark)"; cyclic olefins manufactured by JSR Corporation such as "Arton (registered trademark)". -Based resins; cyclic olefin resins manufactured by Nippon Zeon Co., Ltd. such as "ZEONOR (registered trademark)" and "ZEONEX (registered trademark)"; Mitsui such as "Apel" (registered trademark) A cyclic olefin resin manufactured by Kagaku Co., Ltd. may be mentioned. A commercially available cyclic olefin resin base material can also be used. Examples of commercially available cyclic olefin resin base materials include cyclic olefin resin base materials manufactured by Sekisui Chemical Co., Ltd. such as "ESCINA (registered trademark)" and "SCA40 (registered trademark)"; "Zeonor film (registered trademark)" A cycloolefin resin base material manufactured by Optes Co., Ltd.; and a cyclic olefin resin base material manufactured by JSR Co., such as “Arton Film (registered trademark)”.

The thickness of the substrate is usually 5 to 300 μm, and preferably 10 to 150 μm, from the viewpoints of thinning the laminate, easiness of peeling of the substrate, handleability of the substrate, and the like.

As a method for applying the polymerizable liquid crystal composition to a substrate or the like, a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, a coating method such as an applicator method, and a printing method such as a flexo method. And other known methods.

Then, the solvent is removed by drying or the like to form a dry coating film. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method and a reduced pressure drying method. At this time, by heating the coating film obtained from the polymerizable liquid crystal composition, the solvent is removed from the coating film by drying and the primary antioxidant is removed, and the polymerizable liquid crystal compound is applied to the coating film plane. It can be oriented in any desired direction (eg horizontal or vertical). The heating temperature of the coating film can be appropriately determined in consideration of the polymerizable liquid crystal compound to be used and the material such as the base material forming the coating film, but it is at least a temperature at which the primary antioxidant can be volatilized, and In order to cause the polymerizable liquid crystal compound to undergo a phase transition to a liquid crystal phase state, it is usually necessary that the temperature is not lower than the liquid crystal phase transition temperature.
In order to bring the polymerizable liquid crystal compound into a desired alignment state while removing the solvent and the primary antioxidant contained in the polymerizable liquid crystal composition, for example, a liquid crystal phase of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition is used. It can be heated to a temperature of about the transition temperature (smectic phase transition temperature or nematic phase transition temperature) or higher.
The liquid crystal phase transition temperature can be measured using, for example, a polarization microscope equipped with a temperature adjustment stage, a differential scanning calorimeter (DSC), a thermogravimetric differential thermal analyzer (TG-DTA), or the like. Further, when two or more polymerizable liquid crystal compounds are used in combination, the above-mentioned phase transition temperature is the polymerization in which all polymerizable liquid crystal compounds constituting the polymerizable liquid crystal composition are mixed in the same ratio as the composition in the polymerizable liquid crystal composition. Means a temperature measured in the same manner as in the case of using one kind of polymerizable liquid crystal compound using a mixture of the polymerizable liquid crystal compounds. Further, it is generally known that the liquid crystal phase transition temperature of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition may be lower than the liquid crystal phase transition temperature of the polymerizable liquid crystal compound itself.

The heating time can be appropriately determined depending on the heating temperature, the type of polymerizable liquid crystal compound used, the type of solvent and the boiling point and amount thereof, etc., but is usually 15 seconds to 10 minutes, preferably 0.5 to 10 minutes. 5 minutes.

The removal of the solvent from the coating film may be carried out at the same time as heating the liquid crystal phase transition temperature of the polymerizable liquid crystal compound or higher, or may be carried out separately, but it is preferably carried out simultaneously from the viewpoint of improving productivity. Before heating to above the liquid crystal phase transition temperature of the polymerizable liquid crystal compound, the solvent in the coating film is moderately added under the condition that the polymerizable liquid crystal compound contained in the coating film obtained from the polymerizable liquid crystal composition does not polymerize. A preliminary drying step for removing may be provided. Examples of the drying method in the preliminary drying step include a natural drying method, a ventilation drying method, a heating drying method and a reduced pressure drying method. The drying temperature (heating temperature) in the drying step is the kind of the polymerizable liquid crystal compound used, the solvent. It can be appropriately determined according to the type, the boiling point and the amount thereof.

Then, in the obtained dry coating film, while maintaining the alignment state of the polymerizable liquid crystal compound, by polymerizing the polymerizable liquid crystal compound by light irradiation, a polymer of the polymerizable liquid crystal compound existing in a desired alignment state. A liquid crystal cured film is formed. Since the polymerizable liquid crystal composition of the present invention can be highly polymerized by irradiation with light such as high-intensity ultraviolet light while suppressing damage to the polymerizable liquid crystal compound, the polymerization method is usually a photopolymerization method. Is used. In the photopolymerization, as the light to be applied to the dry coating film, the type of the photoradical polymerization initiator contained in the dry coating film, the type of the polymerizable liquid crystal compound (particularly, the type of the polymerizable group contained in the polymerizable liquid crystal compound) ) And its amount. Specific examples thereof include one or more kinds of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α rays, β rays and γ rays and active electron rays. Among them, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction, and that those widely used in the art as a photopolymerization device can be used, and by ultraviolet light, photopolymerization is possible. It is preferable to select the type of the polymerizable liquid crystal compound or the photoradical polymerization initiator contained in the polymerizable liquid crystal composition. Further, during the polymerization, the polymerization temperature can be controlled by irradiating with light while cooling the dried coating film by an appropriate cooling means. By adopting such a cooling means, if the polymerizable liquid crystal compound is polymerized at a lower temperature, the liquid crystal cured film can be appropriately formed even if the base material has a relatively low heat resistance. It is also possible to accelerate the polymerization reaction by raising the polymerization temperature in a range where defects due to heat during light irradiation (deformation due to heat of the substrate, etc.) do not occur. It is also possible to obtain a patterned cured film by performing masking or development during photopolymerization.

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

The ultraviolet irradiation intensity is usually 10 to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the photopolymerization initiator. The irradiation time with light is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and further preferably 0.1 seconds to 1 minute. is there. When it is irradiated once or plural times with such an ultraviolet irradiation intensity, the integrated light amount thereof is 10 to 3,000 mJ/cm ² , preferably 50 to 2,000 mJ/cm ² , and more preferably 100 to 1,000 mJ/cm 2. It is ² .

The thickness of the liquid crystal cured film can be appropriately selected according to the applied display device, and is preferably 0.2 to 3 μm, more preferably 0.2 to 2 μm.

The coating film of the polymerizable liquid crystal composition may be formed on the alignment film. The alignment film has an alignment regulating force for aligning the polymerizable liquid crystal compound in a desired direction. Among these, an alignment film having an alignment controlling force for horizontally aligning the polymerizable liquid crystal compound may be called a horizontal alignment film, and an alignment film having an alignment controlling force for vertically aligning the liquid crystal compound may be called a vertical alignment film. The alignment control force can be arbitrarily adjusted depending on the type of the alignment film, the surface condition, the rubbing conditions, etc., and when the alignment film is made of a photoalignable polymer, it can be adjusted arbitrarily by the polarized light irradiation conditions, etc. It is possible to

It is preferable that the alignment film has solvent resistance such that it is not dissolved by coating the polymerizable liquid crystal composition and the like, and has heat resistance in the heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound described later. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film and a glob alignment film having an uneven pattern and a plurality of grooves on the surface, a stretched film stretched in the alignment direction, and the like. From the viewpoint of quality, a photo-alignment film is preferable.

Examples of the oriented polymer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule and polyamic acid which is a hydrolyzate thereof, polyvinyl alcohol, alkyl modified polyvinyl alcohol, polyacrylamide, polyacrylamide. Examples include oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic acid esters. Of these, polyvinyl alcohol is preferable. The oriented polymer may be used alone or in combination of two or more kinds.

The alignment film containing the alignment polymer is usually obtained by applying a composition in which the alignment polymer is dissolved in a solvent (hereinafter, sometimes referred to as “alignment polymer composition”) to a substrate to remove the solvent, or It is obtained by applying the oriented polymer composition to a substrate, removing the solvent, and rubbing (rubbing method). Examples of the solvent include the same solvents as those exemplified above as the solvent that can be used for the polymerizable liquid crystal composition.

The concentration of the oriented polymer in the oriented polymer composition may be in the range where the oriented polymer material can be completely dissolved in the solvent, but is preferably 0.1 to 20% in terms of solid content in the solution, and 0 It is more preferably about 1 to 10%.

A commercially available alignment film material may be used as it is as the alignment polymer composition. Examples of commercially available alignment film materials include Sanever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optomer (registered trademark, manufactured by JSR Corporation).

As the method of applying the oriented polymer composition to the substrate, the same methods as those exemplified as the method of applying the polymerizable liquid crystal composition to the substrate can be mentioned.

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

Rubbing treatment can be performed as necessary to give the alignment control force to the alignment film (rubbing method). As a method of imparting an orientation regulating force by a rubbing method, a rubbing cloth is wrapped around a rubbing roll which is rotated, and the orientational polymer composition is applied to the substrate and annealed to form the substrate surface. Examples include a method of bringing a film of an oriented polymer into contact. If masking is performed during the rubbing treatment, a plurality of regions (patterns) having different alignment directions can be formed in the alignment film.

The photo-alignment film is usually prepared by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as “composition for forming photo-alignment film”) to a substrate and polarizing the film after removing the solvent. (Preferably polarized UV). The photo-alignment film is also advantageous in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

▽ Photoreactive group refers to a group that produces liquid crystal alignment ability when irradiated with light. Specific examples thereof include a group involved in a photoreaction which is a source of liquid crystal alignment ability such as an orientation induction or isomerization reaction of molecules generated by light irradiation, a dimerization reaction, a photocrosslinking reaction or a photodecomposition reaction. Of these, a group involved in a dimerization reaction or a photocrosslinking reaction is preferable in terms of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond is preferable, and a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond is preferable. A group having at least one selected from the group consisting of a heavy bond (N=N bond) and a carbon-oxygen double bond (C=O bond) is particularly preferable.

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

Among them, a photoreactive group involved in the photodimerization reaction is preferable, the irradiation amount of polarized light required for photoalignment is relatively small, and in that a photoalignment film excellent in thermal stability and stability over time is easily obtained, Cinnamoyl and chalcone groups are preferred. As the polymer having a photoreactive group, a polymer having a cinnamoyl group such that the end portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

The photo-alignment inducing layer can be formed on the substrate by applying the composition for forming a photo-alignment film onto the substrate. Examples of the solvent contained in the composition include the same solvents as those exemplified above as the solvent that can be used in the polymerizable liquid crystal composition, and are appropriately selected depending on the solubility of the photoreactive group-containing polymer or monomer. can do.

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

As a method of applying the composition for forming a photo-alignment film to a base material, the same method as the method of applying the oriented polymer composition to the base material can be mentioned. Examples of the method for removing the solvent from the applied composition for forming a photo-alignment film include a natural drying method, a ventilation drying method, a heat drying method and a reduced pressure drying method.

In order to irradiate polarized light, even in the form of directly irradiating polarized UV on a composition obtained by removing the solvent from the composition for forming a photo-alignment film applied on the substrate, the polarized light is irradiated from the substrate side. It may be in a form of transmitting and irradiating. Further, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet) having a wavelength range of 250 to 400 nm is particularly preferable. Examples of the light source used for the irradiation of polarized light include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. High-pressure mercury lamps, ultra-high-pressure mercury lamps and metal halide lamps are more preferable. preferable. Among these, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, and a metal halide lamp are preferable because they have high emission intensity of ultraviolet rays having a wavelength of 313 nm. Polarized UV can be irradiated by irradiating the light from the light source through an appropriate polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.

Note that if rubbing or polarized light irradiation is performed, masking can be performed to form a plurality of regions (patterns) having different liquid crystal alignment directions.

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

As a method for obtaining a glube alignment film, after exposure through an exposure mask having a patterned slit on the surface of a photosensitive polyimide film, a method of forming an uneven pattern by developing and rinsing, a plate having a groove on the surface A method for forming a layer of UV curable resin before curing on a sheet-shaped master, transferring the formed resin layer to a substrate, and then curing, and a film of the UV curable resin before curing formed on the substrate, Examples include a method in which a roll-shaped master having a plurality of grooves is pressed to form irregularities and then cured.

Further, as the material exhibiting the alignment regulating force for aligning the polymerizable liquid crystal compound in the direction perpendicular to the liquid crystal cured film plane, in addition to the above-mentioned alignment polymer, a fluorine-based polymer such as perfluoroalkyl and a silane compound and those You may use the polysiloxane compound obtained by the condensation reaction of.

When a silane compound is used as a material for forming the alignment film, the constituent elements include a Si element and a C element from the viewpoints of easily lowering the surface tension and easily increasing the adhesiveness with a layer adjacent to the alignment film. Compounds are preferable, and silane compounds can be preferably used. A silane-containing ionic compound or the like can be used as the silane compound, and the use of such a silane compound can enhance the vertical alignment control force. As the silane compound, one type may be used alone, two or more types may be used in combination, and may be used as a mixture with other materials. When the silane compound is a nonionic silane compound, a silane compound having an alkyl group at the molecular end is preferable, and a silane compound having an alkyl group having 3 to 30 carbon atoms is more preferable, from the viewpoint of easily increasing the vertical alignment control force. ..

The thickness of the alignment film (the alignment film containing an alignment polymer or the photo-alignment film) is usually in the range of 10 to 10000 nm, preferably 10 to 1000 nm, more preferably 10 to 500 nm or less, and further preferably Is in the range of 10 to 300 nm, particularly preferably in the range of 50 to 250 nm.

The present invention includes an elliptically polarizing plate including the retardation plate of the present invention and a polarizing film.
The polarizing film is a film having a polarizing function, and examples thereof include a stretched film having adsorbed a dye having absorption anisotropy and a film including a film coated with a dye having absorption anisotropy as a polarizer. Examples of the dye having absorption anisotropy include dichroic dyes.

A film containing a stretched film adsorbing a dye having absorption anisotropy as a polarizer is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, by dyeing the polyvinyl alcohol-based resin film with a dichroic dye, At least a polarizer produced through a step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film on which a dichroic pigment is adsorbed with a boric acid aqueous solution, and a step of washing with water after the treatment with the boric acid aqueous solution. It is produced by sandwiching one surface with a transparent protective film via an adhesive.

Polyvinyl alcohol resin is obtained by saponifying polyvinyl acetate resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

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

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

Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with the dichroic dye, simultaneously with dyeing, or after dyeing. When the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to carry out uniaxial stretching in these plural stages. In the uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or wet stretching in which a polyvinyl alcohol-based resin film is swollen using a solvent. The draw ratio is usually about 3 to 8 times.

The dyeing of the polyvinyl alcohol-based resin film with the dichroic dye is performed by, for example, immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye.

Specifically, iodine or a dichroic organic dye is used as the dichroic pigment. Examples of the dichroic organic dye include C.I. I. Examples include dichroic direct dyes composed of disazo compounds such as DIRECT 39 and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo. The polyvinyl alcohol-based resin film is preferably immersed in water before dyeing.

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

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

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

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

After drying with water, a polarizer is obtained. The drying treatment can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The drying treatment time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By the drying treatment, the water content of the polarizer is reduced to a practical level. The water content thereof is usually about 5 to 20% by mass, preferably 8 to 15% by mass. When the water content is within the above range, a polarizer having appropriate plasticity and good thermal stability can be obtained.

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

Examples of the film coated with a dye having absorption anisotropy include a composition containing a dichroic dye having liquid crystallinity or a film obtained by coating a composition containing a dichroic dye and a polymerizable liquid crystal. Can be mentioned. The film preferably has a protective film on one side or both sides thereof. Examples of the protective film include the same resin films as those exemplified above as the substrate that can be used for producing the liquid crystal cured film.

It is preferable that the film coated with a dye having absorption anisotropy is thin, but if it is too thin, the strength will decrease and the processability will tend to be poor. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 to 3 μm.

Specific examples of the film coated with the dye having the absorption anisotropy include films described in JP 2012-33249 A and the like.

A polarizing film can be obtained by laminating a transparent protective film on at least one surface of the thus obtained polarizer with an adhesive. As the transparent protective film, the same transparent film as the resin film exemplified above as a substrate that can be used for producing a liquid crystal cured film can be preferably used.

The elliptically polarizing plate of the present invention is configured to include the retardation plate of the present invention and a polarizing film. For example, the retardation plate of the present invention and the polarizing film may be provided with an adhesive layer or a pressure-sensitive adhesive layer. The elliptically polarizing plate of the present invention can be obtained by laminating the elliptically polarizing plates.

In one aspect of the present invention, when a retardation plate of the present invention including a horizontally aligned liquid crystal cured film and a polarizing film are laminated, a slow axis (optical axis) of the horizontally aligned liquid crystal cured film forming the retardation plate. It is preferable to laminate so that the angle between the absorption axis of the polarizing film and the absorption axis of the polarizing film is 45±5°.

The elliptically polarizing plate of the present invention may have a conventional general elliptically polarizing plate, or a configuration that a polarizing film and a retardation plate have. As such a structure, for example, it is used for the purpose of protecting the surface of an adhesive layer (sheet) for laminating an elliptically polarizing plate on a display element such as an organic EL, a polarizing film or a retardation plate from scratches and dirt. The protective film etc. which are used are mentioned.

The elliptically polarizing plate of the present invention can be used in various display devices.
A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light-emitting source. As the display device, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (for example, field emission display device (FED), surface field emission display device). (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg, grating light valve (GLV) display device, display device having digital micromirror device (DMD)) ) And piezoelectric ceramic displays, etc. Liquid crystal display devices include any of transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices, and projection liquid crystal display devices. These display devices may be a display device that displays a two-dimensional image or may be a stereoscopic display device that displays a three-dimensional image.In particular, the elliptically polarizing plate of the present invention is an organic electroluminescence ( EL) display devices and inorganic electroluminescence (EL) display devices can be suitably used, and the retardation plate of the present invention can be suitably used for liquid crystal display devices and touch panel display devices. By providing the elliptically polarizing plate of the present invention having excellent characteristics, good image display characteristics can be exhibited.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, "%" and "part" in an example mean mass% and mass part, respectively, unless otherwise specified.

1. Example 1
(1) Preparation of composition for forming horizontal alignment film 5 parts of a photo-alignment material having the following structure (weight average molecular weight: 30,000) and 95 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was mixed with 80 parts. The composition for horizontal alignment film formation (1) was obtained by stirring at 0° C. for 1 hour.
Photo-alignment material:

(2) Preparation of Polymerizable Liquid Crystal Composition Based on 100 parts by mass of the polymerizable liquid crystal compound (A-1) produced according to the method described in JP 2010-31223 A, a polyacrylate compound (leveling agent) ( BYK-361N; BYK-Chemie) 0.1 parts by mass, and as a photopolymerization initiator, Irgacure OXE-03 (manufactured by BASF Japan Ltd.) 7.5 parts by mass, 2-dimethylamino-2-benzyl-1. 3.0 parts by mass of -(4-morpholinophenyl)butan-1-one (Irgacure 369 (Irg369); manufactured by BASF Japan Ltd.), and as a primary antioxidant, Sumirizer GS (phenolic antioxidant, Sumitomo Chemical ( (Manufactured by K.K.) and 1.0 part by mass of Adeka Stab TTP (phosphorus antioxidant, manufactured by ADEKA) as a secondary antioxidant. Further, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration became 13%, and the mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition.
A 1 mg/50 mL tetrahydrofuran solution of the polymerizable liquid crystal compound (A-1) was prepared, and the solution was put into a measuring cell having an optical path length of 1 cm as a measuring sample, and the ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation UV-2450") and the absorption spectrum was measured. When the wavelength at which the maximum absorption was obtained was read from the obtained absorption spectrum, the maximum absorption wavelength λ _max in the wavelength range of 300 to 400 nm was 350 nm.

Polymerizable liquid crystal compound (A-1):

(3) Storage stability evaluation of the polymerizable liquid crystal composition The obtained polymerizable liquid crystal composition was irradiated in a transparent vial with a fluorescent lamp (FHF32EX-NH manufactured by Mitsubishi Electric, total luminous flux: 3520 lm (32 W)). After storing for 15 hours under the presence of gel, the presence or absence of gelation was visually confirmed.
<Evaluation criteria>
◯: Gelation was not visually observed.
X: Gelation was visually observed.

(4) Preparation of horizontally aligned liquid crystal cured film A cycloolefin polymer (COP) film (ZF-14) manufactured by Nippon Zeon Co., Ltd. as a substrate was subjected to corona treatment using a corona treatment device. Then, the above-mentioned composition (1) for forming a horizontal alignment film was applied to the surface of the COP film subjected to the corona treatment by using a bar coater, and dried at 80° C. for 1 minute, and then, a polarized UV irradiation device (SPOT CURE). (SP-9; manufactured by Ushio Inc.) was used to perform polarized UV exposure with a cumulative light amount at a wavelength of 313 nm: 100 mJ/cm ² to obtain a horizontal alignment film.
Then, the above-mentioned polymerizable liquid crystal composition was applied onto the above alignment film by using a bar coater, heated at 120° C. for 90 seconds, and dried by applying hot air. Then, using a high-pressure mercury lamp, ultraviolet rays are irradiated from the coated surface side of the polymerizable liquid crystal composition (integrated light amount at a wavelength of 365 nm: 2000 mJ/cm ² ) to form a horizontally aligned liquid crystal cured film, and then a COP film/horizontal film. An optical film composed of an alignment film/horizontal alignment liquid crystal cured film was formed. The maximum absorption wavelength of the obtained liquid crystal cured film was 350 nm.

(5) Evaluation of physical properties/characteristics of horizontally aligned liquid crystal cured film [measurement of in-plane retardation value of horizontally aligned liquid crystal cured film]
The in-plane retardation value of the obtained horizontally aligned liquid crystal cured film with respect to light having wavelengths of 450 nm, 550 nm and 650 nm was measured using KOBRA-WR manufactured by Oji Scientific Instruments. The in-plane retardation values were Re(450)=118 nm, Re(550)=142 nm, Re(650)=148 nm, and Re(450)/Re(550) was 0.84.
The obtained in-plane retardation values are shown in Table 1. In the present invention, the in-plane retardation value of the horizontal liquid crystal cured film is used as an index of initial optical characteristics and evaluated as follows.
When Re(450)/Re(550) is less than 0.85: Initial optical properties are high. When Re(450)/Re(550) is 0.85 or more and less than 0.87: Initial optical properties are good. When 450)/Re(550) is 0.87 or more: initial optical characteristics are low

[Haze measurement of liquid crystal cured film]
The haze value of the obtained horizontally aligned liquid crystal cured film was measured using a haze meter. The results are shown in Table 1.

[Evaluation of orientation of cured liquid crystal film]
The obtained liquid crystal cured film was observed under a condition of a magnification of 200 using a polarizing microscope (“BX-51” manufactured by Olympus Corporation), and the presence or absence of alignment defects in a visual field of 480 μm×320 μm was observed. The results are shown in Table 1.
<Evaluation criteria>
◯: There was no alignment defect.
Δ: Alignment defects were partially observed.
X: Alignment defects were generated or many were generated in the entire liquid crystal cured film.

[Evaluation of polymerization rate of liquid crystal cured film]
Infrared total reflection absorption spectrum measurement (incident angle: 45°) was performed on the obtained liquid crystal cured film, and the obtained measurement result (in-plane bending vibration (1408 cm ⁻¹ ) of ethylenically unsaturated bond) was obtained. From the peak intensity I(1) and the value of the peak intensity I(2) derived from stretching vibration (1504 cm ⁻¹ ) of the unsaturated bond of the aromatic ring, P′ (perpendicular to the thickness direction of the liquid crystal cured film) Among the surfaces, the P value (peak intensity I(1)/peak intensity I(2)) of the surface irradiated with ultraviolet rays was calculated.
Further, a solution obtained by dissolving the polymerizable liquid crystal compound (A-1) in chloroform was dropped on the germanium crystal and dried to obtain a thin layer of the polymerizable liquid crystal compound (A-1). Infrared total reflection absorption spectrum of the obtained thin layer was measured, and the obtained measurement result (peak intensity I(1)=from in-plane bending vibration (1408 cm ⁻¹ ) of ethylenically unsaturated bond) was obtained. 0.013, peak intensity I(2)=0.0561 derived from stretching vibration (1504 cm ⁻¹ ) of unsaturated bond of aromatic ring was calculated, and P0 (P value of polymerizable liquid crystal compound (A-1)) was calculated. did.
The value of (1−P′/P0)×100 was calculated from the values of P′ and P0, which was taken as the polymerization rate of the liquid crystal cured film.
The polymerization rate of the liquid crystal cured film was evaluated according to the evaluation criteria described later. The results are shown in Table 1.

[Evaluation of antioxidant content in cured liquid crystal film]
The antioxidant content in the liquid crystal cured film was analyzed as follows.
To the liquid crystal cured film (50 mg) isolated from the base material, 5 mL of tetrahydrofuran was added as an extraction solvent, and ultrasonic waves were applied for 20 minutes to extract the antioxidant from the liquid crystal cured film. After filtering the extract with a filter, the antioxidant content was quantified by liquid chromatography measurement (Prominance series manufactured by Shimadzu Corporation, mobile phase: acetonitrile, detection wavelength: 254 nm). Further, the content of the antioxidant with respect to 100 parts by mass of the polymer of the polymerizable liquid crystal compound in the liquid crystal cured film was calculated from the obtained quantitative result and the total mass of the liquid crystal cured film used for the analysis.
3. The content of primary antioxidant (Sumirizer GS) in the cured liquid crystal film measured by the above method is 800 ppm (0.8×10 ⁻³ parts by mass), and the content of secondary antioxidant (TTP) is 4. It was 7 parts by mass.

2. Comparative Example 1
As shown in Table 1, the same operation as in Example 1 was performed except that the antioxidant was not added and the cumulative light amount at the time of ultraviolet irradiation was changed (total light amount at wavelength 365 nm: 500 mJ/cm ² ). A comparative polymerizable liquid crystal composition containing a polymerizable liquid crystal compound was prepared to obtain a comparative horizontally aligned liquid crystal cured film 1.
The storage stability of the comparative polymerizable liquid crystal composition was evaluated in the same manner as in Example 1, and the in-plane retardation value at the wavelength of 450 nm and the wavelength of 550 nm of the obtained comparative horizontally aligned liquid crystal cured film 1 was evaluated as Re. Calculation of (450)/Re(550) value, measurement of haze value and microscopic observation were carried out. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the comparative horizontally aligned liquid crystal cured film 1 was measured and the polymerization rate was calculated. The results are shown in Table 1.

The relative polymerization rate of each horizontally aligned liquid crystal cured film in the above [evaluation of polymerization rate of liquid crystal cured film] to the comparative horizontally aligned liquid crystal cured film 1 was calculated as follows.
Relative polymerization rate (%) of horizontally aligned liquid crystal cured film
= (Polymerization rate of horizontally aligned liquid crystal cured film/Comparison of horizontally aligned liquid crystal cured film) x 100
<Evaluation criteria>
◯ (very good): 103% or more relative polymerization rate of the comparative horizontal alignment liquid crystal cured film 1 △ (good): 101% or more relative polymerization rate of comparative horizontal alignment liquid crystal cured film 1 Less than 103% x (bad): relative polymerization rate is 100% or less with respect to the polymerization rate of the comparative horizontally aligned liquid crystal cured film 1.

3. Example 2
As shown in Table 1, the same operation as in Example 1 was performed except that the polymerizable liquid crystal compound was changed to the polymerizable liquid crystal compound (B-1), and the polymerizable liquid crystal containing the polymerizable liquid crystal compound (B-1) was used. A composition was prepared to obtain a horizontal alignment liquid crystal cured film. The polymerizable liquid crystal compound (B-1) was prepared with reference to JP-A-2016-81035.
In addition, a 1 mg/50 mL tetrahydrofuran solution of the liquid crystal compound (B) was prepared, and the solution was put into a measurement cell having an optical path length of 1 cm as a measurement sample, and the ultraviolet-visible spectrophotometer (“UV-2450” manufactured by Shimadzu Corporation). ) And the absorption spectrum was measured. When the wavelength at which the maximum absorption was obtained was read from the obtained absorption spectrum, the maximum absorption wavelength λ _max in the wavelength range of 300 to 400 nm was 352 nm.

Polymerizable liquid crystal compound (B-1):

In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

4. Example 3
As shown in Table 1, the same operation as in Example 1 was performed except that the polymerizable liquid crystal compound was changed to the polymerizable liquid crystal compound (C-1), and the polymerizable liquid crystal containing the polymerizable liquid crystal compound (C-1) was used. A composition was prepared to obtain a liquid crystal cured film. The polymerizable liquid crystal compound C was prepared with reference to International Patent Publication No. 2015/025793.
In addition, a 1 mg/50 mL tetrahydrofuran solution of the liquid crystal compound (C-1) was prepared, and the solution was put into a measuring cell having an optical path length of 1 cm as a measuring sample, and the ultraviolet-visible spectrophotometer (“UV- manufactured by Shimadzu Corporation” 2450") and the absorption spectrum was measured. When the wavelength at which the maximum absorption was obtained was read from the obtained absorption spectrum, the maximum absorption wavelength λ _max in the wavelength range of 300 to 400 nm was 352 nm.

Polymerizable liquid crystal compound (C-1):

5. Examples 4 to 7
The primary antioxidant was changed to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Chemical Industry Co., Ltd.) and the addition amount shown in Table 1 was used. Then, a polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was prepared in the same manner as in Example 1 except that the primary antioxidant and the secondary antioxidant were added respectively. An oriented liquid crystal cured film was obtained.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

6. Example 8
As shown in Table 1, the secondary antioxidant was used as the primary antioxidant to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Kasei Kogyo). A polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was performed in the same manner as in Example 1 except that the inhibitor was changed to Chelex-O (phosphorus antioxidant, manufactured by SC Organic Chemical Co., Ltd.). The product was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

7. Example 9
As shown in Table 1, the secondary antioxidant was used as the primary antioxidant to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Kasei Kogyo). A polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was prepared in the same manner as in Example 1, except that the antioxidant was changed to DTDPA (sulfur-based antioxidant, manufactured by SC Organic Chemical Co., Ltd.). A horizontal alignment liquid crystal cured film was prepared.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

8. Comparative Examples 2 and 4
As shown in Table 1, the primary antioxidant was changed to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Chemical Industry Co., Ltd.) A polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was prepared in the same manner as in Example 1, except that the secondary antioxidant was not added. Then, a horizontally aligned liquid crystal cured film was obtained.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

9. Comparative Example 3
As shown in Table 1, a polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was prepared by performing the same operation as in Example 1 except that the primary antioxidant was not included, and the horizontal alignment was performed. A liquid crystal cured film was obtained.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

10. Comparative Example 5
As shown in Table 1, the same operation as in Example 1 was performed except that the polymerizable liquid crystal compound was used as the polymerizable liquid crystal compound (B-1) and neither the primary antioxidant nor the secondary antioxidant was added. A polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (B-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

11. Example 10
As shown in Table 1, polymerization was carried out in the same manner as in Example 1 except that the polymerizable liquid crystal compound (A-1) was changed to the polymerizable liquid crystal compound (C-1) and the primary antioxidant was changed to BHT. A polymerizable liquid crystal composition containing the liquid crystal compound (C-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

12. Comparative Example 6
As shown in Table 1, the polymerizable liquid crystal compound (C-1) was used as the polymerizable liquid crystal compound (C-1), and the same operation as in Example 1 was conducted except that the primary and secondary antioxidants were not added. A polymerizable liquid crystal composition containing the liquid crystal compound (C-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

13. Comparative Example 7
As shown in Table 1, the polymerizable liquid crystal compound was used as the polymerizable liquid crystal compound (C-1), and the primary antioxidant was 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT)( Polymerization containing the polymerizable liquid crystal compound (C-1) was performed in the same manner as in Example 1 except that the phenolic antioxidant was manufactured by Tokyo Kasei Kogyo Co., Ltd. and the secondary antioxidant was not added. Liquid crystal composition was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

14. Example 15
Polymerization was performed in the same manner as in Example 4 except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (A-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

15. Example 16
Polymerization was performed in the same manner as in Example 7, except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (A-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

16. Example 17
Polymerization was performed in the same manner as in Example 8 except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (A-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

17. Example 18
Polymerization was performed in the same manner as in Example 9 except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (A-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

18. Example 19
Polymerization was performed in the same manner as in Example 10 except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (C-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

19. Comparative Example 11
Polymerization was performed in the same manner as in Comparative Example 1 except that 6.0 parts by mass of Irgacure OXE-01 (manufactured by BASF Japan Ltd.) was used as the photopolymerization initiator instead of Irgacure OXE-03 and Irgacure 369. A polymerizable liquid crystal composition containing the liquid crystal compound (A-1) was prepared to obtain a horizontally aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and from the in-plane retardation value at a wavelength of 450 nm and a wavelength of 550 nm of the obtained liquid crystal cured film, Re(450)/Re was obtained. Calculation of (550) value, measurement of haze value, and microscopic observation were performed. Further, the infrared total reflection absorption spectrum of the cured liquid crystal film was measured to calculate the polymerization rate. The results are shown in Table 1.

20. Example 11
(1) Preparation of Composition for Forming Vertical Alignment Film 0.5 part of SAN EVER SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is an oriented polymer, and 72.3 parts of N-methyl-2-pyrrolidone as a solvent, 2 -Butoxyethanol (18.1 parts), ethylcyclohexane (9.1 parts), and 0.01% by mass of DPHA (manufactured by Shin-Nakamura Chemical Co., Ltd.) were mixed to obtain a composition (1) for forming a vertical alignment film.

(2) Preparation of polymerizable liquid crystal composition 0.1 part by mass of F-556 (manufactured by DIC) as a leveling agent and 100 parts by mass of the polymerizable liquid crystal compound (A-1) as a photopolymerization initiator, 6.0 parts by mass of 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369 (Irg369); manufactured by BASF Japan Ltd.) and Sumirizer GS as a primary antioxidant (Phenolic antioxidant, manufactured by Sumitomo Chemical Co., Ltd.) 1.0 part by mass was mixed with 5.0 parts by mass of ADEKA STAB TTP (phosphorus antioxidant, manufactured by ADEKA) as a secondary antioxidant. .. Next, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration became 13%, and the mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition.

In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated.

(3) Formation of Vertically Aligned Liquid Crystal Cured Film A cycloolefin polymer (COP) film as a substrate was subjected to corona treatment using a corona treatment device. Next, the composition for vertical alignment film formation (1) described above was applied to the surface of the COP film (base material) that had been subjected to corona treatment using a bar coater, and dried to form an alignment film.
Subsequently, the above-mentioned coating liquid was applied onto the alignment film by using a bar coater, dried at 120° C. for 60 seconds, and then irradiated with ultraviolet rays from the coated surface side of the coating liquid using a high pressure mercury lamp ( A liquid crystal cured film was formed by adjusting the integrated light amount at a wavelength of 365 nm: 2000 mJ/cm ² .

(4) Evaluation of physical properties/characteristics of vertically aligned liquid crystal cured film [Rth measurement of vertically aligned liquid crystal cured film]
In order to measure the Rth of the vertically aligned liquid crystal cured film, the vertically aligned liquid crystal cured film was bonded to glass via an adhesive (pressure sensitive adhesive 15 μm manufactured by Lintec Co., Ltd.), and it was confirmed that there was no phase difference in COP. Above, the phase difference value was measured by changing the incident angle of light to the sample with an ellipsometer. The average refractive index at wavelengths λ of 450 nm and 550 nm was measured using a refractometer (manufactured by Atago Co., Ltd., “Multi-wavelength Abbe refractometer DR-M4”). RthC(450)=−58 nm, RthC(550)=−70 nm, and RthC(450)/RthC(550)=RthC calculated from the obtained film thickness, average refractive index, and ellipsometer measurement results, respectively. It was 0.83.

[Evaluation of vertical alignment liquid crystal cured film]
In the same manner as in Example 1, the haze value of the vertically aligned liquid crystal cured film was measured and observed with a microscope. Further, the infrared total reflection absorption spectrum of the vertically aligned liquid crystal cured film was measured to calculate the polymerization rate. The results are shown in Table 2. In the present invention, the retardation value of the vertically aligned liquid crystal cured film is used as an index of initial optical characteristics and evaluated as follows.
<Evaluation criteria>
When RthC(450)/RthC(550) is less than 0.85: Initial optical characteristics are high. When RthC(450)/RthC(550) is 0.85 or more and less than 0.87: Initial optical characteristics are good RthC( When 450)/RthC(550) is 0.87 or more: Initial optical characteristics are low.

21. Comparative Example 8
As shown in Table 2, the same operation as in Example 11 was carried out except that no antioxidant was added and the cumulative light amount at the time of ultraviolet irradiation was changed (total light amount at wavelength 365 nm: 500 mJ/cm ² ). A comparative polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was prepared to obtain a comparative vertically aligned liquid crystal cured film 1.
The storage stability of the comparative polymerizable liquid crystal composition was evaluated by the same method as in Example 1, and the RthC(450) of the comparative vertically aligned liquid crystal cured film 1 obtained was obtained by the same method as in Example 11. , RthC(550), and RthC(450)/RthC(550) values were calculated, haze values were measured, and microscopic observation was performed.

By the same method as in Example 1, the infrared total reflection absorption spectrum of the comparative vertically aligned liquid crystal cured film was measured and the polymerization rate was calculated. Further, the relative polymerization rate of each vertically aligned liquid crystal cured film with respect to the comparative vertically aligned liquid crystal cured film 1 was determined according to the following criteria.
Relative polymerization rate (%) of vertically aligned liquid crystal cured film
= (Polymerization rate of vertically aligned liquid crystal cured film/Comparison of vertically aligned liquid crystal cured film 1) x 100
<Evaluation criteria>
◯ (very good): 103% or more relative polymerization rate of the comparative vertical alignment liquid crystal cured film 1 Δ (good): 101% or more relative polymerization rate of the comparative vertical alignment liquid crystal cured film 1 Less than 103% × (bad): relative polymerization rate to the polymerization rate of the comparative vertically aligned liquid crystal cured film 1 is 100% or less.

22. Example 12
As shown in Table 2, except that the primary antioxidant was changed to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Kasei Kogyo). Then, the same operation as in Example 11 was performed to prepare a polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) to obtain a vertically aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and in the same manner as in Example 11, the RthC(450)/RthC( of the obtained vertically aligned liquid crystal cured film was obtained. 550) value calculation, haze value measurement, and microscopic observation. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the liquid crystal cured film was measured and the polymerization rate was calculated. The results are shown in Table 2.

23. Example 13
As shown in Table 2, the secondary antioxidant was used as the primary antioxidant with 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Kasei Kogyo). A polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) was performed in the same manner as in Example 11 except that the inhibitor was changed to Chelex-O (phosphorus antioxidant, manufactured by SC Organic Chemical Co., Ltd.). Was prepared to obtain a vertically aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and in the same manner as in Example 11, the RthC(450)/RthC( of the obtained vertically aligned liquid crystal cured film was obtained. 550) value calculation, haze value measurement, and microscopic observation. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the liquid crystal cured film was measured and the polymerization rate was calculated. The results are shown in Table 2.

24. Comparative Example 9
As shown in Table 2, the primary antioxidant was changed to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) (phenolic antioxidant, manufactured by Tokyo Chemical Industry Co., Ltd.). The same operation as in Example 11 was carried out except that the following antioxidant was not added, to prepare a polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (A-1) to obtain a vertically aligned liquid crystal cured film. ..
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and in the same manner as in Example 11, the RthC(450)/RthC( of the obtained vertically aligned liquid crystal cured film was obtained. 550) value calculation, haze value measurement, and microscopic observation. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the liquid crystal cured film was measured and the polymerization rate was calculated. The results are shown in Table 2.

25. Example 14
As shown in Table 2, the polymerizable liquid crystal compound was used as the polymerizable liquid crystal compound (C-1), and the primary antioxidant was used as 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT)( A phenolic antioxidant, manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used, and the same operation as in Example 11 was carried out to prepare a polymerizable liquid crystal composition containing the polymerizable liquid crystal compound (C-1). A film was obtained.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and in the same manner as in Example 11, the RthC(450)/RthC( of the obtained vertically aligned liquid crystal cured film was obtained. 550) value calculation, haze value measurement, and microscopic observation. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the liquid crystal cured film was measured and the polymerization rate was calculated. The results are shown in Table 2.

26. Comparative Example 10
As shown in Table 2, the polymerizable liquid crystal compound was used as the polymerizable liquid crystal compound (C-1), and the primary antioxidant was used as 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT)( Polymerization containing the polymerizable liquid crystal compound (C-1) was performed in the same manner as in Example 11 except that the phenolic antioxidant was manufactured by Tokyo Kasei Kogyo Co., Ltd. and the secondary antioxidant was not added. Liquid crystalline composition was prepared to obtain a vertically aligned liquid crystal cured film.
In the same manner as in Example 1, the storage stability of the polymerizable liquid crystal composition was evaluated, and in the same manner as in Example 11, the RthC(450)/RthC( of the obtained vertically aligned liquid crystal cured film was obtained. 550) value calculation, haze value measurement, and microscopic observation. Further, in the same manner as in Example 1, the infrared total reflection absorption spectrum of the liquid crystal cured film was measured and the polymerization rate was calculated. The results are shown in Table 2.

Claims

A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound, at least one primary antioxidant, at least one secondary antioxidant and a photoradical polymerization initiator, wherein the polymerizable liquid crystal compound has an ester structure ( A polymerizable liquid crystal composition having a (meth)acryloyl group and exhibiting maximum absorption at a wavelength of 300 to 400 nm.
The polymerizable liquid crystal composition according to claim 1, wherein the content of the primary antioxidant is 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound.
The polymerizable liquid crystal composition according to claim 1 or 2, wherein the primary antioxidant is a phenol compound.
The polymerizable liquid crystal composition according to any one of claims 1 to 3, wherein the molecular weight of the primary antioxidant is 400 g/mol or less.
The polymerizable liquid crystal composition according to any one of claims 1 to 4, wherein the content of the secondary antioxidant is 0.1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound.
The polymerizable liquid crystal composition according to any one of claims 1 to 5, wherein the secondary antioxidant is a phosphite compound.
The polymerizable liquid crystal composition according to any one of claims 1 to 6, wherein the secondary antioxidant has a molecular weight of 200 g/mol or more.
The polymerizable liquid crystal composition according to any one of claims 1 to 7, wherein the photoradical polymerization initiator is an oxime photopolymerization initiator.
The polymerizable liquid crystal composition according to any one of claims 1 to 8, which contains a polymerizable liquid crystal compound having a birefringence of a homopolymer exhibiting reverse wavelength dispersion.
A cured product of the polymerizable liquid crystal composition according to any one of claims 1 to 9, and a retardation plate including a liquid crystal cured film that is cured in a state in which the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is aligned.
The retardation plate according to claim 10, wherein the content of the primary antioxidant in the cured liquid crystal film is 0.001 part by mass or less based on 100 parts by mass of the polymer of the polymerizable liquid crystal compound.
The retardation plate according to claim 10 or 11, wherein the content of the secondary antioxidant in the liquid crystal cured film is 0.05 to 15 parts by mass with respect to 100 parts by mass of the polymer of the polymerizable liquid crystal compound.
The liquid crystal cured film has the following formulas (I), (II) and (III):
Re(450)/Re(550)≦1.00 (I)
1.00≦Re(650)/Re(550) (II)
100 nm≦Re(550)≦180 nm (III)
[Wherein Re(λ) represents an in-plane retardation value at a wavelength λnm of the liquid crystal cured film, and Re=(nx(λ)−ny(λ))×d (d is the thickness of the liquid crystal cured film). In the refractive index ellipsoid formed by the liquid crystal cured film, nx represents the main refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film, and ny represents the refractive index ellipsoid formed by the liquid crystal cured film. , Represents the refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film and orthogonal to the nx direction)).
The retardation plate according to any one of claims 10 to 12, which has optical characteristics represented by:
The liquid crystal cured film has the following formulas (IV), (V) and (VI):
Rth(450)/Rth(550)≦1.00 (IV)
1.00≦Rth(650)/Rth(550) (V)
-100 nm ≤ Rth(550) ≤ -40 nm (VI)
[In the formula, Rth(λ) represents a retardation value in the thickness direction of the liquid crystal cured film at a wavelength of λ nm, and Rth=((nx(λ)+ny(λ))/2−nz)×d (d is Nx represents the thickness of the liquid crystal cured film, nx represents the main refractive index at a wavelength λnm in the direction parallel to the plane of the liquid crystal cured film in the refractive index ellipsoid formed by the liquid crystal cured film, and ny represents the liquid crystal cured film formed. In the refractive index ellipsoid, the refractive index at a wavelength λ nm in the direction parallel to the plane of the liquid crystal cured film and orthogonal to the direction of nx is represented, and nz is the refraction formed by the liquid crystal cured film. The retardation plate according to any one of claims 10 to 12, having an optical characteristic represented by a refractive index at a wavelength λnm in a direction perpendicular to the plane of the liquid crystal cured film in the index ellipsoid).
The method for manufacturing a retardation plate according to any one of claims 10 to 14,
Forming a coating film of the polymerizable liquid crystal composition, drying the coating film to remove the primary antioxidant, and aligning the polymerizable liquid crystal compound in the polymerizable liquid crystal composition,
A method for manufacturing, comprising a step of polymerizing a polymerizable liquid crystal compound by light irradiation while maintaining an alignment state to form a liquid crystal cured film.
An elliptically polarizing plate including the retardation plate according to any one of claims 10 to 14 and a polarizing film.
An organic EL display device including the elliptically polarizing plate according to claim 16.