CN113150792A

CN113150792A - Polymerizable liquid crystal mixture and polymerizable liquid crystal composition

Info

Publication number: CN113150792A
Application number: CN202011517870.8A
Authority: CN
Inventors: 吉冈真之介
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2019-12-25
Filing date: 2020-12-21
Publication date: 2021-07-23
Also published as: JP2021103256A; TW202134408A; JP6700468B1; KR20210082369A; JP2021103288A

Abstract

The present invention relates to a polymerizable liquid crystal mixture and a polymerizable liquid crystal composition. A polymerizable liquid crystal mixture comprising a polymerizable liquid crystal compound (1) represented by formula (1) and at least one selected from the group consisting of a compound (2) represented by formula (2) and a compound (3) represented by formula (3).

Description

Polymerizable liquid crystal mixture and polymerizable liquid crystal composition

Technical Field

The present invention relates to a polymerizable liquid crystal mixture, a polymerizable liquid crystal composition containing the polymerizable liquid crystal mixture, a cured product of the polymerizable liquid crystal composition, a retardation film containing the cured product, an elliptically polarizing plate, and an optical display.

Background

As an optical film such as a retardation film used in a Flat Panel Display (FPD), there is an optical film obtained by dissolving a polymerizable liquid crystal compound in a solvent to obtain a coating liquid, applying the coating liquid to a support substrate, and polymerizing the coating liquid. Conventionally, as polymerizable liquid crystal compounds, for example, nematic liquid crystal compounds having a rod-like structure in which about 2 to 4 6-membered rings are connected are known. On the other hand, as one of the characteristics of the retardation film, it is required to be capable of polarization conversion in all wavelength regions, and it is known that uniform polarization conversion is theoretically possible in a wavelength region exhibiting reverse wavelength dispersibility of [ Re (450)/Re (550) ] <1, for example. As a polymerizable compound capable of constituting a retardation film exhibiting such reverse wavelength dispersibility, for example, compounds described in japanese patent application laid-open No. 2019-73496 are known.

Disclosure of Invention

A coating-type optical film can be obtained by dissolving a polymerizable liquid crystal compound disclosed in japanese patent application laid-open No. 2019-73496 in a solvent to obtain a coating liquid, applying the coating liquid to a supporting substrate or the like to form a coating film, then converting the polymerizable liquid crystal compound contained in the coating film into a liquid crystal phase state, drying the coating film, and distilling off the solvent. However, conventional polymerizable liquid crystal compounds often have insufficient solubility in various solvents due to their molecular structures, and such polymerizable liquid crystal compounds having low solubility sometimes precipitate or crystallize in a coating solution, and these may cause not only a decrease in film formability but also a decrease in optical properties of an optical film to be obtained. In particular, it is known that a polymerizable liquid crystal compound containing an aromatic ring can be an appropriate material for obtaining a retardation film having reverse wavelength dispersibility and excellent optical characteristics, but on the other hand, in the case of a compound having a highly symmetrical molecular structure, there is a problem that the solubility is liable to be further lowered due to the molecular structure.

The purpose of the present invention is to provide the following polymerizable liquid crystal composition: the polymerizable liquid crystal compound can be highly dissolved in a solvent, and is preferably used for forming a retardation film having high optical characteristics, which can realize good circular polarization conversion.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have completed the present invention. That is, the present invention provides the following preferred embodiments.

[1] A polymerizable liquid crystal mixture comprising a polymerizable liquid crystal compound (1) represented by formula (1) and at least one selected from the group consisting of a compound (2) represented by formula (2) and a compound (3) represented by formula (3).

In the formulas (1) to (3),

D¹and D²Each independently represents-O-CO-, -CO-O-, -C (═ S) -O-, -O-C (═ S) -, -O-CR¹¹R¹²-、-CR¹¹R¹²-O-、-NR¹¹-CR¹²R¹³-、-CR¹²R¹³-NR¹¹-、-CO-NR¹¹-, or NR¹¹-CO-，R¹¹、R¹²And R¹³Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;

G¹、G²、A¹and A²Each independently represents a divalent aromatic hydrocarbon group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic hydrocarbon group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic hydrocarbon group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom;

D³and D⁴Each independently represents-CR¹⁴R¹⁵-、-CH₂-CH₂-、-O-、-S-、-CO-O-、-O-CO-、-O-CO-O-、-C(＝S)-O-、-O-C(＝S)-、-O-C(＝S)-O-、-CO-NR¹⁴-、-NR¹⁴-CO-、-O-CH₂-、-CH₂-O-、-CH＝CH-COO-、-CH＝CH-OCO-、-COO-CH＝CH-、-OCO-CH＝CH-、-COO-CH₂CH₂-、-OCO-CH₂CH₂-、-CH₂CH₂-COO-、-CH₂CH₂-OCO-、-COO-CH₂-、-OCO-CH₂-、-CH₂-COO-、-CH₂-OCO-、-S-CH₂-、-CH₂-S-or a single bond, R¹⁴And R¹⁵Each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms;

R¹and R²Each independentlyIs a group represented by the following formula (R-1):

-B¹-E¹-P¹(R-1)

[ in the formula (R-1),

B¹represents-CR¹⁴R¹⁵-、-CH₂-CH₂-、-O-、-S-、-CO-O-、-O-CO-、-O-CO-O-、-C(＝S)-O-、-O-C(＝S)-、-O-C(＝S)-O-、-CO-NR¹⁴-、-NR¹⁴-CO-、-O-CH₂-、-CH₂-O-、-S-CH₂-、-CH₂-S-or a single bond, R¹⁴And R¹⁵Each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms;

E¹represents an alkylene group having 1 to 12 carbon atoms, wherein a hydrogen atom contained in the alkylene group may be substituted by an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom, and a methylene group contained in the alkylene group may be replaced by-O-or-CO-;

P¹represents a polymerizable group]，

l1 and l2 each independently represent an integer of 0 or 1, m1 and m2 each independently represent an integer of 1 to 4, and n1 and n2 each independently represent an integer of 0 to 3;

there are a plurality of D³、D⁴、A¹And/or A²When used, each may be the same or different;

substituent X¹And X²Each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, or 1-CH₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 20 carbon atoms which may be independently substituted with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH-COO-, -CH-OCO-, -COO-CH-, -OCO-CH-, -CH-, -CF-or-C.ident.C-, wherein any hydrogen atom in the alkyl group may be replaced by a fluorine atomSubstituted, or, substituent X¹And X²May each independently be-B²-E²-P²A group of formula B²、E²And P²Respectively with the above B¹、E¹And P¹Are defined in the same manner as B above¹、E¹And P¹The same or different, there being a plurality of X' s¹And/or X²When used, each may be the same or different;

Y¹and Y²Each independently selected from the group represented by the following formula (Y-1):

[ in the formula (Y-1),

M¹represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may be substituted with one or more substituents X³Substituted, substituent X³With the above-mentioned substituent X¹And X²Are defined as such;

U¹represents an organic group having 2 to 30 carbon atoms and having an aromatic hydrocarbon group, any carbon atom of the aromatic hydrocarbon group may be replaced by a hetero atom, and the aromatic hydrocarbon group may be substituted by one or more of the substituents X³Substitution;

T¹represents-O-, -S-, -COO-, -OCO-O-, -NU²-、-N＝CU²-、-CO-NU²-、-OCO-NU²-or O-NU²-，U²Represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group in which any carbon atom may be replaced by a hetero atom, or (D)⁵-A³)_q-B³-E³-P³The alkyl, cycloalkyl, cycloalkenyl and aromatic hydrocarbon groups are each unsubstituted or may be substituted by one or more substituents X³Substituted, the alkyl group being substituted by the cycloalkyl or cycloalkenyl group, 1-CH of the alkyl group₂-or non-adjacent 2 or more-CH₂May each be independently substituted by-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -SO₂-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH-COO-, -CH-OCO-, -COO-CH-, -OCO-CH-, -CH-, -CF-or-C.ident.C-, with 1-CH-O-, -CO-NH-, -NH-CO-, -CH-COO-, -CH-or-C.ident.C-substitution in the cycloalkyl or cycloalkenyl group₂-or non-adjacent 2 or more-CH₂May each be independently replaced by-O-, -CO-, -COO-, -OCO-, or O-CO-O-, D⁵、A³、B³、E³And P³Respectively with the above D³～D⁴、A¹～A²、B¹、E¹And P¹Are defined as such and may each be as defined above for D³And D⁴、A¹And A²、B¹、E¹And P¹Q represents an integer of 0 to 4, and a plurality of D's may be present⁵And/or A³Each may be the same or different, U¹And U²Can be bonded to form a ring]。〕

[2] The polymerizable liquid crystal mixture according to [1], wherein the ratio of the total peak area of the compound (2) and the compound (3) to the total peak area of the polymerizable liquid crystal compound (1), the compound (2) and the compound (3) is 0.01% or more and 20% or less, as measured by liquid chromatography.

[3]As described above [1]Or [2]]The polymerizable liquid crystal mixture wherein G in the formulae (1) to (3)¹And G²Is cyclohexane-1, 4-diyl.

[4]As described above [1]～[3]The polymerizable liquid crystal mixture according to any one of the above formulas (1) to (3), wherein A is¹And A²Each independently cyclohexane-1, 4-diyl or 1, 4-phenylene.

[5]As described above [1]～[4]The polymerizable liquid crystal mixture according to any one of the above formulas (1) to (3), wherein T is¹is-O-, -S-, -N ═ CU²-or-NU²-。

[6]As described above [1]～[5]The polymerizable liquid crystal mixture according to any one of the above formulae (1) to (3), wherein T is¹is-NU²-, the U²1-CH in which a hydrogen atom may be substituted by a fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 2 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-or OCO-, a cycloalkyl group having 3 to 12 carbon atoms, or the above alkyl group which may be substituted by the above cycloalkyl group.

[7] The polymerizable liquid crystal mixture according to any one of the above [1] to [6], wherein the solid-liquid crystal phase transition temperature is 25 ℃ or higher and 200 ℃ or lower.

[8] A polymerizable liquid crystal composition comprising the polymerizable liquid crystal mixture according to any one of [1] to [7 ].

[9] The polymerizable liquid crystal composition according to [8] above, further comprising a photopolymerization initiator.

[10] The polymerizable liquid crystal composition according to [8] or [9], which further comprises an organic solvent.

[11] The polymerizable liquid crystal composition according to the above [9] or [10], wherein the photopolymerization initiator is at least one selected from the group consisting of an acylphosphine oxide-based polymerization initiator, an α -aminoalkylphenyl ketone-based polymerization initiator, an α -hydroxyketone-based polymerization initiator and an oxime ester-based polymerization initiator.

[12] The polymerizable liquid crystal composition according to [10] or [11], wherein the organic solvent is at least one selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and N-methylpyrrolidone.

[13] A cured product of the polymerizable liquid crystal composition according to any one of [8] to [12 ].

[14] A retardation film comprising a cured liquid crystal film obtained by curing the polymerizable liquid crystal compound in the polymerizable liquid crystal composition according to any one of [8] to [13] in an aligned state.

[15] The retardation film according to the above [14], which satisfies the following formula:

0.70≤Re(450)/Re(550)<1.00

in the formula, Re (λ) represents an in-plane retardation value at a wavelength λ nm of the retardation film.

[16] An elliptically polarizing plate comprising the retardation film according to [14] or [15 ].

[17] An optical display comprising the elliptically polarizing plate according to [16 ].

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a polymerizable liquid crystal composition which realizes high solubility of a polymerizable liquid crystal compound in a solvent and contains a polymerizable liquid crystal compound which is ideally suited for constituting a retardation film capable of realizing good circular polarization conversion.

Detailed Description

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

< polymerizable liquid Crystal mixture >

The polymerizable liquid crystal mixture of the present invention contains a polymerizable liquid crystal compound (1) (hereinafter, also referred to as "polymerizable liquid crystal compound (1)") represented by formula (1) and at least one selected from the group consisting of a compound (2) (hereinafter, also referred to as "compound (2)") represented by formula (2) and a compound (3) (hereinafter, also referred to as "compound (3)") represented by formula (3). The solubility of the polymerizable liquid crystal compound (1) in a solvent can be improved by including the polymerizable liquid crystal compound (1) in combination with the compound (2) and/or the compound (3), the compound (2) and/or the compound (3) having a molecular structure similar to that of the polymerizable liquid crystal compound (1), particularly the compound represented by the formula (1) including- (A)¹-D³)_m1-G¹-D¹-and-D²-G²-(D⁴-A²)_m2Mesogen (mesogen) moiety and R¹And R²The portions of the structures shown have a common molecular structure. In addition, even when the amount of the compound (2) and/or the compound (3) added to the polymerizable liquid crystal compound (1) is small, the effect of lowering the phase transition temperature of the polymerizable liquid crystal compound (1) is excellent, and therefore, the polymerizable liquid crystal compound can be processed at a lower processing temperature(1) The optical film obtained is advantageous also in terms of being able to reduce the influence of heating on the optical properties of the optical film and in terms of manufacturing efficiency.

The polymerizable liquid crystal compound (1) contained in the polymerizable liquid crystal mixture of the present invention is a compound represented by formula (1).

In the present invention, one or a combination of two or more polymerizable liquid crystal compounds may be used.

In the formula (1), D¹And D²Each independently represents-O-CO-, -CO-O-, -C (═ S) -O-, -O-C (═ S) -, -O-CR¹¹R¹²-、-CR¹¹R¹²-O-、-NR¹¹-CR¹²R¹³-、-CR¹²R¹³-NR¹¹-、-CO-NR¹¹-or-NR¹¹-CO-，R¹¹、R¹²And R¹³Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Wherein D is¹And D²Each independently is preferably-O-CO-, -CO-O-, -C (═ S) -O-, -O-C (═ S) -, -CO-NR-, -¹¹-or-NR¹¹-CO-。R¹¹、R¹²、R¹³And R¹⁴Each independently is preferably a hydrogen atom, a methyl group or an ethyl group.

D¹And D²The polymerizable liquid crystal compounds (1) may be the same or different from each other, and when the polymerizable liquid crystal compounds are the same, they are advantageous in terms of alignment properties of the polymerizable liquid crystal compounds (1), industrial production easiness, productivity, and the like.

In the formula (1), G¹、G²、A¹And A²Each independently represents a divalent aromatic hydrocarbon group or a divalent alicyclic hydrocarbon group, the hydrogen atom contained in the divalent aromatic hydrocarbon group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and the carbon atom constituting the divalent aromatic hydrocarbon group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro groupOxygen atom, sulfur atom or nitrogen atom.

As G¹And G²Examples thereof include alicyclic hydrocarbon groups which may contain hetero atoms represented by the formulae (g-1) to (g-10), preferably alicyclic hydrocarbon groups having 5-or 6-membered rings.

The groups represented by the above formulae (g-1) to (g-10) may be substituted with the following groups: alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, isopropyl, and tert-butyl; alkoxy groups having 1 to 4 carbon atoms such as methoxy and ethoxy; a fluoroalkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and the like.

As G¹And G²Each of the alicyclic hydrocarbon groups having 6-membered rings represented by the formula (g-1) is more preferable, cyclohexane-1, 4-diyl is more preferable, and trans cyclohexane-1, 4-diyl is particularly preferable.

G¹And G²The polymerizable liquid crystal compounds (1) may be the same or different from each other, and when the polymerizable liquid crystal compounds are the same, they are advantageous in terms of ease of industrial production and productivity.

As A¹And A²The divalent alicyclic hydrocarbon group or aromatic hydrocarbon group in (1) includes: an alicyclic hydrocarbon group containing a 5-membered ring, a 6-membered ring or the like represented by the above formulae (g-1) to (g-10); a divalent aromatic hydrocarbon group having about 6 to 20 carbon atoms represented by the formulae (a-1) to (a-8).

In addition, A is defined as¹And A²A part of hydrogen atoms of the above exemplified groups may be substituted with the following groups: an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, or a tert-butyl group; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group or an ethoxy group; a fluoroalkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group;a cyano group; a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and the like.

As A¹And A²Cyclohexane-1, 4-diyl or 1, 4-phenylene is preferred. When m1 and m2 are 1, A is preferably A¹And A²Each of which is 1, 4-phenylene, and m1 and m2 are 2 or more, are preferably bonded to G¹Adjacent D³A of (A)¹And is bonded to G²Adjacent D⁴A of (A)²Each being 1, 4-phenylene.

Each having 1 or more of A¹And A²Each of which may be the same or different, and from the viewpoints of alignment properties of the polymerizable liquid crystal compound (1), ease of industrial production, productivity, and the like, it is preferable that the ring structures constituting 2 mesogen portions are in a symmetrical relationship around the core portion of the polymerizable liquid crystal compound (1) represented by the formula (I):

[ in the formula (I), X¹、X²、Y¹、Y²N1 and n2 are each independently the same as X in the formula (1)¹、X²、Y¹、Y²N1 and n2 are as defined]。

In the formula (1), D³And D⁴Each independently represents-CR¹⁴R¹⁵-、-CH₂-CH₂-、-O-、-S-、-CO-O-、-O-CO-、-O-CO-O-、-C(＝S)-O-、-O-C(＝S)-、-O-C(＝S)-O-、-CO-NR¹⁴-、-NR¹⁴-CO-、-O-CH₂-、-CH₂-O-、-CH＝CH-COO-、-CH＝CH-OCO-、-COO-CH＝CH-、-OCO-CH＝CH-、-COO-CH₂CH₂-、-OCO-CH₂CH₂-、-CH₂CH₂-COO-、-CH₂CH₂-OCO-、-COO-CH₂-、-OCO-CH₂-、-CH₂-COO-、-CH₂-OCO-、-S-CH₂-、-CH₂-S-or a single bond, R¹⁴And R¹⁵Each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms. Wherein the content of the first and second substances,D³and D⁴Each independently preferably being-O-, -S-, -CO-O-, -O-CO-O-, -CO-NR-¹⁴-、-NR¹⁴-CO-、-CH＝CH-COO-、-CH＝CH-OCO-、-COO-CH＝CH-、-OCO-CH＝CH-、-COO-CH₂CH₂-、-OCO-CH₂CH₂-、-CH₂CH₂-COO-、-CH₂CH₂-OCO-or a single bond, more preferably-O-, -CO-O-, -O-CO-, -COO-CH₂CH₂-、-OCO-CH₂CH₂-、-CH₂CH₂-COO-or-CH₂CH₂-OCO-, more preferably-O-, -O-CO-or-CO-O-. R¹⁴And R¹⁵Each independently is preferably a hydrogen atom, a methyl group or an ethyl group.

Each having one or more of D³And D⁴The polymerizable liquid crystal compounds (1) may be the same or different from each other, and from the viewpoints of alignment properties, industrial production easiness, productivity, and the like, it is preferable that D, which constitutes 2 mesogen portions, is centered on the core portion of the polymerizable liquid crystal compound (1)³And D⁴A symmetrical relationship is formed.

In the formula (1), R¹And R²Each independently a group represented by the following formula (R-1):

-B¹-E¹-P¹(R-1)

[ in the formula (R-1),

P¹represents a polymerizable group]。

In the formula (R-1), B¹preferably-O-, -S-, -O-CO-, -CO-O-, -O-CO-O-, -CO-NR¹⁴-or-NR¹⁴-CO-, more preferably-O-, -O-CO-, -CO-O-or-O-CO-O-, further preferably-O-, -O-CO-, or-CO-O-.

In the formula (R-1), P¹Is a polymerizable group. In the present invention, the polymerizable group may be a substituent capable of polymerizing the polymerizable liquid crystal compound (1), and specifically, a vinyl group, a p-stilbene group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, a carboxyl group, a methylcarbonyl group, a hydroxyl group, an amide group, an alkylamino group having 1 to 4 carbon atoms, an amino group, an epoxy group, an oxetanyl group, an aldehyde group, an isocyanate group, an isothiocyanate group, and the like are exemplified. In addition, to combine the groups exemplified above with E¹The linkage, polymerizable group may be contained as B¹The groups shown. As P¹For example, a radical polymerizable group or a cation polymerizable group suitable for photopolymerization is preferable, and particularly, from the viewpoint of easy handling and easy production, an acryloyl group or a methacryloyl group is preferable, and an acryloyl group is more preferable.

In the formula (1), m1 and m2 each independently represent an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and still more preferably 1.

From the viewpoints of improving the alignment properties of the polymerizable liquid crystal compound (1), facilitating industrial production, improving productivity, and the like, it is preferable that the polymerizable liquid crystal compound (1) has a core portion as the center and the number of ring structures in the mesogen portion is symmetrical, and m1 is preferably the same as m2 in the formula (1).

The structure of the core portion of the polymerizable liquid crystal compound (1) [ the structure represented by the formula (I) above ], wherein the substituent X¹And X²Each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl groupSilyl, thioisocyano, or 1-CH₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 20 carbon atoms which may be independently substituted with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH-COO-, -CH-OCO-, -COO-CH-, -OCO-CH-, -CH-, -CF-or-C.ident.C-. Any hydrogen atom in the alkyl group may be substituted with a fluorine atom, or, a substituent X¹And X²May each independently be-B²-E²-P²A group of formula B²、E²And P²Respectively with the above B¹、E¹And P¹Are defined in the same manner as B above¹、E¹And P¹The same or different, there being a plurality of X' s¹And/or X²In the case of (3), they may be the same or different.

The substituent X is a substituent having good liquid crystallinity, good birefringence and easy synthesis¹And X²Preferably a fluorine atom, a chlorine atom, a pentafluorosulfanyl group, a nitro group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, or 1-CH group in which any hydrogen atom may be substituted with a fluorine atom₂-or non-adjacent 2 or more-CH₂A linear or branched alkyl group having 1 to 20 carbon atoms which may be independently replaced with a group selected from-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH-, -CF-or-C.ident.C-, and particularly, from the viewpoint of satisfactory birefringence and easy synthesis, a fluorine atom, a chlorine atom, a hydroxyl group, a methylamino group, a dimethylamino group, or 1-CH-C.ident.C-group is preferable₂-or non-adjacent 2 or more-CH₂A linear or branched alkyl group having 1 to 12 carbon atoms which may be independently replaced with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-. Substituent X¹And X²More preferably 1-CH in which fluorine atom, chlorine atom or any hydrogen atom may be substituted by fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 12 carbon atoms which may be independently replaced with a group selected from-O-, -COO-and-OCO-, a linear or branched alkyl group having 1 to 12 carbon atoms or an alkoxy group in which fluorine atom, chlorine atom, or any hydrogen atom may be substituted with a fluorine atom is more preferable, a fluorine atom, chlorine atom, a linear alkyl group having 1 to 8 carbon atoms or a linear alkoxy group is particularly preferable, and a linear alkyl group having 1 to 6 carbon atoms is particularly preferable.

Substituent X¹And/or X²When each is independently present in the biphenylene group in the core structure represented by the formula (I), the substitution position is preferably the 6-position or 6' -position of the biphenylene group from the viewpoint of satisfactory birefringence. With such a molecular structure, the twist angle of 2 benzene rings in biphenylene group becomes large, and the pi-electron conjugated structure is easily cleaved.

In the formula (1), Y¹And Y²Each independently selected from the group represented by the following formula (Y-1).

In the formula (Y-1), M¹Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The alkyl group may be substituted with one or more substituents X³Substituted, also unsubstituted. As substituents X³Examples thereof include the above-mentioned substituent X¹And X²The same groups as those mentioned above are preferably fluorine atom, chlorine atom, -CF₃、-OCF₃Or a cyano group. M¹Preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which is unsubstituted or substituted with one or more fluorine atoms, and more preferably a hydrogen atom.

U¹Represents an organic group having 2 to 30 carbon atoms and having an aromatic hydrocarbon group. Any carbon atom of the aromatic hydrocarbon group may be replaced by a hetero atom, U¹The organic group has 2-30 carbon atoms and at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocyclic rings. The above aromatic hydrocarbon group may be substituted with one or more of the above substituents X³Substituted, also unsubstituted.

As the aromatic ring, preferred are groups represented by the following formulae (U-1) to (U-22).

In the following formulae, these groups have a group T at an arbitrary position¹The connecting bond of (1).

From the viewpoint of improving wavelength dispersion, U is¹The organic group of the aromatic heterocyclic ring having one or more carbon atoms replaced with a heteroatom is preferable, and the organic group of the aromatic heterocyclic ring having a condensed ring of a 5-membered ring and a 6-membered ring is more preferable in terms of good wavelength dispersibility and high birefringence. Examples of the aromatic heterocyclic ring having a condensed ring of a 5-membered ring and a 6-membered ring include aromatic heterocyclic rings in which one or more carbon atoms are replaced with a hetero atom in a group represented by the above formula (U-10), formula (U-11), formula (U-21) or formula (U-22).

In the above formulae (U-18) to (U-20), Q^arepresents-O-, -S-, -NRQ^a- (in, RQ)^aRepresents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms) or-CO-, in which-CH-may be independently replaced by-N-CH₂May each independently be-O-, -S-, -NRQ^a- (in, RQ)^aRepresents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms), -SO-, -SO₂-or-CO-substitution (wherein the case where oxygen atoms are directly bonded to each other is excluded). One or more hydrogen atoms bonded to these rings may be substituted by the above-mentioned substituent X³And (4) substitution.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and still more preferably 1 carbon atom.

The group represented by the formula (U-1) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted, of the formula (U-1-1)A group represented by the formula (U-1-8). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

The group represented by the formula (U-7) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-7-1) to (U-7-7).

In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

The group represented by the formula (U-10) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-10-1) to (U-10-9). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formulae (U-10-4) and (U-10-8), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-11) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-11-1) to (U-11-12). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formula (U-11-4), formula (U-11-7), formula (U-11-10) and formula (U-11-12), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-13) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-13-1) to (U-13-19). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formula (U-13-4), formula (U-13-7), formula (U-13-10), formula (U-13-13) and formulae (U-13-15) to (U-13-19), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-14) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-14-1) to (U-14-10). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formula (U-14-4), formula (U-14-7), formula (U-14-9) and formula (U-14-10), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-15) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-15-1) to (U-15-4). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formula (U-15-4), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-16) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted byAnd groups represented by the following formulae (U-16-1) to (U-16-16). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

In the above formula (U-16-4), formula (U-16-7), formula (U-16-9), formula (U-16-12) and formulae (U-16-14) to (U-16-16), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-17) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (U-17-1) to (U-17-4).

In the above formula (U-17-4), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-18) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (U-18-1) to (U-18-6).

In the above formulae (U-18-3) and (U-18-6), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-19) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (U-19-1) to (U-19-6).

In the formula, these groups are optionalPosition having a and T¹The connecting bond of (1).

In the above formulae (U-19-3), (U-19-5) and (U-19-6), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-20) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (U-20-1) to (U-20-9).

In the above formula (U-20-3), formula (U-20-6), formula (U-20-8) and formula (U-20-9), R^QRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

The group represented by the formula (U-21) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (U-21-1) and (U-21-2). The group represented by the formula (U-22) is preferably unsubstituted or may be substituted with one or more of the above-mentioned substituent groups X³Substituted groups represented by the following formulae (U-22-1) and (U-22-2). In the formula, these groups have a group with T at an arbitrary position¹The connecting bond of (1).

U¹More preferably, the compound contains a substituent X selected from the group consisting of unsubstituted substituents X and optionally substituted by one or more substituents X³Substituted, the above formula (U-1-1), formula (U-7-2), formula (U-7-7), formula (U-8), formula (U-10-2), formula (U-10-3), formula (U-10-4), formula (U-10-5), formula (U-10-6), formula (U-10-7), formula (U-10-8), formula (U-10-9), formula (U-11-2), formula (U-11-3)) Aromatic groups selected from the group consisting of the formula (U-11-4), the formula (U-11-5), the formula (U-11-6), the formula (U-11-7), the formula (U-11-8), the formula (U-11-9), the formula (U-11-10), the formula (U-11-11), the formula (U-11-12), the formula (U-21-1), the formula (U-21-2), the formula (U-22-1) and the formula (U-22-2), particularly preferably contain at least one substituent X which may be unsubstituted or substituted by at least one of the above substituents X³Substituted, aromatic groups in the above formula (U-10-2), formula (U-10-3), formula (U-10-4), formula (U-10-5), formula (U-10-6), formula (U-10-7), formula (U-10-8), and formula (U-10-9), formula (U-21-1), formula (U-21-2), formula (U-22-1), and formula (U-22-2).

In addition, U¹Wherein the aromatic group is represented by X³When substituted, examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a thioisocyano group, or 1-CH₂-or non-adjacent 2 or more-CH₂A linear or branched alkyl group having 1 to 20 carbon atoms (any hydrogen atom in the alkyl group may be substituted with a fluorine atom), which may be independently substituted with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-or-NH-CO-, and is preferably a fluorine atom, a chlorine atom, a bromine atom, or 1-CH₂-or non-adjacent 2 or more-CH₂A linear or branched alkyl group having 1 to 20 carbon atoms which may be independently replaced with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, or-NH-CO- (any hydrogen atom in the alkyl group may be substituted with a fluorine atom).

Specifically, as U¹Preferably, the group represented by the following formula. In the following formulae, these groups have a group T at an arbitrary position¹The connecting bond of (1).

T¹represents-O-, -S-, -COO-, -OCO-O-, -NU²-、-N＝CU²-、-CO-NU²-、-OCO-NU²-or-O-NU²-。U²Represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group in which any carbon atom may be replaced by a hetero atom, or- (D)⁵-A³)_q-B³-E³-P³. The alkyl, cycloalkyl, cycloalkenyl and aromatic hydrocarbon group may each be substituted with one or more of the above-mentioned substituents X³Substituted, also unsubstituted. In addition, the alkyl group may be substituted with the cycloalkyl group or cycloalkenyl group. 1-CH in the alkyl group₂-or non-adjacent 2 or more-CH₂May each be independently substituted by-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -SO₂-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH ═ CH-COO-, -CH ═ CH-OCO-, -COO-CH ═ CH-, -OCO-CH ═ CH-, -CF ═ CF-, or-C ≡ C-substitution. 1-CH of the cycloalkyl or cycloalkenyl group₂-or non-adjacent 2 or more-CH₂-may be each independently replaced by-O-, -CO-, -COO-, -OCO-, or-O-CO-O-. D⁵、A³、B³、E³And P³Respectively with the above D³～D⁴、A¹～A²、B¹、E¹And P¹Are defined as such and may each be as defined above for D³And D⁴、A¹And A²、B¹、E¹And P¹Q represents an integer of 0 to 4, and a plurality of D's may be present⁵And/or A³In the case, they may be the same or different. In addition, U¹And U²May be bonded to form a ring.

T is good in birefringence and easy to synthesize¹preferably-O-, -S-, -N-CU²-or-NU²-. In addition, T is good in wavelength dispersion and birefringence¹More preferably-O-, -S-, or-NU²-。

U²Preferably, it represents: may be substituted by more than one substituent X as described above³Substituted, 1-CH₂-or out of phaseAdjacent 2 or more-CH₂-an alkyl or alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a cycloalkenyl group having 3 to 12 carbon atoms, each of which may be independently replaced with-O-, -CO-, -COO-, -OCO-, or-O-CO-O-; or the above alkyl group or alkenyl group which may be substituted with the cycloalkyl group, cycloalkenyl group, or aryl group; or (D)⁵-A³)_q-B³-E³-P³。

U²May be appropriately selected depending on the purpose. For example, from the aspect of birefringence, U²Preferred are structures that do not contain heteroatoms. In addition, U²To structures containing more hetero atoms, especially having 1-CH₂-or non-adjacent 2 or more-CH₂When the structures are each independently replaced by-O-, -CO-, -COO-, -OCO-or-O-CO-O-, the solvent solubility of the polymerizable liquid crystal compound (1) is improved, and the options for the combinable substrates are increased, which is advantageous in view of the above. In addition, U²Is- (D)⁵-A³)_q-B³-E³-P³In the case of the liquid crystal composition, the liquid crystal cured film formed from the polymerizable liquid crystal compound (1) is preferably improved in terms of ease of curing and durability.

In one embodiment of the present invention, T¹is-NU²-, the U²Comprises the following steps: 1-CH in which the hydrogen atom may be substituted by fluorine atoms₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 2 to 20 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, each of which may be independently replaced by-O-, -CO-, -COO-or-OCO-; or the above alkyl group which may be substituted with the cycloalkyl group.

Examples of the unsubstituted alkyl or alkenyl group having 1 to 20 carbon atoms, the cycloalkyl group having 3 to 12 carbon atoms, the cycloalkenyl group having 3 to 12 carbon atoms, and the alkyl or alkenyl group which may be substituted with the cycloalkyl, cycloalkenyl or aryl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, 1-methylpentyl, n-heptyl, 1-ethylpentyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, 3, 7-dimethyloctyl, n-undecyl, n-dodecyl, vinyl, allyl, isopropenyl, butenyl, cyclopentyl, cyclohexyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, cyclopentylmethyl, cyclohexylmethyl, benzyl, and the like.

As U²The substituent (2) is preferably a fluorine atom, a chlorine atom, a bromine atom, a cyano group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, or 1-CH₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 20 carbon atoms which may be independently replaced with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH-COO-, -CH-OCO-, -COO-CH-, -OCO-CH-, -CH-, -CF-or-C.ident.C-, more preferably a fluorine atom, a chlorine atom, a cyano group, a hydroxyl group, or 1-CH-C.ident.C-₂-or non-adjacent 2 or more-CH₂A linear or branched alkyl group having 1 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-, or-O-CO-O-.

From the viewpoint of birefringence, solvent solubility or durability, U²Preferably, the substituent X may be substituted by one or more³Substituted, 1-CH₂-or non-adjacent 2 or more-CH₂An alkyl group or alkenyl group having 1 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-, or-O-CO-O-, a cycloalkyl group having 3 to 12 carbon atoms or a cycloalkenyl group having 3 to 12 carbon atoms, or the above-mentioned alkyl group or alkenyl group which may be substituted by the above-mentioned cycloalkyl group or cycloalkenyl group, or- (D)⁵-A³)_q-B³-E³-P³More preferably 1-CH in which any hydrogen atom may be substituted by a fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-, a cycloalkyl group having 3 to 12 carbon atoms, the alkyl group which may be substituted by the cycloalkyl group, or- (D)⁵-A³)_q-B³-E³-P³Excellence inIs selected to be 1-CH₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 12 carbon atoms which may be replaced by-O-, a cycloalkyl group having 3 to 12 carbon atoms, or the alkyl group which may be substituted by the cycloalkyl group, or- (D)⁵-A³)_q-B³-E³-P³。

In addition, the following (D)⁵-A³)_q-B³-E³-P³And D³～D⁴、A¹～A²、B¹、E¹And P¹The preferred structures defined in (1) are the same. q represents an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, and further preferably 0.

In addition, from the viewpoint of birefringence and solvent solubility, U is²Preferably 1-CH in which the hydrogen atom may be replaced by a fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 2 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-, a cycloalkyl group having 3 to 12 carbon atoms, or the above alkyl group which may be substituted by the cycloalkyl group, more preferably 1-CH group in which a hydrogen atom may be substituted by a fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 2 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-, and more preferably 1-CH group in which a hydrogen atom may be substituted by a fluorine atom₂-or non-adjacent 2 or more-CH₂A linear alkyl group having 2 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-, -OCO-.

U²The number of carbon atoms in (b) is preferably 4 or more, more preferably 12 or less.

U¹And U²May be bonded to form a ring. In this case, for example, an NU¹U²A cyclic group represented by or-N ═ CU¹U²The cyclic group shown. As and U¹And U²Examples of the ring formed by the bonded nitrogen atom or carbon atom together include a ring having an aromatic ringAnd a ring having 2 to 30 carbon atoms, preferably 2 to 18 carbon atoms, more preferably 2 to 14 carbon atoms. wherein-NU¹U²The cyclic group represented is preferably selected from the group consisting of unsubstituted or substituted by one or more of the above-mentioned substituents X³Substituted groups represented by the following formulae (UU-1) to (UU-22). -N ═ CU¹U²The cyclic group represented is preferably a group represented by the following formula (UU-23) or formula (UU-24).

Each of-CH ═ in the group selected from formulae (UU-1) to (UU-22) may be independently replaced by-N ═ in, -CH₂May each independently be-O-, -S-, -NRU²- (in, RU)²Represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms), -SO-, or-SO₂-or-CO-substitution (wherein the case where oxygen atoms are directly bonded to each other is excluded). One or more hydrogen atoms bonded to these rings may be substituted with the above-mentioned substituent X3. Examples of the alkyl group constituting the above-mentioned alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and still more preferably 1 carbon atom.

T is a compound having a high degree of crystallinity and a low degree of crystallinity, from the viewpoints of wavelength dispersion characteristics, liquid crystallinity, ease of synthesis and the like¹And U¹The total number of pi electrons contained in (a) is preferably 4 to 24, more preferably 4 to 20.

Y is particularly preferable in terms of easy availability of raw materials, good solubility, and high birefringence¹And Y²Each selected from the group consisting of the groups represented by the following formulae (Y-1 ') to (Y-47').

In the formula (1), n1 and n2 each independently represent an integer of 0 to 3. n1 and n2 are each independently preferably 0 to 2, more preferably 0 or 1.

From the viewpoint of good alignment properties of the polymerizable liquid crystal compound (1), easy industrial production, and productivity improvement, the molecular structure of the polymerizable liquid crystal compound (1) is preferably symmetrical, and n1 in formula (1) is preferably the same as n 2.

As the molecular structure in the core structure represented by the above formula (I), the structures represented by the following formulae (I-1) to (I-8) are preferable.

Specific examples of the polymerizable liquid crystal compound (1) include compounds represented by the following formulas (1-1) to (1-28).

The polymerizable liquid crystal mixture of the present invention contains at least one selected from the group consisting of the compound (2) represented by the formula (2) and the compound (3) represented by the formula (3) in addition to the polymerizable liquid crystal compound (1).

In the formulae (2) and (3), D¹、D²、G¹、G²、D³、D⁴、A¹、A²、R¹、R²、X¹、X²、Y¹、Y²M1, m2, n1 and n2 correspond to D in the formula (1) which constitutes a polymerizable liquid crystal compound (1) of a polymerizable liquid crystal mixture containing the compound (2) and/or the compound (3)¹、D²、G¹、G²、D³、D⁴、A¹、A²、R¹、R²、X¹、X²、Y¹、Y²M1, m2, n1 and n2 are the same. When the polymerizable liquid crystal compound (1) having a plurality of structures represented by the formula (1) is contained, the compound (2) and/or the compound (3) may be contained, and D of the compound (2) and/or the compound (3)¹、D²、G¹、G²、D³、D⁴、A¹、A²、R¹、R²、X¹、X²M1, m2, n1 and n2, and Y¹Or Y²D in the formula (1) corresponding to at least one polymerizable liquid crystal compound (1) of the plurality of compounds¹、D²、G¹、G²、D³、D⁴、A¹、A²、R¹、R²、X¹、X²、Y¹、Y²M1, m2, n1 and n2 are the same.

The polymerizable liquid crystal mixture of the present invention may contain either one of the compound (2) and the compound (3), or both of the compound (2) and the compound (3).

L1 and l2 in the formulae (2) and (3) are each independently an integer of 0 or 1.

The polymerizable liquid crystal mixture of the present invention contains not only the polymerizable liquid crystal compound (1) but also the compound (2) and/or the compound (3) having a molecular structure similar to that of the polymerizable liquid crystal compound (1), thereby improving the solubility of the polymerizable liquid crystal compound (1) in a solvent. Therefore, more polymerizable liquid crystal compound (1) can be easily dissolved in the same amount or less of solvent than in the case where polymerizable liquid crystal compound (1) is dissolved in solvent alone. Thus, the polymerizable liquid crystal compound (1) is less likely to remain undissolved in the coating liquid, and a high coatability during film formation can be ensured, so that a polymerizable liquid crystal composition having excellent film-forming properties can be obtained. Further, it is also advantageous in that the amount of solvent required for preparing the coating liquid can be reduced, and the number of choices of the substrate, the alignment film, and the production conditions to be used increases as the number of solvents to be selected increases. In addition, by improving the solubility of the polymerizable liquid crystal compound (1) in the solvent, precipitation or precipitation of the polymerizable liquid crystal compound (1) in the coating liquid can be suppressed. This can suppress the occurrence of alignment defects due to undissolved polymerizable liquid crystal compound (1), precipitates, and the like, or improve storage stability, and can form a film without degrading optical properties that the polymerizable liquid crystal compound (1) used can originally exhibit. In addition, even when the amount of the compound (2) and/or the compound (3) added to the polymerizable liquid crystal compound (1) is small, the effect of lowering the phase transition temperature of the polymerizable liquid crystal compound (1) is excellent, and therefore, an optical film can be obtained from the polymerizable liquid crystal compound (1) at a lower processing temperature, and the optical film is advantageous in that the influence of heating on the optical characteristics of the optical film can be reduced, and in that the production efficiency can be improved.

The polymerizable liquid crystal mixture of the present invention preferably contains the compound (2) and/or the compound (3) in an amount such that the ratio of the total peak area of the compound (2) and the compound (3) to the total peak area of the polymerizable liquid crystal compound (1), the compound (2), and the compound (3) (hereinafter, also referred to as "area percentage value") is 0.01% to 20%, as measured by liquid chromatography. When the area percentage value of the compound (2) and/or (3) is not less than the lower limit, the solubility of the polymerizable liquid crystal compound (1) in the solvent can be sufficiently improved. When the area percentage value of the compound (2) and/or (3) is equal to or less than the upper limit, the alignment state of the liquid crystal can be favorably maintained when an optical film is produced from a polymerizable liquid crystal composition containing the polymerizable liquid crystal mixture, and thus an optical film having excellent optical characteristics can be obtained. In the present invention, the area percentage value of the compound (2) and/or the compound (3) is more preferably 15% or less, still more preferably 10% or less, particularly preferably 8% or less, and particularly preferably 6% or less. In the present invention, since the effect of greatly improving the solubility of the polymerizable liquid crystal compound (1) in the solvent is excellent even when the compound (2) and/or the compound (3) is contained in a very small amount, the above advantageous effects of the present invention can be sufficiently obtained even when the area percentage value of the compound (2) and/or the compound (3) is 0.5% or less or 0.1% or less in one embodiment of the present invention, which is less than 1.0%.

The area percentage value can be calculated based on the peak area measured by liquid chromatography, and specifically can be calculated by the method described in the examples described later.

The polymerizable liquid crystal mixture of the present invention may contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (1), the compound (2), and the compound (3) as long as the effect of the present invention is not affected. Examples of such polymerizable liquid crystal compounds include polymerizable liquid crystal compounds capable of exhibiting reverse wavelength dispersibility and polymerizable liquid crystal compounds capable of exhibiting positive wavelength dispersibility when formed into a liquid crystal cured film, as described in, for example, japanese patent laid-open publication No. 2011-207765 and japanese patent laid-open publication No. 5962760.

When the polymerizable liquid crystal mixture of the present invention contains a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (1), the compound (2), and the compound (3), the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 7 parts by mass or less, based on 100 parts by mass of the total of the polymerizable liquid crystal compound (1), the compound (2), and the compound (3). In particular, when the content of the liquid crystal compound having a significantly different molecular structure is too large, phase separation may occur and the appearance may be impaired, and therefore, the polymerizable liquid crystal compound constituting the polymerizable liquid crystal mixture of the present invention is preferably substantially composed of a polymerizable liquid crystal compound similar to the polymerizable liquid crystal compound (1). The term "similar" means, for example, that R has a mesogen portion similar to that of the polymerizable liquid crystal compound (1)¹And R²In the case of the structure in which the portions indicated are common, the above-mentioned "substantially … … constitution" means that: the content of the polymerizable liquid crystal compound (1), the compound (2), and the compound (3) is 90% by mass or more with respect to the total mass of the polymerizable liquid crystal compounds contained in the polymerizable liquid crystal mixture of the present invention. In one embodiment of the present invention, the polymerizable liquid crystal mixture does not contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (1), the compound (2), and the compound (3).

The method for producing the polymerizable liquid crystal compounds (1), (2) and (3) constituting the polymerizable liquid crystal composition of the present invention is not particularly limited, and they can be produced by appropriately combining known Organic Synthesis Reactions (for example, condensation reaction, esterification reaction, Williamson reaction, ullmann reaction, Wittig reaction, schiff base generation reaction, benzylation reaction, sonography reaction, suzuki-gong reaction, shozuki-kuyama reaction, kohama reaction, kutakupffer reaction, juniper coupling reaction, buhward-hartivichi reaction, Friedel-Crafts reaction, heuch reaction, aldol reaction, etc.) described in Methoden der Organic chemistry, Organic Reactions, Organic syntheses, new experimental chemistry teaching (Japanese: th) and the like, depending on their structures.

For example, D in the formula (1)¹And D²Each represents O-OCO- (. sup. -, each represents a. unit) and each represents a unit, M each represents a unit, each represents a unit, and M represents a unit, each represents a unit, and each represents a unit, and M represents a unit, each represents a unit, and a unit, each represents a unit, and a unit, each represents a unit, and a unit, each represents a unit, each represents¹In the case of the polymerizable liquid crystal compound (1) represented by the following formula (E) which is a hydrogen atom, it can be produced in the following manner, for example, by the method disclosed in Japanese patent laid-open publication No. 2019-73496. In the following formula (E), G¹、G²、D³、D⁴、A¹、A²、R¹、R²、X¹、X²、U¹、T¹M1, m2, n1 and n2 each represent the same meanings as the corresponding symbols in formula (1).

First, 4' -dihydroxybiphenyl or a derivative thereof having a substituent X introduced thereinto is subjected to the Daff reaction¹And/or X²An aldehyde group is introduced into a desired position of the compound represented by the formula (A) to produce an intermediate A represented by the formula (B).

Then, intermediate A represented by formula (B) and HOOC-G are reacted by condensation reaction or the like¹-(D³-A¹)_m1-R¹Intermediate B (G) shown¹、D³、A¹、R¹And m1 represents the same meaning as the corresponding symbols in formula (1), thereby obtaining an intermediate C represented by formula (C). Further, the intermediate C represented by the formula (C) thus obtained is reacted with HOOC-G²-(D⁴-A²)_m2-R²Intermediate D (G) of²、D⁴、A¹、R²And m2 represents the same meaning as the corresponding symbols in formula (1), thereby obtaining an intermediate E represented by formula (D). In the case where the structures of the above intermediate B and intermediate D are the same,intermediate E can be obtained by reacting intermediate B with intermediate a.

Then, let U for example¹-T¹-NH₂The intermediate F represented by formula (a) can be reacted with the intermediate E represented by formula (D) to obtain a compound represented by formula (a).

Further, the intermediate a represented by the above formula (B) can be obtained by: according to X¹And X²Kind of (2), substitution position, Y¹And Y²For example, the substitution position of (a) is subjected to a davenff reaction, an aldehyde group is introduced into 3, 4-methylenedioxyphenol (manufactured by tokyo chemical industries, Ltd.) or a derivative thereof, and a suzuki-miyaura coupling reaction is performed.

Further, for example, Y as a side chain moiety is introduced in advance to obtain intermediate A represented by formula (B)¹And Y²After the intermediate G has been formed, HOOC-G is reacted¹-(D³-A¹)_m1-R¹Intermediate B (G) shown¹、D³、A¹、R¹And m1 represents the same meaning as the corresponding symbols in formula (1), HOOC-G²-(D⁴-A²)_m2-R²Intermediate D (G) of²、D⁴、A¹、R²And m2 represents the same meaning as the corresponding symbols in formula (1) with the intermediate G, whereby a compound represented by formula (E) can also be obtained.

Further, commercially available intermediates used in the production may be used as appropriate, or may be synthesized by a conventionally known method as appropriate.

In the case of the compound (2) and the compound (3), when l1 in the formula (2) and l2 in the formula (3) are each 0, for example, they can be prepared by the method disclosed in japanese patent No. 5962760. When l1 in formula (2) and l2 in formula (3) are each 1, for example, in the same method as the above-described method for producing the polymerizable liquid crystal compound (1), an intermediate a ' represented by formula (B ') in which an aldehyde group is introduced into only one of biphenyl groups can be produced by introducing an aldehyde group into the compound represented by formula (a), and the intermediate a ' can be used as a compound corresponding to a core structure and reacted with the intermediate B, the intermediate D, and the like by the same procedure as the above-described method for producing the polymerizable liquid crystal compound (1).

The polymerizable liquid crystal compound (1), the compound (2) and/or the compound (3) constituting the polymerizable liquid crystal mixture of the present invention can be prepared independently, and then two or three of them are mixed to prepare a liquid crystal mixture. Further, a liquid crystal mixture containing the polymerizable liquid crystal compound (1), the compound (2) and/or the compound (3) can also be prepared by using the intermediate a represented by the formula (B) derived from the compound represented by the formula (a) and the intermediate a 'represented by the formula (B') and reacting the intermediate B, the intermediate D, and the like in the same manner as in the production method of the polymerizable liquid crystal compound (1). By mixing the liquid crystal mixture with the polymerizable liquid crystal compound (1), or mixing the liquid crystal mixture with the compound (2) or the compound (3), or the like, without separating each compound from the obtained liquid crystal mixture, the content of the polymerizable liquid crystal compound (1) and the compound (2) and/or the compound (3) in the liquid crystal mixture can be controlled, whereby a desired polymerizable liquid crystal mixture can be prepared.

When a polymerizable liquid crystal mixture is produced by the former method, the contents of the compound (2) and the compound (3) can be easily adjusted to a desired range, and the solvent solubility of the polymerizable liquid crystal compound (1) can be easily controlled. On the other hand, when a polymerizable liquid crystal mixture is prepared by the latter method, the synthesis is simple and the polymerizable liquid crystal composition can be produced more efficiently.

The polymerizable liquid crystal composition of the present invention comprises the polymerizable liquid crystal mixture of the present invention. The content of the polymerizable liquid crystal mixture (total amount of all polymerizable liquid crystal compounds) in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and still more preferably 90 to 95 parts by mass, based on 100 parts by mass of the solid components of the polymerizable liquid crystal composition. When the content of the polymerizable liquid crystal mixture is within the above range, it is advantageous from the viewpoint of alignment properties of the obtained liquid crystal cured film. In the present specification, the polymerizable liquid crystal compound may include the polymerizable liquid crystal compound (1), the compound (2), and the compound (3), and if contained, another polymerizable liquid crystal compound different from them, and the polymerizable liquid crystal mixture is usually composed of only the polymerizable liquid crystal compound. The solid component of the polymerizable liquid crystal composition means all components remaining after removing volatile components such as an organic solvent from the polymerizable liquid crystal composition.

The polymerizable liquid crystal composition of the present invention may contain additives such as an organic solvent, a photopolymerization initiator, a polymerization inhibitor, a photosensitizer, and a leveling agent, in addition to the polymerizable liquid crystal mixture of the present invention, i.e., the polymerizable liquid crystal compound (1), the compound (2), and/or the compound (3). These components may be used alone or in combination of two or more.

In the polymerizable liquid crystal mixture of the present invention, it is generally preferable to contain a solvent in order to apply the mixture to a substrate or the like in a state of being dissolved in the solvent. The solvent is preferably a solvent capable of dissolving a polymerizable liquid crystal compound constituting the polymerizable liquid crystal mixture, such as the polymerizable liquid crystal compound (1), the compound (2), and the compound (3), and is preferably a solvent inactive to the polymerization reaction of the polymerizable liquid crystal compound. The polymerizable liquid crystal composition of the present invention contains the polymerizable liquid crystal compound (1) and the compound (2) and/or the compound (3), and thus can significantly improve the solvent solubility of the polymerizable liquid crystal compound (1) as compared with a case where the polymerizable liquid crystal compound (1) is dissolved in a solvent alone. Therefore, various solvents can be applied. Examples of the solvent include: water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; 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; and so on. These solvents may be used alone or in combination of two or more. Among these, organic solvents are preferable, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents, and aromatic hydrocarbon solvents are more preferable, and at least one selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and N-methylpyrrolidone is further preferable from the viewpoint of solubility, industrial production easiness, productivity, and the like.

The content of the solvent in the polymerizable liquid crystal composition is preferably 50 to 98 parts by mass, and more preferably 70 to 95 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal composition. Therefore, the solid content of the polymerizable liquid crystal composition is preferably 2 to 50 parts by mass, and more preferably 5 to 30 parts by mass, per 100 parts by mass of the polymerizable liquid crystal composition. When the solid content is 50 parts by mass or less, the viscosity of the polymerizable liquid crystal composition decreases, and therefore the thickness of the film tends to be substantially uniform, and unevenness tends not to occur easily. The solid content may be determined as appropriate in consideration of the thickness of the liquid crystal cured film to be produced. The polymerizable liquid crystal composition of the present invention is advantageous in that it contains the polymerizable liquid crystal compound (1) and the compound (2) and/or the compound (3) and is excellent in solubility in a solvent, and therefore, the amount of an organic solvent used at the time of coating, storage, or the like can be reduced.

The polymerizable liquid crystal composition of the present invention preferably further contains a photopolymerization initiator. The photopolymerization initiator is a compound that generates reactive species by the action of light and can initiate a polymerization reaction such as a polymerizable liquid crystal. Examples of the reactive species include active species such as radicals, cations, and anions. Among them, a photopolymerization initiator which generates radicals by light irradiation is preferable from the viewpoint of easy control of the reaction. The photopolymerization initiator may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include aromatic ketone compounds including thioxanthone and the like, α -aminoalkylphenone compounds, α -hydroxyketones, acylphosphine oxide compounds, oxime ester compounds, aromatic onium salt compounds, organic peroxides, sulfur compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate ester compounds, azine compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. Among them, from the viewpoint of improving the durability of the liquid crystal cured film, at least one selected from the group consisting of an acylphosphine oxide-based polymerization initiator, an α -aminoalkylphenyl ketone-based polymerization initiator, an α -hydroxyketone-based polymerization initiator, and an oxime ester-based polymerization initiator is preferable.

Examples of the acylphosphine oxide-based polymerization initiator include bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (e.g., Irgacure 819, manufactured by BASF corporation), bis (2, 6-dimethoxybenzoyl) -2,4, 4-trimethyl-pentylphenylphosphine oxide, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide (e.g., Lucirin TPO, manufactured by BASF corporation), and the like.

Examples of the α -aminoalkylphenone-based polymerization initiator include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (e.g., Irgacure 907, manufactured by BASF corporation), 2-benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) -1-butanone (e.g., Irgacure369, manufactured by BASF corporation), and 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) phenyl ] -1-butanone (e.g., Irgacure 379EG, manufactured by BASF corporation).

Examples of the α -hydroxyketone polymerization initiator include 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] -phenyl } -2-methyl-propan-1-ONE (e.g., Irgacure 127, manufactured by BASF corporation), 2-hydroxy-4' -hydroxyethoxy-2-methylpropiophenone (e.g., Irgacure 2959, manufactured by BASF corporation), 1-hydroxy-cyclohexyl-phenylketone (e.g., Irgacure 184, manufactured by BASF corporation), oligo { 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone } (e.g., ESACURE ONE, lamberti, Inc.), and the like.

Examples of the oxime ester polymerization initiator include: 1- [4- (phenylsulfanyl) ] -1, 2-octanedione-2- (O-benzoyloxime) (trade name: Irgacure OXE-01, manufactured by BASF), 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -ethanone-1- (O-acetyloxime) (trade name: Irgacure OXE-02, manufactured by BASF), 1- [ 9-ethyl-6- (1, 3-dioxolane-4- (2-methoxyphenoxy) -9H-carbazol-3-yl ] -methyl ethyl ketone-1- (O-acetyloxime) (trade name: ADEKA OPT-N-1919, manufactured by ADEKA corporation), and the like.

The content of the photopolymerization initiator is usually 0.1 to 20 parts by mass, preferably 1 to 15 parts by mass, and more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable liquid crystal compound. When the amount is within the above range, the reaction of the polymerizable group proceeds sufficiently, and the alignment of the polymerizable liquid crystal compound (1) is not easily disturbed.

The polymerization reaction of the polymerizable liquid crystal compound can be controlled by adding the polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone and hydroquinone compounds having a substituent such as an alkyl ether; catechol compounds having a substituent such as an alkyl ether, such as butylcatechol; radical scavengers such as pyrogallol compounds and 2,2,6, 6-tetramethyl-1-piperidinyloxy radical; thiophenols; beta-naphthylamines and beta-naphthols. In order to polymerize the polymerizable liquid crystal compound (1) without causing disorder of alignment, the content of the polymerization inhibitor is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable liquid crystal compound.

Further, by using a sensitizer, the photopolymerization initiator can be highly sensitized. Examples of the photosensitizing agent include: xanthone compounds such as xanthone and thioxanthone; anthracene and anthracene compounds having a substituent such as alkyl ether; phenothiazine; rubrene. Examples of the photosensitizing agent include: xanthone compounds such as xanthone and thioxanthone; anthracene and anthracene compounds having a substituent such as alkyl ether; phenothiazine; rubrene. 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 3 parts by mass, based on 100 parts by mass of the total amount of the polymerizable liquid crystal compound.

The polymerizable liquid crystal composition of the present invention may further contain a leveling agent. The leveling agent is an additive having a function of adjusting the fluidity of the polymerizable liquid crystal composition to flatten a film obtained by applying the polymerizable liquid crystal composition, and examples thereof include silicone-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all of which are made by Toray Dow Corning Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161a, KF6001 (all of which are made by shin-Etsu chemical industries Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of which are made by Momentive Performance Materials Co., Ltd.), Fluorinert (registered trademark) FC-72, Fluorinert FC-482, Fluorinert-40, Fluorinert-43, Fluorinert FC-3283 (all of which are made by Momentive Performance TSCE Materials), Fluorinert FC-58596, GAF-48, GAF 6326-3978-4790, GAF-443, Zealant-4790, Zealant-443, Zealant-3-4790, Zealant-3, Zealant-4790, Zealant-3-4790, Zealant-3, Zealant-4790, Zealant-150, Zealant-3, Zealant-150, Zealant-K-150, Kd-3, Kd-3, Kd-47drag-47443, Kd-3, Kp-3, Kp-7, Kp-3, Kp-K-7, Kp-K-3, Kp-K-3, Kp-K-3, Kp-K-3, Kp-K-3, Kp-K-3, Kp-K-3, KP-K, MEGAFACE F-483 (both manufactured by DIC corporation), EFTOP (trade name) EF301, EFTOP EF303, EFTOP EF351, EFTOP EF352 (both manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40, SA-100 (both manufactured by AGC SEIMI CHEMICAL Co., Ltd.), trade name E1830, trade name E5844(Daikin Fine Chemical Kenkyus, manufactured by K.K.), BM-1000, 1100K-352, BYK-353 and BYK-361N (both manufactured by BM: Chemie Co., Ltd.), and the like. Among them, polyacrylate leveling agents and perfluoroalkyl leveling agents are preferable.

The content of the leveling agent in the polymerizable liquid crystal composition is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the total amount of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound tends to be easily aligned, and the obtained cured liquid crystal film tends to be smoother, and therefore, the content is preferable. The polymerizable liquid crystal composition may contain two or more leveling agents.

The polymerizable liquid crystal composition of the present invention can be prepared by adding additives such as a solvent, a photopolymerization initiator, a polymerization inhibitor, a photosensitizer, a leveling agent, and the like to the polymerizable liquid crystal compound (1), the compound (2), and/or the compound (3) as needed, and stirring and mixing the mixture at a predetermined temperature.

< retardation film >

The polymerizable liquid crystal composition of the present invention has high solubility of the polymerizable liquid crystal compound (1) in a solvent, and is excellent in coatability and film-forming properties, and therefore, can suppress the occurrence of alignment defects caused by undissolved polymerizable liquid crystal compound (1), precipitates, and the like in the composition. Therefore, by using the polymerizable liquid crystal composition of the present invention, a film can be formed without degrading the optical properties that the polymerizable liquid crystal compound (1) can originally exhibit, and a liquid crystal cured film having excellent optical properties can be obtained. Therefore, the present invention also relates to a cured product of the polymerizable liquid crystal composition of the present invention, and particularly relates to a retardation film comprising a liquid crystal cured film which is a cured product of the polymerizable liquid crystal composition and is cured in a state in which the polymerizable liquid crystal compound (1) in the polymerizable liquid crystal composition is aligned. The retardation film composed of the liquid crystal cured film can sufficiently exhibit optical properties originally exhibited by the polymerizable liquid crystal compound (1) to be used, and can be a retardation film having high optical properties.

The liquid crystal cured film constituting the retardation film of the present invention is preferably composed of a copolymer in an oriented state of a mixture of the polymerizable liquid crystal compound (1), the compound (2) and/or the compound (3), because a polymerization reaction is easy and a uniform liquid crystal cured film is easily obtained.

In one embodiment of the present invention, the retardation film of the present invention includes a liquid crystal cured film which is a cured product of the polymerizable liquid crystal composition of the present invention and generally has optical properties represented by the following formulae (i), (ii) and (iii). 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 a horizontal direction with respect to the plane of the liquid crystal cured film (hereinafter, also referred to as "horizontally aligned liquid crystal cured film").

Re(450)/Re(550)≤1.00 (i)

1.00≤Re(650)/Re(550) (ii)

100nm≤Re(550)≤180nm (iii)

In the formula, Re (λ) represents an in-plane phase difference at a wavelength λ nm of the liquid crystal cured film, Re ═ x (λ) -ny (λ)) × d (d represents a thickness of the liquid crystal cured film, nx represents a main refractive index at the wavelength λ nm in a direction parallel to a plane of the liquid crystal cured film in a refractive index ellipsoid formed by the liquid crystal cured film, and ny represents a refractive index at the wavelength λ nm in a direction parallel to the plane of the liquid crystal cured film and orthogonal to the direction of nx in the refractive index ellipsoid formed by the liquid crystal cured film). Angle (c)

When the horizontally aligned liquid crystal cured film satisfies the formulas (i) and (ii), the horizontally aligned liquid crystal cured film exhibits reverse wavelength dispersibility, that is, an in-plane retardation value at a short wavelength is smaller than an in-plane retardation value at a long wavelength. From the viewpoint of improving the reverse wavelength dispersibility and further improving the optical properties of the retardation film, Re (450)/Re (550) is preferably 0.70 or more, more preferably 0.78 or more, and is usually 1.00 or less, preferably 0.92 or less, more preferably 0.90 or less, further 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 1.00 or more, more preferably 1.01 or more, and further preferably 1.02 or more.

The in-plane phase difference 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 three-dimensional refractive index and the film thickness d may be adjusted to obtain a desired in-plane retardation value (Re (λ): the in-plane retardation value of the horizontally aligned liquid crystal cured film at the wavelength λ (nm)).

When the horizontally aligned liquid crystal cured film satisfies formula (iii), the effect of improving the front reflection color tone (the effect of suppressing coloring) is excellent when an elliptically polarizing plate including a retardation film including the horizontally aligned liquid crystal cured film is applied to an organic EL display device. The in-plane retardation value is more preferably 120 nm. ltoreq. Re (550). ltoreq.170 nm, and still more preferably 130 nm. ltoreq. Re (550). ltoreq.150 nm.

In one embodiment of the present invention, the retardation film of the present invention comprises a liquid crystal cured film which is a cured product of the polymerizable liquid crystal composition of the present invention and has optical properties represented by the following formulae (iv), (v) and (vi). 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 a perpendicular direction with respect to the plane of the liquid crystal cured film (hereinafter, also referred to as "vertically aligned liquid crystal cured film").

Rth(450)/Rth(550)≤1.00 (iv)

1.00≤Rth(650)/Rth(550) (v)

-100nm≤Rth(550)≤-40nm (vi)

In the formula, Rth (λ) represents a phase difference value in a thickness direction of the liquid crystal cured film at a wavelength λ nm, (((nx (λ) + ny (λ))/2-nz) × d (d represents a thickness of the liquid crystal cured film, nx represents a main refractive index at a wavelength λ nm in a direction parallel to a plane of the liquid crystal cured film in a refractive index ellipsoid formed by the liquid crystal cured film, ny represents a refractive index at a wavelength λ nm in a direction parallel to the plane of the liquid crystal cured film and orthogonal to the direction of the nx in the refractive index ellipsoid formed by the liquid crystal cured film, and nz represents a refractive index at a wavelength λ nm in a direction perpendicular to the plane of the liquid crystal cured film in the refractive index ellipsoid formed by the liquid crystal cured film. Angle (c)

When the vertically aligned liquid crystal cured film satisfies the formulae (iv) and (v), in an elliptically polarizing plate including a retardation film including the vertically aligned liquid crystal cured film, a decrease in ellipticity can be suppressed on the short wavelength side, and the side reflection color tone can be improved. 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 further preferably 0.92 or less, more preferably 0.90 or less, further preferably 0.87 or less, particularly preferably 0.86 or less, and more particularly 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.

When the vertically aligned liquid crystal cured film satisfies formula (vi), the color tone of the side reflection can be improved when an elliptically polarizing plate provided with a retardation film including the vertically aligned liquid crystal cured film is applied to an organic EL display device. 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, still more preferably-80 nm or more, and still more preferably-50 nm or less.

The retardation film of the present invention can be produced, for example, by a method comprising:

a step of forming a coating film of the polymerizable liquid crystal composition of the present invention, drying the coating film, and aligning the polymerizable liquid crystal compound in the polymerizable liquid crystal composition; and the number of the first and second groups,

and a step of forming a liquid crystal cured film by polymerizing the polymerizable liquid crystal compound by light irradiation while maintaining the alignment state.

The coating film of the polymerizable liquid crystal composition can be formed by coating the polymerizable liquid crystal composition on a substrate, an alignment film described later, or the like.

Examples of the substrate include a glass substrate and a film substrate, and a resin film substrate is preferable from the viewpoint of processability. Examples of the resin constituting the film base include: polyolefins such as polyethylene, polypropylene, and norbornene polymers; a cycloolefin resin; polyvinyl alcohol; polyethylene terephthalate; polymethacrylates; a polyacrylate; cellulose esters such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; polyethylene naphthalate; a polycarbonate; polysulfones; polyether sulfone; a polyether ketone; polyphenylene sulfide and polyphenylene oxide. Such a resin can be formed into a film by a known means such as a solvent casting method or a melt extrusion method to form a substrate. The surface of the base material may have a protective layer made of an acrylic resin, a methacrylic resin, an epoxy resin, an oxetane resin, a urethane resin, a melamine resin, or the like, and may be subjected to surface treatment such as mold release treatment such as silicone treatment, corona treatment, plasma treatment, or the like.

As the substrate, a commercially available product can be used. Examples of commercially available cellulose ester substrates include cellulose ester substrates manufactured by Fujifilm Corporation such as Fujitac Film; cellulose ester substrates manufactured by Ltd., Konica Minolta Opto Products Co., Ltd., such as "KC 8UX 2M", "KC 8 UY" and "KC 4 UY". Examples of commercially available cycloolefin resins include cycloolefin resins manufactured by Ticona (germany) such as "Topas (registered trademark)"; a cycloolefin resin manufactured by JSR corporation such as "ARTON (registered trademark)"; cyclic olefin resins manufactured by ZEON corporation of japan such as "ZEONOR (registered trademark)", and "ZEONEX (registered trademark)"; a cycloolefin resin manufactured by Mitsui chemical corporation of "Apel" (registered trademark). Commercially available cycloolefin resin substrates can also be used. Examples of commercially available cycloolefin resin substrates include cycloolefin resin substrates manufactured by waterlogging chemical industries, ltd.s.c. "Escena (registered trademark)" and "SCA 40 (registered trademark)"; a cycloolefin resin base material manufactured by OPTES corporation such as "ZeonorFilm (registered trademark)"; a cycloolefin resin base material manufactured by JSR corporation such as "ARTONFILM (registered trademark)".

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

Examples of the method for applying the polymerizable liquid crystal composition to a substrate include known methods such as spin coating, extrusion, gravure coating, die coating, bar coating, coating methods such as applicator method, and printing methods such as flexo method.

Subsequently, the solvent is removed by drying or the like, thereby forming a dried coating film. Examples of the drying method include natural drying, air drying, heat drying, and reduced-pressure drying. In this case, the coating film obtained from the polymerizable liquid crystal composition is heated to dry and remove the solvent from the coating film, and the polymerizable liquid crystal compound can be aligned in a desired direction (for example, horizontal or vertical direction) with respect to the plane of the coating film. The heating temperature of the coating film may be suitably determined in consideration of the material properties of the polymerizable liquid crystal compound to be used, the substrate on which the coating film is formed, and the like, and generally needs to be a temperature not lower than the liquid crystal phase transition temperature in order to cause the phase transition of the polymerizable liquid crystal compound to the liquid crystal phase state. In order to remove the solvent contained in the polymerizable liquid crystal composition and to bring the polymerizable liquid crystal compound into a desired alignment state, for example, the polymerizable liquid crystal composition may be heated to a temperature not lower than the liquid crystal phase transition temperature (smectic phase transition temperature or nematic phase transition temperature) of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition.

In one embodiment of the present invention, the solid-liquid crystal phase transition temperature of the polymerizable liquid crystal mixture constituting the polymerizable liquid crystal composition of the present invention is preferably 25 ℃ to 200 ℃. When the phase transition temperature to the liquid crystal phase is within the above range, it is preferable from the viewpoint of easy industrial production, productivity improvement, and the like. In the present invention, the solid-liquid crystal phase transition temperature of the polymerizable liquid crystal mixture is usually 40 ℃ or higher, more preferably 50 ℃ or higher, further preferably 60 ℃ or higher, from the viewpoint of the compound which can exhibit reverse wavelength dispersion characteristics as the liquid crystal cured film to be obtained, and is more preferably 180 ℃ or lower, further preferably 160 ℃ or lower, particularly preferably 150 ℃ or lower from the viewpoint of productivity.

The liquid crystal phase transition temperature can be measured using, for example, a polarizing microscope equipped with a temperature adjustment stage, a Differential Scanning Calorimeter (DSC), a thermogravimetric differential thermal analyzer (TG-DTA), or the like. The above-mentioned phase transition temperature of the polymerizable liquid crystal mixture of the present invention containing at least two polymerizable liquid crystal compounds is a temperature measured using a mixture of polymerizable liquid crystal compounds obtained by mixing all the polymerizable liquid crystal compounds constituting the polymerizable liquid crystal mixture at the same ratio as the composition of the polymerizable liquid crystal mixture.

The polymerizable liquid crystal composition of the present invention contains the polymerizable liquid crystal compound (1), the compound (2) and/or the compound (3), and can usually undergo liquid crystal phase transition at a temperature lower than the temperature at which each of the polymerizable liquid crystal compound (1), the compound (2) and the compound (3) alone undergoes liquid crystal phase transition. Therefore, in the production of a retardation film using the polymerizable liquid crystal composition of the present invention, excessive consumption of heat energy can be suppressed, and production efficiency can be improved. In addition, since the liquid crystal phase transition can be performed by heating at a relatively low temperature, there are also the following advantages: the choice of the supporting substrate to be coated with the polymerizable liquid crystal composition is wide.

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

The solvent may be removed from the coating film simultaneously with or separately from the heating of the polymerizable liquid crystal compound to a temperature equal to or higher than the liquid crystal phase transition temperature, but is preferably removed simultaneously from the viewpoint of improving productivity. Before heating the polymerizable liquid crystal compound to a temperature equal to or higher than the liquid crystal phase transition temperature, a preliminary drying step may be provided for appropriately removing the solvent in the coating film obtained from the polymerizable liquid crystal composition under such a condition that the polymerizable liquid crystal compound contained in the coating film is not polymerized. Examples of the drying method in the preliminary drying step include a natural drying method, a forced air drying method, a heat drying method, a reduced pressure drying method, and the like, and the drying temperature (heating temperature) in the drying step can be appropriately determined depending on the kind of the polymerizable liquid crystal compound used, the kind of the solvent, the boiling point thereof, the amount thereof, and the like.

Next, in the obtained dried coating film, the polymerizable liquid crystal compound is polymerized by light irradiation while maintaining the alignment state of the polymerizable liquid crystal compound, thereby forming a liquid crystal cured film which is a polymer of the polymerizable liquid crystal compound existing in a desired alignment state. The polymerizable liquid crystal composition of the present invention is usually polymerized by a photopolymerization method because the polymerizable liquid crystal composition can be highly polymerized by irradiation with light such as high-intensity ultraviolet rays while preventing damage to the polymerizable liquid crystal compound. In photopolymerization, the light to be irradiated to the dried coating film is appropriately selected depending on the kind of the polymerization initiator contained in the dried coating film, the kind of the polymerizable liquid crystal compound, and the amount thereof. Specific examples thereof include at least one kind 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, in view of the ease of controlling the progress of the polymerization reaction and the availability of a device widely used in the art as a photopolymerization device, ultraviolet light is preferable, and the types of the polymerizable liquid crystal compound and the polymerization initiator contained in the polymerizable liquid crystal composition are preferably selected in advance so that photopolymerization can be performed by ultraviolet light. In addition, the polymerization temperature can also be controlled by irradiating light while cooling the dried coating film by an appropriate cooling means at the time of polymerization. By using such a cooling means, polymerization of the polymerizable liquid crystal compound is carried out at a lower temperature, and thus a liquid crystal cured film can be formed appropriately even when a base material having low heat resistance is used as the base material. In addition, the polymerization reaction can also be accelerated by increasing the polymerization temperature in a range in which defects due to heat at the time of light irradiation (deformation of the base material due to heat, etc.) do not occur. In photopolymerization, a patterned cured film can be obtained by masking, development, or the like.

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

The ultraviolet irradiation intensity is usually 10-3,000 mW/cm². Purple pigmentThe intensity of the external irradiation is preferably an intensity in a wavelength region effective for activation of the photopolymerization initiator. The time for irradiating light is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and still more preferably 0.1 second to 1 minute. When the ultraviolet irradiation intensity is applied for 1 or more times, the cumulative light amount is 10 to 3,000mJ/cm²Preferably 50 to 2,000mJ/cm²More preferably 100 to 1,000mJ/cm²。

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

A 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 liquid crystal of the polymerizable liquid crystal compound in a desired direction. Among them, an alignment film having an alignment regulating force for aligning a polymerizable liquid crystal compound in a horizontal direction is sometimes referred to as a horizontal alignment film, and an alignment film having an alignment regulating force for aligning in a vertical direction is sometimes referred to as a vertical alignment film. The alignment regulating force can be arbitrarily adjusted depending on the kind, surface state, rubbing condition, and the like of the alignment film, and in the case where the alignment film is formed of a photo-alignment polymer, it can be arbitrarily adjusted depending on the polarization irradiation condition, and the like.

The alignment film preferably has solvent resistance that does not dissolve due to application of the polymerizable liquid crystal composition or the like, and heat resistance in heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound, which will be described later. The alignment film includes an alignment film containing an alignment polymer, a photo-alignment film, a groove alignment film having a surface with a concavo-convex pattern and a plurality of grooves, a stretched film stretched in an alignment direction, and the like, and the photo-alignment film is preferable from the viewpoint of accuracy and quality of an alignment angle.

Examples of the orientation polymer include polyamides having an amide bond in the molecule, gelatins, polyimides having an imide bond in the molecule, and polyamic acids, polyvinyl alcohols, alkyl-modified polyvinyl alcohols, polyacrylamides, polyoxazoles, polyethyleneimines, polystyrenes, polyvinylpyrrolidones, polyacrylic acids, and polyacrylates as hydrolysates thereof. Among them, polyvinyl alcohol is preferable. The alignment polymer may be used alone or in combination of 2 or more.

The alignment film containing an alignment polymer can be generally obtained by: a method for producing a substrate having a structure in which a composition obtained by dissolving an oriented polymer in a solvent (hereinafter, sometimes referred to as "oriented polymer composition") is applied to a substrate and the solvent is removed; alternatively, the oriented polymer composition is applied to a substrate, the solvent is removed, and rubbing is performed (rubbing method). Examples of the solvent include the same solvents as those exemplified above as the solvents usable in the polymerizable liquid crystal composition.

The concentration of the oriented polymer in the oriented polymer composition may be in a range in which the oriented polymer material can be completely dissolved in the solvent, and is preferably 0.1 to 20%, and more preferably about 0.1 to 10% in terms of solid content with respect to the solution.

As the alignment polymer composition, a commercially available alignment film material can be used as it is. Examples of commercially available alignment film materials include suniver (registered trademark, manufactured by nippon chemical industry corporation), OPTOMER (registered trademark, manufactured by JSR corporation), and the like.

The method of applying the alignment polymer composition to the substrate may be the same as the method exemplified as the method of applying the polymerizable liquid crystal composition to the substrate.

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

In order to impart an alignment regulating force to the alignment film, a rubbing treatment (rubbing method) may be performed as necessary. Examples of the method for imparting orientation restriction by the rubbing method include: a method of bringing a rubbing roll, which is wound with a rubbing cloth and rotated, into contact with a film of an alignment polymer, which is formed on the surface of a base material by applying an alignment polymer composition to the base material and annealing the same. When masking is performed during rubbing treatment, a plurality of regions (patterns) having different alignment directions can be formed on the alignment film.

The photo alignment film is generally obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as a "photo alignment film-forming composition") to a substrate, removing the solvent, and then irradiating polarized light (preferably polarized UV light). The photo alignment film is advantageous also in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

The photoreactive group refers to a group that generates liquid crystal alignment ability by light irradiation. Specifically, there may be mentioned groups which participate in photoreaction originating from liquid crystal aligning ability, such as orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction of molecules by light irradiation. Among them, a group participating in dimerization reaction or photocrosslinking reaction is preferable from the viewpoint of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond is preferable, and a group having at least 1 selected from the group consisting of a carbon-carbon double bond (C ═ C bond), a carbon-nitrogen double bond (C ═ N bond), a nitrogen-nitrogen double bond (N ═ N bond), and a carbon-oxygen double bond (C ═ O bond) is particularly preferable.

Examples of the photoreactive group having a C ═ C bond include a vinyl group, a polyene group, a stilbene group, a stilbenazolyl 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 an aromatic schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N ═ N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, and a methyl group

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 substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, and haloalkyl.

Among them, a photoreactive group participating in a photodimerization reaction is preferable, and cinnamoyl group and chalcone group are preferable in terms of easily obtaining a photo alignment film which requires a small amount of polarized light irradiation and is excellent in thermal stability and temporal stability. As the polymer having a photoreactive group, a polymer having a cinnamoyl group at a terminal of a side chain of the polymer, which has a cinnamic acid structure, is particularly preferable.

By applying the composition for forming a photo-alignment film on a substrate, a photo-alignment inducing layer can be formed on the substrate. The solvent contained in the composition may be the same solvent as the solvent used in the polymerizable liquid crystal composition and exemplified above, and may be appropriately selected depending on the solubility of the polymer or monomer having a photoreactive group.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo alignment film may be appropriately adjusted according to the kind of the polymer or monomer and the thickness of the target photo alignment film, and is preferably at least 0.2% by mass, and more preferably in the range of 0.3 to 10% by mass, based on the mass of the composition for forming a photo alignment film. The composition for forming a photo alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, and a photosensitizer, within a range that does not significantly impair the characteristics of the photo alignment film.

The method of applying the composition for forming a photo-alignment film to a substrate may be the same as the method of applying the alignment polymer composition to a substrate. Examples of the method for removing the solvent from the coated composition for forming the photo-alignment film include a natural drying method, a forced air drying method, a heat drying method, and a reduced pressure drying method.

The irradiation with polarized light may be performed by directly irradiating polarized UV light to a product obtained by removing a solvent from the composition for forming a photo-alignment film applied to the substrate, or by irradiating polarized light from the substrate side and transmitting the polarized light. In addition, the polarized light is particularly preferably substantially parallel light. The wavelength of the polarized light to be irradiated may be a wavelength in a wavelength region where the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet) light having a wavelength of 250 to 400nm is particularly preferable. Examples of the light source used for the polarized light irradiation include a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, and ultraviolet laser such as KrF and ArF, and the high-pressure mercury lamp, the ultrahigh-pressure mercury lamp, and the metal halide lamp are more preferable. Among these, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp are preferable because the emission intensity of ultraviolet rays at a wavelength of 313nm is large. Polarized UV light can be irradiated by irradiating light from the light source through an appropriate polarizer. As the polarizer, a polarizing filter, a polarizing prism of glan-thompson, glan-taylor, or the like, a wire grid type polarizer may be used.

In the case of rubbing or polarized light irradiation, a plurality of regions (patterns) having different liquid crystal alignment directions may be formed by masking.

The groove (groove) alignment film is a film having a concave-convex 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 grooves arranged at equal intervals, liquid crystal molecules are aligned in a direction along the grooves.

As a method for obtaining a trench alignment film, the following methods can be mentioned: a method of forming a concave-convex pattern by exposing the surface of a photosensitive polyimide film through an exposure mask having a slit with a pattern shape, and then performing development and rinsing; a method of forming a layer of a UV curable resin before curing on a plate-like master having grooves on the surface, transferring the formed resin layer to a substrate, and then curing it; a method of pressing a roll-shaped master plate having a plurality of grooves against a film of a UV curable resin before curing formed on a base material to form irregularities, and then curing the irregularities; and so on.

As a material showing an orientation regulating force for orienting the polymerizable liquid crystal compound in a direction perpendicular to the plane of the liquid crystal cured film, a fluorine-based polymer such as a perfluoroalkyl group, a silane compound, a polysiloxane compound obtained by a condensation reaction of these, and the like can be used in addition to the above-described orienting polymer and the like.

When a silane compound is used as a material for forming the alignment film, a compound containing an Si element and a C element among the constituent elements is preferable from the viewpoint of easily reducing the surface tension and easily improving the adhesion to a layer adjacent to the alignment film, and a silane compound can be suitably used. As the silane compound, an ionic compound containing silane or the like can be used, and by using such a silane compound, the vertical alignment regulating force can be improved. The silane compound may be used alone or in combination of two or more, and may be used in admixture with other materials. When the silane compound is a nonionic silane compound, the silane compound having an alkyl group at a molecular terminal is preferable, and the silane compound having an alkyl group having 3 to 30 carbon atoms is more preferable, from the viewpoint of easily improving the vertical alignment regulating force.

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

The present invention includes an elliptical polarizing plate comprising the phase difference film of the present invention and a polarizing film.

Examples of the polarizing film include a polarizing plate as a film having a polarizing function, a stretched film in which a dye having absorption anisotropy is adsorbed, a film as a polarizing plate including a film to which a dye having absorption anisotropy is applied, and the like. Examples of the dye having absorption anisotropy include dichroic dyes.

A film including a stretched film having a dye having absorption anisotropy adsorbed thereon as a polarizer is generally produced by sandwiching at least one surface of the following polarizer, which is produced through the following steps, with a transparent protective film via an adhesive: a step of uniaxially stretching a polyvinyl alcohol resin film; a step of staining a polyvinyl alcohol resin film with a dichroic pigment to thereby adsorb the dichroic pigment; treating the dichroic pigment-adsorbed polyvinyl alcohol resin film with an aqueous boric acid solution; and a step of washing with water after the treatment with the boric acid aqueous solution.

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

A film made of such a polyvinyl alcohol resin can be used as a polarizing sheet blank film (Japanese: formerly Across フイル ). The method for forming the film of the polyvinyl alcohol resin is not particularly limited, and the film can be formed by a known method. The thickness of the polyvinyl alcohol base film may be, for example, about 10 to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before, simultaneously with, or after the dyeing with the dichroic pigment. In the case of performing uniaxial stretching after dyeing, the uniaxial stretching may be performed before boric acid treatment or may be performed in boric acid treatment. In addition, uniaxial stretching may be performed at a plurality of stages among them. In the case of uniaxial stretching, the uniaxial stretching may be performed between rolls having different peripheral speeds, or the uniaxial stretching may be performed using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which stretching is performed in a state where the polyvinyl alcohol resin film is swollen with a solvent. The draw ratio is usually about 3 to 8 times.

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

As the dichroic dye, specifically, iodine or a dichroic organic dye can be used. Examples of the dichroic organic dye include a dichroic direct dye composed of a disazo compound such as c.i. direct red (DIRECT RED)39, and a dichroic direct dye composed of a compound such as trisazo or tetraazo. The polyvinyl alcohol resin film is preferably subjected to an immersion treatment in water before the dyeing treatment.

When iodine is used as the dichroic dye, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing iodine and potassium iodide to dye the film can be generally employed. The iodine content in the 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 ℃. The immersion time (dyeing time) in the 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 resin film in an aqueous solution containing a water-soluble dichroic dye to dye the resin film is generally used. The content of the dichroic organic dye in the aqueous solution is usually 1X 10 relative to 100 parts by mass of water^-4About 10 parts by mass, preferably 1X 10^-3About 1 part by mass, more preferably about 1X 10^-3～1×10^-2And (4) parts by mass. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the dichroism dye water solution used for dyeing is usually about 20-80 ℃. The immersion time (dyeing time) in the aqueous solution is usually about 10 to 1,800 seconds.

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

Usually, the polyvinyl alcohol resin film after the boric acid treatment is subjected to a water washing treatment. The water washing treatment can be performed, for example, by a method of immersing the boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ℃. The dipping time is usually about 1 to 120 seconds.

A drying process may be performed after water washing, thereby obtaining a polarizer. 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 ℃, preferably 50 to 80 ℃. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The moisture content of the polarizer can be reduced to a practical level by the drying treatment. The water content is usually about 5 to 20 mass%, preferably 8 to 15 mass%. When the water content is within the above range, a polarizer having appropriate flexibility and excellent thermal stability can be easily obtained.

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

Examples of the film coated with a pigment having absorption anisotropy include a film coated with a composition containing a dichroic pigment having liquid crystallinity, a film coated with a composition containing a dichroic pigment and a polymerizable liquid crystal, and the like. The film preferably has a protective film on one or both sides thereof. Examples of the protective film include the same resin films as those exemplified above as substrates usable in the production of liquid crystal cured films.

The thinner the film coated with the dye having absorption anisotropy is, the more preferable it is, but if it is too thin, the strength tends to decrease and the processability tends 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 a dye having absorption anisotropy include films described in japanese patent laid-open No. 2012-33249 and the like.

A transparent protective film is laminated on at least one surface of the polarizer obtained as described above with an adhesive interposed therebetween, thereby obtaining a polarizing film. As the transparent protective film, the same transparent film as the resin film exemplified above as a base material that can be used in the production of the liquid crystal cured film can be preferably used.

The elliptical polarizing plate of the present invention is composed of the retardation film of the present invention and a polarizing film, and can be obtained by laminating the retardation film of the present invention and the polarizing film via an adhesive layer, or the like, for example.

In one embodiment of the present invention, when the retardation film of the present invention including the horizontally oriented liquid crystal cured film is laminated with a polarizing film, the lamination is preferably performed such that an angle formed by the slow axis (optical axis) of the horizontally oriented liquid crystal cured film constituting the retardation film and the absorption axis of the polarizing film becomes 45 ± 5 °.

The elliptical polarizing plate of the present invention may have a structure as in a conventional elliptical polarizing plate, or a polarizing film and a retardation film. Examples of such a structure include an adhesive layer (sheet) for bonding an elliptically polarizing plate to a display element such as an organic EL, and a protective film used for protecting the surface of a polarizing film or a retardation film from damage or contamination.

The elliptically polarizing plate of the present invention can be used for various display devices, particularly for optical displays.

The 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. Examples of the display device include 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 (e.g., an electric field emission display device (FED), a surface field emission display device (SED)), electronic paper (a display device using electronic ink or an electrophoretic element, a plasma display device, a projection display device (e.g., a Grating Light Valve (GLV) display device, a display device having a Digital Micromirror Device (DMD)), a piezoelectric ceramic display, and the like, and the liquid crystal display device includes any of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, a projection liquid crystal display device, and the like, a stereoscopic display device that displays a three-dimensional image may be used. In particular, the elliptically polarizing plate of the present invention can be suitably used for an organic Electroluminescence (EL) display device and an inorganic Electroluminescence (EL) display device. These display devices (optical displays) can exhibit good image display characteristics by including the elliptically polarizing plate of the present invention having excellent optical characteristics.

Examples

The present invention will be described more specifically with reference to examples. In the examples, "%" and "part" are mass% and part, respectively, unless otherwise specified.

< preparation of polymerizable liquid Crystal mixture >

The polymerizable liquid crystal compound (a1) having the following molecular structure is produced by the method described in japanese patent application laid-open No. 2019-73496.

The polymerizable liquid crystal compound (B1) having the following molecular structure was prepared by the method described in japanese patent No. 5962760.

[ example 1]

The polymerizable liquid crystal compound (a1) was mixed so that the amount was 99.97 parts by mass and the polymerizable liquid crystal compound (B1) was 0.03 part by mass, to obtain a polymerizable liquid crystal mixture.

The obtained polymerizable liquid crystal mixture was subjected to HPLC analysis under the measurement conditions described later, and the area percentage value of the polymerizable liquid crystal compound (B1) based on the total amount of the polymerizable liquid crystal compound (a1) and the polymerizable liquid crystal compound (B1) was measured. The result was 0.03%.

[ HLPC assay ]

The HPLC measurement can be performed under any conditions as long as the peaks from the polymerizable liquid crystal compound (a1) and the polymerizable liquid crystal compound (B1) can be separated. Examples of HPLC measurement conditions are shown below.

(measurement conditions)

A measuring device: HPLC LC-10AT (manufactured by Shimadzu corporation)

A chromatographic column: L-Column ODS (inner diameter 3.0mm, length 150mm, particle size 3 μm)

Temperature: 40 deg.C

Mobile phase A: 0.1% (v/v) -TFA/water

Mobile phase B: 0.1% (v/v) -TFA/acetonitrile

Flow rate: 0.5mL/min

Sample introduction amount: 5 μ L

Detection wavelength: 254nm

[ example 2]

The polymerizable liquid crystal compound (a1) was mixed so that the amount was 99.56 parts by mass and the polymerizable liquid crystal compound (B1) was 0.44 part by mass, to obtain a polymerizable liquid crystal mixture.

The obtained polymerizable liquid crystal mixture was subjected to HPLC analysis under the measurement conditions described later, and the area percentage value of the polymerizable liquid crystal compound (B1) based on the total amount of the polymerizable liquid crystal compound (a1) and the polymerizable liquid crystal compound (B1) was measured. The result was 0.44%.

[ example 3]

The polymerizable liquid crystal compound (a1) was mixed so that it was 94.87 parts by mass and the polymerizable liquid crystal compound (B1) was 5.13 parts by mass, to obtain a polymerizable liquid crystal mixture.

The obtained polymerizable liquid crystal mixture was subjected to HPLC analysis under the measurement conditions described later, and the area percentage value of the polymerizable liquid crystal compound (B1) based on the total amount of the polymerizable liquid crystal compound (a1) and the polymerizable liquid crystal compound (B1) was measured. The result was 5.12%.

[ comparative example 1]

A comparative polymerizable liquid crystal comprising 100 parts by mass of the polymerizable liquid crystal compound (a1) alone was used.

The obtained polymerizable liquid crystal mixture was analyzed by HPLC under the measurement conditions described later, and the area percentage value of the polymerizable liquid crystal compound (B1) based on the total amount of the polymerizable liquid crystal compound (a1) and the polymerizable liquid crystal compound (B1) was measured, but was not detected.

< measurement of nematic phase transition temperature >

1g of the polymerizable liquid crystal mixture of example 1 was weighed into a vial, and 2g of chloroform was further added thereto and dissolved. The obtained solution was applied to a glass substrate having a PVA alignment film subjected to rubbing treatment, and dried. The substrate was placed on a cooling and heating apparatus ("LNP 94-2" manufactured by Japan High Tech Co., Ltd.), heated from room temperature to 180 ℃ and then cooled to room temperature. The state of the film during temperature change was observed with a polarizing microscope (LEXT, Olympus corporation), and the temperature at which the film became a nematic phase was measured and used as the nematic phase transition temperature. The polymerizable liquid crystal mixtures of examples 2 and 3 and the comparative polymerizable liquid crystal of comparative example 1 were similarly operated, and the nematic phase transition temperature was measured. The obtained results are shown in table 1.

[ Table 1]

< measurement of solubility >

Cyclopentanone (1 g) was charged into a screw bottle, and the polymerizable liquid crystal mixture of example 1 was added into a vial while confirming whether or not the mixture was completely dissolved by visual observation, and the solubility was measured. The polymerizable liquid crystal mixtures of examples 2 and 3 and the comparative polymerizable liquid crystal of comparative example 1 were similarly subjected to the same procedure, and the solubilities thereof in organic solvents were measured. The obtained results are shown in table 2.

[ Table 2]

< preparation of composition for Forming photo-alignment film >

The following components were mixed, and the resulting mixture was stirred at 80 ℃ for 1 hour to obtain a composition for forming a photo-alignment film.

A photo-alignment material (5 parts) represented by the following formula:

(number average molecular weight: about 28000, Mw/Mn: about 1.8, polymer described in JP2013-033249A 1)

Solvent (95 parts): cyclopentanone

< production of optical film (retardation film) >

An optical film was manufactured in the following manner. A cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon corporation) was treated 1 time with a corona treatment apparatus (AGF-B10, manufactured by Chunshi electric Motor Co., Ltd.) under conditions of an output of 0.3kW and a treatment speed of 3 m/min. Coating the composition for forming a photo-alignment film using a bar coaterThe sheet was then applied to a corona-treated surface, dried at 80 ℃ for 1 minute, and irradiated with polarized UV light (SPOT CURE SP-7; manufactured by Ushio Motor Co., Ltd.) at 100mJ/cm²The polarized UV light exposure is performed. The thickness of the obtained alignment film was measured by a laser microscope (LEXT, manufactured by Olympus corporation), and found to be 100 nm.

Next, the polymerizable liquid crystal mixture of example 1 was put into a vial, and a photopolymerization initiator, a leveling agent, a polymerization inhibitor, and a solvent were added according to the composition described in table 3, followed by stirring at 80 ℃ for 30 minutes using a rotary disk (carousel), to obtain a polymerizable liquid crystal composition (1).

The amounts of the photopolymerization initiator, the leveling agent and the polymerization inhibitor shown in table 3 were added to 100 parts by mass of the polymerizable liquid crystal mixture obtained in example 1. The amount of the solvent to be blended is set so that the mass% of the composition is 13% of the total amount of the solution.

[ Table 3]

Polymerization initiator: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by BASF Japan Co., Ltd.)

Leveling agent: polyacrylate Compound (BYK-361N; manufactured by BYK Chemie Japan)

Polymerization inhibitor: BHT (manufactured by Heguang pure chemical industry Co., Ltd.)

Solvent: n-methylpyrrolidone (NMP; manufactured by KANTO CHEMICAL CO., LTD.)

The obtained polymerizable liquid crystal composition was applied to an alignment film using a bar coater, dried at 120 ℃ for 1 minute, and then irradiated with ultraviolet rays (wavelength: 365nm, cumulative amount of light at wavelength 365nm under nitrogen atmosphere: 1000 mJ/cm) using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured BY Ushio Motor Co., Ltd.)²) Thereby, an optical film was produced.

< measurement of optical Properties Re (450)/Re (550) >

The optical film prepared as described above was used as a measurement sample, and the front phase difference with respect to light having a wavelength of 450nm and a wavelength of 550nm was measured using a measuring instrument ("KOBRA-WR" manufactured by prince measuring machine), and Re (450)/Re (550) was calculated, and as a result, Re (450)/Re (550) was 0.81, and the optical film had reverse wavelength dispersion characteristics.

Claims

1. A polymerizable liquid crystal mixture comprising a polymerizable liquid crystal compound (1) represented by formula (1) and at least one selected from the group consisting of a compound (2) represented by formula (2) and a compound (3) represented by formula (3),

in the formulae (1) to (3),

R¹and R²Each independently a group represented by the following formula (R-1),

-B¹-E¹-P¹(R-1)

in the formula (R-1),

P¹represents a polymerizable group, and is characterized in that,

substituent X¹And X²Each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group,Amino, hydroxy, mercapto, methylamino, dimethylamino, diethylamino, diisopropylamino, trimethylsilyl, dimethylsilyl, thioisocyano, or 1-CH₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 1 to 20 carbon atoms which may be independently substituted with-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH ═ CH-COO-, -CH ═ CH-OCO-, -COO-CH ═ CH-, -OCO-CH ═ CH-, -CF ═ CF-, or-C ≡ C-, wherein any hydrogen atom in the alkyl group may be substituted with a fluorine atom, or a substituent X may be substituted with a fluorine atom¹And X²May each independently be-B²-E²-P²A group of formula B²、E²And P²Are respectively connected with the B¹、E¹And P¹Are defined as such and can be respectively identical to the B¹、E¹And P¹The same or different, there being a plurality of X' s¹And/or X²When used, each may be the same or different;

in the formula (Y-1),

M¹represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may be substituted with one or more substituents X³Substituted, substituent X³With said substituent X¹And X²Are defined as such;

U¹represents an organic group having 2 to 30 carbon atoms and having an aromatic hydrocarbon group, any carbon atom of the aromatic hydrocarbon group may be replaced by a hetero atom, and the aromatic hydrocarbon group may be replaced by one or more substituents X³Substitution;

T¹represents-O-, -S-, -COO-, -OCO-O-, -NU²-、-N＝CU²-、-CO-NU²-、-OCO-NU²-or O-NU²-，U²Represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group (any carbon atom of the aromatic hydrocarbon group may be replaced by a hetero atom), or (D)⁵-A³)_q-B³-E³-P³The alkyl, cycloalkyl, cycloalkenyl and aromatic hydrocarbon groups are each unsubstituted or may be substituted by one or more substituents X³Substituted, said alkyl being substituted by said cycloalkyl or cycloalkenyl, 1-CH of said alkyl₂-or non-adjacent 2 or more-CH₂May each be independently substituted by-O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -SO₂-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH ═ CH-COO-, -CH ═ CH-OCO-, -COO-CH ═ CH-, -OCO-CH ═ CH-, -CF ═ CF-, or-C ≡ C-substitutions, 1-CH-in said cycloalkyl or cycloalkenyl group₂-or non-adjacent 2 or more-CH₂May each be independently replaced by-O-, -CO-, -COO-, -OCO-, or O-CO-O-, D⁵、A³、B³、E³And P³Respectively with said D³～D⁴、A¹～A²、B¹、E¹And P¹Are defined as such and can be respectively identical to said D³And D⁴、A¹And A²、B¹、E¹And P¹Q represents an integer of 0 to 4, and a plurality of D's may be present⁵And/or A³Each may be the same or different, U¹And U²May be bonded to form a ring.

2. The polymerizable liquid crystal mixture according to claim 1, wherein the ratio of the total peak area of the compound (2) and the compound (3) to the total peak area of the polymerizable liquid crystal compound (1), the compound (2), and the compound (3) is 0.01% or more and 20% or less, as measured by liquid chromatography.

3. The polymerizability as claimed in claim 1 or 2A liquid-crystal mixture in which G in the formulae (1) to (3)¹And G²Is cyclohexane-1, 4-diyl.

4. The polymerizable liquid crystal mixture according to any one of claims 1 to 3, wherein A in the formulae (1) to (3)¹And A²Each independently cyclohexane-1, 4-diyl or 1, 4-phenylene.

5. The polymerizable liquid crystal mixture according to any one of claims 1 to 4, wherein T in the formulae (1) to (3)¹is-O-, -S-, -N ═ CU²-or-NU²-。

6. The polymerizable liquid crystal mixture according to any one of claims 1 to 5, wherein T is represented by one of the formulae (1) to (3)¹is-NU²-, said U²1-CH in which a hydrogen atom may be substituted by a fluorine atom₂-or non-adjacent 2 or more-CH₂-a linear or branched alkyl group having 2 to 20 carbon atoms which may be independently replaced by-O-, -CO-, -COO-or OCO-, a cycloalkyl group having 3 to 12 carbon atoms, or the alkyl group which may be substituted by the cycloalkyl group.

7. The polymerizable liquid crystal mixture according to any one of claims 1 to 6, wherein the solid-liquid crystal phase transition temperature is 25 ℃ or higher and 200 ℃ or lower.

8. A polymerizable liquid crystal composition comprising the polymerizable liquid crystal mixture according to any one of claims 1 to 7.

9. The polymerizable liquid crystal composition according to claim 8, further comprising a photopolymerization initiator.

10. The polymerizable liquid crystal composition according to claim 8 or 9, further comprising an organic solvent.

11. The polymerizable liquid crystal composition according to claim 9 or 10, wherein the photopolymerization initiator is at least one selected from the group consisting of an acylphosphine oxide-based polymerization initiator, an α -aminoalkylphenyl ketone-based polymerization initiator, an α -hydroxyketone-based polymerization initiator and an oxime ester-based polymerization initiator.

12. The polymerizable liquid crystal composition according to claim 10 or 11, wherein the organic solvent is at least one selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and N-methylpyrrolidone.

13. A cured product of the polymerizable liquid crystal composition according to any one of claims 8 to 12.

14. A retardation film comprising a cured liquid crystal film obtained by curing a polymerizable liquid crystal compound in the polymerizable liquid crystal composition according to any one of claims 8 to 13 in an aligned state.

15. The phase difference film according to claim 14, which satisfies the following formula:

0.70≤Re(450)/Re(550)<1.00

16. An elliptically polarizing plate comprising the phase difference film according to claim 14 or 15.

17. An optical display comprising the elliptically polarizing plate of claim 16.