JP2023143910A - Polymerizable liquid crystal composition, polarizing film and method for manufacturing the same, polarizing plate and display device - Google Patents

Abstract

To provide a polymerizable liquid crystal composition suitable for forming a polarizing film (polarizer) that has a high suppression effect on modification of a dichroic dye when exposed to sun rays and that can suppress decrease in the polarization performance with time.SOLUTION: The polymerizable liquid crystal composition comprises a polymerizable liquid crystal compound having at least one polymerizable group and exhibiting smectic liquid crystallinity, a dichroic dye, and an antioxidant, in which the polymerizable group of the polymerizable liquid crystal compound is a radically polymerizable group, and the antioxidant satisfies an expression (1): 0.8°C≤T1-T2 in relation to the polymerizable liquid crystal compound. In expression (1), T1 is a phase transition temperature of the polymerizable liquid crystal compound to a liquid crystal phase that develops on the lowest temperature side when, after the polymerizable liquid crystal compound is heated in air to 130°C, the phase transition temperature is measured while cooling the compound at a rate of 5°C/min down to 23°C; and T2 is a phase transition temperature of a mixture comprising 100 pts.mass of the polymerizable liquid crystal compound and 1 pt.mass of the antioxidant to a liquid crystal phase that develops on the lowest temperature side when, after the mixture is heated in air to 130°C, the phase transition temperature is measured while cooling the mixture at a rate of 5°C/min down to 23°C.SELECTED DRAWING: None

Description

The present invention relates to a polymerizable liquid crystal composition, a polarizing film, a method for manufacturing the same, a polarizing plate, and a display device equipped with the same.

Conventionally, polarizing plates have been used in various image display panels such as liquid crystal display panels and organic electroluminescence (organic EL) display panels, by being attached to image display elements such as liquid crystal cells and organic EL display elements. As such a polarizing plate, triacetylcellulose is applied to at least one surface of a polarizer, which is made by adsorbing and orienting a dichroic compound such as iodine or dichroic dye to a polyvinyl alcohol resin film. Polarizing plates having a structure in which protective layers such as films are laminated are known.

In recent years, there has been a continuous demand for thinning of displays such as image display panels, and further thinning of polarizing plates and polarizers, which are one of the constituent elements thereof, is also required. In response to such demands, for example, a thin host-guest type polarizer made of a polymerizable liquid crystal compound and a dichroic compound has been proposed (Patent Document 1 and Patent Document 2).

Special Publication No. 2007-510946 JP2013-37353A

Furthermore, in recent years, as displays have been used in various places including outdoors, there has been a demand for the development of polarizers with excellent light resistance.
Therefore, the present invention provides a method for forming a polarizing film (polarizer) that has a high inhibitory effect on the degeneration of dichroic dyes when exposed to sunlight and can suppress deterioration of polarization performance over time. An object of the present invention is to provide a suitable polymerizable liquid crystal composition.

〔式（２）および（３）中、Ｒ_１～Ｒ_５は、それぞれ独立して、－Ｈ、－ＯＨ、－ＮＨ_２、炭素数１～１２の分枝若しくは非分枝アルキル基、または、炭素数１～１２の分枝若しくは非分枝アルコキシ基であり、式（２）および（３）において、それぞれ、Ｒ_１～Ｒ_５の少なくとも１つは－ＯＨまたは－ＮＨ_２である〕
で表されるいずれかの構造を有する、前記［１］～［６］のいずれかに記載の重合性液晶組成物。
［８］酸化防止剤が、式（５）：
Ａ_１－Ｌ_１－(Ａ_２－Ｌ_２)_ｎ－Ａ_３ （５）
［式中、
Ｌ_１およびＬ_２は、それぞれ独立して、単結合または二価の連結基であり、
Ａ_１は、式（２）、（３）または（４）：

〔式（２）および（３）中、Ｒ_１～Ｒ_５は前記［７］と同様に定義される〕
で表される基であり、
Ａ_２は、式（６）または（７）：

〔式（６）および（７）中、Ｒ_６～Ｒ_９は、それぞれ独立して、－Ｈ、－ＯＨ、－ＮＨ_２、炭素数１～１２の分枝若しくは非分枝アルキル基、または、炭素数１～１２の分枝若しくは非分枝アルコキシ基である〕
で表される基であり、
Ａ_３は、式（８）または（９）：

〔式（８）および（９）中、Ｒ_１０～Ｒ_１４は、それぞれ独立して、－Ｈ、－ＯＨ、－ＮＨ_２、炭素数１～１２の分枝若しくは非分枝アルキル基、または、炭素数１～１２の分枝若しくは非分枝アルコキシ基である〕
で表される基であり、ｎは０～２の整数であり、ｎが２の場合、２つのＡ_２は互いに同一であっても異なっていてもよい］
で示される化合物である、前記［７］に記載の重合性液晶組成物。
［９］二色性色素、重合性液晶化合物および酸化防止剤を含む重合性液晶組成物の硬化物である偏光膜であって、
Ｘ線回折測定において該偏光膜がブラッグピークを示し、
前記酸化防止剤が、前記重合性液晶化合物との関係において式（１）：
０．８℃ ≦ Ｔ１－Ｔ２ （１）
〔式中、Ｔ１は前記重合性液晶化合物を大気中で１３０℃まで昇温した後、５℃／分で２３℃まで冷却しながら相転移温度を測定した際に最も低温度側で発現する液晶相への相転移温度であり、Ｔ２は１００質量部の前記重合性液晶化合物と１質量部の前記酸化防止剤とからなる混合物を、大気中で１３０℃まで昇温した後５℃／分で２３℃まで冷却しながら相転移温度を測定した際に最も低温度側で発現する液晶相への相転移温度である〕
を満たす、偏光膜。
［１０］前記［９］に記載の偏光膜と位相差フィルムとを備えてなる偏光板。
［１１］位相差フィルムが式（Ｘ）：
１００ ≦ Ｒｅ（５５０） ≦ １８０ （Ｘ）
〔式中、Ｒｅ（５５０）は波長５５０ｎｍにおける面内位相差値を表す〕
を満たし、前記位相差フィルムの遅相軸と前記偏光膜の吸収軸との成す角度が実質的に４５°である、前記［１０］に記載の偏光板。
［１２］位相差フィルムが式（Ｙ）：
Ｒｅ（４５０）／Ｒｅ（５５０） ＜ １ （Ｙ）
〔式中、Ｒｅ（４５０）およびＲｅ（５５０）は、それぞれ、波長４５０ｎｍおよび５５０ｎｍにおける面内位相差値を表す〕
を満たす、前記［１０］または［１１］に記載の偏光板。
［１３］位相差フィルムが、重合性液晶化合物の配向状態における重合体から構成される、前記［１０］～［１２］のいずれかに記載の偏光板。
［１４］前記［９］に記載の偏光膜、または、前記［１０］～［１３］のいずれかに記載の偏光板を備えてなる表示装置。
［１５］前記［１］～［８］のいずれかに記載の重合性液晶組成物の塗膜を形成すること、
前記塗膜から溶剤を除去すること、
重合性液晶化合物が液体相に相転移する温度以上まで昇温した後に降温して、該重合性液晶化合物をスメクチック相に相転移させること、および、
前記スメクチック相を保持したまま重合性液晶化合物を重合させること
を含む、偏光膜の製造方法。 The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention provides the following preferred embodiments.
[1] A polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group and exhibiting smectic liquid crystallinity, a dichroic dye, and an antioxidant,
The polymerizable group possessed by the polymerizable liquid crystal compound is a radically polymerizable group,
The antioxidant has the formula (1) in relation to the polymerizable liquid crystal compound:
0.8℃ ≦ T1-T2 (1)
[In the formula, T1 is the liquid crystal that appears at the lowest temperature when the phase transition temperature is measured while heating the polymerizable liquid crystal compound to 130°C in the air and then cooling it to 23°C at a rate of 5°C/min. T2 is the phase transition temperature to phase, and T2 is a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant, heated at 5 °C/min after heating to 130 °C in the atmosphere. When the phase transition temperature is measured while cooling to 23°C, it is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature side.]
A polymerizable liquid crystal composition that satisfies the following.
[2] The polymerizable liquid crystal composition according to [1] above, further comprising a solvent.
[3] The polymerizable liquid crystal composition according to [1] or [2] above, wherein the dichroic dye is an azo dye.
[4] The polymerizable liquid crystal composition according to any one of [1] to [3] above, wherein the polymerizable group of the polymerizable liquid crystal compound is an acryloyloxy group.
[5] The polymerizable liquid crystal composition according to any one of [1] to [4] above, which contains 0.1 to 15 parts by mass of an antioxidant per 100 parts by mass of the polymerizable liquid crystal composition.
[6] The polymerizable compound according to any one of [1] to [5] above, wherein the antioxidant is at least one selected from the group consisting of phenolic compounds, alicyclic alcohol compounds, and amine compounds. liquid crystal composition.
[7] The antioxidant has formulas (2), (3) and (4):

[In formulas (2) and (3), R ₁ to R ₅ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms, and in formulas (2) and (3), at least one of R ₁ to R ₅ is -OH or -NH _2. ]
The polymerizable liquid crystal composition according to any one of [1] to [6] above, which has any structure represented by:
[8] The antioxidant has formula (5):
A ₁ -L ₁ -(A ₂ -L ₂ ) _n -A ₃ (5)
[In the formula,
L ₁ and L ₂ are each independently a single bond or a divalent linking group,
_A1 is the formula (2), (3) or (4):

[In formulas (2) and (3), R ₁ to R ₅ are defined as in [7] above]
is a group represented by
_A2 is the formula (6) or (7):

[In formulas (6) and (7), R ₆ to R ₉ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
is a group represented by
_A3 is the formula (8) or (9):

[In formulas (8) and (9), R ₁₀ to R ₁₄ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
is a group represented by, n is an integer from 0 to 2, and when n is 2, the two _A2s may be the same or different from each other]
The polymerizable liquid crystal composition according to the above [7], which is a compound represented by:
[9] A polarizing film that is a cured product of a polymerizable liquid crystal composition containing a dichroic dye, a polymerizable liquid crystal compound, and an antioxidant,
The polarizing film exhibits a Bragg peak in X-ray diffraction measurement,
The antioxidant has the formula (1) in relation to the polymerizable liquid crystal compound:
0.8℃ ≦ T1-T2 (1)
[In the formula, T1 is the liquid crystal that appears at the lowest temperature when the phase transition temperature is measured while heating the polymerizable liquid crystal compound to 130°C in the air and then cooling it to 23°C at a rate of 5°C/min. T2 is the phase transition temperature to phase, and T2 is a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant, heated at 5 °C/min after heating to 130 °C in the atmosphere. When the phase transition temperature is measured while cooling to 23°C, it is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature side.]
A polarizing film that satisfies the following.
[10] A polarizing plate comprising the polarizing film according to [9] above and a retardation film.
[11] The retardation film has the formula (X):
100≦Re(550)≦180 (X)
[In the formula, Re (550) represents the in-plane retardation value at a wavelength of 550 nm]
The polarizing plate according to [10], wherein the angle between the slow axis of the retardation film and the absorption axis of the polarizing film is substantially 45°.
[12] The retardation film has the formula (Y):
Re(450)/Re(550) < 1 (Y)
[In the formula, Re (450) and Re (550) represent in-plane retardation values at wavelengths of 450 nm and 550 nm, respectively.]
The polarizing plate according to [10] or [11], which satisfies the following.
[13] The polarizing plate according to any one of [10] to [12], wherein the retardation film is composed of a polymer in an oriented state of a polymerizable liquid crystal compound.
[14] A display device comprising the polarizing film according to [9] above or the polarizing plate according to any one of [10] to [13] above.
[15] Forming a coating film of the polymerizable liquid crystal composition according to any one of [1] to [8] above,
removing the solvent from the coating film;
Raising the temperature to a temperature at which the polymerizable liquid crystal compound undergoes a phase transition to a liquid phase or higher and then lowering the temperature to cause the polymerizable liquid crystal compound to undergo a phase transition to a smectic phase;
A method for producing a polarizing film, comprising polymerizing a polymerizable liquid crystal compound while maintaining the smectic phase.

According to the present invention, the polymerizability is suitable for forming a polarizing film that has a high inhibitory effect on the degeneration of dichroic dyes when exposed to sunlight and can suppress deterioration of polarizing performance over time. A liquid crystal composition can be provided.

Embodiments of the present invention will be described in detail below. Note that the scope of the present invention is not limited to the embodiments described here, and various changes can be made without departing from the spirit of the present invention.

<Polymerizable liquid crystal composition>
The polymerizable liquid crystal composition of the present invention includes a polymerizable liquid crystal compound having at least one polymerizable group and exhibiting smectic liquid crystallinity (hereinafter also referred to as "polymerizable liquid crystal compound (A)"). By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity, a polarizing film with a high degree of orientation order can be formed. The liquid crystal state exhibited by the polymerizable liquid crystal compound (A) is a smectic phase (smectic liquid crystal state), and from the viewpoint of realizing a higher degree of orientational order, a higher order smectic phase (higher order smectic liquid crystal state) is preferable. preferable. Here, the higher-order smectic phases include smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase, and smectic L phase. Among these, smectic B phase, smectic F phase and smectic I phase are more preferred. The liquid crystal may be thermotropic liquid crystal or lyotropic liquid crystal, but thermotropic liquid crystal is preferable because it allows precise control of the film thickness.
The polymerizable liquid crystal compound may be a monomer, but may also be an oligomer or a polymer in which a polymerizable group is polymerized.

The polymerizable liquid crystal compound (A) is a liquid crystal compound having at least one polymerizable group. Here, the polymerizable group refers to a group that can participate in a polymerization reaction by active radicals, acids, etc. generated from a polymerization initiator.
Examples of the polymerizable group that the polymerizable liquid crystal compound (A) has include a vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, and oxetanyl group. etc. Among these, radically polymerizable groups are preferred, acryloyloxy groups, methacryloyloxy groups, vinyl groups, and vinyloxy groups are more preferred, acryloyloxy groups and methacryloyloxy groups are even more preferred, and acryloyloxy groups are even more preferred.

The polymerizable liquid crystal compound (A) is not particularly limited as long as it has at least one polymerizable group and exhibits smectic liquid crystal properties, and any known polymerizable liquid crystal compound can be used.
As the polymerizable liquid crystal compound (A), for example, a compound represented by formula (A1) and a polymer of the compound (hereinafter, the compound and the polymer are collectively referred to as "polymerizable liquid crystal compound (A1)") ) can be mentioned.
U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (A1)
[In formula (A1),
X ¹ , X ² and X ³ each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group; The hydrogen atom contained in the hydrocarbon group of the formula is 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. The carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. It is.
Y ¹ and Y ² are each independently a single bond or a divalent linking group.
U ¹ represents a hydrogen atom or a polymerizable group.
U ² represents a polymerizable group.
W ¹ and W ² are each independently a single bond or a divalent linking group.
V ¹ and V ² each independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group is -O-, -CO-, -S- or NH- may be substituted. ]

In the polymerizable liquid crystal compound (A1), X ¹ , X ² and X ³ are preferably a 1,4-phenylene group which may have a substituent or a 1,4-phenylene group which may have a substituent, independently of each other. a cyclohexane-1,4-diyl group which may have a substituent, and at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent or a substituent is a cyclohexane-1,4-diyl group which may have In particular, X ¹ and X ³ are preferably cyclohexane-1,4-diyl groups which may have substituents, and the cyclohexane-1,4-diyl group is trans-cyclohexane-1,4-diyl. More preferably, it is a 1,4-diyl group. The optional substituents of the 1,4-phenylene group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent include a methyl group, an ethyl group, Examples include alkyl groups having 1 to 4 carbon atoms such as butyl groups, cyano groups, and halogen atoms such as chlorine atoms and fluorine atoms. Preferably it is unsubstituted. Moreover, when Y ¹ and Y ² have the same structure, it is preferable that at least one of X ¹ , X ² and X ³ has a different structure. When at least one of X ¹ , X ² and X ³ has a different structure, smectic liquid crystallinity tends to occur easily.

Y ¹ and Y ² each independently represent -CH ₂ CH ₂ -, -CH ₂ O-, -CH ₂ CH ₂ O-, -COO-, -OCOO-, single bond, -N=N-, -CR ^a =CR ^b -, -C≡C-, -CR ^a =N- or -CO-NR ^a - is preferred. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ¹ is more preferably -CH ₂ CH ₂ -, -COO- or a single bond, and Y ² is more preferably -CH ₂ CH ₂ - or CH ₂ O-. Moreover, when X ¹ , X ² and X ³ all have the same structure, it is preferable that Y ¹ and Y ² have different structures. When Y ¹ and Y ² have different structures, smectic liquid crystallinity tends to occur easily.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, preferably a polymerizable group. It is preferable that both U ¹ and U ² are polymerizable groups, and it is preferable that both U 1 and U 2 are radically polymerizable groups. Examples of the polymerizable group include the same groups as those exemplified above as the polymerizable group possessed by the polymerizable liquid crystal compound (A). The polymerizable group represented by U ¹ and the polymerizable group represented by U ² may be different from each other, but are preferably of the same type.

Examples of the alkanediyl group represented by V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,3-diyl group. 1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group and icosane-1,20-diyl group. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, more preferably alkanediyl groups having 6 to 12 carbon atoms.

Examples of the optional substituents of the alkanediyl group include a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted and is an unsubstituted linear alkanediyl group. is more preferable.

W ¹ and W ² are preferably a single bond, -O-, -S-, -COO- or -OCOO-, and more preferably a single bond or -O-.

Examples of the polymerizable liquid crystal compound (A1) include compounds represented by formulas (A-1) to (A-25). When the polymerizable liquid crystal compound (A1) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably in the trans form.

Among these, formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A- 8), at least one compound selected from the group consisting of compounds represented by formula (A-13), formula (A-14), formula (A-15), formula (A-16), and formula (A-17) Seeds are preferred. As the polymerizable liquid crystal compound (A1), one type may be used alone, or two or more types may be used in combination.

The polymerizable liquid crystal compound (A1) is described by Lub et al., Recl. Trav. Chim. It can be produced by the known method described in Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156.

The polymerizable liquid crystal composition of the present invention may contain other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound (A) as long as the effects of the present invention are not impaired. From the viewpoint of obtaining a polarizing film with a high degree of orientational order, the ratio of the polymerizable liquid crystal compound (A) to the total mass of all polymerizable liquid crystal compounds in the polymerizable liquid crystal composition is preferably 51% by mass or more, more preferably It is 70% by mass or more, more preferably 90% by mass or more.

When the polymerizable liquid crystal composition of the present invention contains two or more types of polymerizable liquid crystal compounds (A), at least one of them may be a polymerizable liquid crystal compound (A1), and all of them may be a polymerizable liquid crystal compound (A1). (A1) may also be used. By combining multiple polymerizable liquid crystal compounds, it may be possible to temporarily maintain liquid crystallinity even at temperatures below the liquid crystal-crystal phase transition temperature.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition of the present invention is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, based on the solid content of the polymerizable liquid crystal composition. and more preferably 70 to 99% by mass. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high.
In this specification, the solid content refers to the total amount of components excluding the solvent from the polymerizable liquid crystal composition.

The polymerizable liquid crystal composition of the present invention contains a dichroic dye. Here, the dichroic dye refers to a dye that has a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction of the molecule. The dichroic dye that can be used in the present invention is not particularly limited as long as it has the above properties, and may be a dye or a pigment. Two or more types of dyes or pigments may be used in combination, or a dye and a pigment may be used in combination.

The dichroic dye preferably has a maximum absorption wavelength (λ _MAX ) in the range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes.

Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred, such as compounds represented by formula (I) (hereinafter referred to as "compounds"). (I).).
K ¹ -(-N=N-K ² ) _p -N=N-K ³ (I)
[In formula (I), K ¹ and K ³ are each independently a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a naphthyl group which may have a substituent. Represents a good monovalent heterocyclic group. K ² is a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocycle which may have a substituent. represents a group. p represents an integer from 1 to 4. When p is an integer of 2 or more, a plurality of K ² may be the same or different from each other. The -N=N- bond may be replaced by a -C=C-, -COO-, -NHCO-, or -N=CH- bond within a range that exhibits absorption in the visible region. ]

Examples of the monovalent heterocyclic group include groups obtained by removing one hydrogen atom from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. Examples of the divalent heterocyclic group include a group obtained by removing two hydrogen atoms from the above-mentioned heterocyclic compound.

As a substituent optionally possessed by the phenyl group, naphthyl group, and monovalent heterocyclic group in K ¹ and K ³ , and the p-phenylene group, naphthalene-1,4-diyl group, and divalent heterocyclic group in K ² is an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, and a butoxy group; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; Nitro group; halogen atom; substituted or unsubstituted amino group such as amino group, diethylamino group, pyrrolidino group (substituted amino group refers to an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two It refers to an amino group in which substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms.An unsubstituted amino group is _-NH2 .

［式（Ｉ－１）～（Ｉ－８）中、
Ｂ^１～Ｂ^３０は、互いに独立して、水素原子、炭素数１～６のアルキル基、炭素数１～４のアルコキシ基、シアノ基、ニトロ基、置換または無置換のアミノ基（置換アミノ基および無置換アミノ基の定義は前記のとおり）、塩素原子またはトリフルオロメチル基を表わす。
ｎ１～ｎ４は、互いに独立に０～３の整数を表わす。
ｎ１が２以上である場合、複数のＢ^２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＢ^６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＢ^９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＢ^１４は互いに同一でも異なっていてもよい。］ Among compounds (I), compounds represented by any of formulas (I-1) to (I-6) are preferred.

[In formulas (I-1) to (I-8),
B ¹ to B ³⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (substituted amino group) and the definition of unsubstituted amino group is as above), represents a chlorine atom or a trifluoromethyl group.
n1 to n4 each independently represent an integer of 0 to 3.
When n1 is 2 or more, the plurality of ^B2s may be the same or different from each other,
When n2 is 2 or more, the plurality of ^B6s may be the same or different from each other,
When n3 is 2 or more, multiple ^B9s may be the same or different from each other,
When n4 is 2 or more, the plurality of ^B14s may be the same or different from each other. ]

［式（Ｉ－９）中、
Ｒ^１～Ｒ^８は、互いに独立して、水素原子、－Ｒ^ｘ、－ＮＨ_２、－ＮＨＲ^ｘ、－ＮＲ^ｘ _２、－ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］ The anthraquinone dye is preferably a compound represented by formula (I-9).

[In formula (I-9),
R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（Ｉ－８）中、
Ｒ^９～Ｒ^１５は、互いに独立して、水素原子、－Ｒ^ｘ、－ＮＨ_２、－ＮＨＲ^ｘ、－ＮＲ^ｘ _２、－ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］ The oxazone dye is preferably a compound represented by formula (I-10).

[In formula (I-8),
R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（Ｉ－１１）中、
Ｒ^１６～Ｒ^２３は、互いに独立して、水素原子、－Ｒ^ｘ、－ＮＨ_２、－ＮＨＲ^ｘ、－ＮＲ^ｘ _２、－ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］
式（Ｉ－９）、式（Ｉ－１０）および式（Ｉ－１１）において、Ｒ^ｘの炭素数１～６のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基およびヘキシル基等が挙げられ、炭素数６～１２のアリール基としては、フェニル基、トルイル基、キシリル基およびナフチル基等が挙げられる。 The acridine dye is preferably a compound represented by formula (I-11).

[In formula (I-11),
R ¹⁶ to R ²³ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]
In formula (I-9), formula (I-10) and formula (I-11), the alkyl group having 1 to 6 carbon atoms in R ^x includes methyl group, ethyl group, propyl group, butyl group, pentyl group. Examples of the aryl group having 6 to 12 carbon atoms include phenyl group, tolyl group, xylyl group, and naphthyl group.

［式（Ｉ－１２）中、
Ｄ^１およびＤ^２は、互いに独立に、式（Ｉ－１２ａ）～式（Ｉ－１２ｄ）のいずれかで表される基を表わす。

ｎ５は１～３の整数を表わす。］

［式（Ｉ－１３）中、
Ｄ^３およびＤ^４は、互いに独立に、式（Ｉ－１３ａ）～式（１－１３ｈ）のいずれかで表される基を表わす。

ｎ６は１～３の整数を表わす。］ The cyanine dye is preferably a compound represented by formula (I-12) or a compound represented by formula (I-13).

[In formula (I-12),
D ¹ and D ² each independently represent a group represented by any one of formulas (I-12a) to (I-12d).

n5 represents an integer from 1 to 3. ]

[In formula (I-13),
D ³ and D ⁴ each independently represent a group represented by any one of formulas (I-13a) to (1-13h).

n6 represents an integer from 1 to 3. ]

The polymerizable liquid crystal composition of the present invention has an excellent effect of suppressing photodeterioration of dichroic dyes in the polarizing film when it is formed, so it is susceptible to light such as ultraviolet rays in sunlight and photodegradation. When using a dichroic dye that tends to cause , the effects of the present invention can be particularly markedly exhibited. Therefore, the polymerizable liquid crystal composition of the present invention is particularly advantageous when using dichroic dyes that are prone to photodeterioration. The dichroic dye contained in the polymerizable liquid crystal composition of the present invention is preferably an azo dye.

The content of the dichroic dye in the polymerizable liquid crystal composition of the present invention can be appropriately determined depending on the type of dichroic dye used, but is preferably 0.00 parts by weight based on 100 parts by mass of the polymerizable liquid crystal compound. The amount is 1 to 50 parts by weight, more preferably 0.1 to 20 parts by weight, and even more preferably 0.1 to 12 parts by weight. When the content of the dichroic dye is within the above range, it is difficult to disturb the orientation of the polymerizable liquid crystal compound, and a polarizing film having a high degree of orientational order can be obtained.

The polymerizable liquid crystal composition of the present invention contains an antioxidant.
In the polymerizable liquid crystal composition of the present invention, the antioxidant has the following formula (1) in relation to the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition:
0.8℃ ≦ T1-T2 (1)
satisfy.

In formula (1), T1 is the phase transition temperature of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition, which is heated to 130°C in the atmosphere and then cooled to 23°C at a rate of 5°C/min. This is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature when measured.
In T2, a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant is heated to 130°C in the atmosphere, and then cooled to 23°C at a rate of 5°C/min to undergo a phase transition. This is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature when temperature is measured.
When the polymerizable liquid crystal composition of the present invention contains two or more types of polymerizable liquid crystal compounds, the above T1 and T2 are polymerizable liquid crystal compounds ( mixture). Detailed methods for measuring T1 and T2 are as described in Examples below.

Generally, excellent polarization performance can be obtained when the polymerizable liquid crystal compound and the dichroic dye are oriented with a high degree of order. However, in such an oriented state, the dichroic dye is included in the polymerizable liquid crystal compound, so the addition of an antioxidant disturbs the orientation of the polymerizable liquid crystal compound, resulting in a decrease in polarization performance. This can cause problems.

The polymerizable liquid crystal composition of the present invention contains an antioxidant that satisfies the above formula (1), so that it can be highly effective in suppressing deterioration of polarizing performance when a polarizing film is formed.
In formula (1), T1-T2 is an index representing the influence of the antioxidant on the phase transition temperature in the liquid crystal state. The larger the value of T1-T2, the more similar the polymerizable liquid crystal compound and antioxidant are in terms of molecular structure, and the more mixed the antioxidant is in the liquid crystal state, the more the antioxidant is oriented together with the polymerizable liquid crystal compound. It means there is. Therefore, the larger the value of T1-T2, the closer the intermolecular distance between the dichroic dye and the antioxidant present in the polymerizable liquid crystal compound, and the higher the suppression of photodegradation of the dichroic dye. It is estimated that it is possible to obtain a polarizing film that is effective, is difficult to disturb the orientation of the polymerizable liquid crystal compound, and has a high degree of orientational order.

In the antioxidant contained in the polymerizable liquid crystal composition of the present invention, the value of T1-T2 is 0.8°C or higher, preferably 0.9°C or higher, more preferably 1.0°C or higher. The temperature is more preferably 1.2°C or higher, particularly preferably 1.5°C or higher.
When the value of T1-T2 is less than 0.8°C, the molecular structure of the polymerizable liquid crystal compound and the molecular structure of the antioxidant are greatly different, and the antioxidant is oriented with a high degree of order together with the polymerizable liquid crystal compound. It's difficult. As a result, it is difficult to fully exhibit the effect of suppressing photodeterioration of dichroic dyes. On the other hand, if the value of T1-T2 is within the above range, the antioxidant can be placed near the dichroic dye clathrated in the polymerizable liquid crystal compound, and a high suppressive effect on the deterioration of polarization performance can be obtained. You can expect it.
In the present invention, the upper limit of T1-T2 is not particularly limited, but is usually 35°C or lower, preferably 30°C or lower, and more preferably 25°C or lower.

In the polymerizable liquid crystal composition, the antioxidant is not particularly limited as long as it satisfies the above formula (1) with the polymerizable liquid crystal compound and can exhibit the effects of the present invention, and may be any known antioxidant. can be used. From the viewpoint of having a high inhibitory effect on photodeterioration of dichroic dyes, so-called primary antioxidants that have an effect of scavenging radicals and preventing autooxidation are preferred. Therefore, it is more preferable that the antioxidant contained in the polymerizable liquid crystal composition of the present invention is at least one selected from the group consisting of phenolic compounds, alicyclic alcohol compounds, and amine compounds. The antioxidants may be used alone or in combination of two or more.

で表されるいずれかの構造を有する化合物が挙げられる。 Examples of the antioxidant selected from the group consisting of phenolic compounds, alicyclic alcohol compounds, and amine compounds include formulas (2), (3), and (4):

Examples include compounds having any of the structures represented by:

In formulas (2) and (3), R ₁ to R ₅ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or a carbon It is a branched or unbranched alkoxy group having numbers 1 to 12, and in formulas (2) and (3), at least one of R ₁ to R ₅ is -OH or -NH ₂ , respectively.

Branched or unbranched alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, pentyl group, hexyl group, 2-ethylhexyl group, heptyl group. , octyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc.

Branched or unbranched alkoxy groups having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, Examples include decyloxy group, undecyloxy group, dodecyloxy group, and the like.

In formulas (2) and (3), -OH or -NH ₂ present in at least one of R ₁ to R ₅ is preferably present in R ₁ , and in this case, R ₂ to R ₅ are - It is more preferably H, a branched or unbranched alkyl group having 1 to 12 carbon atoms, or a branched or unbranched alkoxy group having 1 to 12 carbon atoms, and even more preferably -H.

Examples of the antioxidant having the structure represented by the above formula (2), (3) or (4) include formula (5):
A ₁ -L ₁ -(A ₂ -L ₂ ) _n -A ₃ (5)
Examples include compounds represented by:

In formula (5), L ₁ and L ₂ are each independently a single bond or a divalent linking group.

A ₁ is a group represented by the above formula (2), (3) or (4).

〔式（６）および（７）中、Ｒ_６～Ｒ_９は、それぞれ独立して、－Ｈ、－ＯＨ、－ＮＨ_２、炭素数１～１２の分枝若しくは非分枝アルキル基、または、炭素数１～１２の分枝若しくは非分枝アルコキシ基である〕
で表される基である。
Ａ_３は、式（８）または（９）：

〔式（８）および（９）中、Ｒ_１０～Ｒ_１４は、それぞれ独立して、－Ｈ、－ＯＨ、－ＮＨ_２、炭素数１～１２の分枝若しくは非分枝アルキル基、または、炭素数１～１２の分枝若しくは非分枝アルコキシ基である〕
で表される基である。
ｎは０～２の整数であり、ｎが２の場合、２つのＡ_２は互いに同一であっても異なっていてもよい。 _A2 is the formula (6) or (7):

[In formulas (6) and (7), R ₆ to R ₉ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
It is a group represented by
_A3 is the formula (8) or (9):

[In formulas (8) and (9), R ₁₀ to R ₁₄ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
It is a group represented by
n is an integer from 0 to 2; when n is 2, two A ₂ 's may be the same or different from each other.

Examples of the divalent linking group in L ₁ and L ₂ include a single bond, an ether group, a carbonyl group, an ester group, an amide group, and an azo group. As L ₁ and L ₂ , bond species that do not absorb visible light as antioxidants are preferable, single bonds, ether groups and ester groups are more preferable, and single bonds and ether groups are particularly preferable.

Examples of A ₁ include groups similar to the structures exemplified above as structures represented by formulas (2), (3), and (4) above, and groups represented by formulas (2) or (4). is preferably a group represented by formula (2), R ₁ is -OH, and R ₂ to R ₅ are each independently -H or -CH ₃ is more preferred, and it is particularly preferred that R ₂ to R ₅ are all -H.

A branched alkyl group having 1 to 12 carbon atoms, an unbranched alkyl group having 1 to 12 carbon atoms, a branched alkoxy group having 1 to 12 carbon atoms _, and R ₆ to R ₁₄ in A 2 and A ₃ ; Examples of the unbranched alkoxy group having 1 to 12 carbon atoms include the branched alkyl groups having 1 to 12 carbon atoms exemplified above as R ₁ to R ₅ in A ₁ , and the unbranched alkyl groups having 1 to 12 carbon atoms. group, a branched alkoxy group having 1 to 12 carbon atoms, and an unbranched alkoxy group having 1 to 12 carbon atoms.

In A ₂ , R ₆ to R ₉ are each independently preferably -H or -CH ₃ , more preferably -H, and even more preferably all of R ₆ to R ₉ are -H or -CH 3 . -CH ₃ , particularly preferably all of R ₆ to R ₉ are -H.

In A ₃ , R ₁₂ is a branched or unbranched alkyl group having 1 to 12 carbon atoms, or a branched or unbranched alkoxy group having 1 to 12 carbon atoms, and R ₁₀ , R ₁₁ , R ₁₃ and It is preferred that R ₁₄ is each independently -H or -CH ₃ , and it is particularly preferred that R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ are all -H.

The weight average molecular weight of the antioxidant is preferably 600 or less, more preferably 500 or less, still more preferably 450 or less.
When the weight average molecular weight of the antioxidant is 600 or less, the antioxidant can be placed near the dichroic dye without significantly disturbing the orientation of the polymerizable liquid crystal compound, so that the light of the dichroic dye is The deterioration suppression effect can be further improved. Furthermore, it is more preferable that the weight average molecular weight of the antioxidant is 400 or less, since it becomes difficult to absorb in the visible light wavelength region and deterioration in polarization performance can be more effectively reduced.

In the polymerizable liquid crystal composition of the present invention, examples of the antioxidant include the following compounds.

Among these, antioxidants having a molecular structure with little steric hindrance and high linearity are preferred because they tend to be easily aligned with the polymerizable liquid crystal compound and have an excellent effect of suppressing photodeterioration of dichroic dyes. Antioxidants in the polymerizable liquid crystal composition of the present invention include, but are not limited to, 4-n-octyloxyphenol, 4-n-decyloxyphenol, 4-n-dodecyloxyphenol, 4-n-dodecyloxyphenol, 4'-biphenol, 4-ethoxy-4'-hydroxybiphenyl, 4-butoxy-4'-hydroxybiphenyl, 4-octyloxy-4'-hydroxybiphenyl, 4-decyloxy-4'-hydroxybiphenyl, 4-dodecyloxy-4 '-Hydroxybiphenyl is preferred.

The content of the antioxidant in the polymerizable liquid crystal composition of the present invention is preferably 0.1 to 15 parts by mass, more preferably 0.3 parts by mass or more, based on 100 parts by mass of the polymerizable liquid crystal compound. More preferably, it is 0.5 parts by mass or more, more preferably 12 parts by mass or less, still more preferably 8 parts by mass or less, and particularly preferably 4 parts by mass or less.
When the content of the antioxidant is at least the above lower limit, photodeterioration of the dichroic dye can be effectively suppressed. Moreover, when the content of the antioxidant is below the above-mentioned upper limit, it is difficult to disturb the alignment of the polymerizable liquid crystal compound, and a high effect of suppressing photodeterioration of the dichroic dye can be expected.

The polymerizable liquid crystal composition of the present invention may contain a polymerization initiator.
The polymerization initiator is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound, and a photopolymerization initiator is preferable because it can initiate the polymerization reaction under lower temperature conditions. Specifically, photopolymerization initiators that can generate active radicals or acids by the action of light can be mentioned, and among them, photopolymerization initiators that can generate radicals by the action of light are preferred. Polymerization initiators can be used alone or in combination of two or more.

Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone. and 2,4,6-trimethylbenzophenone.

Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, and 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane. -1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[ 4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one Examples include oligomers.

Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

As triazine compounds, 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6- [2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1 ,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine Examples include methyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine.

A commercially available polymerization initiator can be used. Commercially available polymerization initiators include, for example, "Irgacure (registered trademark) 907", "Irgacure (registered trademark) 184", "Irgacure (registered trademark) 651", "Irgacure (registered trademark) 819", " Irgacure (registered trademark) 250", "Irgacure (registered trademark) 369" (Ciba Japan Co., Ltd.); "Seiqual (registered trademark) BZ", "Seiqual (registered trademark) Z", "Seiqual (registered trademark) BEE ” (Seiko Chemical Co., Ltd.); “Kayacure (registered trademark) BP100” (Nippon Kayaku Co., Ltd.); “Kayacure (registered trademark) UVI-6992” (manufactured by Dow Corporation); “Adeka Optomer SP -152'', ``ADEKA Optomer SP-170'' (ADEKA Co., Ltd.); ``TAZ-A'', ``TAZ-PP'' (Japan Siberhegner Co., Ltd.); and ``TAZ-104'' (Sanwa Chemical Co., Ltd.), etc. Can be mentioned.

When the polymerizable liquid crystal composition contains a polymerization initiator, the content may be appropriately determined depending on the type and amount of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition. The amount is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 10 parts by weight, and even more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the compound. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

When the polymerizable liquid crystal composition contains a photopolymerization initiator, it may further contain a photosensitizer. By using a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound can be further promoted.
Examples of photosensitizers include xanthone compounds such as xanthone and thioxanthone (2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and anthracene containing an alkoxy group (dibutoxyanthracene, etc.); phenothiazine and rubrene, etc. can be mentioned. The photosensitizers can be used alone or in combination of two or more.

The content of the photosensitizer in the polymerizable liquid crystal composition of the present invention may be appropriately determined depending on the type and amount of the photopolymerization initiator and the polymerizable liquid crystal compound. On the other hand, it is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 10 parts by weight, and even more preferably 0.5 to 8 parts by weight.

The polymerizable liquid crystal composition of the present invention may contain a leveling agent. The leveling agent has the function of adjusting the fluidity of the polymerizable liquid crystal composition and making the coating film obtained by applying the polymerizable liquid crystal composition more flat. Can be mentioned. The leveling agent is preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component. Leveling agents can be used alone or in combination of two or more.

Leveling agents containing polyacrylate compounds as main components include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N", " BYK-361N, BYK-380, BYK-381 and BYK-392 (BYK Chemie).

Leveling agents whose main component is a fluorine atom-containing compound include "Megafac (registered trademark) R-08", "Megafac (registered trademark) R-30", "R-90", "F-410", and "Megafac (registered trademark)". -411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-" 482" and "F-483" (DIC Corporation); "Surflon (registered trademark) S-381", "S-382", "S-383", "S-393", " "SC-101", "SC-105", "KH-40" and "SA-100" (AGC Seimi Chemical Co., Ltd.); "E1830", "E5844" (Daikin Fine Chemical Laboratories Co., Ltd.); Examples include "F-TOP EF301", "F-TOP EF303", "F-TOP EF351", and "F-TOP EF352" (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

The content of the leveling agent in the polymerizable liquid crystal composition of the present invention is preferably 0.05 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound, and there is a tendency for a smoother polarizing film to be obtained with less unevenness.

The polymerizable liquid crystal composition of the present invention may contain additives other than the polymerization initiator, photosensitizer, and leveling agent. Examples of other additives include mold release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. When the polymerizable liquid crystal composition contains other additives, the content of the other additives is preferably more than 0% and 20% by mass or less based on the solid content of the polymerizable liquid crystal composition. , more preferably more than 0% and 10% by mass or less.

The polymerizable liquid crystal composition of the present invention may contain a solvent. Generally, compounds exhibiting smectic liquid crystal properties have high viscosity, so adding a solvent to the polymerizable liquid crystal composition facilitates coating, and as a result, it often becomes easier to form a polarizing film. The solvent can be appropriately selected depending on the solubility of the polymerizable liquid crystal compound and the dichroic dye, and examples thereof include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl. Alcohol solvents such as ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl Ketone solvents such as isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chloroform, Examples include chlorinated hydrocarbon solvents such as chlorobenzene.
These solvents can be used alone or in combination of two or more. The content of the solvent is preferably 100 to 1900 parts by mass, more preferably 150 to 900 parts by mass, and even more preferably 180 to 600 parts by mass, based on 100 parts by mass of the solid components constituting the polymerizable liquid crystal composition. Part by mass.

The polymerizable liquid crystal composition of the present invention can usually be prepared by mixing and stirring a polymerizable liquid crystal compound, a dichroic dye, an antioxidant, and, if necessary, the above-mentioned additives and solvents. .

The polymerizable liquid crystal composition of the present invention has an excellent effect of suppressing photodeterioration of dichroic dyes, and is suitable for producing a polarizing film because it can provide a polarizing film whose polarizing performance is unlikely to deteriorate over time. It can be used for.

A polarizing film with a high degree of alignment order can be manufactured using the polymerizable liquid crystal composition of the present invention.
A polarizing film with a high degree of orientational order can obtain a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement.
The Bragg peak means a peak derived from a planar periodic structure of molecular orientation. Therefore, in the polarizing film formed from the polymerizable liquid crystal composition of the present invention, the polymerizable liquid crystal compound or its polymer is preferably oriented such that the polarizing film exhibits a Bragg peak in X-ray diffraction measurement. , "horizontal alignment" in which the molecules of the polymerizable liquid crystal compound are aligned in the direction of light absorption is more preferable. In the present invention, a polarizing film having a plane periodic interval of molecular orientation of 3.0 to 6.0 Å is preferable. A high degree of orientational order that exhibits a Bragg peak can be achieved by controlling the type of polymerizable liquid crystal compound used, the type and amount of antioxidant, the type and amount of dichroic dye, etc.

As mentioned above, by incorporating an antioxidant that satisfies formula (1) in relation to the polymerizable liquid crystal composition, photodegradation of the dichroic dye can be prevented while maintaining a high degree of orientational order of the polymerizable liquid crystal compound. As a result, a polarizing film which has excellent polarization performance and whose polarization performance is less likely to deteriorate over time can be obtained. Therefore, the present invention provides a polarizing film that is a cured product of a polymerizable liquid crystal composition containing a dichroic dye, a polymerizable liquid crystal compound, and an antioxidant, the polarizing film exhibiting a Bragg peak in X-ray diffraction measurements. , the antioxidant has the formula (1) in relation to the polymerizable liquid crystal compound:
0.8℃ ≦ T1-T2 (1)
[In the formula, T1 is the liquid crystal that appears at the lowest temperature when the phase transition temperature is measured while heating the polymerizable liquid crystal compound to 130°C in the air and then cooling it to 23°C at a rate of 5°C/min. T2 is the phase transition temperature to phase, and T2 is a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant, heated at 5 °C/min after heating to 130 °C in the atmosphere. When the phase transition temperature is measured while cooling to 23°C, it is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature side.]
This also applies to polarizing films that satisfy the following criteria.

In the polymerizable liquid crystal composition used to form the polarizing film of the present invention, as the polymerizable liquid crystal compound, dichroic dye, and antioxidant, the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition of the present invention, Examples of dichroic dyes and antioxidants include those listed above. The polymerizable liquid crystal composition used to form the polarizing film of the present invention may contain a polymerization initiator, a leveling agent, other additives, a solvent, and the like. Examples of these components include those similar to those exemplified above as components contained in the polymerizable liquid crystal composition of the present invention.

The polarizing film of the present invention can be obtained by, for example, forming a coating film of the polymerizable liquid crystal composition of the present invention;
removing the solvent from the coating film;
Raising the temperature to a temperature at which the polymerizable liquid crystal compound undergoes a phase transition to a liquid phase or higher and then lowering the temperature to cause the polymerizable liquid crystal compound to undergo a phase transition to a smectic phase (smectic liquid crystal state), and
It can be produced by a method including polymerizing a polymerizable liquid crystal compound while maintaining the smectic phase (smectic liquid crystal state).

Formation of a coating film of a polymerizable liquid crystal composition is carried out by applying a polymerizable liquid crystal composition, especially a polymerizable liquid crystal composition whose viscosity has been adjusted by adding a solvent (hereinafter referred to as a "polarizing film"), on a substrate or an alignment film (described later). This can be done by applying a "forming composition"). The polymerizable liquid crystal composition may be directly applied onto the retardation film and other layers constituting the polarizing plate of the present invention.

The substrate is usually a transparent substrate. When the base material is not installed on the display surface of the display element, for example, when a laminate obtained by removing the base material from the polarizing film is installed on the display surface of the display element, the base material does not need to be transparent. Transparent substrate refers to a substrate that has transparency that allows light, particularly visible light, to pass through, and transparency refers to the property that the transmittance for light rays with a wavelength of 380 to 780 nm is 80% or more. say. A specific example of the transparent base material is a translucent resin base material. Examples of resins constituting the translucent resin base material include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate ester; polyacrylate ester; triacetyl cellulose; Examples include cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cyclic olefin resin, or polycarbonate are preferred. Cellulose ester is obtained by esterifying some or all of the hydroxyl groups contained in cellulose, and can be easily obtained from the market. Furthermore, cellulose ester base materials are also easily available on the market. Examples of commercially available cellulose ester base materials include "Fujitac Film" (Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opto Co., Ltd.).

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

The thickness of the base material is usually 5 to 300 μm, preferably 20 to 200 μm, and more preferably 20 to 100 μm, since if it is too thin, the strength will decrease and the workability will tend to be poor.

Methods for applying the composition for forming a polarizing film onto a substrate include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing such as flexography. Examples include known methods such as the method.

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

Furthermore, in order to cause a phase transition of the polymerizable liquid crystal compound to a liquid phase, the temperature is raised to a temperature higher than the temperature at which the polymerizable liquid crystal compound undergoes a phase transition to a liquid phase, and then the temperature is lowered to transform the polymerizable liquid crystal compound into a smectic phase (smectic liquid crystal state). cause a phase transition. Such a phase transition may be performed after removing the solvent in the coating film, or may be performed simultaneously with the removal of the solvent.

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

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

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

By performing photopolymerization, the polymerizable liquid crystal compound is polymerized while maintaining a liquid crystal state of a smectic phase, preferably a higher-order smectic phase, and a polarizing film is formed. Due to the action of the dichroic dye, the polarizing film obtained by polymerizing the polymerizable liquid crystal compound while maintaining the smectic phase liquid crystal state is different from the conventional host-guest type polarizing film, that is, from the nematic phase liquid crystal state. It has the advantage of higher polarizing performance than other polarizing films. Furthermore, it has the advantage of being superior in strength compared to those coated with only dichroic dyes or lyotropic liquid crystals.

The thickness of the polarizing film can be appropriately selected depending on the display device to which it is applied, and is preferably 0.1 to 10 μm, more preferably 0.3 to 4 μm, and even more preferably 0.5 to 3 μm.

Preferably, the polarizing film is formed on the alignment film. The alignment film has alignment regulating power to align the polymerizable liquid crystal compound in a desired direction. As the alignment film, one that has a solvent resistance that does not dissolve when a composition containing a polymerizable liquid crystal compound is applied, etc., and also has heat resistance in heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound. preferable. Examples of such alignment films include alignment films containing alignment polymers, optical alignment films, groove alignment films having an uneven pattern or a plurality of grooves on the surface, stretched films stretched in the alignment direction, etc. From the viewpoint of quality, a photo-alignment film is preferred.

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

An oriented film containing an oriented polymer is usually produced by applying a composition in which an oriented polymer is dissolved in a solvent (hereinafter sometimes referred to as an "oriented polymer composition") to a base material, and then removing the solvent, or It is obtained by applying an oriented polymer composition to a substrate, removing the solvent, and rubbing (rubbing method). Examples of the solvent include the same solvents as those exemplified above as solvents that can be used when forming the polarizing film.

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

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

Examples of the method for applying the oriented polymer composition to the substrate include the same methods as those exemplified as the method for applying the polarizing film-forming composition to the substrate.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The present invention includes a polarizing plate (elliptically polarizing plate) comprising the polarizing film of the present invention and a retardation film. In the polarizing plate of the present invention, the retardation film has the formula (X):
100≦Re(550)≦180 (X)
[In the formula, Re (550) represents the in-plane retardation value at a wavelength of 550 nm]
It is preferable to satisfy the following. When the retardation film has an in-plane retardation value represented by (X) above, it functions as a so-called λ/4 plate. The formula (X) preferably satisfies 100 nm≦Re(550)≦180 nm, more preferably 120 nm≦Re(550)≦160 nm. Note that Re(550) can be measured by the method described in Examples.

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

Furthermore, the retardation film has the formula (Y):
Re(450)/Re(550) < 1 (Y)
[In the formula, Re (450) and Re (550) represent in-plane retardation values at wavelengths of 450 nm and 550 nm, respectively.]
It is preferable to satisfy the following. A retardation film that satisfies the above formula (Y) has so-called reverse wavelength dispersion and exhibits excellent polarization performance. The value of Re(450)/Re(550) is preferably 0.93 or less, more preferably 0.88 or less, even more preferably 0.86 or less, preferably 0.80 or more, more preferably 0. 82 or higher.

The retardation film may be a stretched film that provides a retardation by stretching a polymer, but from the viewpoint of making the polarizing plate thinner, a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound (hereinafter referred to as " It is preferably a cured product of a polymerizable liquid crystal composition (also referred to as "polymerizable liquid crystal composition (B)"), and is preferably composed of a polymer in an oriented state of the polymerizable liquid crystal compound. The polymerizable liquid crystal compound that forms the retardation film (hereinafter also referred to as "polymerizable liquid crystal compound (B)") means a liquid crystal compound that has a polymerizable functional group, particularly a photopolymerizable functional group. The photopolymerizable functional group refers to a group that can participate in a polymerization reaction by active radicals, acids, etc. generated from a photopolymerization initiator. Examples of the photopolymerizable functional group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group, and the like. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferred, and acryloyloxy group is more preferred. The liquid crystallinity of the polymerizable liquid crystal compound (B) may be a thermotropic liquid crystal or a lyotropic liquid crystal, and the phase order structure may be a nematic liquid crystal or a smectic liquid crystal. As the polymerizable liquid crystal compound (B), only one type may be used, or two or more types may be used in combination.

Examples of the polymerizable liquid crystal compound (B) include compounds that satisfy all of the following (a) to (e) from the viewpoint of ease of film formation and imparting the retardation property represented by the above formula (Y). .

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

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

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

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

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

L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.

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

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

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

L ¹ and L ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2 -, -R ^a3 COOR ^a4 -, -R ^a5 OCOR ^a6 -, R ^a7 OC=OOR ^a8 -, -N=N-, -CR ^c =CR ^d -, or -C≡C-. Here, R ^a1 to R ^a8 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ^c and R ^d represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and L ² are each independently more preferably a single bond, -OR ^a2-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a4-1 -, or -OCOR ^a6-1 - be. Here, R ^a2-1 , R ^a4-1 , and R ^a6-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. L ¹ and L ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, or -OCO-.

In a preferred embodiment of the present invention, at least one of G ¹ and G ² in formula (II) is a divalent alicyclic hydrocarbon group, and the divalent alicyclic hydrocarbon group is , a polymerizable liquid crystal compound in which a divalent aromatic group Ar, which may have a substituent, is bonded to L ¹ and/or L ² , which are -COO-, is used.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The content of the polymerizable liquid crystal compound (B) in the polymerizable liquid crystal composition (B) is, for example, 70 to 99.5 parts by mass based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition (B). , preferably 80 to 99 parts by weight, more preferably 90 to 98 parts by weight. When the content is within the above range, the orientation of the retardation film tends to be high.
Here, the solid content refers to the total amount of components excluding volatile components such as solvents from the polymerizable liquid crystal composition (B).

The polymerizable liquid crystal composition (B) may contain a polymerization initiator for starting the polymerization reaction of the polymerizable liquid crystal compound (B).
Examples of the polymerization initiator include those similar to those exemplified above as polymerization initiators that can be used in the polymerizable liquid crystal composition (A). The polymerizable liquid crystal composition (B) may contain, as necessary, a photosensitizer, a leveling agent, and the additives exemplified as additives contained in the polymerizable liquid crystal composition (A). . As the photosensitizer and the leveling agent, the same ones as those exemplified above as included in the polymerizable liquid crystal composition (A) can be mentioned.

The retardation film is a composition prepared by adding a solvent to a polymerizable liquid crystal composition (B) containing a polymerizable liquid crystal compound (B) and, if necessary, a polymerization initiator, additives, etc., and mixing and stirring. (hereinafter also referred to as "composition for forming a retardation film") is applied onto a substrate or alignment film, the solvent is removed by drying, and the polymerizable liquid crystal compound (B) in the resulting coating film is removed. It can be obtained by curing by heating and/or active energy rays. As the base material and/or alignment film used for producing the retardation film, the same ones as those exemplified above can be mentioned as those that can be used when producing the polarizing film of the present invention.

The solvent used in the composition for forming a retardation film, the method for applying the composition for forming a retardation film, the curing conditions using active energy rays, etc. are all the same as those that can be adopted in the method for producing a polarizing film of the present invention. Things can be mentioned.

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

The polarizing plate of the present invention comprises the polarizing film and retardation film of the present invention, and preferably comprises a base material, an alignment film (particularly a photo-alignment film), and the polarizing film and retardation film of the present invention. The polarizing plate of the present invention may further include layers other than these (a protective layer, an adhesive layer, etc.). In the polarizing plate of the present invention, the polarizing film of the present invention and the retardation film may be bonded together via an adhesive layer or a pressure-sensitive adhesive layer. In the polarizing plate of the present invention, the retardation film may be directly formed on the polarizing film of the present invention by directly applying the retardation film-forming composition to the polarizing film of the present invention.

The thickness of the polarizing plate of the present invention is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 25 to 100 μm from the viewpoint of flexibility and visibility of the display device.

The present invention includes a display device comprising the polarizing film of the present invention or the polarizing plate of the present invention.
The display device of the present invention can be obtained, for example, by bonding the polarizing film or polarizing plate of the present invention to the surface of the display device via an adhesive layer.
A display device is a device having a display mechanism, and includes a light emitting element or a light emitting device as a light source. Display devices include liquid crystal display devices, organic electroluminescent (EL) display devices, inorganic electroluminescent (EL) display devices, touch panel display devices, electron emission display devices (field emission display devices (FEDs, etc.), surface field emission display devices) (SED)), electronic paper (display device using electronic ink or electrophoretic element), plasma display device, projection type display device (grating light valve (GLV) display device, display device with digital micromirror device (DMD)) etc.) and piezoelectric ceramic displays. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view type liquid crystal display device, a projection type liquid crystal display device, and the like. These display devices may be display devices that display two-dimensional images or stereoscopic display devices that display three-dimensional images. In particular, as the display device of the present invention, an organic EL display device and a touch panel display device are preferable, and an organic EL display device is particularly preferable.

（A－６） ９０部

(A－７) １０部
・二色性色素：
アゾ色素；

（二色性色素 Ａ） ２．５部

（二色性色素 Ｂ） ２．５部

（二色性色素 Ｃ） ２．５部
・重合開始剤：
２－ジメチルアミノ－２－ベンジル－１－（４－モルホリノフェニル）ブタン－１－オン（イルガキュア３６９；チバ・スペシャルティ・ケミカルズ(株)製） ６部
・レベリング剤：
ポリアクリレート化合物（ＢＹＫ－３６１Ｎ；ＢＹＫ－Ｃｈｅｍｉｅ社製） １．２部
・溶剤：
ｏ－キシレン ４００部 <Preparation of polymerizable liquid crystal composition (hereinafter sometimes referred to as "polarizing film forming composition")>
A polarizing film-forming composition (1) was obtained by mixing the following components and stirring at 80° C. for 1 hour. As the dichroic dye, an azo dye described in Examples of JP-A-2013-101328 was used. Hereinafter, "%" and "parts" in the examples mean % by mass and parts by mass, respectively, unless otherwise specified.
・Polymerizable liquid crystal compound:

(A-6) 90 copies

(A-7) 10 parts/dichroic dye:
Azo dye;

(Dichroic dye A) 2.5 parts

(Dichroic dye B) 2.5 parts

(Dichroic dye C) 2.5 parts/polymerization initiator:
2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals Co., Ltd.) 6 parts Leveling agent:
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) 1.2 parts/Solvent:
o-xylene 400 parts

Furthermore, a polarizing film was prepared in the same manner as the composition for forming a polarizing film (1) except that the compound described below as an antioxidant was mixed into the composition for forming a polarizing film (1) in the amount shown in Table 1. Forming compositions (2) to (18) were obtained.
The amounts of antioxidants added in Table 1 are based on 100 parts by mass of the polymerizable liquid crystal compound in the composition for forming a polarizing film.

（酸化防止剤Ａ ： ４－ｎ－オクチロキシフェノール）

（酸化防止剤Ｂ ： ４，４’－ビフェノール）

（酸化防止剤Ｃ ： ４－エトキシ-４’－ヒドロキシビフェニル）

（酸化防止剤Ｄ ： ４－ブトキシ-４’－ヒドロキシビフェニル）

（酸化防止剤Ｅ ： ４－オクチロキシ-４’－ヒドロキシビフェニル）

（酸化防止剤Ｆ ： ジブチルヒドロキシトルエン）

（酸化防止剤Ｇ ： Ｔｉｎｕｖｉｎ ７７０；ＢＡＳＦ社製）

（酸化防止剤Ｈ ： スミライザーＧＰ；住友化学株式会社製）

（酸化防止剤Ｉ ： ｐ－メトキシフェノール） <Structure of antioxidant>
The structure of the antioxidant used in Examples and Comparative Examples is as follows.

(Antioxidant A: 4-n-octyloxyphenol)

(Antioxidant B: 4,4'-biphenol)

(Antioxidant C: 4-ethoxy-4'-hydroxybiphenyl)

(Antioxidant D: 4-butoxy-4'-hydroxybiphenyl)

(Antioxidant E: 4-octyloxy-4'-hydroxybiphenyl)

(Antioxidant F: dibutylhydroxytoluene)

(Antioxidant G: Tinuvin 770; manufactured by BASF)

(Antioxidant H: Sumilizer GP; manufactured by Sumitomo Chemical Co., Ltd.)

(Antioxidant I: p-methoxyphenol)

<Measurement of liquid crystal phase transition temperature change T1-T2>
(1) Formation of alignment film A 2% by mass aqueous solution of polyvinyl alcohol (Polyvinyl Alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) is applied onto a glass substrate by spin coating, and after drying, the thickness is 100 nm. A film was formed. Subsequently, the surface of the obtained film was subjected to a rubbing treatment to form an alignment film. The rubbing process was performed using a semi-automatic rubbing device (product name: LQ-008 model, manufactured by Joyo Engineering Co., Ltd.) with a cloth (product name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) with a pressing depth of 0.15 mm. The rotation speed was 500 rpm and 16.7 mm/s.

(2) Measurement of T1 As polymerizable liquid crystal compounds, 90 parts of the compound represented by formula (A-6), 10 parts of the compound represented by formula (A-7), and 400 parts of o-xylene were heated at 80°C for 1 hour. A uniformly mixed mixed composition was obtained by stirring.
The obtained mixed composition was applied onto the glass with the alignment film by spin coating, and the o-xylene solvent was removed by heating and drying on a hot plate at 130° C. for 3 minutes. Thereafter, the obtained coating film was quickly cooled to room temperature to obtain a dry film of the polymerizable liquid crystal compound. This dried film was heated again to 130°C on a hot plate, and then cooled down to 23°C at a rate of 5°C/min. The phase transition temperature was measured by observing with a polarizing microscope. As a result, a phase transition occurs to a nematic liquid crystal phase at 113.7°C, a phase transition to a smectic A phase at 109.6°C, a phase transition to a smectic B phase at 92.0°C, and a smectic B phase until the temperature reaches 23°C. confirmed that it would be maintained. Since the liquid crystal phase developed at the lowest temperature in the above process was the smectic B phase, T1 was defined as 92.0° C., which is the phase transition temperature to the smectic B phase.

(3) Measurement of T2 Exactly the same as the measurement of T1 in (2) above, except that 1 part by mass of each of antioxidants A to I was added to the above mixed composition per 100 parts by mass of the polymerizable liquid crystal compound. By this method, a dry film consisting of a mixture of an antioxidant and a polymerizable liquid crystal compound was obtained. As a result of measuring the phase transition temperature in the same manner as the measurement of T1 in (2) above, the liquid crystal phase that appeared at the lowest temperature side in all the mixtures was the smectic B phase. Table 2 shows the phase transition temperature (T2) to the liquid crystal phase that occurs at the lowest temperature when each antioxidant is contained.

２部
・溶剤：
ｏ－キシレン ９８部 Example 1
(1) Preparation of a photo-alignment film on a substrate (i) Preparation of a composition for forming a photo-alignment film The following components described in JP-A-2013-033249 were mixed, and the resulting mixture was heated at 80°C for 1 hour. By stirring, a composition for forming a photo-alignment film was obtained.
・Photoalignable polymer:

2 parts/solvent:
o-xylene 98 parts

(ii) Formation of photoalignment film A triacetyl cellulose film (KC8UX2M, manufactured by Konica Minolta, Inc.) is used as a base material, and after corona treatment is applied to the film surface, the above composition for forming a photoalignment film is applied. , and dried at 120° C. to obtain a dry film. A photo-alignment film was formed by irradiating polarized UV on this dry film to obtain a film with a photo-alignment film. The polarized UV treatment was performed using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) under conditions where the intensity measured at a wavelength of 365 nm was 100 mJ.

(2) Preparation of polarizing film On the film with the photo-alignment film obtained as described above, the composition for forming a polarizing film (2) was applied by bar coating method (#9 30 mm/s), and dried at 120°C. The polymerizable liquid crystal compound was subjected to a phase transition to a liquid phase by heating and drying in an oven for 1 minute, and then cooled to room temperature to cause a phase transition of the polymerizable liquid crystal compound to a smectic liquid crystal state. Next, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), the layer formed from the composition for forming a polarizing film is irradiated with ultraviolet rays with an exposure amount of 1000 mJ/cm ² (365 nm standard). As a result, the polymerizable liquid crystal compound contained in the dry film was polymerized while maintaining the smectic liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film was formed from the dry film. The thickness of the polarizing film at this time was measured using a laser microscope (OLS3000 manufactured by Olympus Corporation) and was found to be 2.3 μm. What is thus obtained is a polarizer containing a polarizing film and a base material.
Similar X-ray diffraction measurements were performed on this polarizing film using an X-ray diffraction device X'Pert PRO MPD (manufactured by Spectris Co., Ltd.). ) = approximately 0.17° sharp diffraction peak (Bragg peak) was obtained. Furthermore, similar results were obtained even when the incidence was perpendicular to the rubbing direction. The order period (d) determined from the peak position was approximately 4.4 Å, and it was confirmed that a structure reflecting a higher-order smectic phase was formed.

(3) Preparation of polarizing film laminate After corona treatment was performed on the polarizing film surface of the polarizer obtained above, the corona-treated surface was mixed with carboxyl group-modified polyvinyl alcohol [Co., Ltd.] in 100 parts of water. 7 parts of "Kuraray Poval KL318" manufactured by Kuraray, and a water-soluble polyamide epoxy resin as a thermal crosslinking agent ["Sumirezu Resin 650" obtained from Sumika Chemtex Co., Ltd. (aqueous solution with a solid content concentration of 30% by mass)]3. An aqueous solution (viscosity: 92 cP) to which 5 parts were added was applied using a wire bar coater (#30). By drying at 80° C. for 5 minutes, the aqueous solution was dried to form a protective layer, thereby producing a polarizer with a protective layer. Further, on the protective layer, glass (Eagle A laminate was obtained.

<Measurement of polarization degree Py and single transmittance Ty>
The degree of polarization Py and the single transmittance Ty of the polarizing film laminate of Example 1 were measured as follows. The transmittance (Ta) in the transmission axis direction and the transmittance (Tb) in the absorption axis direction in the wavelength range of 380 nm to 780 nm were measured using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a folder with a polarizer set. It was measured using the double beam method. A mesh that cuts the amount of light by 50% was installed on the reference side of the folder.
Using the following formulas (Formula 1) and (Formula 2), calculate the single transmittance and degree of polarization at each wavelength, and then perform visibility correction using the 2-degree field of view (C light source) of JIS Z 8701. Single transmittance (Ty) and visibility correction polarization degree (Py) were calculated.
Single transmittance Ty (%) = (Ta+Tb)/2 (Formula 1)
Polarization degree Py (%) = (Ta-Tb)/(Ta+Tb)×100 (Formula 2)

Example 2 was prepared in the same manner except that the polarizing film forming compositions (1) and (3) to (18) shown in Table 3 were used instead of the polarizing film forming composition (2). Polarizing film laminates of Comparative Example 1, Comparative Example 2, and Reference Example 1 were obtained.

<Evaluation of light resistance>
The light resistance of the laminates of Examples 1 to 15, Comparative Example 1, Comparative Example 2, and Reference Example 1 was evaluated according to the following method. The results are shown in Table 3.

The above polarizing ^film laminate was placed into a light resistance tester (Suntest The degree of polarization Py and single transmittance Ty of the laminate were measured again, and the amount of change before and after the light resistance test was calculated.

It was confirmed that polarizing film forming compositions 2 to 16, that is, polarizing films prepared from the polymerizable liquid crystal compositions of the present invention (Examples 1 to 15) had good light resistance.

Example 16
<Preparation of circularly polarizing plate>
On the protective layer of the polarizer with a protective layer obtained in the process of producing the polarizing film laminate of Example 5, an adhesive layer formed from a pressure-sensitive adhesive (manufactured by Lintec Corporation, film thickness 25 μm) was applied. A retardation film produced according to Example 1 of JP-A-2015-143786 was transferred. Next, an aluminum metal plate was laminated via an adhesive layer formed from a pressure-sensitive adhesive (manufactured by Lintec Corporation, film thickness: 25 μm) to obtain an elliptically polarizing plate.

<Measurement of reflection hue a*, b*>
The reflected hue of the triacetyl cellulose film surface, which is the base material of the obtained elliptically polarizing plate, was measured using a spectrophotometer (CM-3700d, manufactured by Konica Minolta, Inc.) using the L*a*b* (CIE) color system. The chromaticities a* and b* were measured.

<Evaluation of light resistance>
Next, the triacetyl cellulose film that is the ^base material is placed in a light resistance tester (Suntest The chromaticities a* and b* were measured to calculate the rate of change before and after the light fastness test. The results are shown in Table 4.

It was confirmed that the elliptically polarizing plate including the polarizing film of the present invention had a small amount of change in chromaticity and good light resistance.

Claims (15)

A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound having at least one polymerizable group and exhibiting smectic liquid crystallinity, a dichroic dye, and an antioxidant,
The polymerizable group possessed by the polymerizable liquid crystal compound is a radically polymerizable group,
The antioxidant has the formula (1) in relation to the polymerizable liquid crystal compound:
0.8℃ ≦ T1-T2 (1)
[In the formula, T1 is the liquid crystal that appears at the lowest temperature when the phase transition temperature is measured while heating the polymerizable liquid crystal compound to 130°C in the air and then cooling it to 23°C at a rate of 5°C/min. T2 is the phase transition temperature to phase, and T2 is a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant, heated at 5 °C/min after heating to 130 °C in the atmosphere. When the phase transition temperature is measured while cooling to 23°C, it is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature side.]
A polymerizable liquid crystal composition that satisfies the following. The polymerizable liquid crystal composition according to claim 1, further comprising a solvent. The polymerizable liquid crystal composition according to claim 1 or 2, wherein the dichroic dye is an azo dye. The polymerizable liquid crystal composition according to any one of claims 1 to 3, wherein the polymerizable group possessed by the polymerizable liquid crystal compound is an acryloyloxy group. The polymerizable liquid crystal composition according to any one of claims 1 to 4, comprising 0.1 to 15 parts by mass of an antioxidant based on 100 parts by mass of the polymerizable liquid crystal compound. 6. The polymerizable liquid crystal composition according to claim 1, wherein the antioxidant is at least one selected from the group consisting of phenolic compounds, alicyclic alcohol compounds, and amine compounds. The antioxidant has formulas (2), (3) and (4):

[In formulas (2) and (3), R ₁ to R ₅ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms, and in formulas (2) and (3), at least one of R ₁ to R ₅ is -OH or -NH _2. ]
The polymerizable liquid crystal composition according to any one of claims 1 to 6, having any of the structures represented by: The antioxidant has the formula (5):
A ₁ -L ₁ -(A ₂ -L ₂ ) _n -A ₃ (5)
[In the formula,
L ₁ and L ₂ are each independently a single bond or a divalent linking group,
_A1 is the formula (2), (3) or (4):

[In formulas (2) and (3), R ₁ to R ₅ are defined in the same manner as defined in claim 7]
is a group represented by
_A2 is the formula (6) or (7):

[In formulas (6) and (7), R ₆ to R ₉ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
is a group represented by
_A3 is the formula (8) or (9):

[In formulas (8) and (9), R ₁₀ to R ₁₄ are each independently -H, -OH, -NH ₂ , a branched or unbranched alkyl group having 1 to 12 carbon atoms, or It is a branched or unbranched alkoxy group having 1 to 12 carbon atoms]
is a group represented by, n is an integer from 0 to 2, and when n is 2, the two _A2s may be the same or different from each other]
The polymerizable liquid crystal composition according to claim 7, which is a compound represented by: A polarizing film that is a cured product of a polymerizable liquid crystal composition containing a dichroic dye, a polymerizable liquid crystal compound, and an antioxidant,
The polarizing film exhibits a Bragg peak in X-ray diffraction measurement,
The antioxidant has the formula (1) in relation to the polymerizable liquid crystal compound:
0.8℃ ≦ T1-T2 (1)
[In the formula, T1 is the liquid crystal that appears at the lowest temperature when the phase transition temperature is measured while heating the polymerizable liquid crystal compound to 130°C in the air and then cooling it to 23°C at a rate of 5°C/min. T2 is the phase transition temperature to phase, and T2 is a mixture consisting of 100 parts by mass of the polymerizable liquid crystal compound and 1 part by mass of the antioxidant, heated at 5 °C/min after heating to 130 °C in the atmosphere. When the phase transition temperature is measured while cooling to 23°C, it is the phase transition temperature to the liquid crystal phase that occurs at the lowest temperature side.]
A polarizing film that satisfies the following. A polarizing plate comprising the polarizing film according to claim 9 and a retardation film. The retardation film has the formula (X):
100≦Re(550)≦180 (X)
[In the formula, Re (550) represents the in-plane retardation value at a wavelength of 550 nm]
The polarizing plate according to claim 10, wherein the angle between the slow axis of the retardation film and the absorption axis of the polarizing film is substantially 45°. The retardation film has the formula (Y):
Re(450)/Re(550) < 1 (Y)
[In the formula, Re (450) and Re (550) represent in-plane retardation values at wavelengths of 450 nm and 550 nm, respectively.]
The polarizing plate according to claim 10 or 11, which satisfies the following. The polarizing plate according to any one of claims 10 to 12, wherein the retardation film is composed of a polymer in an oriented state of a polymerizable liquid crystal compound. A display device comprising the polarizing film according to claim 9 or the polarizing plate according to any one of claims 10 to 13. forming a coating film of the polymerizable liquid crystal composition according to any one of claims 1 to 8;
removing the solvent from the coating film;
Raising the temperature to a temperature at which the polymerizable liquid crystal compound undergoes a phase transition to a liquid phase or higher and then lowering the temperature to cause the polymerizable liquid crystal compound to undergo a phase transition to a smectic phase;
A method for producing a polarizing film, comprising polymerizing a polymerizable liquid crystal compound while maintaining the smectic phase.