JP2008239569A - Polymerizable compound - Google Patents

Abstract

で表される重合性液晶化合物（例えば４−[４−[６−（アクリロイルオキシ）ヘキシルオキシ]ベンゾイルオキシ]−３−メトキシ安息香酸２−[４ー[４−[６−（アクリロイルオキシ）ヘキシルオキシ]ベンゾイルオキシ]フェニル]エチル）を提供する。本願発明の重合性液晶化合物は、機械強度が強く、他の液晶化合物との優れた溶解性を有することから液晶組成物の構成部材として有用である。また、本願発明の重合性液晶化合物を構成部材とする重合性液晶組成物は、強い機械強度と優れた光学特性を有する光学異方体を作製することが可能であり、偏向板、位相差板等の用途に有用である。
【選択図】なしA polymerizable liquid crystal compound having high mechanical strength and excellent solubility with other liquid crystal compounds is provided.
SOLUTION: General formula (I)

A polymerizable liquid crystal compound represented by the formula (for example, 4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] -3-methoxybenzoic acid 2- [4- [4- [6- (acryloyloxy) hexyl] Oxy] benzoyloxy] phenyl] ethyl). The polymerizable liquid crystal compound of the present invention is useful as a constituent member of a liquid crystal composition because it has high mechanical strength and excellent solubility with other liquid crystal compounds. Moreover, the polymerizable liquid crystal composition comprising the polymerizable liquid crystal compound of the present invention as a constituent member can produce an optical anisotropic body having strong mechanical strength and excellent optical properties, and includes a deflection plate and a retardation plate. It is useful for such applications.
[Selection figure] None

Description

  The present invention relates to a polymerizable liquid crystal compound, a polymerizable composition containing the compound, and an optical anisotropic body using the polymerizable composition.

  In recent years, with the progress of the information society, the importance of optical compensation films used for deflecting plates, retardation plates and the like essential for liquid crystal displays has been increasing. In addition, there has been reported an example in which a polymerizable liquid crystal composition is polymerized in an optical compensation film that is highly durable and requires high functionality. Since the optical anisotropic body used for the optical compensation film or the like varies depending on the purpose, a compound having characteristics suitable for the purpose is required. In addition to the optical properties, the polymerization rate, solubility, melting point, glass transition point, transparency of the polymer, mechanical strength of the polymer, etc. are important factors.

  As a compound constituting the polymerizable liquid crystal composition, conventionally, a compound having a structure in which 1,4-phenylene groups are linked by an ester bond (see Patent Document 1) and a compound having a fluorene group (see Patent Document 2) have been proposed. Has been. However, the polymerizable liquid crystal compound described in the cited document has problems such as low solubility. On the other hand, a polymerizable liquid crystal compound having an asymmetric structure in order to improve the solubility is disclosed (see Patent Document 3), and the solubility is improved as compared with the conventional polymerizable liquid crystal compound. However, there were problems such as insufficient mechanical strength and low mechanical strength.

Japanese National Patent Publication No. 10-513457 JP 2005-60373 A JP 2001-527570 A

  The problem to be solved by the present invention is to provide a polymerizable liquid crystal compound having high mechanical strength and excellent solubility with other liquid crystal compounds.

As a result of studying various substituents in the polymerizable compound, the present inventors have found that a polymerizable compound having a specific structure can solve the above-mentioned problems, and have completed the present invention.
The present invention relates to the general formula (I)

(Wherein R ¹ and R ² are each independently a polymerizable group represented by the following structural formula group:

S ¹ and S ² each independently represents an alkylene group, a substituted alkylene group or a single bond, and the alkylene group is not bonded directly to each other, and the carbon atom is replaced with an oxygen atom. L ¹ , L ² , L ³ , L ⁴ and L ⁵ may be independently of each other -O-, -S-, -OCH _2- , -CH ₂ O-, -CO-, -COO -, - OCO -, - OCOOCH 2 -, - CH 2 OCOO -, - CONR 3 -, - NR 3 CO -, - SCH 2 -, - CH 2 S -, - CH = CHCOO -, - OCOCH = CH- _{, -COOCH 2 CH 2 -, -} CH 2 CH 2 OCO -, - OCOCH 2 CH 2 -, - CH 2 CH 2 COO -, - COOCH 2 -, - CH 2 OCO -, - OCOCH 2 -, - CH 2 _{COO -, - OCOOCH 2 CH 2} -, - CH 2 CH 2 OCOO -, - OCOOCH 2 -, - CH 2 OCOO -, - CH 2 OCOCH 2 -, - CH 2 COOCH 2 -, - CH 2 CH 2 -, —CH═CH—, —CF═CH—, —CH═CF or —C≡C— (wherein R ³ represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom), L ² , L ³ and L ⁴ are at least one of -COOCH ₂ CH _2- , -CH ₂ CH ₂ OCO-, -O COCH ₂ CH ₂ -or -CH ₂ CH ₂ COO- represents, M ¹ and M ² are each independently 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, Pyrimidine-2,5-diyl group, naphthalene-2,6-diyl group, tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5-diyl group, but the carbon atom in the group is Independently of each other, they may be unsubstituted or substituted by alkyl groups, halogenated alkyl groups, alkoxy groups, halogen groups, cyano groups or nitro groups, and X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ each independently represent a hydrogen atom, an alkyl group, a halogenated alkyl group, an alkoxy group, a halogen group, a cyano group or a nitro group, but X ¹ , X ² , ^{X 3, X 4, X 5} , X 6, at least one alkyl group of X ⁷ and X ^8, the halogenated alkyl group, an alkoxy group A halogen group, a cyano group or a nitro group. And a polymerizable liquid crystal composition using the compound.

  The polymerizable liquid crystal compound of the present invention is useful as a constituent member of a liquid crystal composition because it has excellent solubility with other liquid crystal compounds. Therefore, the polymerizable liquid crystal compound of the present invention and the optically anisotropic body of the polymerizable liquid crystal composition comprising the compound as a constituent member are useful for applications such as a deflection plate and a retardation plate.

In the general formula (I), R ¹ and R ² are polymerizable groups and are cured by radical polymerization, radical addition polymerization, cationic polymerization, and anionic polymerization. In particular, when performing ultraviolet polymerization as a polymerization method, the formula (R-1), formula (R-2), formula (R-4), formula (R-5), formula (R-7), formula (R -11), formula (R-13) or formula (R-15) is preferred, formula (R-1), formula (R-2), formula (R-7), formula (R-11) or formula ( R-13) is more preferred, and formula (R-1) or formula (R-2) is particularly preferred.

S ¹ and S ² each independently represent an alkylene group, a substituted alkylene group or a single bond, but the carbon atom may be replaced with an oxygen atom as the oxygen atoms in the group are not directly bonded to each other. An alkylene group having 10 carbon atoms is preferred, and an alkylene group having 3 to 8 carbon atoms is more preferred from the viewpoint of liquid crystallinity and compatibility with other liquid crystal compounds.

L ¹ , L ² , L ³ , L ⁴ and L ⁵ are independently of each other -O-, -S-, -OCH _2- , -CH ₂ O-, -CO-, -COO-, -OCO-, _{-OCOOCH 2 -, - CH 2 OCOO} -, - CONR 3 -, - NR 3 CO -, - SCH 2 -, - CH 2 S -, - CH = CHCOO -, - OCOCH = CH -, - COOCH 2 CH 2 _{-, - CH 2 CH 2 OCO} -, - OCOCH 2 CH 2 -, - CH 2 CH 2 COO -, - COOCH 2 -, - CH 2 OCO -, - OCOCH 2 -, - CH 2 COO -, - OCOOCH 2 _{CH 2 -, - CH 2 CH} 2 OCOO -, - OCOOCH 2 -, - CH 2 OCOO -, - CH 2 OCOCH 2 -, - CH 2 COOCH 2 -, - CH 2 CH 2 -, - CH = CH-, -CF = CH-, -CH = CF or -C≡C- (wherein R ³ represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom), L ² , L ³ and L ⁴ At least one of them represents -COOCH ₂ CH _2- , -CH ₂ CH ₂ OCO-, -OCOCH ₂ CH ₂ -or -CH ₂ CH ₂ COO-, but L ³ represents -COOCH ₂ CH _2- , -CH ₂ CH ₂ OCO-, -OCOCH ₂ CH ₂ -or -CH ₂ CH ₂ COO- are preferred, and L ¹ , L ² , L ⁴ and L ⁵ are independently of each other -O-, -S-,- _{OCH 2 -, - CH 2 O} -, - CO -, - COO -, - OCO -, - this representing a CH = CHCOO- or -OCOCH = CH- It is preferred.
M ¹ and M ² are preferably each independently 1,4-phenylene group or 1,4-cyclohexylene group.

X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent a hydrogen atom, an alkyl group, a halogenated alkyl group, an alkoxy group, a halogen group, a cyano group or a nitro group. , X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ are at least one alkyl group, halogenated alkyl group, alkoxy group, halogen group, cyano group or nitro group X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ are any one of methyl group, ethyl group, methoxy group, fluorine atom, chlorine atom or cyano group More preferably, it is a methoxy group or a fluorine atom.
Specifically, the compounds represented by the general formula (I) are particularly preferably compounds represented by the following general formulas (I-1) to (I-24).

  In the present invention, production examples of the compound represented by the general formula (I) will be given below. Of course, the gist and scope of the present invention are not limited by these production examples.

The compound (I) of the present invention can be produced, for example, as follows.
Formula (II)

(Wherein R ¹ , S ¹ , L ¹ , L ² , M ¹ , X ¹ , X ² , X ³ and X ⁴ represent the same meaning as in general formula (I)). The derivative may be an acid catalyst such as p-toluenesulfonic acid or a carbodiimide derivative such as dicyclohexylcarbodiimide (DCC), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (WSC), diisopropylcarbodiimide (DIC), or azodiene. In the presence of a dehydrating condensing agent such as azodicarboxylic acid esters such as ethyl dicarboxylate (DEAD) and isopropyl azodicarboxylate (DIAD),

(Wherein R ² , S ² , L ⁴ , L ⁵ , M ² , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)). By acting with a derivative, the general formula (Ia)

(Where R ¹ , R ² , S ¹ , S ² , L ¹ , L ² , L ⁴ , L ⁵ , M ¹ , M ² , X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)).
Alternatively, the general formula (IV)

(Wherein R ¹ , S ¹ , L ¹ , L ² , M ¹ , X ¹ , X ² , X ³ and X ⁴ represent the same meaning as in general formula (I)). The acid derivative may be an acid catalyst such as p-toluenesulfonic acid or a carbodiimide derivative such as dicyclohexylcarbodiimide (DCC), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (WSC), diisopropylcarbodiimide (DIC) or the like. In the presence of a dehydration condensing agent such as azodicarboxylate such as ethyl azodicarboxylate (DEAD) or isopropyl azodicarboxylate (DIAD), general formula (V)

(Where R ¹ , R ² , S ¹ , S ² , L ¹ , L ² , L ⁴ , L ⁵ , M ¹ , M ² , X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I).) By reacting with a phenol derivative represented by general formula (Ib)

(Where R ¹ , R ² , S ¹ , S ² , L ¹ , L ² , L ⁴ , L ⁵ , M ¹ , M ² , X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)).
Or the general formula (VI)

(Wherein, X ¹ , X ² , X ³ and X ⁴ represent the same meaning as in general formula (I)), and 4-hydroxybenzoic acid represented by acid catalyst such as p-toluenesulfonic acid is present. Below, general formula (VII)

(Wherein, X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)), and 4-hydroxyphenethyl alcohol represented by acid catalyst such as p-toluenesulfonic acid is present. Under dehydration condensation, general formula (VIII)

(Wherein, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)). To this, the general formula (IX)

(式中、R¹、S¹、L¹、およびM¹は一般式(I)におけると同じ意味を表す。)で表されるカルボン酸誘導体を、p-トルエンスルホン酸などの酸触媒あるいはジシクロヘキシルカルボジイミド(DCC)、1-エチル-3-(3-ジメチルアミノプロピル)カルボジイミド塩酸塩(WSC)、ジイソプロピルカルボジイミド(DIC)などのカルボジイミド誘導体またはアゾジカルボン酸エチル(DEAD)、アゾジカルボン酸イソプロピル(DIAD)などのアゾジカルボン酸エステルなどの脱水縮合剤存在下、作用させることにより、一般式(I-c)

(Wherein R ¹ , S ¹ , L ¹ , and M ¹ have the same meaning as in general formula (I)), a carboxylic acid derivative represented by an acid catalyst such as p-toluenesulfonic acid or dicyclohexyl Carbodiimide derivatives such as carbodiimide (DCC), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (WSC), diisopropylcarbodiimide (DIC) or ethyl azodicarboxylate (DEAD), isopropyl azodicarboxylate (DIAD) By reacting in the presence of a dehydration condensing agent such as azodicarboxylic acid ester such as general formula (Ic)

(Wherein R ¹ , S ¹ , S ² , L ¹ , M ¹ , X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ are as in general formula (I) A polymerizable liquid crystal compound represented by the same meaning can also be obtained.
Or the general formula (X)

(Wherein Z ¹ represents a protecting group such as a benzyl group, and X ¹ , X ² , X ³ and X ⁴ have the same meaning as in general formula (I)). In the presence of an acid catalyst such as p-toluenesulfonic acid.

(Wherein Z ² represents a protecting group such as a benzyl group, and X ⁵ , X ⁶ , X ⁷ and X ⁸ have the same meaning as in the general formula (I)). Is subjected to dehydration condensation in the presence of an acid catalyst such as p-toluenesulfonic acid to give a compound of the general formula (XII)

(Wherein Z ¹ represents the same meaning as in general formula (X), Z ² represents the same meaning as in general formula (XI), and X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent the same meaning as in general formula (I)). By deprotecting this, a compound represented by the general formula (VIII) can also be obtained.

  Next, the polymerizable liquid crystal composition of the present invention will be described. The polymerizable liquid crystal composition of the present invention is preferably prepared so as to exhibit a smectic A phase or a nematic phase at room temperature. Specifically, it is preferable that the smectic A phase or the nematic phase is maintained even at 35 ° C. or lower, preferably 30 ° C. or lower, more preferably 25 ° C. or lower. The polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition of the present invention preferably has an acryloyloxy group or a methacryloyloxy group as a polymerizable functional group. As the polymerizable liquid crystal compound, those having two or more polymerizable functional groups in the molecule are preferable. As such a bifunctional or higher compound, the general formula (A)

(W ¹ and W ² each independently represent a single bond, -O-, -COO- or -OCO-, and Y ³ and Y ⁴ each independently represent -COO- or -OCO-. , R and s each independently represents an integer of 2 to 18, and the hydrogen atoms of the three 1,4-phenylene groups present in the formula are each independently an alkyl group having 1 to 7 carbon atoms, An alkoxy group, an alkanoyl group, a cyano group, or a halogen atom may be substituted by one or two or more). Among the compounds represented by the general formula (A), compounds represented by (A-1) to (A-8) are particularly preferable.

(Wherein, r and s have the same meaning as in general formula (A).)
r and s are each independently preferably an integer of 3 to 6.
In addition, the general formula (B)

(W ³ and W ⁴ are each independently a single bond, —O—, —COO— or —OCO—, Y ⁵ is —COO— or —OCO—, and p and q are each independently Each of the three kinds of 1,4-phenylene groups present in the formula is independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group, an alkanoyl group, or a cyano group. Alternatively, one or two or more halogen atoms may be substituted.) Is also preferred. Among the compounds represented by the general formula (B), compounds represented by (B-1) to (B-8) are particularly preferable.

(Wherein p and q represent the same meaning as in general formula (B).)
Among such compounds, from the viewpoint of heat resistance and durability, the compound of (B-2), (B-5), (B-6), (B-9) or (B-10) is preferred, The compound B-2) is particularly preferred.
In addition, compounds such as compounds (C-1) to (C-10) can be contained as the polymerizable liquid crystal compound having two or more polymerizable functional groups in the molecule.

(In the formula, u and v independently represent an integer of 2 to 18.)
Of these, the compounds (C-2) and (C-3) are preferred. u and v are preferably an integer of 3 to 18, more preferably an integer of 4 to 16, and particularly preferably 6 to 12.
In addition, the general formula (D)

(In the formula, e represents an integer of 0 to 18, but when e is 0 or 1, f represents 0, or when e represents an integer of 2 to 18, f represents 0 or 1, i represents Represents an integer of 0 to 2, and each of rings C, D and E independently represents 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, tetrahydropyran-2,5- Diyl group, 1,3-dioxane-2,5-diyl group, tetrahydrothiopyran-2,5-diyl group, 1,4-bicyclo [2.2.2] octylene group, decahydronaphthalene-2,6-diyl group Pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6- Naphthylene group, phenanthrene-2,7-diyl group, 9,10-dihydrophenanthrene-2,7-diyl group, 1,2,3,4,4a, 9,10a-octahydrophenanthrene 2,7-diyl group, Represents a fluorene 2,7-diyl group, the 1,4-phenylene group, Trahydronaphthalene-2,6-diyl group, 2,6-naphthylene group, phenanthrene-2,7-diyl group, 9,10-dihydrophenanthrene-2,7-diyl group, 1,2,3,4,4a , 9,10a-Octahydrophenanthrene 2,7-diyl group and fluorene 2,7-diyl group are unsubstituted or substituted as one or more F, Cl, CF ₃ , OCF ₃ or CH ₃ and Y ⁶ and Y ⁷ are each independently a single bond, —COO—, —OCO—, —CH═N—, —N═CH—, —C≡C—, —CH ₂ CH _2- , -CH ₂ CH ₂ CH ₂ CH _2- , -CH ₂ CH ₂ CH ₂ O-, -OCH ₂ CH ₂ CH _2- , -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- , -CH = NN = CH-, -CF = CF-, -CH = CH-, -CH ₂ CH ₂ CH = CH-, -CH = CHCH ₂ CH _2- , -CH ₂ CH = CHCH _2- , -CH = CHCOO-, -OCOCH = CH-, -CH ₂ CH ₂ OCO- or -COOCH ₂ CH _2- , Y ⁸ represents a single bond, -O-, -CO-, -COO-, _{-OCO -, - CH 2 -,} - CH 2 O -, - OCH 2 -, - CONH -, - NHCO -, - CH 2 COO- or an -CH ₂ OCO-, Z 1 to 18 carbon atoms An alkyl group of Represents an alkenyl group having 2 to 18 carbon atoms, a halogen atom, CN or NCS, wherein the alkyl group or alkenyl group is unsubstituted or substituted with one or more F, Cl, CN, CH ₃ Or CF ₃ , wherein one or more CH ₂ groups present in the alkyl or alkenyl group are substituted with O, CO or COO as O atoms are not directly bonded to each other May be. It is also possible to add a monofunctional polymerizable liquid crystal compound represented by The addition amount is preferably 50% or less, more preferably 30% or less, and particularly preferably 15% or less. Among the compounds represented by the general formula (D), compounds represented by (D-1) to (D-11) are particularly preferable.

(Wherein e and f represent the same meaning as in general formula (D), and R represents an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms.)
Furthermore, the polymerizable liquid crystal composition of the present invention may be added with a compound having a polymerizable functional group and not exhibiting liquid crystallinity. Such a compound can be used without particular limitation as long as it is generally recognized as a polymer-forming monomer or polymer-forming oligomer in this technical field. It is necessary to adjust to exhibit sex.

  The concentration of the photopolymerization initiator in the polymerizable liquid crystal composition of the present invention is preferably 0.1 to 10%, more preferably 0.2 to 5%. Examples of the photopolymerization initiator include benzoin ethers, benzophenones, acetophenones, benzyl ketals, and acylphosphine oxides.

  In addition, a stabilizer can be added to the polymerizable liquid crystal composition of the present invention in order to improve its storage stability. Examples of the stabilizer that can be used include hydroquinone, hydroquinone monoalkyl ethers, tert-butylcatechols, pyrogallols, thiophenols, nitro compounds, β-naphthylamines, β-naphthols, nitroso compounds, and the like. . When the stabilizer is used, the addition amount is preferably 0.005 to 1%, more preferably 0.02 to 0.5% with respect to the liquid crystal composition.

  In addition, when the polymerizable liquid crystal composition of the present invention is used for a raw material of a polarizing film or an alignment film, a printing ink, a paint, a protective film or the like, a metal, a metal complex, a dye, or a pigment depending on the purpose. , Dyes, fluorescent materials, phosphorescent materials, surfactants, leveling agents, thixotropic agents, gelling agents, polysaccharides, ultraviolet absorbers, infrared absorbers, antioxidants, ion exchange resins, metal oxides such as titanium oxide, etc. Can also be added.

Next, the optical anisotropic body of the present invention will be described. The optical anisotropic body produced by polymerizing the polymerizable liquid crystal composition of the present invention can be used for various applications. For example, when the polymerizable liquid crystal composition of the present invention is polymerized without being oriented, it can be used as a light scattering plate, a depolarizing plate, or a moire fringe prevention plate. Moreover, the optically anisotropic body produced by polymerizing the polymerizable liquid crystal composition of the present invention in an aligned state has optical anisotropy in physical properties and is useful. Such an optical anisotropic element, for example, a substrate a polymerizable liquid crystal composition surface, substrate was rubbed with a cloth or the like, or the formed surface of the substrate and the organic thin film was rubbed with a cloth or the like of the present invention or SiO _2, Can be produced by polymerizing the liquid crystal of the present invention after it is supported on a substrate having an orientation film deposited obliquely or sandwiched between the substrates.

  Examples of the method for supporting the polymerizable liquid crystal composition on the substrate include spin coating, die coating, extrusion coating, roll coating, wire bar coating, gravure coating, spray coating, dipping, and printing. . Further, an organic solvent may be added to the polymerizable liquid crystal composition during coating. Examples of the organic solvent include ethyl acetate, tetrahydrofuran, toluene, hexane, methanol, ethanol, dimethylformamide, methylene chloride, isopropanol, acetone, methyl ethyl ketone, acetonitrile, and cellosolves. These may be used alone or in combination, and may be appropriately selected in consideration of the vapor pressure and the solubility of the polymerizable liquid crystal composition. As a method for volatilizing the added organic solvent, natural drying, heat drying, reduced pressure drying, or reduced pressure heat drying can be used. In order to further improve the applicability of the polymerizable liquid crystal material, it is also effective to provide an intermediate layer such as a polyimide thin film on the substrate or to add a leveling agent to the polymerizable liquid crystal material. Providing an intermediate layer such as a polyimide thin film on the substrate is also effective as a means for improving the adhesion when the adhesion between the optically anisotropic substance obtained by polymerizing the polymerizable liquid crystal material and the substrate is not good. .

Examples of the orientation treatment other than the rubbing treatment or the oblique deposition of SiO ₂ include the use of fluid orientation of a liquid crystal material and the use of an electric field or a magnetic field. These orientation means may be used alone or in combination. Furthermore, a photo-alignment method can be used as an alignment treatment method instead of rubbing. As a shape of the substrate, in addition to a flat plate, a curved surface may be included as a constituent part. The material which comprises a board | substrate can be used regardless of an organic material and an inorganic material. Examples of the organic material used as the substrate material include polyethylene terephthalate, polycarbonate, polyimide, polyamide, polymethyl methacrylate, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyarylate, polysulfone, and triacetyl. Cellulose, cellulose, polyetheretherketone and the like can be mentioned, and examples of the inorganic material include silicon, glass and calcite.

  If proper orientation cannot be obtained by rubbing these substrates with a cloth or the like, an organic thin film such as a polyimide thin film or a polyvinyl alcohol thin film is formed on the substrate surface according to a known method, and this is rubbed with a cloth or the like. Also good. In the case where the alignment state is controlled by an electric field, a substrate having an electrode layer is used. In this case, it is preferable to form an organic thin film such as the aforementioned polyimide thin film on the electrode.

As a method of polymerizing the polymerizable liquid crystal composition of the present invention, since rapid progress of polymerization is desirable, a method of polymerizing by irradiating active energy rays such as ultraviolet rays or electron beams is preferable. When ultraviolet rays are used, a polarized light source or a non-polarized light source may be used. In addition, when polymerization is performed with the liquid crystal composition sandwiched between two substrates, at least the substrate on the irradiation surface side must be given appropriate transparency to the active energy rays. Moreover, after polymerizing only a specific part using a mask at the time of light irradiation, the orientation state of the unpolymerized part is changed by changing conditions such as an electric field, a magnetic field, or temperature, and further irradiation with active energy rays is performed. Then, it is possible to use a means for polymerization. Moreover, it is preferable that the temperature at the time of irradiation exists in the temperature range by which the liquid crystal state of the polymeric liquid crystal composition of this invention is hold | maintained. In particular, when an optical anisotropic body is to be produced by photopolymerization, the polymerization is carried out at a temperature as close to room temperature as possible from the viewpoint of avoiding unintentional induction of thermal polymerization, that is, typically at a temperature of 25 ° C. It is preferable to make it. The intensity of the active energy ray is preferably 0.1 to 2.0 mW / cm ² . If the intensity is 0.1 mW / cm ² or less, it takes a long time to complete the photopolymerization and the productivity deteriorates. If it is 2.0 W / cm ² or more, the polymerizable liquid crystal compound or the polymerizable liquid crystal There is a risk that the composition will deteriorate.

  The optical anisotropic body of the present invention obtained by polymerization can be subjected to heat treatment for the purpose of reducing initial characteristic changes and achieving stable characteristic expression. The heat treatment temperature is preferably in the range of 50 to 250 ° C., and the heat treatment time is preferably in the range of 30 seconds to 12 hours.

  The optical anisotropic body of the present invention produced by such a method may be peeled off from the substrate and used alone or without peeling. Further, the obtained optical anisotropic bodies may be laminated or bonded to another substrate for use.

  EXAMPLES Hereinafter, although an Example is given and this invention is further explained in full detail, this invention is not limited to these Examples.

The phase transition temperature was measured using a polarizing microscope equipped with a temperature control stage and a differential scanning calorimeter (DSC). The structure of the compound was confirmed by nuclear magnetic resonance spectrum (NMR), infrared resonance spectrum (IR), gel permeation chromatography (GPC) and the like.
Example 1 4- [4- [3- (acryloyloxy) propyloxy] benzoyloxy] -3-methoxybenzoic acid 2- [4- [4- [3- (acryloyloxy) propyloxy] benzoyloxy] Synthesis of phenyl] ethyl (I-7)

(1-1) Synthesis of methyl 4-hydroxy-3-methoxybenzoate
Concentrated sulfuric acid (2.0 ml) was added to a suspension of 4-hydroxy-3-methoxybenzoic acid (50.7 g, 0.302 mol) in methanol (250 ml) while stirring vigorously, and the mixture was heated to reflux for 5 hours. . The reaction was quenched with 5% aqueous sodium hydrogen carbonate solution and extracted with ethyl acetate. The organic layer was collected, washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was distilled off to obtain a pale yellow solid (49.5 g). (Yield 90.1%)

(1-2) Synthesis of methyl 4-benzyloxy-3-methoxybenzoate
While stirring a suspension of methyl 4-hydroxy-3-methoxybenzoate (49.5 g, 0.272 mol) and anhydrous potassium carbonate (56.4 g, 0.408 mol) in 2-butanone (250 ml), benzyl chloride (33.0 ml, 0.287 mol) was added, followed by heating to reflux for 70 hours. The reaction was quenched with 3 M hydrochloric acid and extracted with ethyl acetate. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting yellow solid was recrystallized (methanol) to obtain colorless needle crystals (64.4 g). (Yield 87.1%)

(1-3) Synthesis of 4-benzyloxy-3-methoxybenzoic acid
While stirring a solution of methyl 4-benzyloxy-3-methoxybenzoate (64.4 g, 0.237 mol) in methanol (260 ml), 20% aqueous sodium hydroxide solution (100 ml, 0.475 mol) was added. Thereafter, the mixture was heated to reflux for 6 hours. The reaction was quenched with 3 M hydrochloric acid and extracted with ethyl acetate. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting pale yellow solid was recrystallized (hexane + ethyl acetate) to obtain colorless flake-like crystals (58.3 g). (Yield 95.4%)

(1-4) Synthesis of 2- (4-benzyloxyphenyl) ethanol
While stirring a suspension of 2- (4-hydroxyphenyl) ethanol (50.0 g, 0.362 mol) and anhydrous potassium carbonate (75.0 g, 0.543 mol) in acetone (250 ml) vigorously, benzyl chloride (44.0 ml , 0.382 mol), and then heated to reflux for 40 hours. The reaction was quenched with 3 M hydrochloric acid and extracted with ethyl acetate. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting yellow solid was recrystallized (hexane + ethyl acetate) to obtain colorless flakes (76.4 g). (Yield 92.0%)

(1-5) Synthesis of 2- (4-benzyloxyphenyl) ethyl 4-benzyloxy-3-methoxybenzoate
4-Benzyloxy-3-methoxybenzoic acid (15.0 g, 0.058 mol), 2- (4-benzyloxyphenyl) ethanol (13.2 g, 0.058 mol), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide A suspension of hydrochloride (WSC, 16.7 g, 0.087 mol) and 4-dimethylaminopyridine (DMAP, 10.7 g, 0.088 mol) in dichloromethane (150 ml) was vigorously stirred at room temperature for 24 hours, and then poured into 3 M hydrochloric acid. The reaction was stopped. The organic layer was separated and extracted from the aqueous layer with dichloromethane. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained solid was purified using a column (silica gel / hexane + ethyl acetate) to obtain a white solid (27.2 g). (Yield quantitative)

(1-6) Synthesis of 2- (4-hydroxyphenyl) ethyl 4-hydroxy-3-methoxybenzoate
4-Benzyloxy-3-methoxybenzoate 2- (4-benzyloxyphenyl) ethyl (27.2 g, 0.058 mol), 5% palladium carbon (50% water-containing product, 6.0 g) in tetrahydrofuran / ethanol mixed solution (100 ml / 50 ml) was vigorously stirred under hydrogen pressure (0.5 MPa) at room temperature for 24 hours. After the catalyst was filtered off, the solvent was distilled off, and the resulting solid was purified using a column (silica gel / hexane + ethyl acetate) to obtain a pale yellow viscous liquid (16.5 g). (Yield 91.9%)

(1-7) 4- [4- [3- (acryloyloxy) propyloxy] benzoyloxy] -3-methoxybenzoic acid 2- [4- [4- [3- (acryloyloxy) propyloxy] benzoyloxy] Synthesis of phenyl] ethyl (I-7)
4- [3- (acryloyloxy) propyloxy] benzoic acid (26.6 g, 0.106 mol), 2- (4-hydroxyphenyl) ethyl 4-hydroxy-3-methoxybenzoate (16.5 g, 0.053 mol), N, A suspension of N'-diisopropylcarbodiimide (DIC, 16.0 g, 0.127 mol) and 4-dimethylaminopyridine (DMAP, 15.6 g, 0.128 mol) in dichloromethane (400 ml) was vigorously stirred at room temperature for 16 hours, and then poured into water. The reaction was terminated after emptying. The organic layer was separated and extracted from the aqueous layer with dichloromethane. The organic layer was collected, washed with 3M hydrochloric acid, water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained solid was purified using a column (silica gel / ethyl acetate + dichloromethane) to obtain a white solid (5.8 g). (Yield 14.5%)
¹ H-NMR (400MHz, CDCl ₃ ) δ (ppm) 2.22 (pent, 4H), 3.11 (t, 2H), 3.86 (s, 3H), 4.16 (t, 4H), 4.39 (t, 4H), 4.56 (t, 2H), 5.85 (dd, 2H, J ₁ = 10.4Hz, J ₂ = 1.6Hz), 6.14 (dd, 2H, J ₁ = 17.6Hz, J ₂ = 10.4Hz), 6.43 (dd, 2H, J ₁ = 17.6Hz, J ₂ = 1.6Hz), 6.98 (dd, 4H, J ₁ = 8.8Hz, J ₂ = 2.4Hz), 7.16 (d, 2H, J = 8.4Hz), 7.21 (d, 1H, J = 8.4Hz), 7.34 (d, 2H, J = 8.4Hz), 7.65 (d, 1H, J = 2.0Hz), 7.69 (dd, 1H, J ₁ = 8.4Hz, J ₂ = 2.0Hz), 8.15 (dd, 4H, J ₁ = 9.6Hz, J ₂ = 5.2Hz), phase transition temperature (° C) Cr 84 N 104 Iso

Example 2 4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] -3-methoxybenzoic acid 2- [4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] Synthesis of phenyl] ethyl (I-8)

(2-1) Synthesis of 2- (4-hydroxyphenyl) ethyl 4-hydroxy-3-methoxybenzoate
4-hydroxy-3-methoxybenzoic acid (25.0 g, 0.149 mol), 2- (4-hydroxyphenyl) ethanol (20.5 g, 0.148 mol), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (WSC, 42.7 g, 0.223 mol), 4-dimethylaminopyridine (DMAP, 27.3 g, 0.223 mol) suspension in dichloromethane (200 ml) was vigorously stirred at room temperature for 4 hours, then reacted with 3 M hydrochloric acid. Was stopped. The organic layer was separated and extracted from the aqueous layer with dichloromethane. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting solid was purified using a column (silica gel / hexane + ethyl acetate) to obtain a pale yellow solid (2.9 g). (Yield 6.8%)

(2-2) 4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] -3-methoxybenzoic acid 2- [4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] Synthesis of phenyl] ethyl (I-8)
4- [6- (Acryloyloxy) hexyloxy] benzoic acid (5.8 g, 0.020 mol), 2- (4-hydroxyphenyl) ethyl 4-hydroxy-3-methoxybenzoate (2.8 g, 0.010 mol), N, A suspension of N'-diisopropylcarbodiimide (DIC, 3.0 g, 0.024 mol) and 4-dimethylaminopyridine (DMAP, 2.9 g, 0.024 mol) in 1,2-dichloroethane (100 ml) was stirred vigorously at 40 ° C for 16 hours. Then, the reaction was terminated by emptying with 3 M hydrochloric acid. The organic layer was separated and extracted from the aqueous layer with dichloromethane. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained solid was purified using a column (silica gel / ethyl acetate + dichloromethane) to obtain a white solid (3.0 g). (Yield 36.7%)
¹ H-NMR (400MHz, CDCl ₃ ) δ (ppm) 1.47-1.54 (m, 8H), 1.73 (pent, 4H), 1.84 (pent, 4H), 3.11 (t, 2H), 3.86 (s, 3H) , 4.05 (t, 4H), 4.18 (t, 4H), 4.58 (t, 2H), 5.82 (dd, 2H, J ₁ = 10.4Hz, J ₂ = 1.2Hz), 6.13 (dd, 2H, J ₁ = 17.2Hz, J ₂ = 10.4Hz), 6.40 (dd, 2H, J ₁ = 17.2Hz, J ₂ = 1.2Hz), 6.96 (dd, 4H, J ₁ = 8.8Hz, J ₂ = 2.4Hz), 7.16 ( d, 2H, J = 8.4Hz), 7.21 (d, 1H, J = 8.4Hz), 7.34 (d, 2H, J = 8.4Hz), 7.65 (d, 1H, J = 2.0Hz), 7.68 (dd, 1H, J ₁ = 8.4Hz, J ₂ = 2.0Hz), 8.14 (dd, 4H, J ₁ = 8.4Hz, J ₂ = 4.8Hz), phase transition temperature (° C) Cr 91 N 103 Iso

Example 3 4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] -2-fluorobenzoic acid 2- [4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] Synthesis of phenyl] ethyl (I-2)

(3-1) Synthesis of 2- (4-hydroxyphenyl) ethyl 2-fluoro-4-hydroxybenzoate
2-Fluoro-4-hydroxybenzoic acid (24.5 g, 0.157 mol), 2- (4-hydroxyphenyl) ethanol (20.0 g, 0.145 mol), p-toluenesulfonic acid monohydrate (2.5 g, 0.002 mol) A 2-butanone / hexane (120 ml / 120 ml) mixed solution was heated to reflux for 24 hours, and then the reaction was stopped by emptying in water. The organic layer was separated and extracted from the aqueous layer with tetrahydrofuran. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting solid was purified using a column (silica gel / ethyl acetate + dichloromethane) to obtain a pale yellow solid (30.0 g). (Yield 75.2%)

(3-2) 4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] -2-fluorobenzoic acid 2- [4- [4- [6- (acryloyloxy) hexyloxy] benzoyloxy] Phenyl] ethyl (I-2)
4- [6- (acryloyloxy) hexyloxy] benzoic acid (10.6 g, 0.036 mol), 2- (4-hydroxyphenyl) ethyl 2-fluoro-4-hydroxybenzoate (5.0 g, 0.018 mol), N, A suspension of N'-diisopropylcarbodiimide (DIC, 5.5 g, 0.044 mol), 4-dimethylaminopyridine (DMAP, 0.5 g, 0.004 mol) in dichloromethane (100 ml) was stirred vigorously at room temperature for 6 hours, and then 3 M The reaction was terminated by emptying with hydrochloric acid. The organic layer was separated and extracted from the aqueous layer with dichloromethane. The organic layer was collected, washed with water, 5% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting solid was purified using a column (silica gel / ethyl acetate + dichloromethane) and further recrystallized (dichloromethane + methanol) to obtain a white solid (10.0 g). (Yield 66.9%)
¹ H-NMR (400MHz, CDCl ₃ ) δ (ppm) 1.46-1.54 (m, 8H), 1.73 (pent, 4H), 1.85 (pent, 4H), 3.11 (t, 2H), 4.05 (dt, 4H, J = 3.6Hz), 4.17 (t, 4H), 4.56 (t, 2H), 5.82 (dd, 2H, J ₁ = 10.4Hz, J ₂ = 1.2Hz), 6.13 (dd, 2H, J ₁ = 17.2Hz _{, J 2 = 10.4Hz), 6.40} (dd, 2H, J 1 = 17.2Hz, J 2 = 1.2Hz), 6.97 (dd, 4H, J 1 = 8.8Hz, J 2 = 5.6Hz), 7.08 (d, 2H, J = 2.8Hz), 7.11 (s, 2H), 7.16 (d, 2H, J = 8.4Hz), 7.34 (d, 2H, J = 8.4Hz), 7.98 (t, 1H, J = 8.4Hz) , 8.13 (dd, 4H, J ₁ = 8.8Hz, J ₂ = 6.8Hz), phase transition temperature (° C) Cr 89 N 149 Iso
Example 4
Polymeric liquid crystal composition showing a nematic phase with low viscosity and wide temperature range (M-1)

The nematic phase upper limit temperature (Tni) was 73.0 ° C.
Next, 90% of this polymerizable liquid crystal composition (M-1) compound (I-7) obtained in Example 1

When a polymerizable liquid crystal composition (H-1) was prepared by adding 10% of the above compound, it exhibited a nematic phase at room temperature and Tni was 82.0 ° C. When this composition (H-1) was allowed to stand overnight at room temperature, no precipitation was observed, and its Tni was measured, but hardly changed.
(Example 5)
90% of the polymerizable liquid crystal composition (M-1) obtained in Example 4 and the compound (I-8) obtained in Example 2

When a polymerizable liquid crystal composition (H-2) was prepared by adding 10% of the above compound, it exhibited a nematic phase at room temperature, and Tni was 81.0 ° C. When this composition (H-2) was allowed to stand overnight at room temperature, no precipitation was observed, and its Tni was measured, but hardly changed.
(Example 6)
90% of the polymerizable liquid crystal composition (M-1) obtained in Example 4 and the compound (I-2) obtained in Example 3

A polymerizable liquid crystal composition (H-3) was prepared by adding 20% of the above compound. As a result, a nematic phase was exhibited at room temperature, and Tni was 94.4 ° C. When this composition (H-3) was allowed to stand at room temperature overnight, no precipitation was observed, and its Tni was measured, but hardly changed.
(Comparative Example 1)
Compound (J-1) similar to Compound (I-1) in 90% of the polymerizable liquid crystal composition (M-1) obtained in Example 4

When a polymerizable liquid crystal composition (H-4) was prepared by adding 10% of the above compound, precipitation was observed at room temperature, and Tni was 84.0 ° C.
(Comparative Example 2)
Compound (I-2) and (I-3) similar compound (J-2) to 90% of the polymerizable liquid crystal composition (M-1) obtained in Example 4

When a polymerizable liquid crystal composition (H-5) was prepared by adding 10% of the above compound, it exhibited a nematic phase at room temperature, and Tni was 86.5 ° C. When this composition (H-5) was allowed to stand at room temperature for 30 minutes, precipitation was observed.
As described above, the compound represented by the general formula (I) has good solubility in the polymerizable liquid crystal composition, is stable at room temperature, and is very useful in preparing a liquid crystal composition having a high Tni. I understand.

(Example 7)
Photopolymerization initiator Irgacure-907 (manufactured by Ciba Specialty Chemicals) 3.0% was added to the polymerizable liquid crystal composition (H-1) obtained in Example 4 to prepare a polymerizable liquid crystal composition (H-6). did. Next, a 2- (1-methoxy) propyl acetate solution (PGMEA solution) containing 20% of this polymerizable liquid crystal composition (H-2) was prepared, and this PGMEA solution was spin coated on a glass substrate with a polyimide alignment film ( 3,000 rpm / 30 seconds). The polymerizable liquid crystal composition (H-6) was cured by irradiating the spin-coated substrate with ultraviolet rays (4 mW / cm ² , 120 seconds) in a nitrogen atmosphere. When the solid thus obtained was observed under a polarizing microscope, an optical anisotropic body free from alignment defects and cissing was obtained. Assuming that the phase difference before heating of the obtained optical anisotropic body was 100%, the phase difference after heating at 240 ° C. for 4 hours was 98%, and the phase difference reduction rate was 2%. In addition, the pencil hardness (JIS-K-5400 8.4 pencil scratch test) of the obtained solid was 2H, and the cellophane tape peel test (JIS-5400 8.5 adhesion (8.5.2 cross-cut tape method)) was 100. / 100.

(Comparative Example 3)
Immediately after preparing the polymerizable liquid crystal composition (H-4) obtained in Comparative Example 2, 3.0% of photopolymerization initiator Irgacure-907 (manufactured by Ciba Specialty Chemicals) was added, and the polymerizable liquid crystal composition (H-5 ) Was prepared. Next, a 2- (1-methoxy) propyl acetate solution (PGMEA solution) containing 20% of this polymerizable liquid crystal composition (H-5) was prepared, and this PGMEA solution was spin-coated on a glass substrate with a polyimide alignment film ( 3,000 rpm / 30 seconds). The polymerizable liquid crystal composition (H-5) was cured by irradiating the spin-coated substrate with ultraviolet rays (4 mW / cm ² , 120 seconds) in a nitrogen atmosphere. When the solid obtained in this way was observed under a polarizing microscope, no repelling was observed, but alignment defects were observed.

Claims (8)

Formula (I)

(Wherein R ¹ and R ² are each independently a polymerizable group represented by the following structural formula group:

S ¹ and S ² each independently represents an alkylene group, a substituted alkylene group or a single bond, and the alkylene group is not bonded directly to each other, and the carbon atom is replaced with an oxygen atom. L ¹ , L ² , L ³ , L ⁴ and L ⁵ may be independently of each other -O-, -S-, -OCH _2- , -CH ₂ O-, -CO-, -COO -, - OCO -, - OCOOCH 2 -, - CH 2 OCOO -, - CONR 3 -, - NR 3 CO -, - SCH 2 -, - CH 2 S -, - CH = CHCOO -, - OCOCH = CH- _{, -COOCH 2 CH 2 -, -} CH 2 CH 2 OCO -, - OCOCH 2 CH 2 -, - CH 2 CH 2 COO -, - COOCH 2 -, - CH 2 OCO -, - OCOCH 2 -, - CH 2 _{COO -, - OCOOCH 2 CH 2} -, - CH 2 CH 2 OCOO -, - OCOOCH 2 -, - CH 2 OCOO -, - CH 2 OCOCH 2 -, - CH 2 COOCH 2 -, - CH 2 CH 2 -, —CH═CH—, —CF═CH—, —CH═CF or —C≡C— (wherein R ³ represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom), L ² , L ³ and L ⁴ are at least one of -COOCH ₂ CH _2- , -CH ₂ CH ₂ OCO-, -O COCH ₂ CH ₂ -or -CH ₂ CH ₂ COO- represents, M ¹ and M ² are each independently 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, Pyrimidine-2,5-diyl group, naphthalene-2,6-diyl group, tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5-diyl group, but the carbon atom in the group is Independently of each other, they may be unsubstituted or substituted by alkyl groups, halogenated alkyl groups, alkoxy groups, halogen groups, cyano groups or nitro groups, and X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ each independently represent a hydrogen atom, an alkyl group, a halogenated alkyl group, an alkoxy group, a halogen group, a cyano group or a nitro group, but X ¹ , X ² , ^{X 3, X 4, X 5} , X 6, at least one alkyl group of X ⁷ and X ^8, the halogenated alkyl group, an alkoxy group A halogen group, a cyano group or a nitro group. A polymerizable liquid crystal compound represented by The polymerization according to claim 1, wherein S ¹ and S ² are independently of each other and represent an alkylene group having 2 to 10 carbon atoms in which a carbon atom may be replaced with an oxygen atom as oxygen atoms in the group are not directly bonded to each other. Liquid crystal compound. ^2. The polymerizable liquid crystal compound according to claim 1, wherein M ¹ and M ² each independently represent a 1,4-phenylene group or a 1,4-cyclohexylene group. _2. The polymerizable liquid crystal compound according to claim 1, wherein L ³ represents —COOCH ₂ CH ₂ —, —CH ₂ CH ₂ OCO—, —OCOCH ₂ CH ₂ — or —CH ₂ CH ₂ COO—. L ¹ , L ² , L ⁴ and L ⁵ are independently of each other -O-, -S-, -OCH _2- , -CH ₂ O-, -CO-, -COO-, -OCO-, -CH = 2. The polymerizable liquid crystal compound according to claim 1, which represents CHCOO— or —OCOCH═CH—. 6. A polymerizable liquid crystal composition comprising the polymerizable liquid crystal compound according to claim 1. 7. A polymer obtained by polymerizing the polymerizable liquid crystal composition according to claim 6. 8. An optical anisotropic body using the polymer according to claim 7.