JP2011148746A - Non-polymerizable liquid crystal compound, polymerizable liquid crystal compound, liquid crystal composition, optically anisotropic material, and optical element - Google Patents

Abstract

[PROBLEMS] To provide an optically anisotropic material, an optical element having high refractive index anisotropy and excellent blue laser light resistance, and suppressing an increase in melting point of a liquid crystal composition and a transmittance loss of a cured product, and the production thereof. A novel liquid crystal composition is provided.
A compound represented by the following formula (1): _{^{A-Ph-E 1 -Ph- (}} Ph) m - (E 2) n -B-R 2 ·· (1) ^{_{where, A: CH 2 = CR 1}} -COO- (L) k - or carbons 1 -8 alkyl or alkoxy groups. R ¹ : a hydrogen atom or a methyl group. _{L :-( CH 2) p O -} , - (CH 2) q -. k: 0 or 1. _{B: -CH 2 -, - OCH} 2 -, - SiH 2 - or -Si _{(CH 3)} 2. R ^2: an alkyl group or an alkoxy group having 1 to 7 carbon atoms. m, n: 0 or 1 independently. E ¹ and E ² : each a cyclic group in which the 4-position carbon atom or the 1-position carbon atom of the trans 1,4-cyclohexylene group is substituted with a silicon atom: X ₁ and X ₂ are each independently a hydrogen atom or a methyl group.
[Selection figure] None

Description

  The present invention relates to a novel compound, a liquid crystal composition containing the compound, an optically anisotropic material obtained by polymerizing the liquid crystal composition, and an optical element.

When reading information recorded on an optical disk or writing information on an optical disk, an optical element that modulates laser light (polarization, diffraction, phase adjustment, etc.) is required.
For example, when reading information, linearly polarized light emitted from a laser light source reaches the surface of the optical disc via the deflection element and the phase plate. Since the polarization direction of the forward linearly polarized light is aligned in a direction that does not change by the deflecting element, the forward linearly polarized light is linearly transmitted through the deflecting element and converted into circularly polarized light by the phase plate. This circularly polarized light is reflected by the recording surface to become reversely circularly polarized light, and is converted again to linearly polarized light orthogonal to that before incidence by the phase plate. When the return light beam passes through the deflecting element again, the traveling direction is bent and reaches the light receiving element.

Also, when reading or writing information, if the surface of the optical disc fluctuates, the focus position of the beam spot shifts from the recording surface. This is detected and corrected, and the beam spot follows the uneven pits on the recording surface. A servo mechanism is required. Such an optical disk servo system is configured to detect the position of a track after the focus of a beam spot irradiated from a laser light source is focused on a recording surface and to follow the target track. Further, it is necessary to prevent the laser beam reflected without hitting the pit on the recording surface from returning to the light source as it is.
For this reason, in an optical head device, an optical element that modulates laser light (polarization, diffraction, phase adjustment, etc.) is required. By configuring an optical element using one or a combination of these properties, a servo mechanism, etc. Has been applied. Such an optical element is used not only for an optical pickup element used for reading a record on an optical disc, but also for an imaging element for a projector application and a communication device for a wavelength variable filter application.

  These optical elements can be made from a liquid crystal material. Since liquid crystal molecules having a polymerizable functional group have both the properties as a polymerizable monomer and the properties as a liquid crystal, the alignment of the liquid crystal molecules having a polymerizable functional group causes the alignment of the liquid crystal molecules. A fixed optically anisotropic material can be obtained. Optically anisotropic materials have optical anisotropy such as refractive index anisotropy derived from a mesogen skeleton, and are applied to diffraction elements, phase plates, and the like using these properties.

Furthermore, in recent years, in order to increase the capacity of optical disks, it has been promoted to shorten the wavelength of laser light used for writing and reading information, and to further reduce the size of concave and convex pits on the optical disk. Currently, a laser beam having a wavelength of 780 nm, a DVD having a wavelength of 660 nm, and a BD having a wavelength of 405 nm are used. Further, in next-generation optical recording media, the use of laser light with a wavelength of 300 to 450 nm (hereinafter also referred to as blue laser light including BD) is being studied.
However, when an optical element (such as a phase plate) made of an organic material such as liquid crystal is arranged in a blue laser optical system and used as an optical head device, aberration may occur with time. This is thought to be due to damage to organic matter caused by exposure to blue laser light. When aberration occurs, the light (light beam) emitted from the laser light source and passed through the collimator lens, optical element, etc. passes through the objective lens and reaches the surface of the recording medium. In this case, the efficiency of reading and writing information (light utilization efficiency) may be reduced.

In addition, a material having a high refractive index anisotropy, that is, Δn is required to reduce the size, increase the efficiency, and improve the degree of design freedom of the optical element. Here, Δn is the absolute value of the difference between the extraordinary refractive index ne and the ordinary refractive index no of the optically anisotropic material. In general, a material having a high refractive index anisotropy tends to have a high refractive index. .
As such a high refractive index liquid crystal material, for example, there is a liquid crystal material described in Patent Document 1. However, since the high refractive index liquid crystal material has a large wavelength dispersion of the refractive index, the absorption of light with respect to light having a short wavelength tends to increase (that is, the molar extinction coefficient of the material increases). There is a problem that such short wavelength light is easily absorbed and light resistance is low.

  In order to solve such problems, a liquid crystal composition containing a compound represented by the following formula (I) is polymerized as an optically anisotropic material that achieves both high laser resistance and high refractive index anisotropy. A polymer liquid crystal has been reported (Patent Document 2).

The compound represented by the formula (I) has excellent light resistance to blue laser light and high refractive index anisotropy, but the composition has a high melting point due to the large number of ring groups. Tend to show. Along with this, the compound represented by the above formula (I) has a problem that thermal polymerization of an acrylic site to be subjected to photopolymerization is likely to occur during preparation of the composition. When thermal polymerization occurs in this way, the progress of the polymerization becomes non-uniform, and the resulting film contains a large amount of light scattering components, resulting in a loss of transmittance as an optical element.
In addition, when the number of ring groups is increased, packing between liquid crystal mesogens is strengthened during polymerization, and as a result, there is a problem that the crystal multi-domain is formed, resulting in loss of transmittance due to scattering.

  By the way, a polymerizable cholesteric liquid crystal composition can be obtained by adding a chiral dopant having an asymmetric carbon to the polymerizable liquid crystal composition (nematic liquid crystal composition or smectic liquid crystal composition). Cholesteric liquid crystals have optical properties different from those of nematic liquid crystals and smectic liquid crystals. Therefore, if a polymerizable liquid crystal composition having a corresponding high Δn value is used, these nematic liquid crystal compositions or smectic liquid crystal compositions, etc. An optical element that cannot be realized with a polymerizable liquid crystal composition can be produced.

A cholesteric liquid crystal is formed by overlapping a plurality of layers, and in one thin layer, liquid crystal molecules are aligned with their major axes parallel to the layers and aligned. Moreover, the direction of the molecule is slightly different for each adjacent layer, and has a helical structure as a whole. For this reason, the liquid crystal molecules exhibit unique optical properties.
Specifically, as a result of the liquid crystal molecules having a helically twisted orientation, either one of the left / right circularly polarized components is selectively reflected corresponding to the helical pitch. For example, when the transmittance of a cholesteric liquid crystal is measured using circularly polarized light that exhibits selective reflection, a transmission spectrum having a steep wavelength dependency, that is, a spectrum having a rectangle in a wavelength band having selective reflection is obtained. This property can be applied to a mirror that reflects light of a specific wavelength, a reflective diffraction grating, an anomalous refractive index dispersion using a reflection band, and the like. For this reason, cholesteric liquid crystals are used in various optical elements. For example, Patent Document 3 discloses a polarizing diffraction element configured using refractive index anomalous dispersion of cholesteric liquid crystal.

  Commonly used cholesteric liquid crystals are obtained by adding a chiral dopant having an asymmetric center to a normal nematic liquid crystal or smectic liquid crystal having a relatively low molecular weight. The spiral pitch fluctuates due to the influence of the ambient temperature, and as a result, the above-described reflection characteristic, that is, the selective reflection wavelength fluctuates. In addition, since the twisted alignment structure of liquid crystal molecules is low in stability, the alignment state may be disturbed by impact, which is a problem when an optical element is formed.

In contrast, polymer-type cholesteric polymer liquid crystals have superior reliability compared to the above-mentioned ordinary low molecular weight liquid crystals, and have high temperature characteristics and high reliability when formed into optical elements. In terms of surface.
A cholesteric polymer liquid crystal is obtained by polymerizing a cholesteric liquid crystal composition comprising a nematic or smectic liquid crystalline compound having a polymerizable functional group and a chiral dopant having a polymerizable functional group. Objects often produce rectangular changes in selective reflection with polymerization, and generally the rectangles become broad. In this case, the transmittance is reduced in the vicinity of the selective reflection band, and there is a problem that it is difficult to ensure the light use efficiency in an optical element that uses transmitted light having a wavelength in the vicinity of the selective reflection band.

  Therefore, high melting point of the monomer while having high refractive index anisotropy and excellent blue laser light resistance, such as a polymerizable liquid crystal composition comprising the compound represented by formula (I) and a polymerizable cholesteric liquid crystal composition And a liquid crystal compound having no problem such as loss of transmittance of cured product has been desired.

JP-A-10-195138 WO2007-046294 JP 2005-209327 A

  The present invention has been made to solve the above-mentioned problems, and has a high refractive index anisotropy and excellent blue laser light resistance, while having a non-polymerizable liquid crystal composition and a polymerizable liquid crystal composition ( Nematic liquid crystal or smectic liquid crystal) and polymerizable cholesteric liquid crystal composition, an optically anisotropic material, an optical element, and a novel liquid crystal composition for producing the same, which suppress an increase in melting point and loss of transmittance of these cured products The object is to provide products and compounds.

  In order to solve the above-mentioned problems, the present inventors have intensively studied to arrive at the present invention. The present invention has the following gist.

Ｅ^２：トランス１，4−シクロヘキシレン基の１位炭素原子をケイ素原子で置換した下式に示す環基（但し、環基のＡ側を１位とする。）：

ただし、Ｘ_１、Ｘ_２はそれぞれ独立に水素原子またはメチル基。
また、式（１）中における１，４−フェニレン基は、その環基中の炭素原子に結合した水素原子がフッ素原子、塩素原子またはメチル基に置換されていてもよい。
また、式（１）中におけるＥ^１及びＥ^２は、その環基中の炭素原子に結合した水素原子がフッ素原子、塩素原子またはメチル基に置換されていてもよい。
また、本発明は、上記式（１）において、ｎ＝０である化合物を提供する。
また、本発明は、上記式（１）において、ＡがＣＨ_２＝ＣＲ^１−ＣＯＯ−（Ｌ）_ｋ−である化合物を提供する。
また、本発明は、上記式（１）において、ｋ＝１である化合物を提供する。 The present invention provides a compound represented by the following formula (1).
^{_{A-Ph-E 1 -Ph- (}} Ph) m - (E 2) n -B-R 2 ··· (1)
However, the symbols in the formulas have the following meanings.
A: CH ₂ = CR ¹ —COO— (L) _k — or an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms.
However, the alkyl group and the alkoxy group may be linear or branched, the hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group contain an ether bond. Also good.
R ¹ : a hydrogen atom or a methyl group.
L: — (CH ₂ ) _p O—, — (CH ₂ ) _q —, the hydrogen atom may be replaced by a fluorine atom or a chlorine atom, and the alkylene group may contain an ether bond. (However, p and q are each independently an integer of 2 to 8.)
k: 0 or 1.
_{B: -CH 2 -, - OCH} 2 -, - SiH 2 -, or -Si _{(CH 3)} 2 -.
R ² : an alkyl group having 1 to 7 carbon atoms or an alkoxy group having 1 to 7 carbon atoms.
However, the alkyl group and the alkoxy group may be linear or branched, the hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group contain an ether bond. Also good.
Ph: 1,4-phenylene group. (However, the A side of the cyclic group is the first position.)
m, n: 0 or 1 independently.
E ¹ : A cyclic group represented by the following formula in which the 4-position carbon atom of the trans 1,4-cyclohexylene group is substituted with a silicon atom (provided that the A side of the cyclic group is the 1-position):

E ² : a cyclic group represented by the following formula in which the 1-position carbon atom of the trans 1,4-cyclohexylene group is substituted with a silicon atom (provided that the A side of the cyclic group is the 1-position):

However, X < ₁ >, X < ₂ > is a hydrogen atom or a methyl group each independently.
In the 1,4-phenylene group in the formula (1), a hydrogen atom bonded to a carbon atom in the ring group may be substituted with a fluorine atom, a chlorine atom or a methyl group.
In E ¹ and E ² in formula (1), a hydrogen atom bonded to a carbon atom in the ring group may be substituted with a fluorine atom, a chlorine atom or a methyl group.
The present invention also provides a compound in which n = 0 in the above formula (1).
Further, in the above formula (1), A ^{_{CH 2 = CR 1 -COO- (L}} ) k - provides compounds.
The present invention also provides a compound in which k = 1 in the above formula (1).

The present invention also provides a liquid crystal composition containing the compound represented by the formula (1) of the present invention.
The present invention also provides a polymerizable liquid crystal composition containing the polymerizable compound represented by the formula (1) of the present invention.
The present invention also provides a polymerizable cholesteric liquid crystal composition comprising a polymerizable chiral material in the polymerizable liquid crystal composition of the present invention.

  The present invention also provides an optically anisotropic material obtained by polymerizing a liquid crystal composition containing the polymerizable compound of the present invention.

  The present invention also provides an optical element having a structure in which the optically anisotropic material of the present invention is sandwiched between a pair of supports or laminated on a single support.

The compound of the present invention has a low melting point and can keep the melting point of the composition low. In the cured product, while ensuring high refractive index anisotropy and blue laser light resistance, transmittance loss (of cholesteric cured product) In this case, it is possible to suppress transmission loss at a wavelength near the selective reflection band.
Therefore, the optically anisotropic material and optical element prepared using the compound of the present invention and the liquid crystal composition have high refractive index anisotropy and high transmittance, and exhibit excellent blue laser light resistance. The optically anisotropic material of the present invention can be suitably used for designing complex optical elements due to high refractive index anisotropy.
The polymerizable compound of the present invention can be used as a constituent material for a polymerizable nematic liquid crystal composition, a polymerizable smectic liquid crystal composition, or a polymerizable cholesteric liquid crystal composition.
In addition, the non-polymerizable compound of the present invention exhibits a low melting point and high refractive index anisotropy, similar to the polymerizable compound.

It is a figure which shows the relationship between the retardation (Rd) value of each liquid crystal composition, and the transmittance | permeability of the cured film. It is a spectrum figure which shows the light transmittance of the liquid-crystal composition of this invention in a 350-800 nm wavelength range. It is a spectrum figure which shows the light transmittance of the liquid crystal composition of a comparative example in a 350-800 nm wavelength range.

  In the present specification, the compound represented by the formula (1) is also referred to as the compound (1). The same applies to other compounds.

In this specification, the ring group E ¹ in which the 4-position carbon atom of the 1,4-phenylene group and the trans-1,4-cyclohexylene group is substituted with a silicon atom, and the 1-position carbon atom of the trans-1,4-cyclohexylene group The ring group E ² substituted with a silicon atom may be an unsubstituted group, and a hydrogen atom bonded to a carbon atom constituting a ring part of the ring group is substituted with a fluorine atom, a chlorine atom or a methyl group. May be.
These ring groups have bonds at the 1-position and 4-position. In the present specification, in the cyclic group, the A side of the formula (1) is the 1st position and the B side is the 4th position (the same applies hereinafter).
When the ring group is E ¹ or E ² , the 1- and 4-position bonds are in the trans position. In addition, when there are structurally isomeric groups in the alkyl group, all the groups are included, and a linear alkyl group is preferred.
In the following, “Ph” represents a 1,4-phenylene group which may have the above substituent, and E ¹ and E ² each represent trans-1, which may have the above substituent. A cyclic group in which the 4-position carbon atom or the 1-position carbon atom of the 4-cyclohexylene group is substituted with a silicon atom, respectively.

  A compound having both liquid crystallinity and polymerizability is hereinafter referred to as polymerizable liquid crystal. The description of the wavelength in the following means that it exists in the range of center wavelength +/- 2nm. In this specification, refractive index anisotropy is abbreviated as Δn.

A is CH ₂ ═CR ¹ —COO— (L) _k — or an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, and A is CH ₂ ═CR ¹ —COO— (L ) In the case of _{k-, the} photopolymerization of the compound (1) is facilitated, and it becomes easy to polymerize at a desired temperature having liquid crystallinity, so that it becomes easy to obtain an optically anisotropic material having desired characteristics. preferable.
The compound of the present invention is a compound represented by the following formula (1-1) when A is CH ₂ ═CR ¹ —COO— (L) _k —. This compound (1-1) is a kind of polymerizable liquid crystal having both polymerizability and liquid crystallinity.
^{_{CH 2 = CR 1 -COO- (L}} ) k -Ph-E 1 -Ph- (Ph) m - (E 2) n -B-R 2 (1-1)

R ¹ is a hydrogen atom or a methyl group, preferably a hydrogen atom. When R ¹ is a hydrogen atom or a methyl group, there is an advantage that the characteristics of the optically anisotropic material and optical element obtained by photopolymerization are hardly affected by the external environment (temperature, etc.). Further, when R ¹ is a hydrogen atom, it is preferable because polymerization proceeds rapidly when a liquid crystal composition containing a compound (1) described later is photopolymerized to obtain an optically anisotropic material and an optical element.

R ² is an alkyl group having 1 to 7 carbon atoms or an alkoxy group having 1 to 7 carbon atoms. As R ² , an alkyl group having 2 to 6 carbon atoms is preferable from the viewpoint that both the wide temperature range of the liquid crystal and the low melting point can be balanced.
The alkyl group and the alkoxy group may be linear or branched, but R ² preferably has a linear structure because the temperature range in which the compound (1) exhibits liquid crystallinity can be widened.
In the alkyl group and the alkoxy group, a hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group may include an ether bond.

In the formula (1), k is 0 or 1, but it is preferable that k is 1 because a high Δn value can be maintained even after polymerization. Moreover, when k is 1, the effect of lowering the melting point of the monomer composition is also obtained.
The compound in which k is 0 is slightly inferior in effective Δn value itself after polymerization compared with the compound in which k is 1, but for the purpose of imparting thermal stability to the cured product, It may be included.

L is — (CH ₂ ) _p O— or — (CH ₂ ) _q —, and in either case, there is no significant difference in the characteristics of the compound (1), but from the viewpoint of synthesis convenience, − ( CH _{2) p} O- are preferred.
p and q are each independently an integer of 2 to 8, and p is particularly preferably an integer of 4 to 6 from the viewpoint of achieving both retention of Δn value before and after polymerization and suppression of variation in polymer Δn value due to heat. .
In general, when a polymerizable liquid crystal composition is polymerized, the Δn value after polymerization tends to decrease as the order parameter of the liquid crystal decreases, but L is-(CH ₂ ) _p O-,-(CH ₂ ) _q In the case of a group having a polymethylene group such as-, a decrease in Δn value before and after polymerization can be suppressed. This is because a structure having a polymethylene group is bonded to an acryloyl group or a methacryloyl group.
For this reason, in the case of a nematic liquid crystal composition or a smectic liquid crystal composition, it is possible to ensure a high Δn value even in a polymer state. In this case, also in the cholesteric liquid crystal composition, it is possible to suppress a decrease in the polymer effective Δn value accompanying the polymerization, and it is possible to ensure a high effective Δn value.
Also, - (CH ₂₎ p _O-, and - (CH ₂₎ q _- hydrogen atoms may be substituted by a fluorine atom or a chlorine atom, and the alkylene group may contain an ether bond.

E ¹ and E ² are each a compound shown below, E ¹ is a cyclic group in which the 4-position carbon atom of the trans-1,4-cyclohexylene group is substituted with a silicon atom, and E ² is a trans- It is a cyclic group in which the 1-position carbon atom of the 1,4-cyclohexylene group is substituted with a silicon atom.

Thus, by substituting the carbon atom in the ring group with a silicon atom, the ring of E ₁ or E ₂ is caused by the difference in the bond distance between the carbon-silicon atom and the bond distance between the carbon-carbon atoms. A slight ring structure distortion inside or outside the group, that is, asymmetry occurs. Along with this, it is possible to lower the melting point of the compound (1).

[1] A structure in which an Si atom derived from E ¹ or E ² and Ph are bonded, and [2] a silicon atom and Ph contained in —SiH ₂ — or —Si (CH ₃ ) ₂ — of B described later. The light resistance of the compound (1) is improved by the bonded structure. This effect is particularly significant when Ph is linked to form a π conjugate. This can be a starting point for light resistance degradation due to the difficulty of forming a double bond, ie, —Si═C—, between silicon atoms and carbon atoms, or the suppression of the generation of benzyl radicals. This is because the transfer reaction and bond cleavage are difficult to proceed.

X ₁ and X ₂ are each independently a hydrogen atom or a methyl group.
When X ₁ and X ₂ are hydrogen atoms, the compound (1) exhibits a high Δn value and a low melting point, and has excellent blue light resistance. When X ₁ and X ₂ are methyl groups, it is possible to lower the melting point more effectively than when these are hydrogen atoms. However, the value of Δn slightly decreases. In addition, about (DELTA) n value, it is possible to avoid a fall by selecting suitably the connection mode of a cyclic group so that it may mention later.
When X ₁ and X ₂ are hydrogen atoms, blue light resistance may deteriorate due to the proton abstraction reaction. However, when X ₁ and X ₂ are methyl groups, this possibility may occur. Avoided. Therefore, when X ₁ and X ₂ are methyl groups, the blue color of the cured film obtained from the compound (1) can be obtained even under severe light resistance conditions such as high light irradiation density (irradiation light amount ÷ irradiation area). Deterioration of light resistance can be suppressed.

B is —CH ₂ —, —OCH ₂ —, —SiH ₂ —, or —Si (CH ₃ ) ₂ —. (Hereinafter, Si _{(CH 3) 2} - shown with -SiMe _2.)
In terms of the magnitude of Δn _{value, -CH 2 - ≒ -OCH 2 -} > -SiH 2 -> -SiMe of excellent sequentially _2, in terms of low and light fastness of the melting point, -SiMe ₂ -> - _{SiH 2 -> -CH 2 ->} -OCH 2 - is superior to the order of.
In particular, under severe light resistance conditions, for example, in an environment with high light irradiation density, when the liquid crystal mesogen end is Ph (when m = 1 in formula (1) and n = 0), in compound (1) Although easily occurs deterioration accompanying the generation of benzyl radicals, -SiH ₂ as B - or -SiMe ₂ - selecting, improved light resistance. This, B is _{CH 2} -, - OCH 2 - When a is that the easily occurs deterioration accompanying the generation of benzyl radicals, -SiH ₂ - or -SiMe ₂ - in the case of the benzyl radical This is because generation is suppressed and high light resistance can be maintained.

The structure of _{^{"-Ph-E 1 -Ph- (Ph)}} m - - (E 2) n ""- ^Ph-E 1 -Ph -", ^"- Ph-E 1 -Ph-Ph-" or ^{"-Ph-E 1 -Ph-Ph-} E 2 - " it is preferred.
In the case of a structure in which Ph is linked, the Δn value can be effectively improved by π conjugation. Thus, among these structures, it is preferable that Ph is adjacent from the viewpoint of increasing the Δn value of the compound (1), ^"- Ph-E 1 -Ph-Ph-" and ^{"-Ph-E 1 -Ph-Ph-E 2} - "it is preferred.
“-Ph-E ¹ -Ph-Ph-” is preferable from the viewpoint of synthesis of the compound (1), but “-Ph-E ¹ -Ph-Ph-E ² —” is preferable from the viewpoint of improving the Δn value. Is preferred.
The compound (1) or in terms of lowering the melting point of the composition containing the same, "- ^Ph-E 1 -Ph-" are preferred.
In these structures, as described above, the Δn value, the melting point, etc. of the compound (1) are adjusted by appropriately selecting the types of X ₁ and X ₂ or appropriately introducing substituents into the Ph ring. It is possible.

As described above, the structure in which Ph is linked contributes to the improvement of the Δn value of compound (1), but the Ph linkage is preferably limited to two linkages. If three or more Ph are connected, the light absorption effect becomes too emphasized, so that the light resistance becomes extremely weak.
However, if three Phs are not connected, such a problem does not occur. Therefore, three or more Phs may be included in the formula (1).
In addition, by including a cyclic group such as E ¹ and E ² in the formula (1), the Δn value can be improved, although there is no contribution as much as the Ph ring.

The compound (1) can have a structure containing a maximum of five ring groups, but when the number of ring groups in the formula (1) is large, a methyl group is appropriately introduced into Ph, or as X ₁ and X ₂ It is preferred to select a methyl group.
If all the cyclic groups are unsubstituted, the melting point of the compound (1) becomes too high, and inconveniences such as thermal polymerization occur during the preparation of the composition, but a methyl group is added to the cyclic group such as Ph. When introduced or when a methyl group is selected as X ₁ or X ₂ , the melting point of the compound (1) can be lowered.
As B as described above -SiH ₂ - or -SiMe ₂ - also by selecting, it is possible to lower the melting point.

Thus, although the compound (1) of the present invention has a polycyclic liquid crystal skeleton, as described above, [1] introduction of a silicon atom at the bonding position with the Ph ring [2] in E ¹ or E ² , X ₁ , X ₂ substitution at methyl position [3] Ph, etc., while maintaining a high Δn value and maintaining excellent light resistance while suppressing an increase in melting point.

In addition, a liquid crystal skeleton having four or five ring groups has a potential to increase the monomer Δn value. On the other hand, when a composition is prepared using only these, the melting point when formed into a composition tends to be generally high. Yes, handling becomes difficult. On the other hand, when the number of ring groups is large, a crystalline multi-domain film is formed at the time of curing, and a transmittance loss due to light scattering tends to occur.
For this reason, when the compound (1) having 4 or 5 ring groups is used, a liquid crystal monomer having three ring groups in the formula (1) or a three-ring liquid crystal selected from the other liquid crystal monomers is used. It is preferable to adjust the composition including the monomer. By including such a tricyclic liquid crystal monomer in the composition, problems such as an increase in the melting point of the monomer and a loss of transmittance accompanying light scattering can be solved.

As the polymerizable compound (1), the following compounds (1A) to (1C) are preferable.
_{^{CH 2 = CR 1 -COO-L}} -Ph-E 1 -Ph-B-R 2; (1A)
_{^{CH 2 = CR 1 -COO-L}} -Ph-E 1 -Ph-Ph-B-R 2; (1B)
_{^{CH 2 = CR 1 -COO-L}} -Ph-E 1 -Ph-Ph-E 2 -B-R 2; (1C)
Among these, a compound in which R ¹ is a hydrogen atom is preferable, and a compound in which -L- is — (CH ₂ ) _p O— (p is particularly preferably an integer of 4 to 6) is particularly preferable.
In Ph, E ¹ and E ² , a hydrogen atom bonded to a carbon atom in these groups may be substituted with a fluorine atom, a chlorine atom or a methyl group.
In the present invention, Ph is preferably an unsubstituted group, a group substituted with one fluorine atom, or a group substituted with one methyl group. When Ph has these substituents, it has the effect of lowering the melting point and the viscosity of the compound (1).
In the ring groups E ¹ and E ² , the hydrogen atom bonded to the carbon atom in these groups is preferably an unsubstituted group.
_{X 1} and _{X 2} of ^{E 2} of E ¹ is a hydrogen atom or a methyl group, B _{is, -CH 2 -, - OCH 2} -, - SiH 2 -, or -SiMe ₂ - a.

In (1A), since there is no conjugation of the Ph ring and the influence on light resistance is small, B is preferably —CH ₂ —. (1A), because the number of ring group three and less, -SiH ₂ as B - and -SiMe ₂ - Selecting, anisotropy of the liquid crystal is reduced, [Delta] n value is small.

In (1B) and (1C), the presence or absence of a substituent on the Ph ring, the type of X ₁ and X ₂ (hydrogen atom or methyl group), the type of B (—CH ₂ —, —SiH ₂ —, —SiMe ₂ ) Can be considered by various combinations of skeletons. Regarding these combination methods, do you emphasize the physical properties (melting point and Δn value) surface of compound (1) or emphasize the light resistance? It is preferable to select as appropriate.

For example, when high blue light resistance under a severe light resistance environment with high light irradiation density is required, a methyl group is selected as X ₁ and X ₂ , and —SiMe ₂ — is selected as B. , —SiH ₂ —, and —CH ₂ — are preferably selected in this order. In this case, the effect of lowering the melting point of the compound (1) is also obtained, but the Δn value is lowered. Therefore, in this case, it is preferable not to include a substituent in the Ph of the cyclic group.
On the other hand, in the compound (1), if not required a high degree of light fastness as described _above, the X 1, _{X 2} a hydrogen atom is selected as the _{B -CH 2 -, - SiH 2} -, - It is preferable to select in the order of SiMe ₂ −. In this case, since the melting point of the compound (1) tends to be high, it is preferable to include a substituent such as a methyl group or a fluorine atom in the cyclic group Ph.

Moreover, in Formula (1), A may not contain a polymeric group. Also in this case, a compound (1) having a high Δn value, a low melting point (Tm), and excellent blue light resistance can be obtained. Therefore, it can be used as one of the active liquid crystal compositions used for blue wavelength applications and by applying an electric field. That is, by adding a small amount, it is possible to increase the Δn value of the composition, which can effectively contribute to the high-speed response of the liquid crystal accompanying the reduction of the thickness of the liquid crystal layer.
Similarly to the polymerizable (1A) to (1C), the following compounds (1a) to (1c) are preferable.
^{A 1 -Ph-E 1 -Ph-} B-R 2; (1a)
^{A 1 -Ph-E 1 -Ph-} Ph-B-R 2; (1b)
^{A 1 -Ph-E 1 -Ph-} Ph-E 2 -B-R 2; (1c)

A ¹ is an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. Although there is no significant difference between the two in terms of characteristics, when A ¹ is an alkoxy group, as described later, A has an advantage that an intermediate can be shared with those having a polymerizable group. On the other hand, considering the number of steps in the synthesis, the alkyl group has an advantage that it can be easily prepared as compared with the alkoxy group.
The alkyl group and the alkoxy group may be linear or branched. However, since the temperature range in which the compound (1) exhibits liquid crystallinity can be widened, the linear group is preferable. .
In the alkyl group and the alkoxy group, a hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group may include an ether bond.

As the compound (1), the following compounds are preferable, (1B-1) to (1B-12), (1B-25) to (1B-36), (1C-1) to (1C-8), (1C-17) to (1C-24) are particularly preferable. However, p in a formula shows the same meaning as the above, and the integer of 4-6 is preferable. R ²¹ represents an alkyl group having 1 to 8 carbon atoms, and a linear alkyl group having 1 to 6 carbon atoms is preferable. R ²² represents an alkyl group having 1 to 8 carbon atoms, and a linear alkyl group having 2 to 6 carbon atoms is preferable.

  A method for synthesizing the compound (1) of the present invention will be described with specific examples. The symbols in the following formulas have the same meaning as described above.

(Synthesis method 1)
Examples of methods for synthesizing the compounds (1A-1), (1A-3), and (1A-5) include the methods shown below.

First, the compound (11) and allylmagnesium chloride are reacted to obtain the compound (12). Next, the compound (12) is hydroborated and then oxidized with a base and hydrogen peroxide to obtain the diol (13). Next, the compound (13) is oxidized in the presence of a ruthenium catalyst to obtain a dicarboxylic acid (14). Next, the compound (14) and ethanol are reacted to obtain the compound (15), which is subjected to Dieckmann condensation in the presence of sodium hydride to obtain the compound (16). Next, the compound (16) is refluxed in the presence of an aqueous sodium chloride solution and dimethyl sulfoxide (hereinafter abbreviated as DMSO) to obtain the compound (17). Next, the compound (17) and a separately prepared Grignard reagent (18) are reacted to obtain the compound (19). Next, the compound (19) is reacted with para-toluenesulfonic acid to obtain the compound (20). Next, the compound (20) is reacted with hydrogen gas in the presence of palladium-activated carbon to obtain the compound (21). Next, the compound (21) is reacted with iodine monochloride, and subsequently reacted with lithium aluminum hydride (hereinafter abbreviated as LAH) to obtain the compound (22). Next, the compound (22) is reacted with hydrogen chloride gas in the presence of iron (III) chloride to obtain the compound (22-2) in the reaction system, and this and a separately prepared Grignard reagent (23) are obtained. Reaction is performed to obtain compound (24). Next, the compound (24) is reacted with LiBH (sec-C ₄ H ₉ ) ₃ to obtain the compound (25).
The non-polymerizable compound (1A-1) is obtained by etherifying the compound (25) with R ²¹ —Br or R ²¹ —OH.
A polymerizable compound (1A-3) having no methylene spacer is obtained by reacting the compound (25) with acrylic acid chloride.
The compound (25) is reacted with CH ₂ ═CH—COO— (CH ₂ ) _p —Br or CH ₂ ═CH—COO— (CH ₂ ) _p —OH, whereby a polymerizable compound having a methylene spacer (1A- 5) is obtained.

(Synthesis method 2)
Examples of methods for synthesizing the compounds (1A-2), (1A-4), and (1A-6) include the methods shown below.

  In the synthesis method 1, the compound (26) is obtained by using methylmagnesium bromide instead of LAH in the reaction for obtaining the compound (22) from the compound (21). Furthermore, a method of obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (22) through compound (24) and compound (25) in synthesis method 1 for compound (26) The above-mentioned compounds (1A-2), (1A-4) and (1A-6) can be obtained by using exactly the same method.

(Synthesis method 3)
Examples of methods for synthesizing the compounds (1B-1), (1B-13), and (1B-25) include the methods shown below.

  The compound (28) is obtained by using the compound (27) instead of the compound (23) in the reaction for obtaining the compound (24) from the compound (22) in the synthesis method 1. Furthermore, for compound (28), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-1), (1B-13) and (1B-25).

(Synthesis method 4)
Examples of methods for synthesizing the compounds (1B-4), (1B-16), and (1B-28) include the methods shown below.

  The compound (29) is obtained by using the compound (26) instead of the compound (22) in the reaction for obtaining the compound (28) from the compound (22) in the synthesis method 3. Furthermore, for compound (29), in synthesis method 1, the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) To obtain the above compounds (1B-4), (1B-16) and (1B-28).

(Synthesis method 5)
Examples of methods for synthesizing the compounds (1B-7), (1B-19), and (1B-31) include the methods shown below.

  The compound (31) is obtained by using the compound (30) instead of the compound (27) in the reaction for obtaining the compound (28) from the compound (22) in the synthesis method 3. Furthermore, for compound (31), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-7), (1B-19) and (1B-31).

(Synthesis method 6)
Examples of methods for synthesizing the compounds (1B-10), (1B-22), and (1B-34) include the methods shown below.

  The compound (32) is obtained by using the compound (26) instead of the compound (22) in the reaction for obtaining the compound (31) from the compound (22) in the synthesis method 5. Furthermore, for compound (32), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-10), (1B-22) and (1B-34).

(Synthesis method 7)
Examples of methods for synthesizing the compounds (1B-2), (1B-14), and (1B-26) include the methods shown below.

The compound (34) is obtained by using the compound (33) instead of the compound (27) in the reaction for obtaining the compound (28) from the compound (22) in Synthesis Method 3. Next, Grignard reagent (34-2) of compound (34) is prepared, this is reacted with R ²² -SiCl ₃ , and subsequently reacted with LAH to obtain compound (35). Furthermore, for compound (35), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-2), (1B-14) and (1B-26).

(Synthesis method 8)
Examples of methods for synthesizing the compounds (1B-3), (1B-15), and (1B-27) include the methods shown below.

The compound (36) is obtained by reacting with R ²² -SiMe ₂ Cl instead of R ²² -SiCl _{3 in} the reaction for obtaining the compound (35) from the compound (34) in Synthesis Method 7. Furthermore, for compound (35), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-3), (1B-15) and (1B-27).

(Synthesis method 9)
Examples of methods for synthesizing the compounds (1B-5), (1B-17), and (1B-29) include the methods shown below.

  The compound (37) is obtained by using the compound (26) instead of the compound (22) in the reaction for obtaining the compound (34) from the compound (22) in the synthesis method 7. Next, for compound (37), compound (38) is obtained by using exactly the same method as used for obtaining compound (35) from compound (34) in synthesis method 7. Furthermore, for compound (38), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-5), (1B-17) and (1B-29).

(Synthesis method 10)
Examples of methods for synthesizing the compounds (1B-6), (1B-18), and (1B-30) include the methods shown below.

In the reaction for obtaining compound (38) from compound (37-2) in synthesis method 9, the compound (39) is obtained by reacting with R ²² -SiMe ₂ Cl instead of R ²² -SiCl ₃ . Furthermore, for compound (39), in Synthesis Method 1, the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) via compound (25) To obtain the above compounds (1B-6), (1B-18) and (1B-30).

(Synthesis method 11)
Examples of methods for synthesizing the compounds (1B-8), (1B-20), and (1B-32) include the methods shown below.

  The compound (41) is obtained by using the compound (40) instead of the compound (33) in the reaction for obtaining the compound (34) from the compound (22) in the synthesis method 7. Next, for compound (41), compound (42) is obtained by using the same method as used for obtaining compound (35) from compound (34) in synthesis method 7. Furthermore, for compound (42), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-8), (1B-20) and (1B-32).

(Synthesis Method 12)
Examples of methods for synthesizing the compounds (1B-9), (1B-21), and (1B-33) include the methods shown below.

In the synthesis method 11, in the reaction for obtaining the compound (42) from the compound (41-2), the compound (43) is obtained by reacting with R ²² -SiMe ₂ Cl instead of R ²² -SiCl ₃ . Furthermore, for compound (43), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-9), (1B-21), and (1B-33).

(Synthesis method 13)
Examples of methods for synthesizing the compounds (1B-11), (1B-23), and (1B-35) include the methods shown below.

  The compound (44) is obtained by using the compound (40) instead of the compound (30) in the reaction for obtaining the compound (32) from the compound (26) in the synthesis method 6. Next, for compound (44), compound (45) is obtained by using exactly the same method as used for obtaining compound (35) from compound (34) in synthesis method 7. Furthermore, for compound (45), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-11), (1B-23) and (1B-35).

(Synthesis Method 14)
Examples of methods for synthesizing the compounds (1B-12), (1B-24), and (1B-36) include the methods shown below.

In the synthesis method 13, in the reaction for obtaining the compound (45) from the compound (44-2), the compound (46) is obtained by reacting with R ²² -SiMe ₂ Cl instead of R ²² -SiCl ₃ . Furthermore, for compound (46), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1B-12), (1B-24) and (1B-36).

(Synthesis Method 15)
Examples of methods for synthesizing the compounds (1C-1), (1C-9), and (1C-17) include the methods shown below.

  A Grignard reagent such as compound (47) is prepared and reacted with compound (17) to obtain compound (48). Furthermore, compound (51-2) was obtained in the reaction system by using the same method as the step of obtaining compound (22-2) from compound (19) in synthesis method 1 for compound (48), This is reacted with a separately prepared Grignard reagent (33) to obtain compound (52). Next, magnesium is allowed to act on the compound (52) to prepare a Grignard reagent (53), and the separately prepared compound (22-2) is reacted to obtain the compound (54). Furthermore, for compound (54), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-1), (1C-9) and (1C-17).

(Synthesis Method 16)
Examples of methods for synthesizing the compounds (1C-2), (1C-10), and (1C-18) include the methods shown below.

  The compound (50) obtained from the synthesis method 15 is reacted with iodine monochloride and subsequently reacted with methylmagnesium bromide to obtain the compound (55). Next, in the synthesis method 15, in the reaction for obtaining the compound (52) from the compound (51), the compound (56) is obtained by using the compound (55) instead of the compound (51). Further, compound (58) is obtained by using the same method as the method for obtaining compound (54) from compound (52) in synthesis method 15. Furthermore, for compound (58), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-2), (1C-10) and (1C-18).

(Synthesis Method 17)
Examples of methods for synthesizing the compounds (1C-3), (1C-11), and (1C-19) include the methods shown below.

  The compound (59) is obtained by using the compound (26-2) in place of the compound (22-2) in the reaction for obtaining the compound (54) from the compound (53) in the synthesis method 15. Furthermore, for compound (59), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-3), (1C-11) and (1C-19).

(Synthesis Method 18)
Examples of methods for synthesizing the compounds (1C-4), (1C-12), and (1C-20) include the methods shown below.

  The compound (60) is obtained by using the compound (26-2) instead of the compound (22-2) in the synthesis method 16 in the reaction for obtaining the compound (58) from the compound (57). Furthermore, for compound (60), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-4), (1C-12) and (1C-20).

(Synthesis Method 19)
Examples of methods for synthesizing the compounds (1C-5), (1C-13), and (1C-21) include the methods shown below.

  The compound (62) is obtained by using a Grignard reagent (61) prepared separately in place of the compound (33) in the reaction for obtaining the compound (52) from the compound (51) in the synthesis method 15. Next, the compound (64) is obtained by using the compound (62) in place of the compound (56) in the reaction for obtaining the compound (58) from the compound (56) in the synthesis method 16. Furthermore, for compound (64), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-5), (1C-13) and (1C-21).

(Synthesis Method 20)
Examples of methods for synthesizing the compounds (1C-6), (1C-14), and (1C-22) include the methods shown below.

  The compound (65) is obtained by using the compound (55) instead of the compound (51) in the reaction for obtaining the compound (62) from the compound (51) in the synthesis method 19. Next, the compound (67) is obtained by using the compound (65) in place of the compound (56) in the reaction for obtaining the compound (58) from the compound (56) in the synthesis method 16. Furthermore, for compound (67), in Synthesis Method 1, the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) To obtain the above compounds (1C-6), (1C-14) and (1C-22).

(Synthesis Method 21)
Examples of methods for synthesizing the compounds (1C-7), (1C-15), and (1C-23) include the methods shown below.

  The compound (68) is obtained by using the compound (26-2) instead of the compound (22-2) in the reaction for obtaining the compound (64) from the compound (63) in the synthesis method 19. Furthermore, for compound (68), the same method as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25) in synthesis method 1 To obtain the above compounds (1C-7), (1C-15) and (1C-23).

(Synthesis Method 22)
Examples of methods for synthesizing the compounds (1C-8), (1C-16), and (1C-24) include the methods shown below.

  In the reaction for obtaining compound (67) from compound (66) in synthesis method 20, compound (69) is obtained by using compound (26-2) instead of compound (22-2). Furthermore, for compound (69), in Synthesis Method 1, the method is exactly the same as the method for obtaining compounds (1A-1), (1A-3) and (1A-5) from compound (24) through compound (25). To obtain the above compounds (1C-8), (1C-16) and (1C-24).

  The Grignard reagents (27), (30), (33), (40), and (61) described in the synthesis methods 1 to 22 are palladium acetate and triphenylphosphine in an acetone solvent as described below. The compound synthesized by the Suzuki coupling reaction in the presence of sodium carbonate is further reacted with magnesium. The preparation ratio of the Suzuki coupling was bromoiodobenzenes-0.9 equivalent, palladium acetate-0.05 equivalent, triphenylphosphine-0.09 equivalent, sodium carbonate-2. It can be easily synthesized by adding 7 equivalents (preparing a 20% aqueous solution) and the solvent acetone (amount arbitrary) to the reaction vessel and stirring overnight.

The compound (1) of the present invention [1] has a structure in which three or more ring groups are directly bonded, and the Ph linkage is limited to two, [2] Formula (1) [3] Saturated hydrocarbon ring group that does not absorb light even in a short wavelength region of wavelength of 400 nm or less, that is, E ¹ , E, which does not contain a —Ph—CO— structure (see JP 2004-263037 A) By having ² in the mesogenic skeleton, durability against blue laser light is good.
In addition, the compound (1) of the present invention suppresses a transition reaction that can be a starting point of deterioration by arranging Ph bonded to a silicon atom contained in E ¹ , E ² , B, etc., and has light resistance. Further improve. In particular, when there is a conjugated structure in which two Phs are linked in formula (1), the effect of this structure is great.

The Δn value of the nematic liquid crystal composition and the smectic liquid crystal composition and the effective Δn value of the cholesteric liquid crystal composition can be increased when the ring group has two or more Phs. In particular, as shown in Formula (1B), Formula (1C), and (1b) and (1c), the compound (1) has a structure in which two Phs are linked, and further, ^one Ph via E ¹ , That is, by adopting a structure including a total of three Phs, the Δn value and the effective Δn value can be effectively increased.

In general, when a polymerizable liquid crystal is polymerized, the Δn value and the effective Δn value tend to decrease by polymerization. However, when a structure having a polymethylene group is bonded to an acryloyl group or a methacryloyl group, that is, − When the L- moiety is — (CH ₂ ) _p O— or — (CH ₂ ) _q —, a decrease in Δn value or effective Δn value can be suppressed.

In addition, the presence of silicon atoms derived from E ¹ and E ² in the liquid crystal mesogen skeleton not only has an effect as light resistance, but also has physical properties such as lowering of the melting point of the monomer composition and improvement of transmittance of the cured film. It also contributes to a positive effect. This is derived from slight distortion of the ring structure inside or outside the ring group of E ¹ and E ² , that is, asymmetry due to the difference between the bond distance of the carbon-silicon atom and the bond distance of the carbon-carbon atom. Accordingly, the melting point of the compound (1) and the composition containing the compound (1) decreases.
In general, when a compound has a large number of ring groups, when this is polymerized, strong packing occurs between liquid crystal mesogens, and scattering of crystal multidomain material, that is, loss of transmittance tends to occur. The presence of slight ring structure distortion in the liquid crystal mesogen suppresses scattering in the cured film, and at the same time maintains the anisotropy of the liquid crystal appropriately.

  From the above, the compound (1) containing a silicon atom in the liquid crystal mesogen and the composition containing the same are easy to handle with a low melting point, and the cured product is excellent in durability against blue light and transmittance characteristics. In particular, when k in the formula (1) is 1, a high Δn value or effective Δn value can be obtained, so that the diversity in optical element design is excellent. Furthermore, the optical element obtained by using this is excellent in durability against blue light, and good light utilization efficiency can be obtained even when used in an optical head device.

The compound (1) of the present invention is preferably used as one component of a liquid crystal composition for obtaining a nematic polymer liquid crystal, a smectic polymer liquid crystal and a cholesteric polymer liquid crystal. In this case, the compound (1) of the present invention has a feature that it is easy to obtain a liquid crystal composition having a wide liquid crystal temperature range, and in particular, it is easy to obtain a liquid crystal composition having a wide temperature range exhibiting a liquid crystal phase on the low temperature side. In order for the liquid crystal composition to exhibit a wide liquid crystal temperature range, the melting point of the composition is widened to the low temperature side or the Tc (liquid crystal-phase transition temperature to isotropic phase) of the composition is set to the high temperature side. You can spread to
The liquid crystal composition containing two or more compounds selected from the compound (1) or the compound (1) so that the liquid crystal composition for obtaining the polymer liquid crystal exhibits liquid crystallinity even at a low temperature side. It is preferable that it is a liquid crystal composition containing 1 or more types of these, and 1 or more types of polymerizable liquid crystals other than a compound (1). By using such a liquid crystal composition, a melting point (Tm) drop occurs, so that the handling becomes easy and the temperature range showing the liquid crystal phase can be widened. When it is desired to increase the temperature range of the liquid crystal by increasing Tc, a polymerizable liquid crystal having a high Tc may be selected as the polymerizable liquid crystal other than the compound (1).
Hereinafter, a polymerizable liquid crystal compound other than the compound (1) is referred to as a compound (3).

When the liquid crystal composition contains the compound (1) and the compound (3), the compound (3) is preferably a compound having an acryloyl group or a methacryloyl group, and the compound having an acryloyl group is preferably polymerized. It is preferable because it proceeds quickly. The number of acryloyl groups is preferably monofunctional or bifunctional.
The compound (3), which is a polymerizable liquid crystal, is preferably similar to the compound (1) in terms of blue light resistance and physical properties. Therefore, the molecular structure of the compound (3) is the molecular structure of the compound (1). It is preferable that they are similar. As a result, the liquid crystal composition comprising the compound (1) and the compound (3) effectively exhibits a melting point drop and exhibits a stable nematic liquid crystal phase or smectic liquid crystal phase.

However, the cyclic group constituting the compound (3) is preferably Ph or trans-1,4-cyclohexylene group (hereinafter abbreviated as Cy), and a silicon atom in the cyclic group such as E ¹ and E ² described above. It is preferably not a cyclic group containing When silicon atoms are contained in the liquid crystal skeleton, Tc (liquid crystal-phase transition temperature to isotropic phase) tends to slightly decrease. It is preferable to adjust Tc by appropriately selecting the compound (3) containing no atom.

  As described above, the prepared composition exhibits a stable nematic phase or smectic phase, and further exhibits a stable cholesteric phase even when a polymerizable chiral dopant (4) is added thereto.

As the compound (3), a compound represented by the following formula (3-1) [compound (3-1)] or a compound represented by the following formula (3-2) [compound (3-2)] or The compound represented by formula (3-3) [compound (3-3)] is preferred.
^{_{CH 2 = CR 3 -COO- (α}} ) β -E 3 -E 4 -E 5 -E 6 -R 4 ··· (3-1)
^{_{CH 2 = CR 5 -COO- (γ}} ) δ -E 7 -E 8 -E 9 -R 6 ··· (3-2)
_{^{CH 2 = CR 7 -COO-E}} 10 -E 11 -R 8 ··· (3-3)
However, the symbols in the formulas have the following meanings.
R ³ , R ⁵ , R ⁷ : each independently a hydrogen atom or a methyl group.
R ^4: an alkyl group having 1 to 8 carbon atoms, an alkoxy group, or a ^{_{CH 2 = CR 3 -COO- (α}} ) β -.
R ⁶ : an alkyl group having 1 to 8 carbon atoms, an alkoxy group, or CH ₂ ═CR ⁵ —COO— (γ) _δ —.
R ^8: alkyl or alkoxy group having 1 to 8 carbon atoms.
β, δ: each independently 0 or 1.
α, γ: each independently — (CH ₂ ) _s O— or — (CH ₂ ) _t — (wherein s and t are each independently an integer of 2 to 8).
However, the alkyl group, alkoxy group, and α and γ of R ⁴ , R ⁶ and R ⁸ may be such that a hydrogen atom bonded to a carbon atom may be substituted with a fluorine atom or a chlorine atom, and an ether bond is included. Also good.
E ^{3 to} E ¹¹ : each independently 1,4-phenylene group or trans-1,4-cyclohexylene group. However, at least one of E ⁴ and E ⁵ is a trans-1,4-cyclohexylene group. In addition, at least one of E ^{7 to} E ⁹ is a trans-1,4-cyclohexylene group.
However, in the 1,4-phenylene group and trans-1,4-cyclohexylene group, a hydrogen atom bonded to a carbon atom in these groups may be substituted with a fluorine atom, a chlorine atom or a methyl group. .

Among the compounds (3), preferable compounds are the following compound (3-1-1A), compound (3-1-1C), compound (3-1-3C), compound (3-2-1B), and compound. (3-2-2B) and compound (3-3-2). However, in the following Ph and Cy, a hydrogen atom bonded to a carbon atom in these groups may be substituted with a fluorine atom, a chlorine atom or a methyl group.
^{_{CH 2 = CR 3 -COO- (CH}} 2) s O-Ph-Cy-Ph-Ph-R 4 ··· (3-1-1A)
^{_{CH 2 = CR 3 -COO-Ph}} -Cy-Ph-Ph-R 4 ··· (3-1-1B)
^{_{CH 2 = CR 3 -COO- (CH}} 2) s O-Ph-Cy-Ph-Ph-O (CH 2) s -OOC-CR 3 = CH 2 ··· (3-1-1C)
^{_{CH 2 = CR 3 -COO- (CH}} 2) s O-Ph-Ph-Cy-Ph-R 4 ··· (3-1-2A)
^{_{CH 2 = CR 3 -COO-Ph}} -Ph-Cy-Ph-R 4 ··· (3-1-2B)
^{_{CH 2 = CR 3 -COO- (CH}} 2) s O-Ph-Cy-Cy-Ph-R 4 ··· (3-1-3A)
^{_{CH 2 = CR 3 -COO-Ph}} -Cy-Cy-Ph-R 4 ··· (3-1-3B)
^{_{CH 2 = CR 3 -COO- (CH}} 2) s O-Ph-Cy-Cy-Ph-O (CH 2) s -OOC-CR 3 = CH 2 ··· (3-1-3C)
^{_{CH 2 = CR 5 -COO- (CH}} 2) s O-Ph-Cy-Ph-R 6 ··· (3-2-1A)
^{_{CH 2 = CR 5 -COO-Ph}} -Cy-Ph-R 6 ··· (3-2-1B)
^{_{CH 2 = CR 5 -COO- (CH}} 2) s O-Ph-Cy-Ph-O (CH 2) s -OOC-CR 5 = CH 2 ··· (3-2-1C)
^{_{CH 2 = CR 5 -COO- (CH}} 2) s O-Ph-Ph-Cy-R 6 ··· (3-2-2A)
^{_{CH 2 = CR 5 -COO-Ph}} -Ph-Cy-R 6 ··· (3-2-2B)
^{_{CH 2 = CR 7 -COO-Ph}} -Cy-R 8 ··· (3-3-1)
^{_{CH 2 = CR 7 -COO-Cy}} -Cy-R 8 ··· (3-3-2)

  Although it does not specifically limit as a polymerizable chiral dopant (4), The polymerizable chiral dopant etc. which consist of an isosorbide derivative or an isomannide derivative shown to the following compounds (4-1)-(4-4) are preferable.

ただし、式中の記号は以下の意味を示す。
Ｒ^９〜Ｒ^１１：それぞれ独立に、炭素数１〜８のアルキル基。
ｕ、ｖ、ｘ、ｙ：２〜８の整数。

However, the symbols in the formulas have the following meanings.
R ^{9 to} R ¹¹ : each independently an alkyl group having 1 to 8 carbon atoms.
u, v, x, y: integers of 2 to 8.

Compositions for producing nematic polymer liquid crystals, smectic polymer liquid crystals or cholesteric polymer liquid crystals (hereinafter collectively referred to as “these polymer liquid crystals”) include polymerizable nematic liquid crystals and polymerizable smectics. The liquid crystal composition contains 75% by mass or more of the liquid crystal and the polymerizable chiral dopant, and preferably contains 90% by mass or more of the liquid crystal composition.
This liquid crystal composition may contain a non-liquid crystalline polymerizable compound or a non-polymerizable liquid crystal compound. As the cholesteric liquid crystal composition, a liquid crystal composition containing a polymerizable nematic liquid crystal or a polymerizable smectic liquid crystal in an amount of 75% by mass or more, particularly 85% by mass or more is preferable.
In the present invention, the composition for producing these polymer liquid crystals is preferably a liquid crystal composition containing at least 5% by mass of the compound (1) with respect to the total polymerizable compound in the liquid crystal composition.

  In the present invention, a liquid crystal composition suitable for producing these polymer liquid crystals includes a liquid crystal composition containing at least one compound (1) as described above, and at least one compound (1). It is a liquid-crystal composition containing 1 or more types of a compound (3). The ratio of the compound (1) to the total amount of the compound (1) and the compound (3) in these liquid crystal compositions is preferably 30 to 100% by mass, and particularly preferably 50 to 100% by mass.

  Furthermore, the compound (3) often has a low molecular weight as compared with the compound (1), and therefore the molar ratio of the compound (1) to the total amount of the compound (1) and the compound (3) is more than the mass ratio. Often smaller. Therefore, when expressed in terms of a molar ratio, the ratio of the compound (1) to the total amount of the compound (1) and the compound (3) is preferably 18 mol% or more, and more preferably 30 mol% or more. In the liquid crystal composition containing the compound (1) and the compound (3), the upper limit of the ratio of the compound (1) to the total amount of the compound (1) and the compound (3) is preferably 90 mol%.

Further, in the compound (1), when A does not have a polymerizable group, other liquid crystalline compounds to be contained in the liquid crystal composition together with the compound (1) include, for example, the following non-polymerizable compounds (5) can be used.
(However, R ¹² , R ¹³ , and R ¹⁴ in the formula each independently represent an alkyl group, an alkenyl group, or an alkyl group substituted with a halogen atom).
The following non-polymerizable compound (5) is not limited to the case where the compound (1) is non-polymerizable, and can also be used as a liquid crystal composition when the compound (1) is polymerizable.

  In addition, when the compound (1) is non-polymerizable, the other liquid crystalline compound used by mixing with the compound (1) is not limited to the non-polymerizable compound (5), and is a polymerizable liquid crystal compound. (3) can also be used, and it can also be used by mixing with a commercially available nematic liquid crystal composition.

  The amount of the compound (1) contained in the liquid crystal composition is 0.5% by mass or more, preferably 2 to 30% by mass, and particularly preferably 3 to 20% by mass with respect to the liquid crystal composition. In the case of a polymerizable liquid crystal composition, by using the amount of the compound (1) in the above range, the rise in the melting point of the monomer composition, the transmittance loss accompanying light scattering, etc. are suppressed, and the liquid crystal composition The Δn value can be appropriately improved.

  The polymerizable liquid crystal composition of the present invention may contain components other than the polymerizable nematic liquid crystal, the polymerizable smectic liquid crystal, and the polymerizable chiral dopant (hereinafter referred to as other components). Examples of other components include a polymerization initiator, a polymerization inhibitor, a chiral agent other than the formula (4), an ultraviolet absorber, an antioxidant, a light stabilizer, and a dichroic dye.

  The total amount of polymerizable liquid crystal contained in the polymerizable liquid crystal composition (hereinafter referred to as “total amount of polymerizable liquid crystal”) and the ratio of other components are preferably adjusted depending on the application. For example, when a chiral agent other than the formula (4) is used as the other component, the total amount of the polymerizable liquid crystal is preferably 60 to 95% by mass, particularly preferably 70 to 95% by mass with respect to the polymerizable liquid crystal composition. . The amount of the chiral agent other than the formula (4) is preferably 5 to 40% by mass and particularly preferably 5 to 30% by mass with respect to the polymerizable liquid crystal composition.

  When a dichroic dye is used as the other component, the total amount of the polymerizable liquid crystal is preferably 80 to 99% by mass, and particularly preferably 82 to 97% by mass with respect to the polymerizable liquid crystal composition.

  In the case where an ultraviolet absorber, an antioxidant, a light stabilizer and the like are used as other components, the amount of these components is preferably 5% by mass or less, particularly 3% by mass or less, based on the polymerizable liquid crystal composition. preferable. In this case, the total amount of the polymerizable liquid crystal is preferably 95% by mass or more and less than 100% by mass, particularly preferably 97% by mass or more and less than 100% by mass with respect to the polymerizable liquid crystal composition. The ratio of the polymerization initiator will be described later.

In addition, the liquid crystal composition of the present invention is a non-polymerizable liquid crystal composition other than non-polymerizable liquid crystals such as chiral materials, dichroic dyes, ultraviolet absorbers, antioxidants, and light stabilizers. May be included.
The amount of these other components is preferably 5% by mass or less, particularly preferably 3% by mass or less, based on the non-polymerizable liquid crystal composition. In this case, the total amount of the non-polymerizable liquid crystal is preferably 95% by mass or more and less than 100% by mass, and particularly preferably 97% by mass or more and less than 100% by mass with respect to the non-polymerizable liquid crystal composition.

Next, the optically anisotropic material of the present invention will be described.
The optically anisotropic material of the present invention includes the polymerizable liquid crystal composition, wherein the polymerizable liquid crystal composition is a nematic phase, a smectic phase, or a cholesteric phase (hereinafter collectively referred to as “liquid crystal phase”). And a polymer obtained by polymerization in a state where these liquid crystals are aligned.

To the polymerizable liquid crystal composition keep showing a liquid crystal phase, but the ambient temperature may be below the phase transition temperature (T _c) ° C. to isotropic phase from the liquid phase, the liquid crystal is at a temperature close to T _c Since Δn or effective Δn of the composition is extremely small, the upper limit of the ambient temperature is preferably set to (T _c −10) ° C. or less.

  Examples of the polymerization include photopolymerization and thermal polymerization, and photopolymerization is preferred. The light used for photopolymerization is preferably ultraviolet light or visible light. When performing photopolymerization, it is preferable to use a photopolymerization initiator, which is appropriately selected from acetophenones, benzophenones, benzoins, benzyls, Michler's ketones, benzoin alkyl ethers, benzyl dimethyl ketals, thioxanthones, etc. Photoinitiators are preferred. 1 type (s) or 2 or more types can be used for a photoinitiator. The amount of the photopolymerization initiator is preferably 0.01 to 5% by mass and particularly preferably 0.03 to 2% by mass with respect to the total amount of the liquid crystal composition.

Next, the optical element of the present invention will be described.
In the optical element of the present invention, the liquid crystal composition is sandwiched between a pair of supports subjected to an alignment treatment, and the liquid crystal composition exhibits a liquid crystal phase and is polymerized in a state where the liquid crystal is aligned. Contains the resulting polymer.

  As the support, a support obtained by subjecting a transparent substrate made of glass or resin to an orientation treatment is preferable. The alignment treatment is a method of directly rubbing the transparent substrate surface with fibers such as cotton, wool, nylon, polyester, etc., a method of laminating a polyimide alignment film on the transparent substrate surface and then rubbing the alignment film surface with the above fibers, etc., transparent substrate It is preferable to carry out the method by oblique deposition of an inorganic material on the surface.

Next, spacers such as glass beads are arranged on the surface subjected to the alignment treatment, the plurality of supports are opposed to each other at a desired interval, and the liquid crystal composition is sandwiched between the supports. When the liquid crystal composition sandwiched between the supports is a polymerizable liquid crystal composition, polymerization is performed thereafter. The polymerization can be performed in the same manner as the polymerization for producing the optically anisotropic material. The polymer obtained by polymerization may be used while being sandwiched between supports, or may be used after being peeled from the support.
The optical element of the present invention may be an optical element in which a non-polymerizable liquid crystal composition is simply sandwiched between two supports, or an optical element produced by polymerizing a polymerizable liquid crystal composition. Good.
If the operation is not switched by voltage application, an optical element using a polymerized optically anisotropic material is preferable because there is little variation in characteristics as an optical element. Moreover, although this polymer can be used alone, that is, an optically anisotropic material alone, it is preferable to have a structure held on some support because it is easy to maintain its shape and hardly break. Specifically, a structure in which an optically anisotropic material that is a polymer is sandwiched between a pair of supports, or a structure in which an optically anisotropic material is stacked on a single support is preferable.

Since the optically anisotropic material and optical element of the present invention exhibit good durability against blue laser light, they are useful as optically anisotropic materials and optical elements that are used by transmitting the laser light.
For example, when a nematic liquid crystal composition or a smectic liquid crystal composition is used, an optically anisotropic material used for modulating the phase state and / or wavefront state of laser light utilizing refractive index anisotropy And it is useful as an optical element having a member made of this optically anisotropic material. Further, when a cholesteric liquid crystal composition is used, it is mounted on an optical head device and used as a diffraction element such as a polarization hologram utilizing circularly polarized birefringence. Examples of the polarization hologram include an example in which signal light generated by light emitted from a laser light source being reflected by an information recording surface of an optical disc is separated and guided to a light receiving element. Other applications include optical rotators, circularly polarized light selective mirrors, and compensation films.

  Furthermore, the optically anisotropic material of the present invention is a film obtained by polymerization, having a high Δn value, a low melting point and excellent handleability, as with conventional liquid crystal materials excellent in blue light resistance. Has the advantage of low transmission loss due to scattering. In addition, since the Δn value is high, the degree of freedom in designing the optical element is high.

  Hereinafter, the present invention will be specifically described with reference to synthesis examples of the compound of the present invention, but the synthesis of the compound according to the present invention is not limited by these examples.

[Synthesis Example 1] Synthesis Example of Compound (1A-1-1) (R ²¹ = methyl group, R ²² = propyl group):
[Example 1-1] Synthesis example of compound (13)

A 2000 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus was cooled to 0 ° C., and 500 mL of a 2 mol / L allylmagnesium chloride THF solution (manufactured by Aldrich) was added thereto, to which compound (11) ( 110.0 g, 0.434 mol) dissolved in dehydrated tetrahydrofuran (500 mL) was added dropwise over 30 minutes under a nitrogen stream. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and a 1 mol / L aqueous ammonium chloride solution (200 mL) was added to stop the reaction.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. After drying the organic layer with anhydrous magnesium sulfate, anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated to obtain 12.4 g of compound (12). The yield was 98%. At this stage, no further purification was carried out and the next synthesis step proceeded.

In a 1000 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus, compound (12) (112.4 g, 0.426 mol), NaBH ₄ (9.4 g, 0.249 mol), dehydrated tetrahydrofuran ( 500 mL) was added and dissolved. To this, 49.0 g of BF ₃ -diethyl ether complex manufactured by Tokyo Chemical Industry was dropped over 30 minutes. After completion of dropping, the mixture was stirred at room temperature for 4 hours. Furthermore, 295 mL of 20% -NaOH aqueous solution was dropped into this system over 30 minutes. Subsequently, a 30% aqueous hydrogen peroxide solution was dropped into this system over 30 minutes. After completion of dropping, the mixture was stirred overnight at room temperature.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. After drying the organic layer with anhydrous magnesium sulfate, anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated to obtain 108.8 g of Compound (13). The yield was 85%. At this stage, no further purification was carried out and the next synthesis step proceeded.

３０００ｍＬのナスフラスコに化合物（１３）（１０８．８ｇ、０．３６２モル）、Ｋ_２ＣＯ_３（３００．２ｇ、２．１７３モル）、テトラブチルアンモニウムブロミド（４．７ｇ、０．０１５モル）、塩化ルテニウム（Ｉ）（１．５０ｇ、０．０７２モル）、酢酸エチル５００ｍＬ、水２００ｍＬを加えた。これに、トリクロロイソシアヌル酸（１６８．３ｇ、０．７２４モル）を酢酸エチル（２００ｍＬ）に溶解させたものを、３０分かけて滴下した。滴下終了後、室温で１晩攪拌した。
これにイソプロピルアルコール１００ｃｃを加えて反応を停止させた後、２０％−ＨＣｌ水溶液および酢酸エチルを加えて分液し、有機層を回収した。回収した有機層を飽和塩化ナトリウム水溶液で洗浄し、つぎに水洗し、再度有機層を回収した。有機層を無水硫酸マグネシウムで乾燥した後、減圧濾過によって無水硫酸マグネシウムを除去し、濾液を濃縮し化合物（１４）を１７．８ｇ得た。収率は１５％であった。この段階ではこれ以上の精製を行わず、次の合成ステップに進んだ。 [Example 1-2] Synthesis example of compound (14)

In a 3000 mL eggplant flask, compound (13) (108.8 g, 0.362 mol), K ₂ CO ₃ (300.2 g, 2.173 mol), tetrabutylammonium bromide (4.7 g, 0.015 mol), Ruthenium (I) chloride (1.50 g, 0.072 mol), ethyl acetate 500 mL, and water 200 mL were added. To this, trichloroisocyanuric acid (168.3 g, 0.724 mol) dissolved in ethyl acetate (200 mL) was added dropwise over 30 minutes. After completion of dropping, the mixture was stirred overnight at room temperature.
To this was added 100 cc of isopropyl alcohol to stop the reaction, and then 20% -HCl aqueous solution and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, and then anhydrous magnesium sulfate was removed by filtration under reduced pressure. The filtrate was concentrated to obtain 17.8 g of compound (14). The yield was 15%. At this stage, no further purification was carried out and the next synthesis step proceeded.

還流装置、撹拌機を装備した５００ｍＬのナス型フラスコに化合物（１４）（１７．８ｇ、０．０５４モル）、パラトルエンスルホン酸一水和物（０．１３ｇ、０．００５モル）、エタノール６．４ｃｃ、トルエン（２００ｍＬ）を加え、これに、モレキュラーシーブ４Ａ（２０ｇ）の入った等圧滴下漏斗をつけ、１１０℃で４時間撹拌、還流した。
反応終了後、水および酢酸エチルを加えて分液し、有機層を回収した。回収した有機層を飽和塩化ナトリウム水溶液で洗浄し、つぎに水洗し、再度有機層を回収した。有機層を無水硫酸マグネシウムで乾燥した後、減圧濾過によって無水硫酸マグネシウムを除去し、濾液を濃縮した。得られた濾液を、ジクロロメタンを展開液としたカラムクロマトグラフィーにより精製を行い（Ｒｆ値０．７８）、化合物（１５）（１６．７ｇ）を得た。収率は８０％であった。 [Example 1-3] Synthesis example of compound (16)

In a 500 mL eggplant-shaped flask equipped with a reflux apparatus and a stirrer, compound (14) (17.8 g, 0.054 mol), paratoluenesulfonic acid monohydrate (0.13 g, 0.005 mol), ethanol 6 .4 cc, toluene (200 mL) was added, and an isobaric dropping funnel containing molecular sieve 4A (20 g) was attached thereto, followed by stirring and refluxing at 110 ° C. for 4 hours.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane as a developing solution (Rf value 0.78) to obtain compound (15) (16.7 g). The yield was 80%.

In a 500 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus, compound (15) (16.7 g, 0.043 mol), sodium hydride (60% oil) (2.42 g, 0.0602) were added. Mol) and dehydrated toluene (200 mL) were added, and the mixture was stirred at 100 ° C. for 3 hours while distilling off the generated ethanol.
The reaction was stopped by adding a 20% -hydrogen chloride aqueous solution, and then water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane as a developing solution (Rf value 0.72) to obtain compound (16) (13.3 g). The yield was 91%.

[Example 1-4] Synthesis example of compound (17)

In a 500 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus, compound (16) (13.3 g, 0.039 mol), sodium chloride (3.19 g, 0.055 mol), water (1 mL) ), 100 mL of dimethyl sulfoxide was added, and the mixture was stirred at 140 ° C. overnight.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane as a developing solution (Rf value 0.72) to obtain compound (17) (7.68 g). The yield was 74%.

The ¹ HNMR spectrum of the compound (17) is shown below.
¹ HNMR (400 MHz, solvent: CDCl ₃ , internal standard: TMS) δ (ppm): 1.53 to 1.55 (m, 4H), 2.55 to 2.65 (m, 4H), 7.25 7.65 (m, 10H).

[Example 1-5] Synthesis example of compound (19)

Magnesium (0.97 g, 0.040 mol) and iodine (0.1 g) are added to a 500 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus, and 1-bromo-4-methoxybenzene (6 .48 g, 0.035 mol) dissolved in dehydrated tetrahydrofuran (50 mL) was first dropped a few drops under a nitrogen stream and heated with a dryer. After the reaction started and the iodine color changed to colorless, the remaining solution was added dropwise over 30 minutes. At this time, it is slowly added dropwise so that the reaction temperature does not increase. After completion of dropping, the mixture was stirred at room temperature for 3 hours to prepare a Grignard reagent (18). Next, this four-necked flask was cooled to 0 ° C., and compound (17) (7.68 g, 0.029 mol) dissolved in dehydrated tetrahydrofuran (100 mL) was added for 30 minutes under a nitrogen stream. In short, it was dripped. After completion of the dropwise addition, the mixture was stirred and refluxed at 70 ° C. for 3 hours, and a 1 mol / L aqueous ammonium chloride solution (50 mL) was added to stop the reaction.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, then anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated to obtain a mixture containing the compound (19). At this stage, no further purification was carried out and the next synthesis step proceeded.

[Example 1-6] Synthesis example of compound (20)

In a 500 mL eggplant-shaped flask equipped with a reflux apparatus and a stirrer, compound (19) obtained in [Example 1-5] (weight not measured), paratoluenesulfonic acid monohydrate (0.13 g, 0.005) Mol) and toluene (200 mL) were added, and an isobaric dropping funnel containing molecular sieve 4A (20 g) was attached thereto, followed by stirring and refluxing at 110 ° C. for 4 hours.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane as a developing solution (Rf value 0.89) to obtain compound (20) (7.23 g). The yield from the compound (17) to the compound (20) was 70%.

[Example 1-7] Synthesis example of compound (21)

  To a 500 mL four-necked flask was added compound (20) (7.23 g, 0.020 mol), tetrahydrofuran (200 mL), 10% palladium-activated carbon (1.6 g). The mixture was stirred at room temperature for 24 hours while introducing hydrogen at a pressure of 0.4 MPa. After completion of the reaction, the catalyst was removed by filtration, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 50/50 (vol%) as a developing solution (Rf value 0.68) to obtain Compound (21) (7.13 g). The yield was 98%.

[Example 1-8] Synthesis example of compound (22)

  Compound (21) (7.13 g, 0.020 mol) and dehydrated dichloromethane (50 mL) were added to a 500 mL eggplant flask. A solution obtained by dissolving iodine monochloride (3.55 g, 0.022 mol) in 50 mL of dehydrated dichloromethane was slowly added dropwise thereto. After completion of dropping, the mixture was stirred at room temperature for 3 hours. Further, this reaction solution was slowly dropped into a THF solution of LAH (0.81 g, 0.022 mol). After stirring for several minutes, 20% aqueous hydrogen chloride solution was added to stop the reaction, and water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 30/70 (vol%) as a developing solution (Rf value 0.61) to obtain Compound (22) (5.05 g). The yield was 90%.

[Example 1-9] Synthesis example of compound (24-1)

Compound (22) (5.05 g, 0.018 mol), iron (III) chloride (3.19 g, 0.020 mol), and dehydrated toluene (200 mL) were added to a 500 mL four-necked flask. The mixture was stirred at room temperature for 30 minutes while bubbling hydrogen chloride gas. Thereby, the compound (22-2) described above is generated in the reaction system. The reaction solution was filtered through Celite to remove the catalyst, and the filtrate was concentrated. 50 mL of dehydrated THF was added thereto, and the mixture was kept in a nitrogen atmosphere.
Separately, the Grignard reagent (23-1) was generated from 1-bromo-4-propylbenzene (3.58 g, 0.018 mol) using the same method as in [Example 1-5]. To this, the THF solution of the active compound (22-2) that had been waiting was slowly added dropwise at room temperature under a nitrogen stream. After completion of dropping, the mixture was stirred and refluxed at 70 ° C. for 3 hours.
Water was added to stop the reaction, and water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 30/70 (vol%) as a developing solution (Rf value 0.57), and a cis-trans mixture of compound (24-1) (3 .47 g) was obtained. The yield was 60%.
The cis isomer and the trans isomer are present in a ratio of approximately 70%: 30% (cis isomer: trans isomer), and recrystallization is performed using hexane to obtain the trans isomer (24-1), that is, the compound (1A-1 -1) was obtained 2.00g.

The ¹ HNMR spectrum of the compound (1A-1-1) is shown below.
¹ HNMR (400 MHz, solvent: CDCl ₃ , internal standard: TMS) δ (ppm): 0.85 to 1.00 (m, 5H), 1.15 to 1.35 (d, 2H), 1.50 1.85 (m, 4H), 2.15 to 2.25 (d, 2H), 2.45 (t, 1H), 2.60 (t, 2H), 3.72 (s, 3H), 4 .38 (t, 1H), 6.80 (dd, 2H), 7.00 to 7.32 (m, 4H), 7.45 to 7.60 (dd, 2H).
The phase transition temperature from the crystal phase of the compound (1A-1-1) to the nematic phase was 48.0 ° C., and the phase transition temperature from the nematic phase to the isotropic phase was 85.4 ° C.

[Synthesis Example 2] Synthesis Example of Compound (1A-3-1) (R ²² = propyl group):
[Example 2-1] Synthesis example of compound (25-1)

Compound (24-1) (2.00 g, 0.0062 mol) and dehydrated toluene were added to a 500 mL eggplant flask. To this, 60 mL of a 1.0 mol / L-THF solution (manufactured by Aldrich) of LiBH (sec-C ₄ H ₉ ) ₃ was slowly added dropwise under a nitrogen atmosphere. After completion of dropping, the mixture was stirred at room temperature for 1 week.
Water was added to stop the reaction, and water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane as a developing solution to obtain compound (25-1) (0.96 g). The yield was 50%.

[Example 2-2] Synthesis example of compound (1A-3-1)

To a 300 mL four-necked flask, compound (25-1) (0.96 g, 0.020 mol), tetrahydrofuran (100 mL), and triethylamine (0.34 g, 0.0034 mol) were added. Acrylic acid chloride (0.68 g, 0.0074 mol) was slowly added dropwise thereto while cooling with ice so that the internal temperature did not exceed 20 ° C. under a nitrogen stream. After completion of dropping, the mixture was stirred overnight at room temperature.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 50/50 (vol%) as a developing solution, and further recrystallized using hexane to obtain compound (1A-3-1). (1.01 g) was obtained. The yield was 90%.

The ¹ HNMR spectrum of the compound (1A-3-1) is shown below.
¹ HNMR (400 MHz, solvent: CDCl ₃ , internal standard: TMS) δ (ppm): 0.78 to 1.00 (m, 6H), 1.18 to 1.32 (t, 3H), 1.58 to 1.90 (m, 4H), 2.10-2.30 (d, 2H), 2.40-2.70 (m, 3H), 4.38 (t, 1H), 5.90-6. 10 (d, 1H), 6.20 to 6.40 (m, 1H), 6.45 to 6.70 (d, 1H), 7.05 (dd, 2H), 7.19 to 7.25 ( m, 4H), 7.47-7.49 (dd, 2H).
The phase transition temperature from the crystal phase of the compound (1A-3-1) to the nematic phase was 75.2 ° C., and the phase transition temperature from the nematic phase to the isotropic phase was 117.6 ° C.

[Synthesis Example 3] Synthesis Example of Compound (1B-7-1) (R ²¹ = methyl group, R ²² = propyl group):
[Example 3-1] Synthesis example of compound (31-3)

The precursor of the Grignard reagent (30-1) was prepared by Suzuki coupling of 5-bromo-2-iodotoluene and 4-propylphenylboronic acid as described above. This synthesized precursor (16 g, 0.065 mol) was used to generate a Grignard reagent (30-1) by using the same method as in [Example 1-5] described above.
On the other hand, (22-2) was synthesized from the compound (22) (18.5 g, 0.066 mol) using the method of [Example 1-9] described above to prepare a dehydrated THF solution thereof.
To the Grignard reagent (30-1), the dehydrated THF solution of (22-2) was slowly added dropwise at room temperature under a nitrogen stream. After completion of dropping, the mixture was stirred and refluxed at 70 ° C. for 3 hours.
Water was added to stop the reaction, and water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 30/70 (vol%) as a developing solution (Rf value 0.54 to 0.46), and cis- A trans mixture (17.65 g) was obtained. The yield was 65%. The cis isomer and the trans isomer are present at a ratio of approximately 70%: 30% (cis isomer: trans isomer), and recrystallization is performed using hexane to obtain the trans isomer (31-1), that is, the compound (1B-7). -1) was obtained 10.77g.

The ¹ HNMR spectrum of the compound (1B-7-1) is shown below.
¹ HNMR (400 MHz, solvent: CDCl ₃ , internal standard: TMS) δ (ppm): 0.85 to 1.10 (m, 5H), 1.20 to 1.38 (d, 2H), 1.50 1.90 (m, 4H), 2.05 to 2.30 (m, 5H), 2.50 (t, 1H), 2.62 (t, 2H), 3.80 (s, 3H), 4 .40 (t, 1H), 6.80 (dd, 2H), 7.10 to 7.30 (m, 7H), 7.40 to 7.55 (dd, 2H).
The phase transition temperature from the crystal phase of the compound (1B-7-1) to the nematic phase was 68.0 ° C., and the phase transition temperature from the nematic phase to the isotropic phase was 150.1 ° C.

前記化合物（３１−１）（１０．７７ｇ、０．０２７モル）に対して、[例２−１]と同様の方法を用いて化合物（３１−２）（６．２３ｇ）を得た。収率は６０％であった。 [Synthesis Example 4] Synthesis Example of Compound (1B-31-1) (R ²² = propyl group):
[Example 4-1] Synthesis example of compound (31-2)

With respect to the compound (31-1) (10.77 g, 0.027 mol), a compound (31-2) (6.23 g) was obtained in the same manner as in [Example 2-1]. The yield was 60%.

[Example 4-2] Synthesis example of compound (1B-31-1)

Compound (31-2) (6.23 g, 0.0156 mol), CH ₂ = CH—COO— (CH ₂ ) ₆ —Br () was added to a 500 mL four-necked flask equipped with a reflux apparatus, a stirrer, and a dropping apparatus. 4.39 g, 0.019 mol), potassium carbonate (2.58 g, 0.019 mol), potassium iodide (0.4 g), and acetone (100 mL) were added, and the mixture was stirred and refluxed at 60 ° C. for 24 hours.
After completion of the reaction, water and ethyl acetate were added for liquid separation, and the organic layer was recovered. The collected organic layer was washed with a saturated aqueous sodium chloride solution, then washed with water, and the organic layer was collected again. The organic layer was dried over anhydrous magnesium sulfate, the anhydrous magnesium sulfate was removed by filtration under reduced pressure, and the filtrate was concentrated. The obtained filtrate was purified by column chromatography using dichloromethane / hexane = 30/70 as a developing solution, and further recrystallized from hexane to obtain Compound (1B-31-1) (5.18 g). Obtained. The yield was 60%.

The ¹ HNMR spectrum of the compound (1B-31-1) is shown below.
¹ HNMR (400 MHz, solvent: CDCl ₃ , internal standard: TMS) δ (ppm): 0.83 to 1.10 (m, 5H), 1.15 to 1.38 (d, 2H), 1.39 to 1.88 (m, 12H), 2.05 to 2.35 (m, 5H), 2.45 (t, 1H), 2.60 (t, 2H), 3.94 (t, 2H), 4 .17 (t, 2H), 4.40 (t, 1H), 5.80 (d, 1H), 6.02 to 6.20 (m, 1H), 6.37 (d, 1H), 6. 82 (dd, 2H), 7.10 to 7.35 (m, 7H), 7.38 to 7.50 (dd, 2H).
The phase transition temperature from the crystal phase to the nematic phase of the compound (1B-31-1) was 54.5 ° C., and the phase transition temperature from the nematic phase to the isotropic phase was 105.6 ° C.

Examples 1-4
[Physical properties of liquid crystal compounds]
Table 1 shows compounds (1A-1-1), (1A-3-1), (1B-7-1), and (1B-31-1) obtained in Synthesis Examples 1 to 4 (hereinafter, Comparative Examples 1 to 4 and Comparative Examples 1 to 4 in which the trans 1,4-cyclohexylene group is not substituted with a silicon atom are used (Examples 1 to 4). ) Initial melting point, liquid crystal phase transition temperature, and Δn value.

The liquid crystal phase transition temperature shown in Table 1 is to inject each of the above compounds into a cell with an alignment film, observe the change of the compound with a polarizing microscope while lowering the temperature in the cell, and measure the temperature when the phase transition occurs. Determined by.
The values of the liquid crystal phase transition in Table 1 are, for example, “C 30 N 77 I”, which is a phase transition (Tc) from an isotropic phase to a nematic phase at 77 ° C. and crystallized from the nematic phase at 30 ° C. It shows that the phase has undergone a phase transition (Tm). The notation of “<29” in the phase transition temperature (Tm) from the nematic phase to the crystal phase indicates that the liquid crystal compound was in a supercooled state at room temperature and no melting point was observed.

(Measuring method of Δn)
Each liquid crystal compound was injected into a wedge-shaped cell. The wedge-shaped cell was observed with a polarizing microscope having two orthogonal polarizers (crossed Nicols), and the interval between the interference fringes was observed to calculate Δn.
The temperature at the time of measurement was the same as that shown in Table 1, and the measurement wavelength was 405 nm.

From Table 1, it was confirmed that the compounds of Examples 2 to 4 of the present invention had a lower initial melting point than each of the comparative compounds and were excellent in handleability.
Moreover, also in the cell with an alignment film, it has confirmed that the compound of this invention had low melting | fusing point compared with each comparative compound. Therefore, it can be seen that these compounds of the present invention can obtain the effect of lowering the melting point of the liquid crystal composition.
Further, when the Δn value of the compound (1B-7-1) (Example 3) and the comparative compound (Comparative Example 3) are compared, the compound (1B-7-1) of the present invention has a high Δn value. I was able to confirm.
About the (DELTA) n value of the compound which has a polymeric group, in Example 5 as a composition, it shows below.

Example 5 and Comparative Example 5
[Preparation and polymerization of liquid crystal composition]
A liquid crystal composition A prepared by mixing the polymerizable compound (1B-31-1) of the present invention (Example 4) and “other polymerizable liquid crystal compound” other than the compound of the present invention in the ratios shown in Table 2. Obtained (Example 5). Moreover, the liquid crystal composition B which mixed only the "other polymerizable liquid crystal compound" in the ratio shown in Table 2 was obtained (Comparative Example 5).
As "other polymerizable liquid crystal compounds", the following compounds (3-1-1a), (3-1-1c), (3-2-1b), (3-2-2b1) and (3- 2-2b2) was used.
In addition, the ratio described in Table 2 is a ratio (mol%) of each polymerizable liquid crystal compound to the total polymerizable liquid crystal compound constituting the liquid crystal composition.

Next, 0.5% by mass of a polymerization initiator (manufactured by Ciba Japan Co., Ltd., trade name “Irgacure” 184) is added to the liquid crystal compositions A and B, and a polymerization inhibitor (trade name “AO50”, manufactured by ADEKA CORPORATION). Liquid crystal composition A1 and B1 were added by adding 0.4% by mass and 1.5% by mass of a light stabilizer (trade name “Tinuvin 123” manufactured by Adeka Corporation).
Further, the liquid crystal compositions A1 and B1 were polymerized by the following method to obtain liquid crystal composition polymers A2 and B2.

First, a polyimide solution was applied to a glass substrate having a length of 5 cm, a width of 5 cm, and a thickness of 0.5 mm using a spin coater and dried. Next, a support was prepared by rubbing in a certain direction with a nylon cloth, and two cells were bonded using an adhesive so that the surfaces subjected to the alignment treatment face each other to prepare a cell. Glass beads having a diameter of 6 μm were added to the adhesive, and the distance between the supports was adjusted to 6 μm.
Next, the liquid crystal compositions A1 and B1 were injected into the cell at 90 ° C., followed by irradiation with ultraviolet rays having an intensity of 130 mW / cm ² for 3 minutes at 40 ° C. to perform photopolymerization. Thereby, liquid crystal composition polymers A2 and B2 were obtained. These polymers were horizontally oriented with respect to the rubbing direction of the substrate, and scattering or the like could not be confirmed visually.

Table 3 shows the liquid crystal phase transition temperature during cooling and the monomer Δn value at a wavelength of 405 nm for the liquid crystal compositions A1 and B1, and the polymer Δn value at a wavelength of 405 nm for the liquid crystal composition polymers A2 and B2.
The liquid crystal phase transition temperature and Δn value were measured by the same method as in Examples 1 to 4 and Comparative Examples 1 to 4. The temperature at the time of measuring the Δn value was measured at the temperature described in Table 3 for the Δn value of the monomer, and at room temperature for the Δn value of the polymer.

From Table 3, the liquid crystal composition A1 and the liquid crystal composition polymer A2 containing the compound of the present invention have a high Δn value equivalent to the conventional liquid crystal composition B1 and the liquid crystal composition polymer B2 not containing a silicon atom. It was confirmed to be a thing.
Further, at the time of measuring the liquid crystal phase transition, both the liquid crystal compositions A1 and B1 were in a supercooled liquid crystal state at room temperature. When these cells were allowed to stand for a long time, deposition was confirmed in the liquid crystal composition B1. Therefore, it was confirmed that the liquid crystal composition B1 had a higher phase transition point (melting point) to the crystal phase than the liquid crystal composition A1.

[Characteristics of cured film of liquid crystal composition]
The liquid crystal compositions A1 and B1 were injected into 6 μm cells, 10 μm, and 15 μm cells with alignment films prepared by the above method, and photopolymerization was performed. The transmittance at this time is shown in FIG. In FIG. 1, the horizontal axis represents the Rd value (retardation, Δn × film thickness, unit is nm), and the vertical axis represents the transmittance.

  From FIG. 1, it was confirmed that the film obtained by polymerizing the liquid crystal composition A1 containing the compound of the present invention has very low light scattering and excellent transmittance characteristics even when the Rd value is high, that is, when the film thickness is large. .

[Blue light resistance of cured film]
Liquid crystal compositions A1 and B1 were injected into a 5 μm cell with an alignment film prepared by the above method, and photopolymerization was performed to prepare optically anisotropic films A3 and B3.
This optically anisotropic film (hereinafter referred to as a cured film) A3 and B3 was irradiated with a Kr laser (multimode of wavelengths 407 nm and 413 nm), and a blue laser light exposure acceleration test was performed. The irradiation conditions were a temperature of 80 ° C. and an integrated exposure energy of 20 W · hour / mm ² .
The amount of change in transmittance after exposure to blue laser light with an integrated exposure energy of 20 W · hour / mm ² was −1.6% for cured film A3 and −4.4% for cured film B3. From the above, the liquid crystal composition containing the compound (1B-31-1) of the present invention (Example 4) has a low melting point and excellent handling, and an optically anisotropic film obtained using the liquid crystal composition The (cured film) was confirmed to maintain a high Δn value and extremely low transmittance loss. Further, the optically anisotropic film (cured film) was excellent in light resistance.

Example 6 and Comparative Example 6
[Preparation and polymerization of cholesteric liquid crystal composition]
A liquid crystal composition C in which the polymerizable compound (1B-31-1) of the present invention (Example 4) and other polymerizable liquid crystal compound were mixed at the ratio shown in Table 4 was obtained (Example 6). Further, a liquid crystal composition D was obtained using only the “other polymerizable liquid crystal compound” (Comparative Example 6).
In addition, the ratio described in Table 4 is a ratio (mol%) of each polymerizable liquid crystal compound with respect to the total polymerizable liquid crystal compound constituting the liquid crystal composition.

Next, in the same manner as described above, 0.5% by mass of a polymerization initiator (manufactured by Ciba Japan Co., Ltd., trade name “Irgacure 184”) and a polymerization inhibitor (manufactured by Adeka Co., Ltd. The liquid crystal compositions C1 and D1 were obtained by adding 0.4% by mass of the name “AO50”) and 1.5% by mass of the light stabilizer (trade name “Tinuvin 123” manufactured by Adeka Corporation).
Furthermore, the polymerizable chiral dopant (4-1a) shown below was added to the liquid crystal compositions C1 and D1, respectively, to obtain cholesteric liquid crystal compositions C4 and D4. The amount of the chiral dopant (4-1a) added to the liquid crystal compositions C4 and D4 was 8.01% by mass for C4 and 9.60% by mass for D4, respectively.

Cholesteric liquid crystal compositions C4 and D4 were polymerized in the same manner as in Example 5 and Comparative Example 5 above. However, the cell used for the polymerization was one having a film thickness of 15 μm. Thereby, cured films C5 and D5, which are optical anisotropic films obtained by polymerizing the cholesteric liquid crystal composition, were obtained.
The amount of the chiral dopant (4-1a) added is adjusted in advance so that the short wavelength ends of the selective reflection bands of cured films C5 and D5 described later are both approximately 469 nm. This is because when a diffraction grating is formed using a film in which a selective reflection band is adjusted in such a band, left circularly polarized light is transmitted at a wavelength of 405 nm / right circularly polarized light is diffracted. This is because a special optical element that transmits light can be manufactured (see Patent Document 3).
In these polymers, liquid crystal mesogens were horizontally aligned with the rubbing direction of the substrate. Further, both the cured films C5 and D5 reflected the right circularly polarized light.

[Characteristics of cured film of cholesteric liquid crystal composition]
2 and 3 show light transmittance spectra in the fixed wavelength region for the cured films C5 and D5. However, among the spectra shown in FIGS. 2 and 3, the spectrum having a large selective reflection band on the lower side is due to right circular polarization, and the other is due to left circular polarization.
The light transmittance spectrum is measured by taking out linearly polarized light through a non-polarized light emitted from the light source into a polarizer placed at the tip of the light source and making this linearly polarized light incident on the λ / 4 wavelength plate at a predetermined angle. Then, the light was converted into polarized light (right circular polarization or left circular polarization), this polarized light was transmitted through the sample, and the obtained transmitted light was measured with a spectrometer.

  Of the transmittance spectra shown in FIGS. 2 and 3, the numerical values of the left circularly polarized light transmittance and the right circularly polarized light transmittance at a wavelength of 405 nm, which are particularly important, are extracted and shown in Table 5.

  From Table 5, the cured film of the cholesteric liquid crystal composition C1 containing the compound (1B-31-1) of the present invention (Example 4) is compared with the cured film of the liquid crystal composition D1, left circularly polarized light, right circle It can be seen that both the polarized light and the transmittance characteristics are excellent.

[Light resistance of cholesteric cured film]
A blue laser light exposure acceleration test was performed on the cured films C5 and D5 in the same manner as in Example 5 and Comparative Example 5. The irradiation conditions were a temperature of 80 ° C. and an integrated exposure energy of 15 W · hour / mm ² .
The amount of change in transmittance after exposure to blue laser light with an integrated exposure energy of 15 W · hour / mm ² was within ± 2% for both the cured films C5 and D5.
From the above, the cholesteric liquid crystal composition containing the compound of the present invention can obtain an optically anisotropic film with extremely low transmittance loss. Furthermore, this optically anisotropic film is excellent in light resistance.

Claims (9)

A compound represented by the following formula (1).
_{^{A-Ph-E 1 -Ph- (}} Ph) m - (E 2) n -B-R 2 ··· (1)
However, the symbols in the formulas have the following meanings.
A: CH ₂ = CR ¹ —COO— (L) _k — or an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms.
However, the alkyl group and the alkoxy group may be linear or branched, the hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group contain an ether bond. Also good.
R ¹ : a hydrogen atom or a methyl group.
L: — (CH ₂ ) _p O—, — (CH ₂ ) _q −, the hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkylene group may contain an ether bond. (However, p and q are each independently an integer of 2 to 8.)
k: 0 or 1.
_{B: -CH 2 -, - OCH} 2 -, - SiH 2 -, or -Si _{(CH 3)} 2 -.
R ² : an alkyl group having 1 to 7 carbon atoms or an alkoxy group having 1 to 7 carbon atoms.
However, the alkyl group and the alkoxy group may be linear or branched, the hydrogen atom may be substituted with a fluorine atom or a chlorine atom, and the alkyl group and the alkoxy group contain an ether bond. Also good.
Ph: 1,4-phenylene group. (However, the A side of the cyclic group is the first position.)
m, n: 0 or 1 independently.
E ¹ : A cyclic group represented by the following formula in which the 4-position carbon atom of the trans 1,4-cyclohexylene group is substituted with a silicon atom (provided that the A side of the cyclic group is the 1-position):

E ² : a cyclic group represented by the following formula in which the 1-position carbon atom of the trans 1,4-cyclohexylene group is substituted with a silicon atom (provided that the A side of the cyclic group is the 1-position):

However, X < ₁ >, X < ₂ > is a hydrogen atom or a methyl group each independently.
In the 1,4-phenylene group in the formula (1), a hydrogen atom bonded to a carbon atom in the ring group may be substituted with a fluorine atom, a chlorine atom or a methyl group.
In E ¹ and E ² in formula (1), a hydrogen atom bonded to a carbon atom in the ring group may be substituted with a fluorine atom, a chlorine atom or a methyl group.   The compound according to claim 1, wherein n = 0. A is ^{_{CH 2 = CR 1 -COO- (L}} ) k - A compound according to claim 1 or 2 is.   4. A compound according to claim 3, wherein k = 1.   The liquid crystal composition containing the compound in any one of Claims 1-4.   A polymerizable liquid crystal composition containing the compound according to claim 3.   A polymerizable cholesteric liquid crystal composition comprising a polymerizable chiral material in the polymerizable liquid crystal composition according to claim 6.   An optically anisotropic material obtained by polymerizing a liquid crystal composition containing the compound according to claim 3 or 4.   An optical element having a structure in which the optically anisotropic material according to claim 8 is sandwiched between a pair of supports or laminated on a single support.

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