JP2001122817A - Benzyl ether derivative, liquid crystal material, liquid crystal compositiion, ane liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new benzyl ether derivative capable of being used as an antiferroelectric or non-threshold antiferroelectric liquid crystal, to provide a liquid crystal composition containing the same and having high speed of response, and to provide a liquid crystal device having clear contrast and capable of being driven as an active matrix liquid crystal device by utilizing the same. SOLUTION: This benzyl ether derivative has a chemical structure expressed by formula [1] (R1 is an alkyl; X1 is -COO-, -Oor single bond; X2 and X3 are each -COO-, -CH2O-or single bond; A1 and A2 are each tetralin ring; m and n are each 0-2; and Q1 and Q2 are each a lower alkyl). The liquid crystal device is obtained by filling a liquid crystal cell with the liquid crystal composition containing the benzyl ether derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel benzyl ether derivative, a liquid crystal material comprising the derivative, a liquid crystal composition containing the derivative, and a liquid crystal device using the derivative.

[0002]

BACKGROUND OF THE INVENTION A liquid crystal display is a CRT (ca).
Thode-ray tubes (cathode ray tubes) are thinner, lighter, have lower voltage drive, and are easier on the eyes, so they were initially used for calculators and wristwatches. It is used in various fields as monitors for laptop computers and small televisions.

The liquid crystal currently used for the liquid crystal display is mainly a nematic liquid crystal, but the response time is as long as several tens of ms, so that there is a limit in increasing the display area or the number of pixels. As a solution, TFT (Thin FilmTransister) and STN (Super
Twisted Nematic) has been adopted,
Displays that are 5 inches or larger can now be commercialized. The display quality is also approaching that of CRTs due to improvements in device structures and driving methods. However, in order to obtain a display equal to or higher than that of a CRT, it is necessary to further increase the response speed of the liquid crystal itself.

[0004] Recently, ferroelectric liquid crystals and antiferroelectric liquid crystals have been noticed in place of conventional nematic liquid crystals. These liquid crystals have spontaneous polarization, and the product of the spontaneous polarization and the electric field strength is the effective energy for operating the liquid crystal. Therefore, the response time is expected to be short, and high-speed response is possible.

For example, in a display element (surface-stabilized ferroelectric liquid crystal element) in which a ferroelectric liquid crystal is placed in a cell having a thickness of about several μm, for example, a paper by NA Clark et al.
and ST Lagerwall, Appl. Phys. Lett., 36, 899 (19
As described in 80)), the liquid crystal can take two stable states with respect to the electric field, the switching time for the electric field between these stable states is on the order of a few microseconds, and the response time is It turns out to be very short. Since the antiferroelectric liquid crystal also has three stable states, it is considered that high-speed switching can be performed similarly.

In a television (color moving image, VGA) display,
The writing time per pixel is 1 / ｛30 times / second ×
It is calculated as 640 lines × 3｝ ≒ 17 μsec. In order to realize this short writing time with a conventional nematic liquid crystal, a complicated driving method such as active matrix driving (TFT method) or multi-line driving (STN method) is required. On the other hand, when a ferroelectric liquid crystal or an antiferroelectric liquid crystal having a high response speed is used, driving with a simple matrix is possible. As for the viewing angle of the display, the nematic liquid crystal requires an optical compensation film and a special device structure, but the ferroelectric liquid crystal and the antiferroelectric liquid crystal do not particularly require them.

However, the ferroelectric liquid crystal has a halftone display,
Improvements such as orientation, impact resistance, and baking due to the memory properties of the liquid crystal are required. For antiferroelectric liquid crystals, these points have been solved, but the performance of the liquid crystal temperature range, response speed, contrast, etc. There is a demand for improvement in the aspect.

Recently, among these antiferroelectric liquid crystals, a thresholdless antiferroelectric (TLAF) liquid crystal, which has a characteristic that the amount of transmitted light changes in a V-shape with respect to a voltage, has attracted attention (Tanaka et al. Proceedings of the 21st Symposium on Liquid Crystal, 2C18 (1995);
Proceedings of the 1st Liquid Crystal Symposium, 2C04 (1995)). that is,
In addition to the features of conventional antiferroelectric liquid crystals, analog gradation and low-voltage driving are possible, and halftone display can be performed at high speed. Expectations are growing.

A conventional antiferroelectric liquid crystal having three stable states with respect to an electric field and a thresholdless antiferroelectric (TLAF) liquid crystal in which the amount of transmitted light changes in a V-shape with respect to a voltage are applied to a display device. In such a case, it is required to clear the following conditions. That is, the operating temperature range is around room temperature and the operating temperature range is wide, the response by the electric field is fast, the tilt angle (the tilt angle of the long axis of the liquid crystal from the normal of the liquid crystal layer) is close to 45 degrees, Are good, the switching threshold value or the saturation voltage is within an appropriate range, and the spontaneous polarization is small. In particular, when performing active matrix driving, it is desirable to reduce spontaneous polarization as much as possible.

[0010]

Accordingly, an object of the present invention is to provide a novel benzyl ether derivative-based compound. In addition, the present invention uses a compound that can be used as a liquid crystal material, in particular, a compound having antiferroelectricity or thresholdless antiferroelectricity and having reduced spontaneous polarization, among such compounds.
Provide liquid crystal materials and liquid crystal compositions with high response speed near room temperature for antiferroelectric (SmCA *) and thresholdless antiferroelectric (SmCR *) phases, and liquid crystal devices with high contrast and active matrix driving With the goal.

[0011]

That is, the present invention relates to a benzyl ether derivative having the following chemical structure.

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(In the formula [1], R ₁ is a carbon atom having 1 to
20 alkyl group or at least one -CH ₂ present in the group, - is -O-, at least one group selected from the group consisting of hydrocarbon groups having halomethylene group, and unsaturated bond ( However, excluding those in which -O- are adjacent to each other).

X ₁ is -COO-, -OCO-, -CO
-, - O-and a group or bond selected from the group consisting of a single bond, X ₂ and X ₃ are each independently -
COO -, - OCO -, - CH 2 O -, - OCH 2 -, -
Represents a group or a bond selected from the group consisting of CH ₂ CH ₂ — and a single bond,

A ₁ and A ₂ each independently represent a group selected from the following group which may be substituted with one or more fluorine atoms;

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[0015] m and n is an integer of 0 to 2, Q _{1
Is, -CH 3, -C 2 H 5} , -C 3 H 7, -C 4 H 9, -C
Represents a group selected from the group consisting of F ₃ , —C ₂ F ₅ , and —C ₃ F ₇ , wherein Q ₂ represents an alkyl group, an alkenyl group, an alkynyl group having 1 to 10 carbon atoms, and One group selected from the group consisting of groups in which at least one of —CH ₂ — is substituted with —O—, —COO—, or a halomethylene group (excluding groups in which —O— are adjacent to each other) And C ^* represents an asymmetric carbon, provided that Q ₁ and Q ₂ may be the same or different. )

Further, according to the present invention, there is provided a liquid crystal material comprising the above-mentioned benzyl ether derivative, having an operating temperature range near room temperature, a wide operating temperature range, and a quick response to an electric field, and the above-mentioned benzyl ether derivative. And a liquid crystal composition comprising: It is preferable that the liquid crystal material or the liquid crystal composition has antiferroelectricity or thresholdless antiferroelectricity. Further, according to the present invention, a liquid crystal element which can be used as a liquid crystal display using the above liquid crystal material or the above liquid crystal composition is provided.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Next, a benzyl ether derivative according to the present invention, a liquid crystal material and a liquid crystal composition using the same,
Further, the structure of the liquid crystal element will be specifically described.

Benzyl ether derivative The benzyl ether derivative according to the present invention has the following formula [1]
It is represented by

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Here, R ₁ is a group defined below.
That is, R ₁ is an alkyl group having 1 to 20 carbon atoms, or at least one —CH ₂ — existing in these groups.
Is a group substituted with at least one group selected from the group consisting of —O—, a halomethylene group, and a hydrocarbon group having an unsaturated bond (excluding those in which —O— are adjacent to each other). Specific examples of the latter substituted group include H
(CH ₂ ) _a (CH ₂ O) _b (CH ₂ ) _c- (where a + b +
alkoxyalkyl group represented by c = 1 to 20) or _{C p H q Z (2p +} 2-q) (p = 1~20,, q = 0~40,
Z is a haloalkyl group represented by halogen). The hydrocarbon group having an unsaturated bond described above means a hydrocarbon group in which a carbon atom is bonded by a double bond or a triple bond, for example, -CH =
CH-, -C≡C-, and the hydrogen atom thereof may be substituted with a halogen atom or the like.

In consideration of the liquid crystal characteristics, R ₁ is particularly preferably the following group. (1) An alkyl group having 7 to 14 carbon atoms. (2) One —CH ₂ — present in these groups is —O
- substituted with radicals, _{e.g., CH 3 O (CH 2)} 6 -, C
_{H 3 O (CH 2) 10} -, CH 3 O (CH 2) 13 -, C 2 H 5 O
_{(CH 2) 5 -, C} 2 H 5 O (CH 2) 10 -, C 2 H 5 O (C
H _{2) 12} -. (3) A halogenated alkyl group in which a hydrogen atom present in these groups is replaced by a fluorine atom, for example, CF ₃ (C
_{H 2) 6 -, CF 3} (CH 2) 10 -, CF 3 (CH 2) 13 -,
_{C 2 F 5 (CH 2)} 5 -, C 2 F 5 (CH 2) 10 -, C 2 F
_{5 (CH 2) 12 -,} C 3 F 7 (CH 2) 5 -, C 3 F 7 (C
_{H 2) 10 -, C 3} F 7 (CH 2) 12 -, C 4 F 9 (CH 2) 5
_{-, C 4 F 9 (CH} 2) 10 -, C 4 F 9 (CH 2) 12 -.

X ₁ is -COO-, -OCO-, -CO
Any group or bond selected from the group consisting of-, -O- and a single bond. Considering the liquid crystal characteristics, X
₁ is preferably -COO-, -O-, or a single bond.

X ₂ and X ₃ are each independently —C
OO -, - OCO -, - CH 2 O -, - OCH 2 -, - C
It is a group or a bond selected from the group consisting of H ₂ CH ₂ — and a single bond. Among them, considering liquid crystal properties, X ₂ and X ₃ are each independently —COO—,
_{-CH 2 O -, - CH 2} CH 2 -, or is preferably a single bond.

A ₁ and A ₂ are each independently one group selected from the following group which may be substituted by one or more fluorine atoms.

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When used as a liquid crystal material, A ₁ and A ₂
Is preferably one group selected from the following group, which may be independently substituted by one or more fluorine atoms.

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In consideration of the liquid crystal properties, A ₁ and A ₂ are preferably each independently one group selected from the following group, which may be substituted with one or more fluorine atoms.

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Of these, any of the following groups is particularly preferable.

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M and n represent an integer of 0 to 2, and n is preferably 0 or 1 in consideration of the characteristics of the liquid crystal.

Q ₁ bonded to the asymmetric carbon C ^* is —CH ₃ ,
_{-C 2 H 5, -C 3 H} 7, -C 4 H 9, -CF 3, -C 2 F 5,
It represents a group selected from the group consisting of -C ₃ F _7. In view of the liquid crystal properties, Q ₁ is _{-CH 3, -C 2 H 5,} -C 3 H 7, -C
F ₃ or —C ₂ F ₅ is preferred, and a more preferred group is —CH ₃ .

Similarly, Q ₂ bonded to the asymmetric carbon C ^* is an alkyl group having 1 to 10 carbon atoms, an alkenyl group, an alkynyl group, and at least one of-
A group in which CH ₂ — is substituted with —O—, —COO—, or a halomethylene group (excluding groups in which —O— are adjacent to each other)
Represents one type of group selected from the group consisting of Among them, Q ₂ is preferably an alkyl group having 1 to 10 carbon atoms in consideration of liquid crystal characteristics.

Here, Q ₁ and Q ₂ may be the same or different from each other.
_{CH 3, -C 2 H 5,} -C 3 H 7 or -C ₄ H _9, is equivalent to it.

Accordingly, examples of the benzyl ether derivative represented by the above formula [1] include the compounds shown in Tables 1 to 6. In these tables,
"-" Indicates a single bond.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

[Table 6]

Method for Producing Benzyl Ether Derivative The above-mentioned benzyl ether derivative can be synthesized according to the method described below. Note that the synthesis method is not limited thereto.

(1) The first method can be produced through the following synthetic route.

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That is, 4-bromobenzyl bromide and a chiral alcohol (R ^* OH) are coupled with sodium hydride or the like to obtain 4-bromobenzyl ether. Next, the corresponding boronic acid is obtained by reacting n-butyllithium or magnesium with trialkoxyboron (B (OR ') ₃ ), followed by hydrolysis. Next, the boronic acid is oxidized with aqueous hydrogen peroxide to obtain 4-hydroxybenzyl ether.
Further, this is reacted with 4'-alkoxy-4-biphenylmethyl bromide and potassium carbonate to obtain one of the benzyl ether derivatives of the present invention.
-(4'-Alkoxy-4-biphenylmethoxy) benzyl ether can be obtained. The starting material, 4-bromobenzyl bromide, may be substituted with a fluorine atom. In the above general formula [1], X ₃
There Compound -CH ₂ O-in which it is equivalent to the compounds prepared by this method.

(1) The second method can be produced according to the following synthetic route.

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That is, 4-hydroxybenzyl ether and 4- (6-alkoxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) -benzoic acid obtained in the reaction route of the first method are Is reacted with dicyclohexylcarbodiimide (DCC) or the like to obtain 4-benzyl which is one of the benzyl ether derivatives of the present invention.
(4- (6-Alkoxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) -phenylcarbonyloxy) -benzyl ether is obtained. This compound is a substance in which X ₃ corresponds to —CO ₂ — in the general formula [1].

(1) The third method can be produced according to the following synthetic route.

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That is, the boronic acid obtained in the reaction route of the first method and 4- (6-alkoxy-1,2,3,4
-Tetrahydro-2-naphthalenecarbonyloxy) -bromobenzene by coupling with a palladium catalyst or the like to give 4 ′-(6-alkoxy-1,2,3,4) which is one of the benzyl ether derivatives of the present invention. 4-
Tetrahydro-2-naphthalenecarbonyloxy) -4
-Biphenyl methyl ether is obtained. This compound is a compound in which X ₃ corresponds to a single bond in the general formula [1].

Liquid Crystal Material The liquid crystal material according to the present invention is a compound comprising a benzyl ether derivative represented by the above general formula [1] having an optically active group in the molecule. A compound exhibiting a dielectric property or a thresholdless antiferroelectric property is preferable as a liquid crystal material, and a compound having a small spontaneous polarization is more preferable. On the other hand, although the composition itself does not exhibit liquid crystallinity, when the composition described below is used, even if the composition is a benzyl ether derivative exhibiting liquid crystallinity, it can be used as a liquid crystal material according to the present invention. .

The following are examples of benzyl ether derivatives suitable as such liquid crystal materials.

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Liquid Crystal Composition The liquid crystal composition according to the present invention contains one or more benzyl ether derivatives represented by the above general formula [1]. The aforementioned liquid crystal materials are preferred. The liquid crystal composition may be composed of a mixture of two or more benzyl ether derivatives represented by the general formula [1], and the benzyl ether derivative may contain another liquid crystal compound or a known additive. May also be comprised.

When the liquid crystal composition according to the present invention is composed of the benzyl ether derivative represented by the above general formula [1] and another liquid crystal compound, the benzyl ether derivative accounts for 1 to 99% by weight, preferably It is desirable that the content be 5 to 50% by weight and the other liquid crystal compound be 1 to 99% by weight, more preferably 50 to 95% by weight. Here, the combined total amount of both is set to 100% by weight. That is, the benzyl ether derivative can be used as a main component of a liquid crystal composition or as an auxiliary depending on the type of another liquid crystal compound.

A composition in which the benzyl ether derivative represented by the above general formula [1] is mixed with another liquid crystal compound, particularly an antiferroelectric liquid crystal or a thresholdless antiferroelectric liquid crystal,
Spontaneous polarization can be reduced without substantially lowering the liquid crystal temperature range.

Examples of other liquid crystal compounds to be incorporated in the liquid crystal composition include the compounds shown on the next page.

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[0051]

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[0052]

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The liquid crystal composition may be added, if necessary, with a conductivity-imparting agent, a life-improving agent, etc. within a range that does not impair the antiferroelectricity and thresholdless antiferroelectricity of the liquid crystal composition. An agent may be appropriately compounded.

Liquid Crystal Element The liquid crystal element according to the present invention is formed by filling the above liquid crystal material or liquid crystal composition between a pair of electrodes in a liquid crystal cell to form a liquid crystal display element, an optical switching element, an optical modulation element and the like. can do.

Since this liquid crystal element uses a liquid crystal material or a liquid crystal composition exhibiting antiferroelectricity or thresholdless antiferroelectricity as a filling material for the liquid crystal element, it has a high electro-optical response speed and a room temperature. , And has a high electro-optical contrast, so that high-quality display can be realized. Further, the liquid crystal material or the liquid crystal composition used for this display element has low spontaneous polarization, and thus can be suitably used as an active matrix element.

[0056]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Example 1 Synthesis of 4- (4′-decyloxy-4-biphenylmethyloxy) benzyl (R) -2-octyl ether

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(First step) 4-bromobenzyl bromide
1.0 g (4.0 mmol) and 0.21 g of 60% sodium hydride
(5.2 mmol) in 15 ml of tetrahydrofuran (hereinafter abbreviated as THF), and (R) was added thereto while stirring at room temperature.
0.59 g (4.5 mmol) of -2-octanol was added. After stirring at the same temperature for 12 hours and further at 60 ° C. for 2 hours, hydrolysis was carried out.
After ether extraction, the organic phase was dried, concentrated and purified by column chromatography to obtain 1.26 g of 4-bromobenzyl (R) -2-octyl ether. Yield 100%.

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.1 Hz), 1.18 (d, 3H, J =
4.5 Hz), 1.2-1.7 (m, 10H), 3.48 (m, 1H), 4.40 (d, 1
H, J = 9.0 Hz), 4.51 (d, 1H, J = 9.0 Hz), 7.22 (d, 2
H, J = 9.0 Hz), 7.45 (d, 2H, J = 9.0 Hz)

(Second step) 1.2 g (4.0 mmol) of 4-bromobenzyl (R) -2-octyl ether obtained in the first step
Was added to 25 ml of dry THF, cooled to −80 ° C. in a dry ice acetone bath, and then stirred with 1.53 N
3 ml (4.6 mmol) of n-butyllithium was added. -78 ℃
After stirring for 30 minutes with triisopropyl borate 2.1 ml (9.1
5 mmol), and the temperature was naturally increased to -40 ° C while stirring. After hydrolysis, ether extraction was performed, and the organic phase was dried and concentrated to obtain 1.0 g of (R) -4- (2-octyloxymethyl) benzeneboronic acid. This product was used for the next step without purification.

(Third Step) The (R) -4- (2) obtained in the second step
1.0 g of-(octyloxymethyl) benzeneboronic acid was dissolved in 25 ml of toluene, and 6 ml of 30% hydrogen peroxide solution was added thereto. After stirring at 80 ° C. for 1 hour, the reaction mixture was poured into 50 ml of water, and an aqueous sodium hydrogen sulfite solution was slowly added with cooling until no heat was generated. After ether extraction, the organic phase was dried, concentrated and purified by column chromatography to obtain 0.77 g (3.3 mmol) of 4-hydroxybenzyl (R) -2-octyl ether (yield from the first step).
82%).

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.0 Hz), 1.18 (d, 3H, J =
4.8 Hz), 1.2-1.7 (m, 10H), 3.50 (m, 1H), 4.38 (d, 1
H, J = 8.7 Hz), 4.48 (d, 1H, J = 8.7 Hz), 5.29 (s, 1
H), 6.75 (d, 2H, J = 5.1 Hz), 7.20 (d, 2H, J = 5.1 H)
z)

(Fourth Step) 0.19 g (0.81 m) of 4-hydroxybenzyl (R) -2-octyl ether obtained in the third step
mol), 4'-decyloxy-4-biphenylmethyl bromide
0.33 g (0.83 mmol) and potassium carbonate 0.27 g
(1.93 mmol) was added to 15 ml of acetonitrile, and the mixture was stirred at 65 ° C. for 6 hours. After cooling, the reaction solution was poured into 500 ml of water, neutralized with hydrochloric acid, and the precipitated solid was separated by filtration. The solid product was purified by column chromatography to give 4- (4′-decyloxy-4-biphenylmethyloxy) benzyl (R) -2
-Octyl ether 0.22 g (0.39 mmol) was obtained (yield 4
8%).

The chemical structure of the product was identified and confirmed by ¹ H-NMR. The NMR chart is shown in FIG. Table 7 shows the phase transition temperatures of the obtained compounds.

In the structural formulas of the benzyl ether derivatives shown in FIGS. 1 to 12, the numbers assigned to the hydrogen atoms are assigned to the respective peaks in the ¹ H-NMR chart shown in FIG. Corresponds to the number. (Eq) indicates the conformation of equatorial and (ax) axial. Further, (R) and (S) in the compound names are signs indicating different optical rotations.

Example 2 Synthesis of 4- (4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenylcarbonyloxy) benzyl (R) -2-octyl ether

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0.19 g (0.81 mmol) of 4-hydroxybenzyl (R) -2-octyl ether obtained in the third step of Example 1
l), 4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) benzoic acid 0.38 g (0.84 mmo
l) and 74 mg (0.61 mmol) of 4-dimethylaminopyridine (hereinafter abbreviated as DMAP) were added to 6 ml of dichloromethane, and dicyclohexylcarbodiimide (hereinafter referred to as D) was added thereto.
(Abbreviated as CC) 0.23 g (1.10 mmol) of dichloromethane 4
ml solution was added dropwise. After stirring at room temperature for 24 hours, the mixture was concentrated and purified by column chromatography to give 4- (4- (6-
Decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenylcarbonyloxy) benzyl (R)
0.34 g (0.51 mmol) of 2-octyl ether was obtained (yield: 62%). The chemical structure of the product was identified and confirmed by NMR analysis. The ¹ H-NMR chart at that time is shown in FIG. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 3 Synthesis of 4- (4′-nonylcarbonyloxy-4-biphenylcarbonyloxy) benzyl (R) -2-octyl ether

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0.18 g (0.75 mmo) of 4-hydroxybenzyl (R) -2-octyl ether obtained in the third step of Example 1
l), 0.29 g (0.80 mmol) of 4'-nonylcarbonyloxy-4-biphenylcarboxylic acid, and 46 mg of DMAP (0.38 m
mol) was added to 7 ml of dichloromethane, and DCC 0.2
A solution of 2 g (1.05 mmol) in 4 ml of dichloromethane was added dropwise. After stirring at room temperature for 24 hours, the mixture was concentrated and purified by column chromatography to give 4- (4'-nonylcarbonyloxy-4-biphenylcarbonyloxy) benzyl (R) -2-
0.31 g (0.53 mmol) of octyl ether was obtained (66 yield).
%). The chemical structure of the product was identified and confirmed by NMR analysis. The ¹ H-NMR chart at that time is shown in FIG.
Table 7 shows the phase transition temperatures of the obtained compounds.

Example 4 4- (4'-decyloxyphenylmethyloxy) benzyl
Synthesis of (R) -2-octyl ether

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0.19 g of 4-hydroxybenzyl (R) -2-octyl ether obtained in the third step of Example 1 (0.80 mmo
l), 4-decyloxybenzyl alcohol 0.23 g (0.89
mmol) and 0.26 g of triphenylphosphine (0.99 m
mol) was dissolved in 7 ml of THF, and 0.5 ml of diethyl azodicarboxylate (40% solution in toluene) was gradually added thereto. After stirring at room temperature for 24 hours, the reaction mixture was concentrated and purified by column chromatography to give 0.10 g (0.21 mmol) of 4- (4′-decyloxyphenylmethyloxy) benzyl (R) -2-octyl ether. Was obtained (26% yield).
The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 4 shows the ¹ H-NMR chart at that time. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 5 Synthesis of 4- (4′-decyl-4-biphenylmethyloxy) -2-fluorobenzyl (R) -2-octyl ether

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(First Step) In the first, second and third steps of Example 1, the same reaction was carried out using 4-bromo-2-fluorobenzyl bromide instead of 4-bromobenzyl bromide. -Hydroxy-2-fluorobenzyl
(R) -2-octyl ether was obtained (total yield: 95%).

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 4.8 Hz), 1.20 (d, 3H, J =
4.8 Hz), 1.2-1.7 (m, 10H), 3.51 (m, 1H), 4.43 (d, 1
H, J = 8.7 Hz), 4.52 (d, 1H, J = 8.7 Hz), 5.54 (s, 1
H), 6.47-51 (m, 2H), 7.18-7.22 (m, 1H).

(Second step) 4-hydroxy-2-fluorobenzyl (R) -2-octyl ether obtained in the first step 0.2
1 g (0.83 mmol), 0.33 g (0.85 mmol) of 4'-decyl-4-biphenylmethyl bromide, and potassium carbonate 0.2
8 g (2.0 mmol) was added to 10 ml of acetonitrile.
Stir for 10 hours. After cooling, the reaction solution was poured into 500 ml of water, neutralized with hydrochloric acid, and the precipitated solid was separated by filtration. The solid was purified by column chromatography and recrystallization to give 4- (4′-decyl-4-biphenylmethyloxy) -2-fluorobenzyl (R) -2-octyl ether 0.23 g (0.41 m
mol) was obtained (yield 50%). The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 5 shows the ¹ H-NMR chart at that time. Table 7 shows the phase transition temperatures of the obtained compounds.
It was noted in.

Example 6 4- (4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenylcarbonyloxy) -2-
Synthesis of fluorobenzyl (R) -2-octyl ether

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4-Hydroxy-2-fluorobenzyl (R) -2-octyl ether obtained in the third step of Example 5 0.20
g (0.80 mmol), 4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) benzoic acid 0.37 g
(0.82 mmol) and 42 mg (1.01 mmol) of DMAP were added to 4 ml of dichloromethane, and 0.21 g (1.01 mmol) of DCC was added thereto.
(mmol) was added dropwise. At room temperature
After stirring for 24 hours, the mixture was concentrated and purified by column chromatography to give 4- (4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenylcarbonyloxy) -2-fluorobenzyl 0.36 g (0.52 mmol) of (R) -2-octyl ether was obtained (65% yield). The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 6 shows the ¹ H-NMR chart at that time. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 7 Synthesis of 4- (4′-decyloxy-4-biphenyl) -2-fluorobenzyl (R) -2-octyl ether

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(R) -4- (2-octyloxymethyl) -3-fluorobenzeneboronic acid obtained in Example 5 0.26 g (0.9
3 mmol), 4'-decyloxy-4-bromobiphenyl, and tetrakis (triphenylphosphine) palladium
Dissolve 0.026 mg (0.022 mmol) in 5 ml of dimethoxyethane, and add 0.26 g (1.88 mmol) of potassium carbonate in 1 m of water.
The mixture was dissolved in l and added, followed by stirring at 60 ° C for 10 hours. The reaction is taken up in water and the solid product is filtered off and purified by column chromatography and recrystallization to give 4- (4'-decyloxy-4-biphenyl) -2-fluorobenzyl (R) -2- 0.10 g (0.18 mmol) of octyl ether was obtained (yield 31
%). The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 7 shows the ¹ H-NMR chart at that time.
Table 7 shows the phase transition temperatures of the obtained compounds.

Example 8 4- (4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenyl) -2-fluorobenzyl
Synthesis of (R) -2-octyl ether

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(First Step) 6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarboxylic acid 2.25 g (6.8 mmo)
l), 1.30 g (7.51 mmol) of 4-bromophenol and 0.098 g (0.80 mmol) of DMAP in 15 ml of dichloromethane
And 1.63 g of DCC (7.91 mmo) with stirring.
15 ml of a dichloromethane solution of l) was slowly added. At room temperature
After stirring for 24 hours, the mixture was concentrated, and purified by column chromatography and recrystallization to give 4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) bromobenzene 2.95 g (6.1 mmol) ) Was obtained (yield 89
%).

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.1 Hz), 1.2-1.5 (m, 14
H), 1.7-1.8 (m, 2H), 1.9-2.0 (m, 1H), 2.2-2.4 (m, 1
H), 2.8-3.2 (m, 5H), 3.92 (t, 2H, J = 5.1 Hz), 6.65
(s, 1H), 6.72 (d, 1H, J = 6.3 Hz), 6.99 (d, 2H, J =
5.1 Hz), 7.03 (d, 1H, 6.3 Hz), 7.50 (d, 2H, J = 5.1
Hz).

(Second Step) 0.34 g (0.70 mmol) of 4- (6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) bromobenzene obtained in the first step, Example 5 0.32 g (1.15 mmol) of (R) -4- (2-octyloxymethyl) -3-fluorobenzeneboronic acid obtained in (1) and tetrakis (triphenylphosphine) palladium 0.
047 mg (0.041 mmol) was dissolved in 5 ml of dimethoxyethane, and 0.26 g (1.91 mmol) of potassium carbonate was added thereto in water 1
The mixture was dissolved in ml, and the mixture was stirred at 50 ° C for 10 hours. After hydrolysis, ether extraction was performed and the organic phase was dried. After concentration and purification by column chromatography, 4- (4
-(6-decyloxy-1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy) phenyl) -2-fluorobenzyl (R)-
0.15 g (0.23 mmol) of 2-octyl ether was obtained (yield 33
%). The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 8 shows the ¹ H-NMR chart at that time.
Table 7 shows the phase transition temperatures of the obtained compounds.

Example 9 4- (4- (4-octylphenylcarbonyloxy) phenyl)
Synthesis of 2-fluorobenzyl (R) -2-octyl ether

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(First stage) 1.92 g of 4'-octylbenzoic acid
(8.21 mmol), 1.56 g of 4-bromophenol (9.02 mmo
l), and 0.135 g (1.11 mmol) of DMAP were added to 30 ml of dichloromethane, and DCC 1.94 was added thereto with stirring.
g (9.42 mmol) in 15 ml of dichloromethane was slowly added. After stirring at room temperature for 24 hours, the mixture was concentrated and purified by column chromatography and recrystallization to give 4- (octylphenylcarbonyloxy) bromobenzene 2.63 g.
(6.8 mmol) was obtained (82% yield).

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.3 Hz), 1.2-1.4 (m, 10
H), 1.6-1.7 (m, 2H), 2.70 (t, 2H, J = 5.7 Hz), 7.11
(d, 2H, J = 4.8 Hz), 7.31 (d, 2H, J = 6.3 Hz), 7.54
(d, 1H, 4.8 Hz), 8.09 (d, 2H, J = (6.3 Hz).

(Second step) 0.28 g of 4- (octylphenylcarbonyloxy) bromobenzene obtained in the first step
(0.71 mmol), 0.26 g of (R) -4- (2-octyloxymethyl) -3-fluorobenzeneboronic acid obtained in Example 5 (0.9
2 mmol) and 0.036 mg (0.031 mmol) of tetrakis (triphenylphosphine) palladium were dissolved in 5 ml of dimethoxyethane, and 0.26 g of potassium carbonate was added thereto.
(1.89 mmol) dissolved in 1 ml of water was added, and the mixture was stirred at 50 ° C. for 10 hours. After hydrolysis, ether extraction was performed and the organic phase was dried. After concentration, the residue was purified by column chromatography to obtain 0.10 g (0.18 mmol) of 4- (4- (4-octylphenylcarbonyloxy) phenyl) -2-fluorobenzyl (R) -2-octyl ether. Rate 26%). The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 9 shows the ¹ H-NMR chart at that time. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 10 4- (4'-decyl-4-biphenylcarbonyloxy) benzyl
Synthesis of (S) -2-octyl ether

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In Example 3, 4'-nonylcarbonyloxy-4-biphenylcarboxylic acid was changed to 4'-decyl-4-biphenylcarboxylic acid, and 4-hydroxybenzyl
(R) -2-octyl ether is converted to 4-hydroxybenzyl (S)-
By changing to 2-octyl ether and performing the same reaction, 4- (4′-decyl-4-biphenylcarbonyloxy)
Benzyl (S) -2-octyl ether was obtained. 4-Hydroxybenzyl (S) -2-octyl ether was obtained in the same manner as in Example 1, except that (R) -2-octyl alcohol was changed to (S) -2-octyl alcohol. The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 10 shows the ¹ H-NMR chart at that time.
Table 7 shows the phase transition temperatures of the obtained compounds.

Example 11 Synthesis of 4- (4′-undecyl-4-biphenylcarbonyloxy) benzyl (S) -2-nonyl ether

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(First step) 4-bromobenzyl bromide
3.3 g (13.6 mmol) and 0.93 g of 60% sodium hydride
(23.3 mmol) in 40 ml of tetrahydrofuran (hereinafter abbreviated as THF), and (S)
2.01 g (14.0 mmol) of 2-nonanol was added. At 70 ° C
After stirring for 3 hours, the mixture was hydrolyzed. After ether extraction, the organic phase was dried, concentrated and purified by column chromatography to obtain 4.3 g of 4-bromobenzyl (S) -2-nonyl ether. Yield 100%.

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.1 Hz), 1.18 (d, 3H, J =
4.5 Hz), 1.2-1.7 (m, 12H), 3.48 (m, 1H), 4.40 (d,
1H, J = 9.0 Hz), 4.51 (d, 1H, J = 9.0 Hz), 7.22 (d,
2H, J = 9.0 Hz), 7.45 (d, 2H, J = 9.0 Hz),

(Second step) 4.3 g (13.6 mmol) of 4-bromobenzyl (S) -2-nonyl ether obtained in the first step
Was added to 50 ml of dry THF, cooled to −78 ° C. in a dry ice acetone bath, and stirred at 1.6 N with stirring.
Of n-butyllithium (11 ml, 17.6 mmol) was added. -78
After stirring at 40 ° C for 40 minutes, triisopropyl borate 15 ml (65
mmol) and the temperature was allowed to rise to −20 ° C. with stirring. After the hydrolysis, ether extraction was performed, and the organic phase was dried and concentrated to obtain 3.72 g of (S) -4- (2-nonyloxymethyl) benzeneboronic acid. This product was used in the next step without purification.

(Third Step) The (S) -4- (2) obtained in the second step
1.87 g of (nonyloxymethyl) benzeneboronic acid was dissolved in 30 ml of toluene, and 5 ml of 30% hydrogen peroxide solution was added thereto. After stirring at 80 ° C. for 1 hour, the reaction mixture was put into 100 ml of water, and an aqueous solution of sodium hydrogen sulfite was slowly added with cooling until no heat was generated. After ether extraction, the organic phase was dried, concentrated and purified by column chromatography to obtain 1.33 g (5.3 mmol) of 4-hydroxybenzyl (S) -2-nonyl ether (yield from the first step).
77%).

The results of ¹ H-NMR (CDCl ₃ ) analysis of the product were as follows. δ (ppm): 0.88 (t, 3H, J = 5.0 Hz), 1.18 (d, 3H, J =
4.8 Hz), 1.2-1.7 (m, 12H), 3.50 (m, 1H), 4.38 (d,
1H, J = 8.7 Hz), 4.48 (d, 1H, J = 8.7 Hz), 5.29 (s,
1H), 6.75 (d, 2H, J = 5.1 Hz), 7.20 (d, 2H, J = 5.1
Hz).

(Fourth step) 0.20 g (0.80 mmo) of 4-hydroxybenzyl (S) -2-nonyl ether obtained in the third step
l), 4'-undecyl-4-biphenylcarboxylic acid 0.30 g
(0.86 mmol) and 24 mg (0.20 mmol) of DMAP were added to 6 ml of dichloromethane, and 0.26 g (1.2%) of DCC was added thereto.
(6 mmol) in 4 ml of dichloromethane was added dropwise. After stirring at room temperature for 24 hours, the mixture was concentrated and purified by column chromatography to give 4- (4′-undecyl-4-biphenylcarbonyloxy) benzyl (S) -2-nonyl ether 0.37
g (0.63 mmol) was obtained (79% yield). The chemical structure of the product was identified and confirmed by NMR analysis. ¹ H-NM at that time
The R chart is shown in FIG. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 12 Synthesis of 4- (4-tetradecyloxyphenylcarbonyloxy) benzyl (S) -2-octyl ether

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In Example 3, 4'-nonylcarbonyloxy-4-biphenylcarboxylic acid was changed to 4-decyloxybenzoic acid, and 4-hydroxybenzyl (R) -2-octyl ether was changed to 4-hydroxybenzyl ( By changing to (S) -2-octyl ether and reacting similarly,
4- (4-Tetradecyloxyphenylcarbonyloxy) benzyl (S) -2-octyl ether was obtained. 4-Hydroxybenzyl (S) -2-octyl ether was obtained in the same manner as in Example 1, except that (R) -2-octyl alcohol was changed to (S) -2-octyl alcohol.
The chemical structure of the product was identified and confirmed by NMR analysis. FIG. 12 shows the ¹ H-NMR chart at that time. Table 7 shows the phase transition temperatures of the obtained compounds.

Example 13 The phase transition temperatures (° C.) of the compounds obtained in Examples 1 to 12 were measured, and the results are shown in Table 7.

[Table 7]

In Table 7, Cry is a crystal phase, SmCA * is an antiferroelectric phase, SmCR * is a thresholdless antiferroelectric phase, SmC * is a ferroelectric phase, and SmA
Represents a smectic A phase, SmX represents an unidentified phase, and Iso represents an isotropic liquid phase. In addition, in each Example, the number described below each phase indicates that the phase exists, and indicates the temperature at which the phase disappears when the temperature rises. The numbers in parentheses indicate the temperature at which the phase develops when the temperature drops. "-" Indicates that no phase is present.

(Examples 14 to 22) (Comparative Examples 1 and 2) The benzyl ether derivative obtained in Examples 1 to 9 and the liquid crystal compound represented by the following formula [A] or the following formula [B] The liquid crystal compounds represented by Table 8 were mixed in the proportions shown in Table 8 to prepare liquid crystal compositions. The case where only the liquid crystal compound [A] and the liquid crystal compound [B] were used is shown as a comparative example.

[0101]

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A liquid crystal cell with an ITO electrode having a rubbed polyimide thin film (cell gap of about 2 μm)
m), heating and injecting the previously prepared liquid crystal composition. 2
The polarizing plates are arranged so that the polarization planes are orthogonal to each other, and a cell containing a liquid crystal composition is inserted between the polarizing plates to form a liquid crystal element.

A rectangular wave of ± 10 to 30 V / 2 μm was applied to the liquid crystal element (30 ° C.), and the switching speed (τr) at 10 V, spontaneous polarization (Ps), and tilt angle (θ) were measured.

First, in a state where no voltage is applied to the liquid crystal element (an antiferroelectric state or a thresholdless antiferroelectric state), the transmittance of light transmitted through the liquid crystal element is minimized (substantially 0%). The position of the cell is adjusted between the two polarizing plates. next,
When a voltage is gradually applied to the liquid crystal element, the transmittance gradually increases, and thereafter, the liquid crystal element enters a ferroelectric state in which the transmittance hardly increases.
%. The switching speed (τr) represents the time (μs) from when 0% to 90% of the light transmittance when a voltage of ± 10 V is applied.

The tilt angle (θ) was measured by the following method. A DC voltage (± 30 V / 2 μm) is applied to the liquid crystal cell, and the liquid crystal cell is arranged in two crossed Nicols so that the light transmittance of the liquid crystal element becomes the darkest when a positive voltage and a negative voltage are applied. Rotate within. The angles at this time are obtained, and are set to θ1 and θ2, respectively. At this time, the θ value represented by θ = (θ1−θ2) / 2 was defined as the tilt angle.

First, a spontaneous polarization (Ps) was measured by connecting a load resistor in series with a liquid crystal element, and measuring ± 30 V / 2 μm, 10 μm.
A rectangular wave of 0 Hz was applied to the liquid crystal element, and the polarization reversal current flowing through the load resistance at that time was defined as Ps (unit: nC / c)
m ² ).

Table 8 shows the measurement results of the switching speed (τr), spontaneous polarization (Ps), and tilt angle (θ) of each liquid crystal composition.

[0108]

[Table 8] *: The name of the liquid crystal compound was indicated by the number of each example in which it was synthesized. **: Operation was not possible at 10V. ***: SmCA * phase

As is clear from Table 8, the liquid crystal composition containing the benzyl ether derivative according to the present invention exhibited a value showing spontaneous polarization (Comparative Examples 1 and 2) which did not contain the compound. Ps) is greatly reduced.
At this time, it was also found that the upper limit temperature and the tilt angle of the thresholdless antiferroelectric phase did not decrease significantly.

[0110]

According to the present invention, a novel benzyl ether derivative is provided. Some of the benzyl ether derivatives exhibit liquid crystallinity by themselves, and particularly exhibit antiferroelectricity or thresholdless antiferroelectricity. Suitable as. Further, by adding the benzyl ether derivative compound to a host liquid crystal exhibiting antiferroelectric or thresholdless antiferroelectricity, the tilt angle of the host liquid crystal can be improved, the antiferroelectricity or thresholdless antiferroelectricity can be improved. Can be improved and the spontaneous polarization can be reduced.

Further, the liquid crystal element filled with the liquid crystal material or liquid crystal composition according to the present invention has a low spontaneous polarization, so that it can be suitably used as an active matrix element, and has a high quality and a contrast close to that of a CRT. A large display element can be provided. In particular, since the display element has a fast electro-optical response, it can be used as a high-speed light switching element or a high-speed light modulation element.

[Brief description of the drawings]

FIG. 1 4- (4′-decyloxy-4-synthesized in Example 1)
¹ shows a chart of ¹ H-NMR spectrum of (biphenylmethyloxy) benzyl (R) -2-octyl ether.

FIG. 2 shows 4- (4- (6-decyloxy-) synthesized in Example 2.
1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy)
¹ shows a chart of ¹ H-NMR spectrum of phenylcarbonyloxy) benzyl (R) -2-octyl ether.

FIG. 3 4- (4′-nonylcarbonyloxy-4-biphenylcarbonyloxy) benzyl (R) -2 synthesized in Example 3
¹ shows a chart of ¹ H-NMR spectrum of -octyl ether.

FIG. 4 shows the synthesis of 4- (4′-decyloxyphenylmethyloxy) benzyl (R) -2-octyl ether synthesized in Example 4.
¹ shows a chart of ¹ H-NMR spectrum.

5 shows a chart of ¹ H-NMR spectrum of 4- (4′-decyl-4-biphenylmethyloxy) -2-fluorobenzyl (R) -2-octyl ether synthesized in Example 5. FIG.

FIG. 6: 4- (4- (6-decyloxy-) synthesized in Example 6
1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy)
(Phenylcarbonyloxy) -2-fluorobenzyl (R) -2
¹ shows a chart of ¹ H-NMR spectrum of -octyl ether.

FIG. 7: 4- (4′-decyloxy-4-synthesized in Example 7)
¹ shows a chart of ¹ H-NMR spectrum of (biphenyl) -2-fluorobenzyl (R) -2-octyl ether.

FIG. 8: 4- (4- (6-decyloxy-) synthesized in Example 8
1,2,3,4-tetrahydro-2-naphthalenecarbonyloxy)
¹ shows a chart of ¹ H-NMR spectrum of (phenyl) -2-fluorobenzyl (R) -2-octyl ether.

FIG. 9: 4- (4- (4-octylphenylcarbonyloxy) phenyl) -2-fluorobenzyl synthesized in Example 9
¹ shows a chart of ¹ H-NMR spectrum of (R) -2-octyl ether.

10 shows a chart of ¹ H-NMR spectrum of 4- (4′-decyl-4-biphenylcarbonyloxy) benzyl (S) -2-octyl ether synthesized in Example 10. FIG.

FIG. 11: 4- (4′-undecyl-4) synthesized in Example 11
¹ shows a chart of ¹ H-NMR spectrum of -biphenylcarbonyloxy) benzyl (S) -2-nonyl ether.

12 shows a chart of ¹ H-NMR spectrum of 4- (4-tetradecyloxyphenylcarbonyloxy) benzyl (S) -2-octyl ether synthesized in Example 12. FIG.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 19/20 C09K 19/20 19/32 19/32 19/34 19/34 G02F 1/13 500 G02F 1 / 13 500 (72) Hideo Hama Inventor F-term (reference) 4H006 AA01 AA03 AB64 BJ50 BM30 BP30 GP03 4H027 BA06 BA07 BC04 BD02 BD08 BD18 BD19 BD20 BE04 CB08 CE08 CF08 CG08 DK08

Claims (19)

[Claims] 1. A benzyl ether derivative represented by the following formula [1]: Embedded image (In the formula [1], R ₁ is an alkyl group having 1 to 20 carbon atoms, or at least one —CH ₂ — present in these groups is —O—,
At least one group selected from the group consisting of a halomethylene group and a hydrocarbon group having an unsaturated bond (provided that
X ₁ represents a group or a bond selected from the group consisting of —COO—, —OCO—, —CO—, —O— and a single bond. X ₂ and X ₃ are each independently -COO-, -O
_{CO -, - CH 2 O -} , - OCH 2 -, - CH 2 CH 2 - and a group or bond selected from the group consisting of a single bond, A ₁ and A ₂ are each independently a fluorine atom Represents a group selected from the following group which may be substituted one or more times: m and n represent an integer of 0 to 2, and Q ₁ represents -CH ₃ , -C ₂ H ₅ , -C ₃ H ₇ , -C ₄ H ₉ , -C
Represents a group selected from the group consisting of F ₃ , —C ₂ F ₅ , and —C ₃ F ₇ , Q ₂ represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group,
An alkynyl group and a group in which at least one —CH ₂ — present in these groups is substituted with —O—, —COO—, or a halomethylene group (excluding those in which —O— are adjacent to each other) And C ^* represents an asymmetric carbon, provided that Q ₁ and Q ₂ may be the same or different. ) 2. In the above formula [1], R ₁ has 1 to ₁ carbon atoms.
20 alkyl groups or a group in which at least one —CH ₂ — present in these groups is substituted with —O— (excluding those in which —O— are adjacent to each other). The benzyl ether derivative according to claim 1, wherein 3. In the above formula [1], X ₁ is —COO
The benzyl ether derivative according to claim 1 or 2, which is a group or a bond selected from the group consisting of-, -O- and a single bond. 4. In the above formula [1], X ₂ and X ₃ are
_{Independently, -COO -, - CH 2 O} -, - CH 2
CH ₂ -, and benzyl ether derivative according to claim 1, characterized in that it is a group or bond selected from the group consisting of a single bond. 5. In the above formula [1], A ₁ and A ₂ are
The benzyl ether derivative according to any one of claims 1 to 4, wherein each independently represents a group selected from the following group which may be substituted with one or more fluorine atoms. Embedded image 6. In the above formula [1], A ₁ and A ₂ are
The benzyl ether derivative according to any one of claims 1 to 4, which is independently a group selected from the following group which may be substituted with one or more fluorine atoms. Embedded image 7. In the above formula [1], A ₁ and A ₂ are
Each independently: The benzyl ether derivative according to any one of claims 1 to 4, wherein the benzyl ether derivative is a group selected from the group consisting of: 8. The benzyl ether derivative according to claim 1, wherein n is 0 or 1 in the formula [1]. 9. In the above formula [1], Q ₁ is -CH ₃ ,-
Benzyl ether derivative according to any one of claims 1 to 8, wherein the C ₂ H _5, a group selected from the group consisting of -C ₃ H _7. 10. The benzyl ether derivative according to claim ₁ , wherein in the formula [1], Q ₁ is —CH ₃ . 11. The benzyl ether derivative according to claim 1, wherein in the formula [1], Q ₁ is —CF ₃ or —C ₂ F ₅ . 12. In the above formula [1], Q ₂ has 1 carbon atom.
It is an alkyl group of 10 to 10, characterized by the above-mentioned.
12. The benzyl ether derivative according to any one of 11. 13. A liquid crystal material comprising the benzyl ether derivative according to claim 1. 14. The liquid crystal material according to claim 13, wherein said benzyl ether derivative has antiferroelectricity or thresholdless antiferroelectricity. 15. A liquid crystal composition comprising the benzyl ether derivative according to claim 1 as a component. 16. The composition according to claim 15, wherein the composition comprises the benzyl ether derivative according to any one of claims 1 to 12 and another liquid crystal compound and / or an additive. Liquid crystal composition. 17. The liquid crystal composition according to claim 15, wherein the composition has antiferroelectricity or thresholdless antiferroelectricity. 18. A liquid crystal device using the liquid crystal material according to claim 13. (19) A liquid crystal device comprising the liquid crystal composition according to any one of (15) to (17).