JP2004190024A - Indane compound-containing nematic liquid crystal composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nematic liquid crystal composition containing 4,6-difluoroindane-based compound(s), low in the lower limit temperature(T<SB>→N</SB>) of the liquid crystal phase and high in the upper limit temperature(T<SB>N-I</SB>) through improving or without aggravating various liquid crystal properties including speed of response and threshold voltage within an optimum Δn range, and wide in liquid crystal phase temperature range, and to provide the 4,6-difluoroindane-based compound(s). <P>SOLUTION: The nematic liquid crystal composition contains at least one compound having a 4,6-difluoroindane-2,5-diyl group in the skeleton, having a refractive index anisotropy index of 0.08-0.15, the upper limit temperature of the liquid crystal phase of ≥70°C, the lower limit temperature of ≤-20°C, and the difference between the the upper limit temperature and the lower limit temperature of the liquid crystal phase of ≥90°C. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a nematic crystal composition useful as an electro-optical liquid crystal display material, a liquid crystal display element using the composition, and an indane compound useful as a constituent material of the nematic liquid crystal composition.

  In liquid crystal display elements such as twisted nematic, super twisted nematic or active matrix, especially in small and medium portable liquid crystal display elements, the stability of display with respect to the operating environment temperature is an important point. Liquid crystal material with lower driving voltage that can reduce power consumption, driving voltage in the temperature range of -30 to 0 ° C or 40 to 80 ° C, steepness, desired duty driving frequency dependency, etc. It has been demanded.

In particular, the lower limit temperature of liquid crystal phases (T _{→ N)} and a liquid crystal phase temperature range is the absolute value of the difference of the liquid crystal phase upper limit temperature (T _NI) (ΔT) is outdoors by taking advantage of low power consumption of the liquid crystal display device This is important because of the increased use of. However, with the combination of conventional materials, although the liquid crystal phase temperature range can be expanded, the threshold voltage increases, the response speed increases, and Δn deviates from the optimum range. Is not obtained (see Patent Documents 1 and 2). Therefore, it has been desired to develop a liquid crystal composition having a wide liquid crystal phase temperature range without deteriorating liquid crystal characteristics such as response speed, or to develop a liquid crystal material optimal for this application.

  On the other hand, liquid crystal compounds having indane in the skeleton are already known, and some compounds have been disclosed. However, the liquid crystal composition using the already disclosed indane derivative has the following problems. For example, a compound having a 5,6-difluoroindan-2-yl group (see Patent Documents 3 and 4) has a characteristic that the response speed is fast despite a relatively large Δε, but the minimum temperature of the liquid crystal phase is considerably high. Application is delayed as a highly practical nematic liquid crystal composition.

  In addition, an invention that comprehensively includes a compound having a 4,6-difluoroindane-2,5-diyl group is also disclosed (see Patent Document 5). However, there is no specific disclosure of the production method and physical property values of the compound having fluorine atoms at the 4-position and 6-position of the indane ring in the cited document, although there is a description that it can be used as a nematic liquid crystal composition. In addition, there is no disclosure of what kind of compound the compound is combined with to form a nematic liquid crystal composition and what characteristics are obtained when this liquid crystal composition is used. In addition, liquid crystal compositions using indane compounds are already known, and specific examples of preferred compounds are disclosed (see Patent Document 6). However, the compounds disclosed here do not have fluorine atoms at the 4-position and 6-position of the indane ring, and the substituent at the 2-position mainly has a special ring structure or a non-ring structure. Moreover, the liquid crystal composition disclosed herein is a liquid crystal composition used for a ferroelectric liquid crystal display device, and there is no disclosure regarding a nematic liquid crystal composition.

  From the above, a compound having a fluorine atom at the 4-position and 6-position of the indane ring and a nematic liquid crystal composition to which the compound is applied are not known and have a 4,6-difluoroindane-2,5-diyl group. Development of a nematic liquid crystal composition having a wide range of liquid crystal phase temperature and having excellent characteristics using a compound has been desired.

International Publication No. 00/17287 Pamphlet JP 2001-11450 A (page 6) WO94 / 18285 pamphlet (27-29 pages) JP-A-6-263663 (pages 9 to 10) European Patent Application No. 633585 (Example from page 31), JP-A-7-70060 (Example from page 30) WO99 / 19420 pamphlet (30-35 pages)

An object of the present invention is to use a compound having a 4,6-difluoroindan-2,5-diyl group without improving or deteriorating various liquid crystal characteristics such as response speed and threshold voltage within the optimum range of Δn. , the lower limit temperature of liquid crystal phases (T _{→ N)} is low, the liquid crystal phase high maximum temperature (T _NI), further provides a broad nematic liquid crystal composition of the liquid crystal phase temperature range, for use in the liquid crystal composition together 4 It is to provide a compound having a 6,6-difluoroindane-2,5-diyl group.

  As a result of studying a nematic liquid crystal composition containing a 4,6-difluoroindane compound in order to solve the above problems, the present inventor has completed the present invention.

  That is, the present invention contains one or more compounds having a 4,6-difluoroindan-2,5-diyl group in the skeleton, and a refractive index anisotropy in the range of 0.08 to 0.15. The liquid crystal phase upper limit temperature is 70 ° C. or higher, the liquid crystal phase lower limit temperature is −20 ° C. or lower, and the difference between the liquid crystal phase upper limit temperature and the liquid crystal phase lower limit temperature is 90 ° C. A liquid crystal display element as a material is provided.

  In addition, the general formula (Ib) used for the liquid crystal composition

(Wherein R represents an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and n represents 1 or 2), a 4,6-difluoroindane compound represented by provide.

  The nematic liquid crystal composition of the present invention, using a 4,6-difluoroindane compound, has good liquid crystal characteristics such as response speed and threshold voltage, low liquid crystal phase lower limit temperature, liquid crystal phase upper limit temperature, It became possible to provide a nematic liquid crystal composition having a wide phase temperature range.

An example of the present invention will be described below.
In the present invention, it contains at least one compound having a 4,6-difluoroindane-2,5-diyl group, preferably 1 to 6 types, more preferably 1 to 4 types, and more preferably 1 to 3 types. Species are particularly preferable, and the total content is preferably in the range of 5 to 50% by mass because the response speed deteriorates if the content is too high, and the threshold voltage increases if the content is too low, and preferably 10 to 40% by mass. It is particularly preferable that the range is

  The compound having a 4,6-difluoroindane-2,5-diyl group in the nematic liquid crystal composition of the present invention may be represented by the general formula (I)

(In the formula, R ¹ represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or a hydrogen atom, and the alkyl group or alkenyl group is unsubstituted or has 1 as a substituent. Or two or more fluorine atoms, chlorine atoms, methyl groups or trifluoromethyl groups, and one or more methylene groups present in the alkyl group or alkenyl group may be —CO—. May be substituted, and may be substituted with -S-, -O-, -OCOO-, -OCO- or -COO- as those in which oxygen atoms are not directly bonded to each other;
A ¹ and A ² are each independently
(a) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(b) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom), and
(c) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the above group (a), group (b) or group (c) Group, fluorine atom or chlorine atom may be substituted,
l and m each independently represents 0, 1 or 2, but the sum of l and m is 2 or less,
Z ¹ and Z ² are each independently —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, — (CH ₂ ) ₄ −, —CH═CH—CH ₂ CH ₂ —, —CH ₂ CH ₂ —CH═CH— or a single bond,
R ² has the same meaning as a hydrogen atom, fluorine atom, chlorine atom, cyano group, trifluoromethyl group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group, 2,2,2-trifluoroethyl group or R ¹ Represents
When there are a plurality of A ¹ , A ² , Z ¹ and Z ^2, they may be the same or different. ) Is preferred.

In general formula (I), R ¹ is preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, since the side chain is too long to easily develop a smectic phase. More preferred is an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and the alkenyl group is more preferably a structure represented by the following formulas (a) to (e).

(The structural formula shall be connected to the ring at the right end.)
A ¹ preferably represents a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group or 3,5-difluoro-1,4-phenylene group, More preferably, it represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group.

A ² preferably represents a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group or 3,5-difluoro-1,4-phenylene group, More preferably, it represents a 1,4-phenylene group, a 3-fluoro-1,4-phenylene group or a 3,5-difluoro-1,4-phenylene group.

Z ¹ and Z ² each independently preferably represent —COO—, —OCO—, —CH ₂ CH ₂ —, —C≡C—, — (CH ₂ ) ₄ — or a single bond, ₂ CH ₂ -, - C≡C- or more preferably represents a single bond, -CH ₂ CH ₂ - and particularly preferably a or a single bond.

l preferably represents 1 or 2, and m preferably represents 0.
R ² preferably represents a fluorine atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, a linear alkyl group having 1 to 8 carbon atoms or an alkoxyl group, and represents a trifluoromethoxy group or a fluorine atom. Is more preferable, and it particularly preferably represents a fluorine atom.

  As a specific structure of the general formula (I), the following general formula (Ia)

(式中R¹、A¹、Z¹、l、及びR²は一般式(I)におけると同じ意味を表し、A¹及びZ¹が複数存在する場合はそれらは同一でも良く異なっていても良い。)で表される化合物が好ましく、一般式(Ib)で表される化合物がより好ましく、以下の式で表される化合物が特に好ましい。

(Wherein R ¹ , A ¹ , Z ¹ , l and R ² represent the same meaning as in general formula (I), and when there are a plurality of A ¹ and Z ^1, they may be the same or different) The compound represented by general formula (Ib) is more preferable, and the compound represented by the following formula is particularly preferable.

(In the formula, R ¹ represents an alkyl group or an alkoxyl group having 1 to 8 carbon atoms.)
Among these compounds selected from the general formula (I), at least one dielectric anisotropy (Δε) is preferably 1.5 or more, and more preferably 2 or more.
In the nematic liquid crystal composition of the present invention, the general formula (II) having a small absolute value of Δε

(Wherein, R ³ and R ⁴ each independently represent the same meaning as R ¹ in formula (I),
B ^1, B ² and B ³ are each independently
(a) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(b) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom), and
(c) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the above group (a), group (b) or group (c) Group, fluorine atom or chlorine atom may be substituted,
o represents 0, 1 or 2;
L ¹ , L ² and L ³ each independently represent a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O— or —C≡C—, When a plurality of L ² and B ³ are present, they may be the same or different. It is preferable to contain the compound represented by this.

In the general formula (II), R ³ and R ⁴ preferably represent an unsubstituted linear alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms. More preferably, it represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and particularly preferably represents an unsubstituted linear alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 6 carbon atoms. The structure represented by the formulas (a) to (e) is more preferable for the alkenyl group. R ³ and R ⁴ may be the same or different, but R ³ and R ⁴ in the same molecule are more preferably different.

L ¹ and L ² preferably represent —COO—, —OCO—, —CH ₂ CH ₂ —, —C≡C—, — (CH ₂ ) ₄ — or a single bond, and —CH ₂ CH ₂ — , —C≡C— or a single bond is more preferable, —CH ₂ CH ₂ — or a single bond is particularly preferable, and when a plurality of L ¹ and L ² are present, at least one represents a single bond It is preferable.
o preferably represents 0 or 1.

C ^1, C ² and C ³ are each independently trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene or 3,5-difluoro-1, preferably represents 4-phenylene group, more preferably it represents a cyclohexylene group or 1,4-phenylene group trans-1,4-cyclohexylene, C ^1, C at least one of ² and C ³ are trans -1 It preferably represents a 4-cyclohexylene group.
The general formula (II) is preferably a structure represented by the following general formula (IIa) as a specific structure.

(Expressed in the formula, the alkyl group or alkoxyl group of R ³ and R ⁴ are from 1 to 8 carbon atoms, an alkenyl group having a carbon number of 2 to 8, the alkenyloxy group having 3 to 16 carbon atoms, B ³ is 1 , 4-phenylene group or trans-1,4-cyclohexylene group, r represents 0 or 1)
General formula (II) is preferably a structure represented by the following general formula (II-1) to general formula (II-3) as a more specific structure.

(Represented in the formula, the alkyl group or alkoxyl group of R ⁶ and R ⁸ from 1 carbon atom independently 8, an alkenyl group having a carbon number of 2 to 8, the alkenyloxy group having 3 to 16 carbon atoms. )
A structure represented by the following general formula is also preferable.

(Represented in the formula, the alkyl group or alkoxyl group of R ⁶ and R ⁸ from 1 carbon atom independently 8, an alkenyl group having a carbon number of 2 to 8, the alkenyloxy group having 3 to 16 carbon atoms. )
The compound selected from the general formula (II) has low viscosity and is effective in improving the response speed when contained, but if the content is increased, the threshold voltage may be increased. When the compound selected from the general formula (II) is contained, it is preferably contained in one to six types, particularly preferably in one to four types.

  The content of the compound represented by the general formula (II) is preferably in the range of 10 to 80% by mass, and more preferably in the range of 10 to 60% by mass.

  In the present invention, Δε having a relatively large general formula (IIIa), general formula (IIIb) and general formula (IIIc)

(Wherein R ⁵ represents the same meaning as R ¹ in general formula (I), and C ¹ , C ² and C ³ are each independently
(d) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(e) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom);
(f) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, 1,2,3,4 A group selected from the group consisting of -tetrahydronaphthalene-2,6-diyl group and decahydronaphthalene-2,6-diyl group, wherein the group (d), group (e) or group (f) is cyano Group, fluorine atom or chlorine atom may be substituted,
K ¹ , K ² and K ³ are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO— or -C≡C-
X ¹ , X ³ , X ⁴ , X ⁵ and X ⁶ each independently represent a hydrogen atom or a fluorine atom,
p and q each independently represent 0, 1 or 2, but the sum of p and q is 2 or less,
X ² has the same meaning as hydrogen atom, fluorine atom, chlorine atom, cyano group, trifluoromethyl group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group, 2,2,2-trifluoroethyl group or R ¹ Represents. It is preferable to contain the compound represented by this.

Formula (IIIa), R ⁵ in the general formula (IIIb) and formula (IIIc), preferably represents a straight-chain alkyl or alkenyl group having 2 to 15 carbon atoms having 1 to 15 carbon atoms, carbon atoms More preferably, it represents a linear alkyl group having 1 to 10 or an alkenyl group having 2 to 10 carbon atoms, and particularly represents a linear alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 6 carbon atoms. Preferably, the alkenyl group more preferably represents the structure of formulas (a) to (e). K ^1, K ² and K ³ are, -COO -, - OCO -, - CH 2 CH 2 -, - C≡C -, - (CH 2) 4 - or preferably represents a single bond, -CH ₂ More preferably, it represents CH ₂ —, —C≡C— or a single bond, particularly preferably represents —CH ₂ CH ₂ — or a single bond, and at least one of K ¹ , K ² or K ³ is present. One is preferably a single bond. p and q preferably represent 0 or 1. C ¹ , C ² and C ³ are each independently a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group or 3,5-difluoro-1, It preferably represents a 4-phenylene group, more preferably represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and particularly preferably represents a trans-1,4-cyclohexylene group. .

X ² preferably represents a fluorine atom, a cyano group, a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group or a trifluoromethoxy group, and particularly preferably represents a fluorine atom.
Specifically, it is preferable to represent a structure represented by the following general formula (IIIa-1).

Wherein R ⁷ represents an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and L ⁵ and L ⁶ are each independently _{-CH 2 CH 2 -, - CH} = CH -, - C≡C -, - (CH 2) 4 - or a single bond, I is a 1,4-phenylene group or a trans-1,4-cyclohexylene group the stands, X ⁶ represents a hydrogen atom or a fluorine atom, n represents 0 or 1, Y ⁴ represents a cyano group, a fluorine atom, a chlorine atom, a trifluoromethyl group, fluoromethoxy group, difluoromethoxy group or trifluoromethoxy Represents a group.)
More specifically, the following general formula (IIIa-2a) to general formula (IIIa-4d)

(Wherein R ⁷ represents an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, and X ³ and X ⁴ are each independently hydrogen. Y ⁴ represents a cyano group, a fluorine atom, a chlorine atom, a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group, or a trifluoromethoxy group. General formula

(Wherein R ⁷ represents an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, and X ³ and X ⁴ are each independently hydrogen. Y ⁴ represents a cyano group, a fluorine atom, a chlorine atom, a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group, or a trifluoromethoxy group. .
General formula (IIIb) has the following general formula as a specific structure:

(Wherein R ⁷ represents an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and Y ⁴ represents a cyano group, a fluorine atom, or a chlorine atom. Represents a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group or a trifluoromethoxy group).
General formula (IIIc) has the following general formula as a specific structure:

(Wherein R ⁷ represents an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and Y ⁴ represents a cyano group, a fluorine atom, or a chlorine atom. , Represents a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group or a trifluoromethoxy group).

  Compounds selected from the group consisting of compounds represented by general formula (IIIa), general formula (IIIb) and general formula (IIIc) have a large Δε, and the inclusion of these in the nematic liquid crystal composition reduces the threshold voltage. Although effective, if the content is too large, the viscosity increases and the response speed decreases. In the case of containing a compound selected from the group consisting of compounds represented by the general formula (IIIa), general formula (IIIb) and general formula (IIIc), it is preferable to contain 1 to 10 types, preferably 2 to 8 types It is particularly preferable to contain, and the content of the group consisting of the compounds represented by general formula (IIIa), general formula (IIIb) and general formula (IIIc) is preferably 5 to 50% by mass, and preferably 10 to 50%. More preferably, it is mass%.

The nematic liquid crystal composition of the present invention contains at least one compound represented by general formula (Ia), and is further represented by general formula (IIIa), general formula (IIIb) and general formula (IIIc). Preferably it contains at least one compound selected from the group consisting of:
It preferably contains at least one compound selected from the compounds represented by the general formula (Ia), and further contains at least one compound represented by the general formula (II),
Containing at least one compound of the compound represented by the general formula (Ia), at least one compound represented by the general formula (II), and further comprising the general formula (IIIa), the general formula (IIIb) and More preferably, it contains at least one compound selected from the group consisting of compounds represented by formula (IIIc),
It contains at least one compound of the compound represented by the general formula (Ia), contains at least one compound represented by the general formula (II), and further contains the general formula (IIIa), the general formula (IIIb) And at least two compounds selected from the group consisting of compounds represented by formula (IIIc) are particularly preferable.

  In addition, at least one compound of the compound represented by the general formula (Ia) is contained, at least one compound represented by the general formula (II) is contained, and the compound represented by the general formula (IIIa) And at least one compound selected from the group consisting of compounds represented by general formula (IIIb) and general formula (IIIc), and having general formula (IIIa) and general formula (IIIb) And the content of the group consisting of the compounds represented by formula (IIIc) is more preferably in the range of 10 to 50% by mass.

  Containing at least one compound represented by the general formula (Ib) in a range of 5 to 50% by mass, and containing at least one compound of the general formula (IIa), the content of which Containing at least one compound selected from the group consisting of compounds represented by general formula (IIIa), general formula (IIIb) and general formula (IIIc) in the range of 10 to 60% by mass, The rate is particularly preferably in the range of 5 to 50% by weight.

  In the nematic liquid crystal composition of the present invention, Δn is preferably in the range of 0.08 to 0.14, and more preferably 0.08 to 0.13.

  The nematic liquid crystal composition of the present invention has a wide liquid crystal phase temperature range (the absolute value of the difference between the liquid crystal phase lower limit temperature and the liquid crystal phase upper limit temperature), but the liquid crystal phase temperature range is preferably 95 ° C or higher, preferably 100 ° C or higher. Is more preferable. The upper limit temperature of the liquid crystal phase is preferably 70 ° C. or higher, and more preferably 80 ° C. or higher. Furthermore, the liquid crystal phase lower limit temperature is preferably −20 ° C. or lower, and more preferably −30 ° C. or lower.

The above nematic liquid crystal composition is useful for AM-LCD (active matrix liquid crystal display element) and STN-LCD (super twisted nematic liquid crystal display element), but is particularly useful for AM-LCD, and is a transmissive or reflective liquid crystal display. It can be used for an element. The nematic liquid crystal composition of the present invention may contain a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal and the like in addition to the above compounds.
The compound represented by the general formula (Ib) can be produced as follows. Formula (IV)

(Wherein R represents an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and n represents 1 or 2). An acetic acid ester derivative represented by lithium diisopropylamide, lithium After enolization with hexamethyldisilazide, butyllithium, etc., by reacting 3,4,5-trifluorobenzyl bromide, general formula (V)

(Wherein, R and n represent the same meaning as in general formula (IV)). This compound is hydrolyzed with a base such as sodium hydroxide or potassium hydroxide, and the resulting carboxylic acid is converted into an acid chloride using a chlorinating agent such as thionyl chloride, followed by Lewis acid such as aluminum chloride. By reacting with general formula (VI)

(Wherein R and n represent the same meaning as in formula (IV)), and an indanone derivative represented by formula (IV) can be obtained. This is reduced by using a reducing agent such as sodium borohydride or lithium aluminum hydride, and the resulting alcohol derivative is heated in the presence of an acid catalyst such as p-toluenesulfonic acid to give a general formula (VII)

(Wherein R and n represent the same meaning as in general formula (IV)). This Pd-C, Rh-C, Pt-C, Pd (OH) a metal catalyst presence of such _2, by hydrogenating, it is possible to obtain a compound represented by the general formula of interest (Ib).

  EXAMPLES Hereinafter, although an Example is given and this invention is further explained in full detail, this invention is not limited to these Examples. Further, “%” in the compositions of the following examples and comparative examples means “mass%”.

In the examples, the measured characteristics are as follows.
Liquid crystal phase upper limit temperature (T _NI ): Nematic phase-isotropic liquid phase transition temperature (° C)
Liquid crystal phase lower limit temperature (T _{→ N} ): Solid phase or smectic phase-nematic phase transition temperature (° C)
Nematic liquid crystal phase temperature range (ΔT): | T _NI −T _{→ N} |
Vth: Threshold voltage (V) when a TN-LCD with a cell thickness of 6μm is constructed
Δε: Dielectric anisotropy Δn: Refractive index anisotropy η: Viscosity (mPa · s)
The following abbreviations are used in compound descriptions.

Terminal n (number) C _n H _{2n + 1-}
C trans-1,4-cyclohexylene group
P 1,4-phenylene group
E -COO-
e -OCO-
A -CH ₂ CH _2-
t -C≡C-
CN -C≡N
On -OC _n H _{2n + 1}
F -F
OCFFF -OCF ₃
ndm- C _n H _{2n + 1} -C = C- (CH ₂ ) _m-1-
-O (dm) n -O (CH2) m-2-C = C-CnH2n + 1

Example 1 Synthesis of 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indane (I-1)

(1-1) Synthesis of ethyl 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionate into a solution of diisopropylamine (4.8 g) in tetrahydrofuran (THF) (50 ml) 1.5M butyllithium-hexane solution (31 ml) was added at -78 ° C, and the mixture was stirred at -78 ° C for 30 minutes and at 0 ° C for 15 minutes. After cooling to -78 ° C, a solution of ethyl (trans-4-propylcyclohexyl) acetate (10 g) in THF (30 ml) was added. After stirring for 1 hour, a solution of 3,4,5-trifluorobenzyl bromide (10 g) in THF (30 ml) was added, and the temperature was raised to room temperature over 3 hours. The reaction mixture was poured into 10% hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 9: 1) and ethyl 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionate (15.8 g )

(1-2) Synthesis of 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionic acid
Ethyl 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionate (15 g) was added to ethanol (100 ml), water (40 ml), sodium hydroxide (9 g) was added and heated to reflux for 4 hours. Ethanol (about 60 ml) was distilled off under reduced pressure, concentrated hydrochloric acid was added, extracted with toluene, concentrated, 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionic acid Crude product (12.9 g) was obtained.

(1-3) Synthesis of 5,6,7-trifluoro-2- (trans-4-propylcyclohexyl) -1-indanone
Dichloromethane (25 ml) and thionyl chloride (20 ml) were added to 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) propionic acid crude product (12.3 g), and 4 Heated to reflux for hours. Dichloromethane was distilled off at normal pressure, thionyl chloride was distilled off under reduced pressure, dichloromethane (50 ml) was added to the residue, and 2- (trans-4-propylcyclohexyl) -3- (3,4,5-trifluorophenyl) was added. ) A solution of propionate chloride in dichloromethane was prepared. This was added dropwise to a suspension of aluminum chloride (8 g) in dichloromethane (20 ml) at room temperature over 30 minutes. After further stirring for 2 hours, the reaction solution was poured into 10% hydrochloric acid under ice cooling. The organic layer was dried over anhydrous sodium sulfate and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 20: 1), and 5,6,7-trifluoro-2- (trans-4-propylcyclohexyl) -1-indanone crude product (8.8 g, 73% purity) was obtained. This was recrystallized from ethanol to obtain 5,6,7-trifluoro-2- (trans-4-propylcyclohexyl) -1-indanone (5 g, purity 99%). This compound had a molecular weight of 310 by mass spectrometry.

(1-4) Synthesis of 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indene
To a solution of 5,6,7-trifluoro-2- (trans-4-propylcyclohexyl) -1-indanone (5 g) in ethanol (50 ml) was added sodium borohydride (2 g), and 1 Stir for hours. The reaction mixture was poured into 10% hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated. Toluene (100 ml) and p-toluenesulfonic acid (1 g) were added to the residue, and the mixture was heated to reflux for 15 minutes. The reaction mixture was allowed to cool to room temperature, washed with 10% hydrochloric acid and saturated brine, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (hexane) to obtain 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indene (4.5 g). This compound had a molecular weight of 294 by mass spectrometry.
(1-5) Synthesis of 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indane
Ethanol (70 ml), ethyl acetate (30 ml) and 5% palladium-carbon (450 mg) were added to 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indene (4.5 g). The mixture was stirred for 1 hour under a hydrogen atmosphere. The reaction solution was filtered through Celite, the filtrate was concentrated, the residue was purified with a silica gel short column (hexane), and 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indane (4.5 g) was added. Obtained. Further, recrystallization from ethanol gave 4,5,6-trifluoro-2- (trans-4-propylcyclohexyl) indane (4.5 g, purity 99.8%). The melting point of this compound was 52 ° C.
1H NMR 3.0 (s, 1 H), 7.4-8.0 (m, 5 H)
MS m / z 296 (M +)

Example 2 Synthesis of 4,5,6-trifluoro-2- (trans-4- (trans-4-propylcyclohexyl) cyclohexyl) indane In Example 1, in (trans-4-propylcyclohexyl) ethyl acetate Instead, starting from ethyl (trans-4- (trans-4-propylcyclohexyl) cyclohexyl) acetate, 4,5,6-trifluoro-2- (trans-4- (trans-4-propyl-4-propyl) was prepared according to the same procedure. Cyclohexyl) cyclohexyl) indane was obtained.

(Examples 3 and 4 and Comparative Examples 1 and 2) Adjustment of Wide Temperature Range Liquid Crystal Composition 4,5,6-Trifluoro-2- (trans-4-propylcyclohexyl) indane synthesized in Example 1 (in the table) Is described as 3-Cy-In6), and nematic liquid crystal compositions (No. 1) and (No. 2) having a wide temperature range were prepared. The composition of the prepared liquid crystal composition is shown in Table 1 below. These liquid crystal compositions were prepared so that the liquid crystal phase temperature range was about 140 °.

For comparison of physical properties, nematic liquid crystal compositions R-1 and R-2 of Comparative Examples 1 and 2 shown in Table 2 were prepared as liquid crystal compositions having a wide temperature range.

Table 3 shows the physical property values of Examples 3 and 4 and Comparative Examples 1 and 2.

As shown in Table 3, the nematic liquid crystal compositions of Examples 3 and 4 have a low liquid crystal phase lower limit temperature (T _{→ N} ), a higher liquid crystal phase upper limit temperature (T _NI ), and a wide liquid crystal temperature range. I understand.

  Using this nematic liquid crystal composition, a TFT liquid crystal display device having excellent display quality could be produced.

  The nematic liquid crystal composition of Comparative Example 1 has a structure that is relatively close to that of the present invention, and the liquid crystal phase temperature range is considerably close, but the upper limit temperature of the liquid crystal phase is inferior to that of Examples 3 and 4. Further, the dielectric anisotropy of the nematic liquid crystal composition of Comparative Example 1 is smaller than those of Examples 3 and 4 of the present invention, and the threshold value of the TFT liquid crystal display device manufactured using the nematic liquid crystal composition of Comparative Example 1 The voltage characteristics were worse than those using Example 3 and Example 4 of the present invention.

  The liquid crystal composition of Comparative Example 2 in which the upper limit temperature of the liquid crystal phase was close to the liquid crystal composition of the example was the same as that of Example 1 at the upper limit temperature of the liquid crystal phase, but this time the lower limit temperature of the liquid crystal phase was significantly increased It can be seen that the temperature range is significantly inferior.

(Examples 5 and 6 and Comparative Examples 3 and 4) Adjustment of Low Viscosity Liquid Crystal Composition Nematic liquid crystal compositions (No. 3) and (No. 4) shown in Table 4 were prepared as low viscosity liquid crystal compositions.
These liquid crystal compositions were prepared with a target of Δε of 5 to 6 and a viscosity of 16 mPa · s.

For comparison of physical properties, nematic liquid crystal compositions R-3 and R-4 of Comparative Examples 3 and 4 shown in Table 5 were prepared as low-viscosity liquid crystal compositions.

Table 5 shows the physical property values of Examples 5 and 6 and Comparative Examples 3 and 4.

As shown in Table 6, the nematic liquid crystal compositions of Examples 5 and 6 have sufficiently large dielectric anisotropy as a low-viscosity liquid crystal composition, and further the lower limit temperature of the liquid crystal phase (T _{→ N} ) Was low, the liquid crystal phase upper limit temperature (T _NI ) was high, and the liquid crystal phase temperature range was wide.

  Using this nematic liquid crystal composition, a TFT liquid crystal display device having a high-speed response and excellent display quality could be produced.

  The liquid crystal composition of Comparative Example 3 has a structure that is relatively close to that of Examples 5 and 6, but the viscosity does not drop to a value necessary for a low-viscosity liquid crystal composition and is inferior in the liquid crystal phase temperature range.

  As shown in Comparative Example 4, it can be seen that when the viscosity is brought close to the liquid crystal compositions of Examples 5 and 6, the liquid crystal phase temperature range is significantly narrowed.

(Example 7 and Comparative Example 5) Preparation of liquid crystal composition The nematic liquid crystal composition (No. 5) shown below was prepared and measured for physical properties. The results are shown in Table 5. Further, the nematic liquid crystal composition of Comparative Example 5 was prepared and the physical properties thereof are shown together in Table 5.
These liquid crystal compositions were prepared so that Δn was around 0.12.

  The liquid crystal composition of Example 7 is a liquid crystal composition having a relatively large Δn, but has a sufficiently wide liquid crystal phase temperature range and low viscosity.

The liquid crystal composition of Comparative Example 5 having a similar Δn is slightly inferior to the liquid crystal composition of Example 7 due to the liquid crystal phase temperature range and viscosity.

Claims (14)

Containing one or more compounds having 4,6-difluoroindane-2,5-diyl group in the skeleton, with refractive index anisotropy in the range of 0.08 to 0.15, upper limit of liquid crystal phase A nematic liquid crystal composition having a temperature of 70 ° C. or higher, a liquid crystal phase lower limit temperature of −20 ° C. or lower, and a difference between the liquid crystal phase upper limit temperature and the liquid crystal phase lower limit temperature of 90 ° C. or higher. Compounds having a 4,6-difluoroindane-2,5-diyl group in the skeleton are represented by the general formula (I)

(In the formula, R ¹ represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or a hydrogen atom, and the alkyl group or alkenyl group is unsubstituted or has 1 as a substituent. Or two or more fluorine atoms, chlorine atoms, methyl groups or trifluoromethyl groups, and one or more methylene groups present in the alkyl group or alkenyl group may be —CO—. May be substituted, and may be substituted with -S-, -O-, -OCOO-, -OCO- or -COO- as those in which oxygen atoms are not directly bonded to each other;
A ¹ and A ² are each independently
(a) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(b) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom), and
(c) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the above group (a), group (b) or group (c) Group, fluorine atom or chlorine atom may be substituted,
l and m each independently represents 0, 1 or 2, but the sum of l and m is 2 or less,
Z ¹ and Z ² are each independently —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, — (CH ₂ ) ₄ −, —CH═CH—CH ₂ CH ₂ —, —CH ₂ CH ₂ —CH═CH— or a single bond,
R ² is a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group, the same meanings as 2,2,2-trifluoroethyl group, or R ¹ Represents
A ^1, A ^2, if Z ¹ and Z ² there are a plurality may they be different it may be the same. The nematic liquid crystal composition according to claim 1, which is a compound represented by A compound having a 4,6-difluoroindane-2,5-diyl group in the skeleton has the general formula (Ia)

(Wherein R ¹ , A ¹ , Z ¹ , l and R ² represent the same meaning as in general formula (I), and when there are a plurality of A ¹ and Z ^1, they may be the same or different) The nematic liquid crystal composition according to claim 1, which is a compound represented by The nematic liquid crystal composition according to claim 3, wherein the content of the compound represented by the general formula (1a) is in the range of 5 to 50% by mass. Formula (II)

(Wherein R ³ and R ⁴ each independently represent the same meaning as R ¹ in formula (I),
B ^1, B ² and B ³ are each independently
(a) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(b) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom), and
(c) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the above group (a), group (b) or group (c) Group, fluorine atom or chlorine atom may be substituted,
o represents 0, 1 or 2;
L ^1, L ² and L ³ are each independently a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O- or represents -C≡C-, When a plurality of L ² and B ³ are present, they may be the same or different. 4. A nematic liquid crystal composition according to claim 1, 2 or 3, comprising at least one compound represented by formula (1). General formula (IIIa), general formula (IIIb) and general formula (IIIc)

(The same meaning as R ¹ wherein R ⁵ in the general formula ^{(I), C 1, C} 2 and C ³ are each independently,
(d) trans-1,4-cyclohexylene group (one methylene group present in this group or two or more methylene groups not adjacent to each other may be replaced by -O- or -S-) ),
(e) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom);
(f) 1,4-cyclohexenylene group, 1,4-bicyclo (2.2.2) octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, 1,2,3,4 A group selected from the group consisting of -tetrahydronaphthalene-2,6-diyl group and decahydronaphthalene-2,6-diyl group, wherein the group (d), group (e) or group (f) is cyano Group, fluorine atom or chlorine atom may be substituted,
K ^1, K ² and K ³ are each independently a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO- or -C≡C-
X ¹ , X ³ , X ⁴ , X ⁵ and X ⁶ each independently represent a hydrogen atom or a fluorine atom,
p and q each independently represent 0, 1 or 2, but the sum of p and q is 2 or less,
X ² has the same meaning as hydrogen atom, fluorine atom, chlorine atom, cyano group, trifluoromethyl group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group, 2,2,2-trifluoroethyl group or R ¹ Represents. 4. The nematic liquid crystal composition according to claim 1, 2 or 3, comprising at least one compound selected from the group consisting of compounds represented by formula (1): The nematic liquid crystal composition according to claim 6, wherein the content of the compound consisting of the group consisting of general formula (IIIa), general formula (IIIb) and general formula (IIIc) is in the range of 10 to 50 mass%. Formula (IIa)

(Wherein R ³ and R ⁴ represent an alkyl group or alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms, and B ³ represents 1 6. A nematic liquid crystal composition according to claim 5, comprising a compound represented by: 1,4-phenylene group or trans-1,4-cyclohexylene group, and r represents 0 or 1. The nematic liquid crystal composition according to claim 8, wherein the content of the compound represented by the general formula (IIa) is in the range of 10 to 80% by mass. Formula (Ib)

(Wherein R represents an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and n represents 1 or 2). A compound having a 4,6-difluoroindane-2,5-diyl group in the skeleton has the general formula (Ib)

7. A nematic compound according to claim 6, wherein R represents an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and n represents 1 or 2. Liquid crystal composition. The content of the compound represented by the general formula (Ib) is in the range of 5 to 50% by mass, and the general formula (IIa)

(Expressed in the formula, the alkyl group or alkoxyl group of R ³ and R ⁴ are from 1 to 8 carbon atoms, an alkenyl group having a carbon number of 2 to 8, the alkenyloxy group having 3 to 8 carbon atoms, B ³ is 1 , 4-phenylene group or trans-1,4-cyclohexylene group, r represents 0 or 1), and the content is in the range of 10 to 60% by mass. In addition, at least one compound selected from the group consisting of general formula (IIIa), general formula (IIIb) and general formula (IIIc) is contained, and the content thereof is in the range of 10 to 50% by mass. 11. The nematic liquid crystal composition according to 11. A liquid crystal display element using the nematic liquid crystal composition according to any one of claims 1 to 9, 11, or 12. An active matrix liquid crystal display device using the nematic liquid crystal composition according to any one of claims 1 to 9, 11, or 12.