JPS62148570A - Anthraquinone-based compound and liquid crystal composition containing said compound - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [X is S or Se; R is (substituted) phenyl, naphthyl, heterocycle or tetrahydronaphthyl]. EXAMPLE:A compound of formula II. USE:For liquid crystal composition; having high dichromatic ratio and good solubility to liquid crystal. PREPARATION:A compound of formula II and a second compound of formula III are allowed to react, pref. at 80-150 deg.C, in a solvent such as DMF in the presence of an organic acid bonding agent such as potassium carbonate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel anthraquinone compound and a liquid crystal composition containing the compound.

2. Description of the Related Art Conventionally, it has been known that a liquid crystal composition in which a dye compound is dissolved in liquid crystal is interposed between two opposing electrodes, and color display is performed by utilizing the guest-host effect between the dye compound and the liquid crystal. ing.

The dye compound used in such a liquid crystal composition is particularly required to have properties such as a high dichroic ratio and high solubility in the liquid crystal.

It is known that anthraquinone compounds exhibiting a yellow to yellow-orange hue are used in liquid crystal compositions (JP-A-7-73067, JP-A-J7-/J).
! - Publication No. 2).

However, conventional anthraquinone compounds do not necessarily satisfy the properties required of dye compounds used in liquid crystal compositions as described above.

Problems to be Solved by the Invention The present invention aims to provide an anthraquinone compound that exhibits a high dichroic ratio and good solubility in liquid crystals, and a liquid crystal composition that provides good color display. It is.

Means to solve problems The present invention relates to general formula [I] (In the formula, or represents a sulfur atom or a selenium atom.

R represents a phenyl group, a naphthyl group, a heterocyclic group, or a tetrahydronaphthyl group which may have a substituent) and a liquid crystal composition containing the compound.

In the general formula [I], examples of the heterocyclic group represented by R include nitrogen-containing heterocyclic groups such as pyridyl group and pyrimidinyl group.

Also, a phenyl group or a naphthyl group represented by R.

Examples of substituents that the heterocyclic group or tetrahydronaphthyl group may have include an alkyl group, an alkoxy group, a halogen atom, -0+()f2 CH20yaR1 (m is 7~!
represents an integer and R1 represents an alkyl group), (-OH=OHS0OOR2 (: n is 0 or /
R2 is an alkyl group, +CIh0IhOf R'
A group represented by (m and R1 are the same as defined above),
a phenyl group which may have a substituent, a cycloalkyl group, a transalkylcyclohexyl group], t! Examples include a phenyl group which may have one substituent, a cycloalkyl group, and a lance-gualkylcyclohexyl group.

Examples of the alkyl group include alkyl groups having a carbon number of /~/♂, preferably a carbon number of l~! Examples include alkyl groups.

Examples of the above EC alkoxy group include alkoxy groups having a carbon number of / to //, preferably an alkoxy group having a carbon number of 7 to r.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and the like.

The phenyl group which may have the above-mentioned substituents includes goualkyl (e.g., alkyl having a carbon number of up to 13, preferably carbon number up to r), a phenyl group% goualkoxy (
For example, carbon number/~/3, preferably carbon number/~/? alkoxy) phenyl group, biphenyl group, hexylphenyl group, trans-gualkyl (e.g., alkyl having 1 to 3 carbon atoms, preferably 1 to 3 carbon atoms)
Cyclohexylphenyl group etc. 731 Listed by Iff et al.

are mentioned, preferably a cyclohexyl group.

(-L-C, above) The trans-guoalkylcyclohexyl group includes a trans-guoalkyl (eg, alkyl having 1 to 3 carbon atoms, preferably 1 to 3 carbon atoms) cyclohexyl group.

In addition, the alkyl group and alkoxy group having 3 or more carbon atoms are:
It may be linear or branched.

The anthraquinone compound represented by the general formula m is synthesized, for example, by the following method.

[■] [■] (X and R in the above general formulas CD to [JIT] have the same meanings as above) Using solvents such as sulfoxide and sulfolane,
Acid binders, such as alkali metal carbons such as potassium carbonate and sodium carbonate M4. 50 to 200°C in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an acetate such as potassium acetate or sodium acetate, or an organic acid binder such as triethylamine.

Preferably, it can be carried out under a temperature condition of 20 to 110°C.

The anthraquinone compound of the present invention can be dissolved in liquid crystal and used as a liquid crystal composition in liquid crystal display devices and the like.

The liquid crystal used in the liquid crystal composition of the present invention includes nematic liquid crystals, and can be selected from a wide range as long as it exhibits a nematic state within the operating temperature range. By adding an optically active substance, which will be described later, to such a nematic liquid crystal, it can be made to take a cholesteric state. Examples of nematic liquid crystals include the substances listed in Table 1 or Towara derivatives.

Table 1 In the above table, R' represents an alkyl group or an alkoxy group,
represents an alkyl group, an alkoxy group, a nido α group, a cyano group, or a hegen atom.

All of the liquid crystals listed in Table 1 have positive dielectric anisotropy, but the known ester-based, azoxy-based, ammonium-based, and
Schiff series, pyrimidine series.

Diester or biphenyl ester liquid crystals are also available.
It can be mixed with a liquid crystal with positive dielectric anisotropy to create an overall positive liquid crystal, and even liquid crystal with negative dielectric anisotropy can be used as is if an appropriate device configuration and driving method are used. .

The host liquid crystal material used in the present invention may be any of the liquid crystals shown in Table 1 or a mixture thereof, including the liquid crystal sold by Merck & Co. under the trade name ZLnie//32 and ZLnie/! 6! LCD sold under the trade name or E from British Drug House.
A liquid crystal sold under the trade name ``-7'' is useful in the present invention.7 Examples of optically active substances used in the present invention include chiral nematic compounds such as 2-methylbutyl group, 3-methylbutoxy group, and 3-methylpentyl group. base%
3-Methylpentoxy group% Goomethyl. Tokukai Akira again! Alcohol derivatives such as λ-menthol and d-borneol described in /-4tjj4t4 publication, d
-Ketones such as camphor and 3-methylcyclohexane
pμ rest, d-citronellaic acid,! - Optically active substances such as carboxylic acid derivatives such as camphoric acid, aldehyde derivatives such as d-citronellal, alkene derivatives such as d-1,1-nonene, and other amine, amide, and nitrile derivatives can be used.

Seriously, the anthraquinone compound of the present invention.

It can be used by mixing it with other dichroic dyes and adjusting the color to any desired hue.

As an element for performing liquid crystal display using the liquid crystal composition of the present invention, a known liquid crystal display element can be used. That is, generally, transparent electrodes in an arbitrary pattern are provided on two glass substrates, at least one of which is transparent. An element is used in which two glass substrates are arranged parallel to each other with a suitable spacer interposed therebetween so that their pole faces face each other. In this case, the spacer caps the element. As an element cap, 1 to 50 in 3 to /θ0μms%
μm is preferred from a practical standpoint.

Effects The anthraquinone compound of the present invention exhibits good solubility in liquid crystal, and the obtained liquid crystal composition has a high dichroic ratio, so that clear color display is possible.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

The order parameter indicating the dichroic ratio will be explained below. The Goo parameter S of a single dye compound can be determined experimentally from the following equation.

Here, A7 and A above are the absorbance of the dye for light polarized parallel and perpendicular to the alignment direction of the liquid crystal, respectively.

Order parameter 8 is specifically a value that indicates the display contrast of a guest-host type liquid crystal element, and the closer this value is to theoretically /, the less the residual color in the white area decreases.
A bright and clear display with high contrast is possible.

Example 1 Potassium hydroxide 0. Add /, 2°3.4t-tetrahydronaphthalene-≦-thiol 0, datry and a compound represented by the following structural formula /, θ2 to 30 d of NMP (N-methyl biaridone) solution in which /rt is dissolved, 1-2o~73
The mixture was stirred at 0°C for 3 hours. After cooling down, one reaction solution was discharged into a 30% saline solution. The precipitated crystals were filtered and dried, and subjected to column chromatography using silica gel (manufactured by Wako Pure Chemical Industries, Ltd., 0-200, trade name) as a carrier and a mixed bath medium of chloroform and n-hexane as a separation solvent. The impurities were separated and purified using a graphite to obtain the anthraquinone compound 3 of the present invention represented by the following formula: I got ■. Is this compound Kota Otsu 0-29? , exhibits a melting point of 0°C.

The obtained compound was mixed into the above-mentioned mixed liquid crystal ZL Any! 6! The compound (dye) was dissolved by repeating the steps of heating the mixture to 70° C. or higher for 710°C to turn the liquid crystal into an isotropic liquid, stirring well, and dispersingly cooling the mixture.

The above-mentioned liquid crystal composition adjusted in this manner was placed between two glass substrates, each consisting of an upper and lower glass substrate, each having a transparent electrode, coated with a polyamide resin on the surface in contact with the liquid crystal, cured, and then rubbed to give a homogeneous alignment treatment. It was sealed in an element with a gap of 10 gm. In the element subjected to the above alignment treatment, the liquid crystal was in a homogeneous alignment state during voltage and heat impression, and the dye molecules were also aligned in the same manner according to the host liquid crystal.

The absorption spectra of the six guest-host molecules thus prepared were measured using light polarized parallel to and perpendicular to the orientation direction of the liquid crystal molecules, respectively.
The maximum absorption wavelength of the dye for each of these polarized lights was determined. When determining the absorbance of the dye, corrections were made for absorption by the host liquid crystal and glass substrate, and reflection loss of the element.

Just to be sure, using 8/ and A for each polarization, the above equation The value of the order parameter S was calculated from.

The above results are shown in Table 4 below.

Examples 2 to 33 The anthraquinone compounds of the present invention shown in Table 2 below were produced by the same operations as in Example/, and the same operations as above were carried out.
The maximum absorption wavelength and order parameter fsl of the chemotactic compound isolated from ζ were measured, and the results are also shown in Table $2.

(However, L) indicates lance-cyclohexyl. ) Table - Table

Claims (2)

[Claims] (1) General formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼......[I] (In the formula, X represents a sulfur atom or a selenium atom, and R is phenyl which may have a substituent. Anthraquinone compound represented by a naphthyl group, a naphthyl group, a heterocyclic group, or a tetrahydronaphthyl group. (2) General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼......[I] (In the formula, X represents a sulfur atom or a selenium atom, and R represents phenyl which may have a substituent. 1. A liquid crystal composition containing an anthraquinone compound represented by a naphthyl group, a naphthyl group, a heterocyclic group, or a tetrahydronaphthyl group.