JP2822083B2 - Alkyneoxyphenylbicyclohexanes compounds - Google Patents

Description

The present invention relates to a novel alkyneoxyphenylbicyclohexane compound and a liquid crystal composition containing the compound.

[Conventional technology and its problems]

Display elements using liquid crystals are widely used in watches, calculators, and the like. These liquid crystal display devices utilize the optical anisotropy and the dielectric anisotropy of a liquid crystal material. Liquid crystal includes a nematic liquid crystal phase, a smectic liquid crystal phase, and a cholesteric liquid crystal phase as a state phase, and the liquid crystal phase utilizing the nematic liquid crystal phase is most widely used. In response to the electro-optic effect applied to liquid crystal displays,
There are display devices such as TN (twisted nematic) type, DS (dynamic scattering) type, guest-host type, and DAP type, and the liquid crystal material used for each type shows a liquid crystal phase in a temperature range as wide as possible in nature. desirable. Many liquid crystal substances or compounds are already known, but at present there is no single liquid crystal compound that satisfies such conditions, and at present the composition is a mixture of several liquid crystal compounds or even non-liquid crystal compounds Has been put to practical use. It is natural that the compound constituting the composition is stable against moisture, light, heat, air, etc., but when added as a liquid crystal component for the following reason, the viscosity of the liquid crystal composition must be increased. In addition, there is a demand for a material which raises the transition point between the monetic phase and the isotropic liquid phase (hereinafter abbreviated as NI point). That is, in recent years, with the expanding use of liquid crystal display devices, devices that can be used in a wider temperature range are being demanded. Incidentally, the conventional operating temperature range was usually about -20 to 60 ° C), but recently, a temperature range of -30 to 110 ° C or higher has been desired. As a component of the composition, shows a liquid crystal phase over a wide temperature range,
It is desired to exhibit a liquid crystal phase up to a high temperature (generally 150 ° C. or higher) and a viscosity as low as possible. However, a liquid crystal compound that satisfies such a requirement has not always been known.

[Problems to be solved by the invention]

The present invention has been accomplished by finding that the novel compounds described below can improve the conventional disadvantages of liquid crystal compositions.

That is, an object of the present invention is to provide a novel compound which is effective as a component of a liquid crystal composition, and a liquid crystal composition having the conventional disadvantages improved by containing the novel chemical compound.

[Means for solving the problem]

To achieve the above object, the present invention provides a compound represented by the general formula (Wherein, R ¹ is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and R ² is a linear or branched alkyne having 3 to 15 carbon atoms having one triple bond.) Indicates a group)
And a liquid crystal composition containing at least one such compound.

Among the components used in the liquid crystal composition of the present invention, other components other than the compound of the present invention include, for example, ester-based compounds,
Known compounds such as Schiff bases, biphenyls, phenylcyclohexanes, and heterocyclics can be widely used.

The compound of the present invention can be obtained by any method capable of producing the compound, and for example, can be obtained by the following reaction formula.

(Wherein R ¹ and R ² are the same as those shown in the above-mentioned general formula) That is, trans-4- (trans-4-alkylcyclohexyl) cyclohexylphenol and alkyne bromide were present in the presence of anhydrous potassium carbonate. It can be produced by reacting in an N, N-dimethylformamide (hereinafter abbreviated as DMF) solvent.

[Functions and Effects of the Invention]

The compound of the present invention exhibits a smectic liquid crystal phase and a nematic liquid crystal up to a high temperature range, and exhibits a phase with many other liquid crystal compounds, that is, a compound such as an ester, a Schiff base, a biphenyl, a phenylcyclohexane, or a heterocyclic compound. Good solubility. Therefore, by adding this compound to an ordinary liquid crystal composition, the NI point can be increased without a particular increase in Δn and viscosity, thereby increasing the use of the compound including expansion to a high temperature region. A liquid crystal composition for a liquid crystal display element having a wide temperature range can be provided.

 Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 1- (2-propynyloxy) -4- [trans-4-
Production of (trans-4-propylcyclohexyl) cyclohexyl] benzene 1-hydroxy-4- (trans-4-propylcyclohexyl-trans-4-cyclohexyl) benzene 3.
30 g of anhydrous potassium carbonate and 200 ml of DMF were added to 0 g (0.01 mol). The reaction mixture thus obtained is stirred for 1 hour at room temperature under stirring.
-Addition of 3.6 g (0.03 mol) of bromo-2-propylene and 80 ° C
For 12 hours. After allowing the reaction to cool, it was poured into water 1 and then extracted twice with 500 ml of toluene. The toluene layer was washed with 2N sodium hydroxide and then with water until neutral. After drying the toluene layer with anhydrous sodium sulfate, the toluene was distilled off under reduced pressure, and the remaining crystals were recrystallized from acetone, thus obtaining 1.5 g (44% yield) of a crystalline compound. Its properties were a crystal-smectic phase transition point of 64.3 ° C, a smectic phase-nematic phase transition point of 140.2 ° C, and a clearing point of 180.3 ° C.

Example 2 30% by weight of trans-4-propyl- (4-cyanophenyl) cyclohexane 40% by weight of trans-4-pentyl- (4-cyanophenyl) cyclohexane 30% by weight of trans-4-heptyl- (4-cyanophenyl) cyclohexane The NI point of the liquid crystal composition (A) is 52.1 ° C., Δε is
11.2, viscosity at 20 ° C. is 23.4 mPa · s, and Δn is 0.119. Separately, a silicon oxide-coated, rubbed substrate having a tin oxide transparent electrode is assembled to face each other, and a liquid crystal cell having a distance between the electrodes of 10 μm is prepared as a liquid crystal cell, and the above liquid crystal composition (A) is sealed therein. When the characteristics were measured at 20 ° C., the threshold voltage (hereinafter, Vth
Was abbreviated as 1.55V.

85% by weight of the liquid crystal composition (A) was added to 1% of the liquid crystal composition obtained in Example 1.
-(2-propynyloxy) -4- [trans-4-
(Trans-4-propylcyclohexyl) cyclohexyl] benzene (15% by weight) was added and dissolved, and the characteristics of the composition thus obtained were determined. The NI point was 61.3%.
° C, Δε is 9.9, Δn is 0.120, viscosity at 20 ° C is 23.9
mPa · s. From these results, the composition according to the present invention is an excellent liquid crystal composition corresponding to a high temperature application of a liquid crystal display element, since the NI point is greatly increased while the viscosity is hardly increased. You can see that.

Claims (2)

(57) [Claims] (1) General formula Wherein R ¹ is hydrogen or a straight-chain or branched alkyl group having 1 to 15 carbon atoms, and R ² is a straight-chain or branched alkyne having 3 to 15 carbon atoms having one triple bond. Indicates a group)
An alkyneoxyphenylbicyclohexanes compound represented by the formula: 2. A liquid crystal composition comprising at least one alkyneoxyphenylbicyclohexane compound according to claim 1.