JPS6069049A - Trans,trans-4-alkyl-4'-alkoxybicyclohexyl - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (the group of formula II is trans- 1,4,-disubstituted cyclohexane ring; R and R' are 1-8C alkyl). EXAMPLE:trans,trans-4-n-Propyl-4'-ethoxybicyclohexyl. USE:A component of a liquid crystal composition. It is a compound having low viscosity, and exhibiting liquid crystal nature with small refractive index anisotropy and high chemical stability. It gives a liquid crystal display element having rapid response and wide view angle. PREPARATION:The compound of formula I can be produced by reacting the compound of formula III with metallic Na in an inert organic solvent such as dimethoxyethane, etc., and reacting the resultant compound of formula IV with an alkylation agent of formula R'X (X is eliminable group such as halogen) e.g. CH3I, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compound having liquid crystallinity with low viscosity and small refractive index anisotropy (Δn).

In the field of display elements, low power consumption and high-speed response electrical and/or thermo-optical elements are desired. It has been used extensively, and has attracted attention as a product that meets such demands. However, conventionally used liquid crystals have a narrow viewing angle due to their large Δn, and are unable to provide sufficient high-speed response due to their high viscosity. The development of a sex compound was awaited.

The present inventors have been searching for such liquid crystalline compounds, and found that -(D-OR') (where ℃・- represents a trans-1,4-disubstituted cyclohexane ring). ,R
and R' is an alkyl group having 1 to 8 carbon atoms) has an extremely low viscosity and Δn
found a small E. Therefore, a liquid crystal display element containing this compound can display a display having an extremely fast response and a wide viewing angle.

In the compound represented by the formula p to DK-OR' (1), both R and R' are alkyl groups having 1 to 8 carbon atoms, but when the number of carbon atoms is small, the liquid crystal phase generally changes to an isotropic state. The total number of carbon atoms in R and R' is preferably 4 or more because the temperature at which it transitions to a liquid phase (clearing point, hereinafter abbreviated as Tc) is low or the Tc of a liquid crystal composition containing one or more of the compounds is low. . Also, the total number of carbon atoms in R and R' is 4.
If it is less than 1, the boiling point of the compound is low, so that only the compound volatilizes when the liquid crystal composition is injected under reduced pressure, and the composition of the liquid crystal composition tends to change.

On the other hand, when R and R' have a large number of carbon atoms, the viscosity is generally high and the response becomes slow. Therefore, the number of carbon atoms in R and R' is preferably 8 or less each, and the total number is preferably 10 or less.

In addition, when R or R' is a branched alkyl group, 're' is generally lower than when it is a linear alkyl group having the same number of carbons, so R and R' are linear alkyl groups. Alkyl groups are preferred.

The liquid crystalline compound of the present invention is preferably used by mixing 1'm or one or more types with other liquid crystalline compounds to form a liquid crystal composition having a desired liquid crystal temperature range. It is used in an amount of 1 to 90 wt% in the mixture, preferably 3 to 50 wt%.

The components of the liquid crystal composition other than the liquid crystal compound of formula (1) of the present invention vary depending on the use, required performance, etc., but include components that exhibit liquid crystallinity at high temperatures, low viscosity components for low temperatures, and other antistatic anisotropic components. A component that improves properties, a component that imparts cholesteric properties, a component that has dichroism, a component that imparts conductivity, and other transfer additives may be appropriately mixed and used.

Specifically, the following compounds are included.

Unlike R in the present invention, R and R' in the following formula represent groups such as an alkyl group, an alkoxy group, a halogen atom, and a cyano group.

R℃・÷R・R−□−R′ R<)−@−R′ R−@−CoO+000+R′ R+COO+0004R′ R+COO+oCO+R′ Substitution of a hydrogen atom with a halogen atom, cyano group, methyl group, etc., substitution of a cyclohexane ring or benzene ring with another six-membered ring, five-membered ring, etc., change of bonding group between rings, etc. Various materials are selected and used.

The composition of the present invention is used by being injected into a liquid crystal cell.

A typical liquid crystal cell is twisted nematic (TN
) type liquid crystal cell, which is machined on the inner surface of a transparent substrate such as glass or plastic. Form transparent electrodes such as on-8nu1 in a desired pattern, overcoat with polyimide or the like as necessary, place the substrates with horizontal alignment layers facing each other, seal the periphery, and inject liquid crystal. The injection port is sealed, and polarizing plates are laminated on both outer surfaces. Further, an external phase transition type, a guest host type, a dynamic scattering type, or a combination thereof may be used.

Furthermore, as for the cell layout, an undercoat layer of 5iOz, Al2O3, etc. is provided between the transparent substrate and the transparent 8A electrode, a reflective electrode is used, a two-layer electrode is used, a color polarizing plate is used, and a color filter is used. , a variety of applications are possible for the tube as a two-layer element using a ten-layer substrate,
It can be used for a variety of purposes such as watches, calculators, measuring instruments, moving wheel instruments, games, computer terminals, etc.

According to the invention, the formula
' has the above meaning) can be produced by the following method.

(In the formula, X represents a leaving group such as a halogen atom)
2 Ql) compound with diethyl ether, tetrahydro7
In an inert organic solvent such as Ran, dimethoxyethane, etc., the compound of formula @) is prepared by reacting with a metal (IJ), and then reacted with an alkylating agent such as an alkyl halide, an alkyl tosylate, etc. to achieve the desired reaction. A compound of formula (I) is prepared.

By performing a series of purification treatments such as extraction, distillation, column chromatography and recrystallization, the desired compound (1) can be obtained.

Next, the present invention will be specifically explained using examples.

Example 1 Trans-4-(trans-4'-n-propylcyclohexylcocyclohexanol (11,2 to, 05 moles) is dissolved in 100 d of dimethoxyethane to which sodium metal (2,3 to, x gram atoms) is dissolved. was added and stirred for 5 hours at reflux temperature, a white precipitate was formed.Ethyl iodide (15,6P 0.1 mol) was added to this mixture and further stirred overnight at reflux temperature.The reaction mixture was diluted with water. After extraction with diethyl ether, the solvent was distilled off using a volator to leave a yellow solid.

When this is recrystallized from 200 ml of hexane, unreacted alcohol 3. Of was recovered as crystals.

After distilling off the solvent of the filtrate, the remaining yellow liquid was recrystallized twice with methanol/I/100d to obtain the desired trans, trans-4-n-propyl-4'-ethoxybicyclohexyl. the law of nature. Yield: 5.2 f, Yield: 41 h. Observation under a polarizing microscope with a hot stage shows that the compound changes from a crystalline phase to a smectic phase at 47.0°C, and from a smectic phase to a nematic phase at 48.3°C. It was found that the nematic phase transitions to an isotropic liquid phase at 2°C.

The IHNMR spectrum of this compound is shown in FIG. 1 and FIG. 2, respectively.

Example 2 In Example 1, by using n-butyl iodide (18,4! iP 0.1 mol) in place of ethyl iodide and performing the following series of operations in four orders of magnitude as in the same example, trans ,
Trans-4-n-propyl-4'-n-butoxybicyclohexyl was obtained. Yield: 5.6 tons, Yield: 40 inches. Observation under a polarizing microscope with a hot stage shows that this compound has a smectic phase at room temperature, and transitions from the smectic phase to an isotropic liquid phase at 72.0°C. I understand.

The R spectrum of this compound is shown in FIG.

Example 3 In Example 1, formula n-07H was used instead of iodochemical
Using a compound (xy, 9ro, t mol) of 1sBr, the following series of operations were carried out in the same manner as in the same example.
-n-hebutyloxybicyclohexyl was obtained. Collection f1
6. Observation under a polarizing microscope equipped with a hot stage revealed that the compound transitioned from a crystalline phase to a smectic phase at 33.0°C, and from a smectic phase to an isotropic liquid phase at 66.4°C. It was found that it metastasized.

The IHN spectrum of this compound is shown in Figure 4.
The MR spectrum diagram is shown in FIG.

Examples 4-13 The following compound was obtained in the same manner as in Example 1.

trans, trans-4-n-propyl A/-4'-methoxybicyclohexyl trans, trans-4-n-piμvir-4'-n -
,/roboxybicyclohexyltrans,trans-4-n-propyl A/-4'-n-
Pentyloxybicyclohexyl trans, trans-4-n-propy/I/ -4'-
n-hexyloxybicyclohexyltrans, trans-4-n-butyl-4'-methoxybicyclohexyltrans, trans-4-n-butyl-4'-ethoxybicyclohexyltrans, trans-4-n-butyl-4 '-n-proboxycyclohexyltrans, trans-4-n-butyl-4/-n-butoxybicyclohexyltrans, trans-4-n-butyl-4'-n-hentyloxybicyclohexyltrans, trans- 4-n-Butyl-4'-n-hexyloxybicyclohexyl Practical Example 14 Merck liquid crystal ZLI-1565 has a Δn of 013, but the compound of Example 1 was added to ZLI-1565 by 1 tswt%.
In the mixture, Δn decreased to 0.10. This shows that Δn of the compound of Example 1 is extremely small. The mixture also transitioned from a nematic phase to an isotropic liquid phase at 77.6°C. On the other hand, trans-1-
n-propyl-4-(4'-ethoxyphenyl)cyclohexane 25vrt%, trans-1-n-propyl-4-(4'-n'-phthoxyphenyl)cyclohexane 20wt* and Merck Liquid Crystal ZLI-108355
wt% mixture had a viscosity of 45.3 cat at 0°C, but the viscosity of the mixed liquid crystal of 9 wt% of this mixture and 10 wt% of the compound of Example 1 was reduced to 42.1 cat. This shows that the viscosity of the compound of Example 1 is extremely low.

The compound of the present invention is a liquid crystal obtained by mixing Iat or one or more types of Iat with other nematic, cholesteric, smectic liquid crystals, dichroic liquid crystal dyes, especially dichroic dyes, etc., and is sealed between transparent substrates having electrodes of a desired shape. It is used as a liquid crystal display element.

In addition, various undercoats,
It may have an overcoat for alignment control, a polarizing plate, a filter, a reflective layer, etc., and can be used in various ways such as forming a multilayer cell, combining with other display elements, using a semiconductor substrate, or using a light source. Things can be used.

In addition, the driving methods for liquid crystal display elements include dynamic scattering (DSM) method, twisted nematic (TI) method, guest host (()H) method, dual frequency method, and smectic phase electrical and/or thermo-optical method. A method known in the field of liquid crystal display can be adopted.

The compound of the present invention has low viscosity, small refractive index anisotropy,
Furthermore, since it has features such as being extremely chemically stable, a liquid crystal display element containing the compound of the present invention can display a display exhibiting quick response.

[Brief explanation of the drawing]

Figures 1, 3 and 4 are R spectra of the compounds of Examples of the present invention, and Figures 2 and 5 are IHNMR spectra of the compounds of Examples of the present invention. Kaya / )■ etc. 3) ¥1 Kaya 4 River

Claims (1)

[Scope of Claims] A compound represented by the formula (wherein heli- represents a trans-1,4-disubstituted cyclohexane term, and R and R/ are an alkyl group having 1 to 8 carbon atoms). @(Summer) In the formula, both R and R' are linear alkyl groups, and the total number of carbon atoms in both is 4 or more lO
A dispute over the contention of claim #g1, which is as follows: