JPH0283346A - Alkynyloxytolan compound - Google Patents

Abstract

NEW MATERIAL:The alkynyloxytolan compound of formula (R is 3-18C alkynyl; R' is 1-18C alkyl). EXAMPLE:4-n-Propyl-4'-(2-butynyloxy)tolan. USE:An electro-optical display material. It is useful for increasing the anisotropy of refractive index of a liquid crystal material by mixing to an STN-type liquid crystal material. PREPARATION:The objective alkynyloxytolan compound of formula can be produced by reacting an alcohol of formula R-CH2-OH with a 4-alkyl-4'- hydroxytolan.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tolan compound useful as an electro-optical display material, and more particularly to a tolan compound useful for increasing the anisotropy of the refractive index of a liquid crystal material by mixing it with an STN type liquid crystal material. This relates to alkynyloxytran compounds.

Currently, STN type liquid crystal cells are being developed from green or blue mode to monochrome and full color, and at the same time, studies are underway to increase the speed of response to support moving images. As for high-speed response, ferroelectric liquid crystals have been studied so far, but high-speed response is expected by making the layer thickness of the STN liquid crystal cell thinner. In that case,
A liquid crystal material with a large refractive index anisotropy (Δn) is required to fill the cell, and tolan compounds, which have low viscosity and a high Δn, have been proposed as a typical example, but this is still insufficient. , a compound exhibiting even higher Δn has been desired.

In view of the above-mentioned current situation, the inventors of the present invention have developed a method that has a low viscosity and a high Δn.
As a result of intensive studies to find a compound exhibiting the following, it was discovered that the addition of a novel alkynyloxytran compound represented by the following general formula (I) to the liquid crystal significantly improves the Δn of the liquid crystal.

(In the formula, R represents an alkynyl group having 3 to 18 carbon atoms, and Ro represents an alkyl group having 1 to 18 carbon atoms.) In the compound represented by the above-mentioned formula (I) according to the present invention, , As the alkynyl group represented by R, for example, 1-
Propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 1-hexynyl, 4-hebutynyl, 6-octenyl, 6-nonynyl, 7-nonynyl, 8-
Examples of the alkyl group represented by R'' include randecynyl, 10-)ridecinyl, 12-pentadecynyl, etc.
Examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, and the like.

Further, the compound represented by the above formula (I) is R-CI
It can be produced by reacting an alcohol represented by 1□-OH with 4-alkyl-4'-hydroxytran.

The thus obtained alkynyloxytran compound of the present invention can be used not only to increase the anisotropy of the refractive index of the liquid crystal material by mixing it with the STN type liquid crystal material, but also to increase the anisotropy of the refractive index of the liquid crystal material.
Due to its excellent reactivity, it is used as a variety of synthetic intermediates, and is particularly useful as an intermediate for obtaining alkyltran compounds, which are well known as liquid crystal compounds.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 4-n-propyl-4°-(2-butynyloxy)tone of 4-n-propyl-4”-hydroxytolan 1.OOg
, 0.36 g of 2-butyn-1-ol and 1.22 g of triphenylphosphine were dissolved in 10 ml of ether, and 0.81 g of azodicarboxylic acid diethyl ester was added dropwise thereto. After stirring at room temperature for 3 hours and filtering off the precipitated triphenylphosphine oxyto, the filtrate was desolvented. The residue was purified using a silica gel column using n-hexane/diethyl ether (8/2) as a developing solvent, and then purified with n-
White crystals with a melting point of 85.7℃ after recrystallization from hexane 0.6
7g was obtained.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorption, and was confirmed to be the desired product.

2975cm-', 1600cm-', 1575cm-
', 1570cm-'1260cm''', 10510
5O'840cm-'Example 2 To see the improvement of Δn of liquid crystal by adding the compound to liquid crystal, 10% tolan compound was mixed into a 1:1:1 mixture having the following composition. The procedure of Example 1 was repeated except that 2-pentyn-1-ol was used instead of 2-butyn-1-ol to obtain 0.62 g of a white crystal product with a melting point of 67.8°C.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorption, and was confirmed to be the desired product.

2975cm'', 1600cm-', 1575cm
-', 1570cm-'1260cm-', 1051
05O' 840cm-Heavy Reference Example The change in Δn of each of the novel alkynyloxytranations of the present invention was measured, and the results are shown below.

As is clear from the above results, the novel alkynyloxytran compound of the present invention has the effect of increasing the value of Δn of the mother liquid crystal.

hand Continued Supplementary Positive calligraphy (spontaneous) 7. Contents of correction (I) The table on page 6 of the specification was amended as follows.

October 17, 1986 l.

Display of incidents Patent Application No. 232997, 1988 that's all 2゜ name of invention Alkynyloxytran compounds 3゜ person who makes corrections Relationship to the case Patent applicant ADEKA ARGUS CHEMICAL CO., LTD. 4゜

Claims (1)

[Claims] An alkynyloxytran compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R represents an alkynyl group having 3 to 18 carbon atoms, and R' represents an alkyl group having 1 to 18 carbon atoms.)