DD143625A1 - NEMATIVE LIQUID CRYSTALLINE SUBSTANCES - Google Patents

Abstract

Nematic liquid crystalline substances are used in optoelectronic Arrangements for modulation of the continuous or striking Light as well as for black-and-white or colored reproduction of numbers, Characters and illustrations used. The aim of the invention is the Use of nematic liquid-crystalline substances with high positive dielectric. anisotropy, low threshold and Operating voltages and high clearing points. It was found that as liquid-crystalline substances for optoelectronic arrangements Mixtures are suitable which as an essential ingredient one or several compounds from the class of 5-cyano-2- [4-acyloxy-phenyl] - pyrimidines of the general formula. - Formula -

Description

212 877 -λ-.

Nematic liquid environments dev s s i g-krietalline substances

• Field of application of the invention

Nematic liquid-crystalline substances are used in optoelectronic arrangements for the modulation of continuous or incident light and for black-and-white or colored reproduction of numbers, characters and images.

^ Characteristic of beka Nnten technical solutions

Nematic liquid-crystalline substances with positive dielectric anisotropy are used for optoelectronic devices. based on the field effects, in particular the Schadt-Helfrich effect it uses, [G. Meier, E. Sackmann, JG Grabier, Applications of Liquid Crystals, Sp.'ringer-Verlag, Berlin-Heidelberg-New York 1975] The previously used substances, which always consist of mixtures of several compounds, sometimes have too high threshold and operating voltages and on the other hand, low clearing points, so that they are not suitable for applications at higher temperatures.

Object of the invention

The aim of the invention is the use of nematic liquid-crystalline substances with high positive dielectric anisotropy, low threshold and operating voltages and high clearing points.

Explanation of the 'essence of the invention

It has been found that mixtures are suitable as liquid-crystalline substances for optoelectronic arrangements for the modulation of the transmitted or incident light and for black-and-white or colored Y / reproduction of numerals, characters and figures mixtures containing as an essential part of one or more compounds of the Class of the 5-cyano-2- [4-acyloxy-phenyl] -pyrimidines of the general formula

• 10 with R ¹ =

^C n ^H 2n ₊ 1 ^{C 00} ' ^C n ^H 2n ₊ 1 ^OCO ° 5

^C n ^H 2n ₊ 1 < ^GH 3 ^{) N;} η = 1 to 10

η = 1 to 10

contain.

The substances have a high dielectric anisotropy, low threshold and operating voltages and high clearing points.

example 1

The following table contains examples of the 5-cyano-2 - [4-acyloxy-phenyl-pyrimidines examples.

Table 1 ·

R ¹ -COO

R ¹ KS Έ

C ₄ H ₉ O , 121 - - , 129. C ₆ H ₁₃ O •. 83 .96 , 121. C ₆ H ₁₃ -®- , 106 .112 , 249. CH ₃ O - @ - , 224 , '334. C ₅ H ₁₁ O- ^) -. 130 _ _ .278. ^C 5 ^H 11- <£> - , 117 , 192 , 248.

Example 2

A mixture of the composition

4-n-Propylcyclohexanecarboxylic acid 4-cyanophenyl ester 30 %

4-n-butylcyclohexanecarboxylic acid 4-cyanophenyl ester 30 #

4-n-Pentylcyclohexanecarboxylic acid 4-cyanophenyl ester 30 fo

5-cyano-2-L4-hexyloxycarbonyloxy-ph'enyl] -pyriraidin 10 ° h

is suitable for optoelectronic components based on the Schadt-Helfrich effect and has the following properties:

_: Melting point: 0-10 ⁰ C

Clarification point: 73 ⁰ C

Threshold voltage: 1.3 V; 50 Hz

Operating voltage: 2.6V

Claims (1)

invention claim 1. Application of nematic 'liquid-crystalline substances based on biphenyl-analogous heterocyclic compounds for optoelectronic arrangements for the modulation of through-. going or striking light and for black and white or colored reproduction of numerals, characters and figures, characterized in that as such substances mixtures with one or more compounds from the class of 5-cyano-2- 4 ~ acyloxy-phenyl-pyrimidines of general formula ". R ¹ -CO (Wf) V ^ * \ - CN with R ¹ = ^r2 ^ ©> ~ " ^ε3 " {Ξ} " ^{or C} n ^H 2n + 1 °" ² 5 ^C n ^H 2n-M ^S ' ^F   η = 1 to 10 ^{R s} ° n ^H 2n + 1 ^; η = 1 to "10 be used. -'JUL19 / 9 * 79 / ei H ;: