DD248136A1 - NEMATIC CRYSTALLINE-LIQUID MIXTURES - Google Patents

Abstract

The invention relates to the use of liquid crystals in optoelectronic displays for displaying numbers, characters and images. The object of the invention are crystalline-liquid nematic mixtures for optoelectronic displays with high Klaerpunkten. It has been found that novel crystalline 1,4-disubstituted 2,5,7-trioxa-bicyclo (2.2.2) octanes of the general formula I which contain preferably substituted phenyl radicals in the 1- and / or 4-position that Klaerpunkte increase nematic mixtures and thus can be used advantageously in optoelectronic displays.

Description

, - ^0C n ^H 2n ₊ 1 '

with η = 1 to 8

mean to be used.

Field of application of the invention

The invention relates to the use of liquid crystals in optoelectronic displays for displaying numbers, characters and images.

Characteristic of the known solutions

Displays based on liquid crystals are used for many different purposes. Accordingly, the properties of the displays and the liquid crystal mixtures used have to be modified B.Behadur: Liquid Crystal Displays, Mol. Cryst. Liq. Cryst. 109 (1) 1-104 (1984).

In order to be able to influence the properties of crystalline-liquid mixtures in a targeted manner, it is necessary to have corresponding mixture components with very different properties. Although today more than 13,000 liquid crystal substances are known (D. Demus, H. Zaschke: Liquid crystals in Tables Leipzig 1984), there are no substances that have all the required properties, so that one is constantly on the lookout for new substances, especially those derive from new classes of substance is.

Object of the invention

The object of the invention are crystalline liquid nematic mixtures for optoelectronic displays with high clearing points. Explanation of the essence of the invention

The object of the invention are new crystalline-liquid substances which increase the clearing points of nematic mixtures.

It has been found that novel crystalline liquid 1,4-disubstituted 2,6,7-trioxa-bicyclo (2.2.2) octanes of the general formula I which contain preferably substituted phenyl radicals in the 1- and / or 4-position.

in which

^R = ^C n ^H 2n ₊ l- ' ^C n ^H 2n ₊ l ^ö -'

= - ^C n ^H 2n ₊ i '

with η = 1 to 8,

increase the clearing points of nematic mixtures used for optoelectronic dispays and thus substantially improve the utility of such mixtures.

The new substances are colorless and stable against thermal influences or irradiation.

The substances are smectic in the pure state, but give nematic mixtures in mixtures with nematic components

Mixtures.

embodiments Example 1:

The following tables show the transformation temperatures of novel substances according to the invention.

Table 1

R ¹

^ 6 ¹ m

CeH

C5H

'5 ⁿ 11

C ₇ H ₁ S

74 (50) 45 • 64 35 • 87 43 • 85

Table 2

R ¹

2.1. 2.2 2.3 2.4 2.5 2.6 2.7

C ₆ H ₁₃

C ₆ H ₁₃

C ₆ H ₁₃

C ₆ Hi ₃ O

C ₆ Hi ₃ O

br

br

C ₃ H ₇ • 95 CsH ₁₁ • 96 C ₆ H ₁₃ • 81 C5H11  86 C ₆ Hi ₃ • 84 CsH ₁₁  222 C ₆ H ₁₃ • 204 crystalline-sfest

• 193 • 194 • 194 197 • 182 (• 203) (• 198)

Table 4

CH ₃ CH ₃

C7H15 C7H15 C7H15 C7H15 C7H15 C7H15 C ₇ H ₁₅ C ₆ H ₁₃ O-

OC ₃ H ₁₇

-C ₆ H ₁

COO

OC ₄ H ₉

OC ₅ H ₁ ", OC ₆ H ₁₃ OC ₇ H ₁₅ OC ₈ H ₁₇

CN

CH ₂ -CH ₂ -CN

CN

• 68 • 42 • 48 • 45 • 44 • 92 82 • 169

 135

• 86.5

 90

 93

• 94

• 72

• 155

(• 166)

Example 2:

For use in optoelectronic displays, the following basic mixture MiA is used:

61.7 mol% of 5-n-hexyl-2- (4-n-hexyloxyphenyl) -pyrimidine 38.3 mol% of 5-n-hexyl-2- (4-n-nonyloxyphenyl) -pyrimidine

This Mi A changes the clearing temperature by adding substance 2/1 as follows:

mol .-% mol .-% clearing temperature

MiA .

100 95 85 80

5 15 20

59 62 66 70

Example 3: ·

The following basic mixture Mi B is used: 22 mol% of 5-n-butyl-2- (4-cyanophenyl) -1,3-dioxane 26 mol% of 5-n-pentyl-2- (4-cyanophenyl) -1 , 3-dioxane 32 mol% 5-n-hexyl-2- (4-cyanophenyl) -1,3-dioxane 20 mol% 5- (4-n-hexylphenyl) -2- (4-cyanophenyl) -1 , 3-dioxane

This Mi B changes the clearing temperature by adding substance 2/1 as follows:

Clearing temperature [ ⁰ C]

MiB

Substance 2/1

100 95 85 80

5 15 20

58 59 65 70

Example 4:

The substance

has the following optical birefringence in the state of the smectic B phase:

Temperature [° CJ

45 56 60

0.15 0.13

0.11

Claims (1)

Nematic crystalline-liquid mixtures for optoelectronic components, characterized in that as components new crystalline liquid 1,4-disubstituted 2,6,7-trioxa-bicyclo (2.2.2) octanes of the general formula I, which in 1- and / or 4-position preferably contain substituted phenyl radicals, where X = -. R KO) - R = C E _{0 Λ} - , C _n Hp • .O-, Br-