# US 4,391,730 A · Nematic liquid crystal compounds and use and device for using the same

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- Number: US 4,391,730 A
- Document ID: US4391730A
- Status: Granted
- Kind: A
- Application number: 06/183,567
- Filed: 1980-09-02
- Granted: 1983-07-05
- Earliest claimed: 1979-08-09
- Assignees: VEB Werk fuer Fernsehelektronik Berlin im VEB Kombinat Mikroelektronik
- Inventors: Frank Kuschel; Dietrich Demus; Doris Pfeiffer; Hans-Joachim Deutscher
- Web page: https://patentgrep.com/patent/US4391730A

## CPC

- C09K 19/3458: {Uncondensed pyrimidines}
- C09K 19/42: Mixtures of liquid crystal compounds covered by two or more of the preceding groups C09K19/06 - C09K19/40
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

A nematic liquid crystal for modulating light in electrooptical devices comprises: A. A 5-substituted-2-(4-substituted-phenyl)-pyrimidine of the formula ##STR1## or a homolog thereof, R.sup.1 and R.sup.2 being the same or different and being selected from the group consisting of C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 COO-- or C.sub.n H.sub.2n+1 CO-- and n=1 to 12; B. A 4-substituted-cyclohexanecarboxylic acid-(4-substituted-phenylester) of the formula ##STR2## or a homolog thereof, R being --C.sub.m H.sub.2m+1, --OC.sub.m H.sub.2m+1, --COC.sub.m H.sub.2m+1, --CN or --NO.sub.2, and n, m=1-10, and C. A 4-substituted-benzoic acid-(4-cyanophenylester) of the formula ##STR3## or a homolog thereof, R being C.sub.n H.sub.2n+1 -- or C.sub.n H.sub.2n+1 O-- and n=1 to 14.

## Claims

### Claim 1

A nematic liquid crystal composition for use in electro-optical devices for modulating transmitted or reflected light and for the rendition of numerals, symbols and images, comprising a mixture of at least one compound of formula (A) ##STR10## wherein R.sup.1 is C.sub.n H.sub.2n+1 O-- and R.sup.2 is C.sub.n H.sub.2n+1 --, where n=1 to 12, and at least one compound of formula (B) ##STR11## where m=1 to 10.

### Claim 2 (depends on 1)

The composition of claim 1 wherein the individual components are present in the following proportions:
component A, 10 to 50 mol % and
component B, 30 to 90 mol %.

### Claim 3 (depends on 1)

The composition of claim 1 wherein the individual components are present in the following proportions:
component A, 20 to 80 mol % and
component B, 10 to 60 mol %, and
component C, 20 to 65 mol %.

### Claim 4 (depends on 1)

The composition of claim 1 wherein component A is at least one of a 5-n-alkyl-2-(4-n-alkyloxyphenyl)pyrimidine having from 4 to 9 carbon atoms in the alkyl groups.

### Claim 5 (depends on 4)

The composition of claim 4 wherein component A is a mixture of 5-n-hexyl-2-(4-n-hexyloxyphenyl)-pyrimidine and 5-n-hexyl-2-(4-n-nonyloxyphenyl)-pyrimidine.

### Claim 6 (depends on 4)

The composition of claim 4 wherein component A is 5-n-butyl-2-(4-n-heptyloxyphenyl)pyrimidine.

### Claim 7 (depends on 1)

The composition of claim 1 wherein component B is at least one of a 4-n-alkylcyclohexane carboxylic acid-(4-cyanophenylester) having from 3 to 5 carbon atoms in the alkyl group.

### Claim 8 (depends on 7)

The composition of claim 7 wherein component B is a mixture of the 4-cyanophenylesters of 4-n-propyl-cyclohexanecarboxylic acid, 4-n-butyl-cyclohexanecarboxylic acid, and 4-n-pentyl-cyclohexanecarboxylic acid.

### Claim 9 (depends on 1)

The composition of claim 1 additionally comprising a dichroitic dyestuff.

### Claim 10 (depends on 9)

The composition of claim 9 wherein said dichroitic dyestuff is indophenol blue.

### Claim 11 (depends on 1)

An electro-optical device for modulating transmitted or reflected light and for the rendition of numerals, symbols, and images containing a composition of claim 1 having a melting point equal to or less than approximately 0.degree. C. and a 10% voltage below approximately 2 volts.