Fluorescent liquid crystal display compositions and devices

Claim 2

A fluorescent liquid crystal composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting visible fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising as the main component a mixture of liquid crystal compounds comprising at least one compound of the formula (I) ##STR10## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR11## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano, and at least one compound of the formula (II) ##STR12## wherein R 2 is alkyl having 1 to 8 carbon atoms or alkylcarbonyloxy having 2 to 9 carbon atoms, and Z is a group of the formula ##STR13## R 3 being cyano or alkoxy having 1 to 8 carbon atoms.

Claim 3

A fluorescent liquid crystal composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising at least one compound of the formula (I) ##STR14## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR15## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano.

Claim 4

A fluorescent liquid crystal composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising at least one compound of the formula (I) ##STR14## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR15## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano.

Claim 5

A fluorescent liquid crystal display device substantially comprising at least one pair of electrodes, voltage applying means and two parallel plates having a fluorescent liquid crystal composition placed therebetween, the composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting visible fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising as the main component a mixture of liquid crystal compounds comprising at least one compound of the formula (I) ##STR16## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR17## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano, and at least one compound of the formula (II) ##STR18## wherein R 2 is aklyl having 1 to 8 carbon atoms or alkylcarbonyloxy having 2 to 9 carbon atoms, and Z is a group of the formula ##STR19## R3 being cyano or alkoxy having 1 to 8 carbon atoms.

Claim 6

A fluorescent liquid crystal display device substantially comprising at least one pair of electrodes, voltage applying means and two parallel plates having a fluorescent liquid crystal composition placed therebetween, the composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting visible fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising as the main component a mixture of liquid crystal compounds comprising at least one compound of the formula (I) ##STR16## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR17## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano, and at least one compound of the formula (II) ##STR18## wherein R 2 is aklyl having 1 to 8 carbon atoms or alkylcarbonyloxy having 2 to 9 carbon atoms, and Z is a group of the formula ##STR19## R3 being cyano or alkoxy having 1 to 8 carbon atoms.

Claim 7

A fluorescent liquid crystal display device substantially comprising at least one pair electrodes, voltage applying means and two parallel plates having a fluorescent liquid crystal composition placed therebetween, the composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising at least one compound of the formula (I) ##STR20## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR21## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano.

Claim 8

A fluorescent liquid crystal display device substantially comprising at least one pair electrodes, voltage applying means and two parallel plates having a fluorescent liquid crystal composition placed therebetween, the composition comprising a liquid crystal material and a coumarin fluorescent dye capable of emitting fluorescence and soluble in said liquid crystal material, said liquid crystal material comprising at least one compound of the formula (I) ##STR20## wherein R 1 is alkyl having 3 to 9 carbon atoms, and Y is a group of the formula ##STR21## X being cyano, alkyl having 3 to 9 carbon atoms, alkoxy having 3 to 9 carbon atoms or alkylcarbonyloxy having 4 to 10 carbon atoms, X 1 being cyano.

Claim 9

A composition as defined in either of claims 1 or 2 wherein the main component of the liquid crystal material is contained in an amount of at least about 70% by weight of the composition.

Claim 10

A composition as defined in either or claims 1 or 2 wherein the coumarin fluorescent dye is contained in an amount of about 0.005 to about 1.0% by weight of the composition.

Claim 11

A composition as defined in claim 2 wherein the liquid crystal material is a mixture of at least two compounds represented by the formula (III) ##STR22## wherein R 1 and X 1 are as defined in the formula (I).

Claim 12

A composition as defined in claim 2 wherein the liquid crystal material is a mixture of at least one compound of the formula (III) ##STR23## wherein R 1 and X 1 are as defined in the formula (I), and at least one compound of the formula (IV) ##STR24## wherein R 1 and X are as defined in the formula (I).

Claim 13

A composition as defined in claim 2 wherein the liquid crystal material is a mixture of at least one compound of the formula (III) ##STR25## wherein R 1 and X 1 are as defined in the formula (I), and at least one compound of the formula (V) ##STR26## wherein R 1 and X are as defined in the formula (I).

Claim 14

A composition as defined in claim 2 wherein the liquid crystal material is a mixture of 4-cyano-4'-n-propyl-bicyclohexyl, 4-cyano-4'-n-pentyl-bicyclohexyl and 4-cyano-4'-n-heptylbicyclohexyl.

Claim 15

A composition as defined in claim 2 wherein the liquid crystal material is a mixture of 4'-n-propylcyclohexyl-4-cyanobenzene, 4'-n-pentylcyclohexyl-4-cyanobenzene and 4'-n-heptylcyclohexyl-4-cyanobenzene.

Claim 16

A composition as defined in either claim 1 or 2, wherein said coumarin fluorescent dye is selected from the group consisting of Coumarin 6 and Coumarin 7.