Asymmetric dichroic dye molecules having poly(arylazo) linking groups, a bis-substituted aryl thiazyl end group, and another end group

Claim 2

A dichroic dyestuff having the formula Q--A--Z wherein: is a poly(arylazo) linking group wherein the aryl comprises 6 to 10 carbon atoms and has 4,4'-azo linkages; Q is a bis-substituted aryl thiazyl substituent wherein the aryl comprises 6 to 10 carbon atoms; and Z is selected from the group consisting of naphthalene having an alkyl substituted amino in the 4 position, 2,3-dihydro-2,2'-substituted-permidine and julolidine groups.

Claim 3

The dichroic dyestuff of claim 1 wherein the poly(arylazo) linking group A has the formula: ##STR62## wherein m is 0, or an integer from about 1 to 6, and x is independently 0, 1, 2 or 4, provided that where x is 4, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms; where x is 2, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms, and the two R groups are not substituted on adjacent ring carbon atoms; and when x is 1, in from 0 to m ##STR63## R is the group --C═CH--CH═CH-- which is substituted on two adjacent ring carbon atoms.

Claim 4

The dichroic dyestuff of claim 1 wherein the bis-substituted aryl thiazyl group Q has the formula: ##STR64## wherein B and B' are independently selected from the group consisting of H, C n H 2n+1 , OC n H 2n+1 , phenyl, phenoxy, trifluoromethylsulfonyl, cyano, and thiocyanato, wherein n is an integer from about 1 to 10.

Claim 5

The dichroic dyestuff of claim 1 wherein the bis-substituted aryl thiazyl group Q has the formula: ##STR65##

Claim 6

The dichroic dyestuff of claim 1 wherein the bis-substituted aryl thiazyl group Q has the formula ##STR66##

Claim 7

The dichroic dyestuff of claim 1 wherein Z has the formula: ##STR67## wherein R is selected from the group consisting of H and C n H 2n+1 and wherein R 2 is C n H 2n+1 , wherein n is an integer from about 1 to 20.

Claim 8

The dichroic dyestuff of claim 1 wherein Z has the formula: ##STR68## wherein R 3 and R 4 are independenytly selected from the group consisting of alkyls and alkenes having about 1-20 carbon atoms, aryls, cycloaliphatic and heterocyclic rings, or R 3 and R 4 are combined and, together with the 2 carbon of the perimidine moiety, form cycloaliphatic or heterocyclic rings, said cycloaliphatic and heterocyclic rings having from 4 to 12 carbon atoms and said rings consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, and sulfur.

Claim 9

The dichroic dyestuff of claim 1 wherein Z is selected from the group consisting of: ##STR69## wherein R 5 is a lower alkyl having about 1 to 6 carbon atoms, and wherein the cyclopentyl and cyclohexyl rings are substituted in available positions by groups independently selected from the group consisting of H and lower alkyls having about 1-8 carbon atoms.

Claim 10

The dichroic dyestuff of claim 1 wherein Z is a julolidine group having the formula: ##STR70##

Claim 11

A dichroic dyestuff having the formula Q--A--Z-- wherein A has the formula ##STR71## wherein m is 0, or an integer from 1 to 6, and x is independently 0, 1, 2 or 4 provided that where x is 4, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms; where x is 2, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms, and the two R groups are not substituted on adjacent ring carbon atoms; and when x is 1 in from 0 to m ##STR72## R is the group --C═CH--C═CH--, which is substituted on two adjacent ring carbon atoms; Q is selected from the group consisting of ##STR73## wherein B and B' are independently selected from the group consisting of H, C n H 2n+1 , OC n H 2n+1 , phenyl, phenoxy, trifluoromethylsulfonyl, cyano, and thiocyanato, wherein n is an integer from about 1 to 10; and Z is selected from the group consisting of naphthalene having an alkyl substituted amino in the 4 position, julolidine and 2,3-dihydroperimidine wherein the 2 carbon atom of the perimidine moiety is substituted by groups consisting of alkyls and alkenes having about 1-20 carbon atoms, aryls, and cycloaliphatic and heterocyclic rings, or the 2 carbon atom of the perimidine moiety is substituted with a group which combines with the 2 carbon atom of the perimidine moiety to form a cycloaliphatic or heterocyclic ring said cycloaliphatic or heterocyclic rings having from 4 to 12 carbon atoms and said rings consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen and sulfur.

Claim 12

A dichroic dyestuff having the formula Q--A--Z-- wherein A has the formula ##STR71## wherein m is 0, or an integer from 1 to 6, and x is independently 0, 1, 2 or 4 provided that where x is 4, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms; where x is 2, the R groups are independently selected from the group consisting of alkyl or alkoxy groups having from about 1 to 8 carbon atoms, and the two R groups are not substituted on adjacent ring carbon atoms; and when x is 1 in from 0 to m ##STR72## R is the group --C═CH--C═CH--, which is substituted on two adjacent ring carbon atoms; Q is selected from the group consisting of ##STR73## wherein B and B' are independently selected from the group consisting of H, C n H 2n+1 , OC n H 2n+1 , phenyl, phenoxy, trifluoromethylsulfonyl, cyano, and thiocyanato, wherein n is an integer from about 1 to 10; and Z is selected from the group consisting of naphthalene having an alkyl substituted amino in the 4 position, julolidine and 2,3-dihydroperimidine wherein the 2 carbon atom of the perimidine moiety is substituted by groups consisting of alkyls and alkenes having about 1-20 carbon atoms, aryls, and cycloaliphatic and heterocyclic rings, or the 2 carbon atom of the perimidine moiety is substituted with a group which combines with the 2 carbon atom of the perimidine moiety to form a cycloaliphatic or heterocyclic ring said cycloaliphatic or heterocyclic rings having from 4 to 12 carbon atoms and said rings consisting of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen and sulfur.

Claim 13

A composition of matter comprising a nematic liquid crystal material and, in admixture therewith, the dichroic dyestuff of claim 1.

Claim 14

The composition of claim 11 wherein said composition additionally comprises at least one dichroic dye having maximum absorption at wavelengths between about 400 and 600 nm.

Claim 15

The composition of claim 11 wherein said dichrioc dyestuff is present in an amount of about 0.5 to about 5 percent by weight.

Claim 16

The composition of claim 11 wherein there is additionally present an optically active compound in an amount sufficient to provide a cholesteric phase.

Claim 17

An improved "guest-host" type liquid crystal display device which is responsive to the absence or presence of an electric field, said device comprising a layer of a nematic liquid crystal composition and two conductive electrodes positioned, respectively, adjacent opposing surfaces of said layer, wherein the improvement comprises the presence of a dichroic dyestuff according to claim 1 in admixture with said liquid crystal composition.

Claim 18

An improved "guest-host" type liquid crystal display which is responsive to the absence or presence of an electric field, and which appears neutral black in the absence of said electric field and clear in the presence of said electric field, said device comprising: (a) a "guest-host" layer comprising a nematic liquid crystal material and a plurality of dichroic dyes which together strongly absorb throughout the region between about 400 and 600 nm; and (b) two conductive electrodes positioned, respctively, adjacent opposing surfaces of said layer; wherein the improvement comprises the presence of a dichroic dyestuff according to claim 1 in admixture with said "guest-host", liquid crystal-dichroic dye mixture.

Claim 19

An improved "phase change" type liquid crystal display device which is responsive to the absence or presence of an electric field, said device comprising a layer of a nematic liquid crystal material in admixture with an optically active compound, and two conductive electrodes positioned, respectively, adjacent opposing surfaces of said layer, wherein the improvement comprises the presence of the dichroic dyestuff of claim 1 in admixture with said liquid crystal material.

Claim 20

An improved "phase-change" type liquid crystal display device which is responsive to the absence or presence of an electric field, and which appears neutral black in the absence of said electric field and clear in the presence of said electric field, said device comprising: (a) a layer of a nematic liquid crystal material in admixture with a plurality of dichroic dyes which together absorb strongly throughout the region between about 400 and 600 nm, and an optically active compound; and (b) two conductive electrodes positioned, respectively, adjacent opposing surfaces of said layer; wherein the improvement comprises the presence of the dichroic dyestuff of claim 1 in admixture with said liquid crystal material.

Claim 21

A display device according to claims 15, 16, 17 or 18 wherein said device includes a means for applying an electric field across said electrodes.