US4308164A — Novel yellow azo dyes and dichroic liquid crystal…

Claim 1

Independent Claim 111 words

A liquid crystal composition for use in a liquid crystal display comprising: a host liquid crystal material; and a guest dichroic dye dissolved in said host liquid crystal material, said dichroic dye having the general formula: ##STR44## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR45## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy or cyano substituted alkyl and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3, 5-dialkoxyphenyl radical.

Claim 2

Dependent Claim 111 words

A liquid crystal composition for use in a liquid crystal display comprising: a host liquid crystal material; and a guest dichroic dye dissolved in said host liquid crystal material, said dichroic dye having the general formula: ##STR44## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR45## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy or cyano substituted alkyl and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3, 5-dialkoxyphenyl radical.

Claim 3

Dependent Claim 7 words

The composition of claim 1, wherein R═R'.

Claim 4

Dependent Claim 31 words

The composition of claim 1, wherein R 2 is selected from the group consisting of n-butyl, iso-butyl, n-amyl, n-hexyl, n-heptyl and stearyl and the halogen, nitro, amino and cyano derivatives thereof.

Claim 5

Dependent Claim 28 words

The composition of claim 1, wherein R 2 is an alkyl having from 4 to about 20 carbon atoms or the halogen, nitro, amino, or cyano derivatives thereof.

Claim 6

Dependent Claim 27 words

The composition of claim 1, wherein the phenyl or phenylalkyl parasubstituent is selected from the group consisting of halogen, hydroxy, nitro, cyano, amino, alkyl, aryloxy and alkoxy.

Claim 7

Dependent Claim 28 words

The composition of claim 1, wherein the acyl group is selected from the group consisting of benzoyl, 4-methoxybenzoyl, 4-pentoxybenzoyl, 4-heptoxybenzoyl, 3,5-dimethoxybenzoyl, 4-pentylbenzoyl, 4-heptylbenzoyl, 4-cyanobenzoyl, 4-nitrobenzoyl, 4-N,N-dimethylaminobenzoyl and 4-phenoxybenzoyl.

Claim 8

Dependent Claim 32 words

The composition of claim 1, wherein about 0.05% by weight to about 1.0% by weight (based upon the weight of the liquid crystal) of dye is dissolved in the host liquid crystal.

Claim 9

Dependent Claim 44 words

The composition of claim 1, wherein the host material is a nematic liquid crystal of positive or negative dielectric anisotropy, a cholesteric liquid crystal of positive or negative dielectric anisotropy and mixtures thereof or any of the foregoing modified with other optically active compounds.

Claim 10

Independent Claim 165 words

A method of improving the black color of dichroic dyes for use in black liquid crystal displays, comprising adding to a host liquid crystal material, a dye composition having a mixture of dichroic dyes of various colors in proper proportion to obtain a material which absorbs radiation in the spectral range of about 400-700 nm wherein at least one of the dichroic dyes of various colors is a yellow azo dichroic dye having the general formula: ##STR46## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR47## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy or cyano substituted alkyl and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is a phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3,5-dialkoxyphenyl radical; and heating the composition to dissolve the dyes in the liquid crystal host material.

Claim 11

Independent Claim 165 words

A method of improving the black color of dichroic dyes for use in black liquid crystal displays, comprising adding to a host liquid crystal material, a dye composition having a mixture of dichroic dyes of various colors in proper proportion to obtain a material which absorbs radiation in the spectral range of about 400-700 nm wherein at least one of the dichroic dyes of various colors is a yellow azo dichroic dye having the general formula: ##STR46## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR47## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy or cyano substituted alkyl and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is a phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3,5-dialkoxyphenyl radical; and heating the composition to dissolve the dyes in the liquid crystal host material.

Claim 12

Dependent Claim 31 words

The method of claim 9, wherein about 0.05% to about 1.0% of the yellow azo dichroic dye is added to the host liquid material and the dichroic dyes of various colors.

Claim 13

Dependent Claim 22 words

The method of claim 10, wherein about 0.5% to about 1.0% blue dichroic dye is added to the host liquid crystal material.

Claim 14

Dependent Claim 7 words

The method of claim 9, wherein R═R'.

Claim 15

Dependent Claim 28 words

The method of claim 9, wherein R 2 is an alkyl having from 4 to about 20 carbon atoms or the halogen, nitro, amino or cyano derivatives thereof.

Claim 16

Dependent Claim 27 words

The method of claim 9, wherein the mixture is heated at about 60° C. to about 105° C. to dissolve the dichroic dyes in the host material.

Claim 17

Dependent Claim 27 words

The method of claim 9, wherein the phenyl or phenylalkyl parasubstituent is selected from the group consisting of halogen, hydroxy, nitro, cyano, amino, alkyl, phenyloxy and alkoxy.

Claim 18

Dependent Claim 148 words

An improved black dichroic liquid crystal display comprising: a host liquid crystal material; and a dye composition dissolved in said host, the dye composition having a mixture of dichroic dyes of various colors in proper proportion to obtain a material which absorbs radiation in the spectral range of about 400-700 nm wherein at least one of the dichroic dyes of various colors is a yellow azo dichroic dye having the general formula: ##STR48## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR49## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy, or cyano substituted alkyl, and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is a phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3, 5-dialkoxyphenyl radical.

Claim 19

Dependent Claim 148 words

An improved black dichroic liquid crystal display comprising: a host liquid crystal material; and a dye composition dissolved in said host, the dye composition having a mixture of dichroic dyes of various colors in proper proportion to obtain a material which absorbs radiation in the spectral range of about 400-700 nm wherein at least one of the dichroic dyes of various colors is a yellow azo dichroic dye having the general formula: ##STR48## wherein R and R' are acyl groups and form an ester with the general formula, and R and R' have the formula: ##STR49## wherein R 2 is alkyl or halogen, nitro, amino, hydroxy, or cyano substituted alkyl, and the alkyl has from about 4 to about 20 carbon atoms, or R 2 is a phenyl; phenylalkyl; halogen, nitro, cyano, hydroxy, dialkylamino, amino, alkyl, phenyloxy, phenyl, or alkoxy parasubstituted phenyl or phenylalkyl; or 3, 5-dialkoxyphenyl radical.

Claim 20

Dependent Claim 31 words

The black dichroic liquid crystal display of claim 16, comprising about 0.05% to about 1.0% by weight (based upon the weight of the liquid crystal) of the yellow azo dichroic dyes.

Claim 21

Dependent Claim 18 words

The black dichroic liquid crystal display of claim 16, comprising about 0.5% to about 1.0% blue dichroic dye.

Claim 22

Dependent Claim 11 words

The black dichroic liquid crystal display of claim 16, wherein R═R'.

Claim 23

Dependent Claim 32 words

The black dichroic liquid crystal display of claim 16, wherein R 2 is an alkyl having from 4 to about 20 carbon atoms or the halogen, nitro, amino or cyano derivatives thereof.

Claim 24

Dependent Claim 31 words

The black dichroic liquid crystal display of claim 16, wherein the phenyl or phenylalkyl parasubstituent is selected from the group consisting of halogen, hydroxy, nitro, cyano, amino, alkyl, phenyloxy and alkoxy.

Claim 25

Dependent Claim 28 words

The composition of claim 16, wherein the acyl group is selected from the group consisting of benzoyl, 4-methoxybenzoyl, 4-pentoxybenzoyl, 4-heptoxybenzoyl, 3,5-dimethoxybenzoyl, 4-pentylbenzoyl, 4-heptylbenzoyl, 4-cyanobenzoyl, 4-nitrobenzoyl, 4-N,N-dimethylaminobenzoyl and 4-phenoxybenzoyl.

Claim 26

Dependent Claim 44 words

The composition of claim 16, wherein the host material is a nematic liquid crystal of positive or negative dielectric anisotropy, a cholesteric liquid crystal of positive or negative dielectric anisotropy and mixtures thereof or any of the foregoing modified with other optically active compounds.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-12-28	1985-06-29	1985-12-29	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-12-28	1989-06-29	1989-12-29	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-12-28	1993-06-29	1993-12-29	$7700.00	Window Closed / Lapsed

Novel yellow azo dyes and dichroic liquid crystal composition made therewith

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