Nematic liquid crystal compositions

Claim 2

A composite liquid crystal composition made up of biphenyl and non-biphenyl constituents for use in field-effect liquid crystal display devices, said composition comprising: Constituent One -- nematic alkylcyanobiphenyl liquid crystal material; Constituent Two -- ester type nematic liquid crystal material which is incompatible with Constituent One and forms a smectic phase in binary mixture therewith and is present in a concentration sufficient to supplement the composite composition with improved electro-optical properties; Constituent Three 13 at least one chloro-substituted double ester nematic liquid crystal material having the general formula ##STR17## wherein R and R' are alkyl and either a or b is chlorine, either a or b being hydrogen which is compatible with Constituent One and present in a concentration sufficient so that the composite composition forms a satisfactory nematic phase for use in a field-effect display device.

Claim 3

The nematic liquid crystal composition of claim 1 wherein the alkylcyanobiphenyl liquid crystal material is 4-cyano-4'-n-pentylbiphenyl or 4-cyano-4'-n-heptylbiphenyl or mixtures thereof.

Claim 4

The nematic liquid crystal composition of claim 2 wherein Constituent Two is 4'-n-hexyloxyphenyl-4-n-butylbenzoate.

Claim 5

The nematic liquid crystal composition of claim 1 wherein Constituent Three is 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentylbenzoyloxy) benzoate.

Claim 6

The nematic liquid crystal composition of claim 1 wherein Constituent Three is 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentylbenzoyloxy) benzoate and the composition further contains 4'-cyanophenyl-4-n-heptylbenzoate.

Claim 7

The nematic liquid crystal composition of claim 1 wherein Constituent One is 4-cyano 4'-n-pentylbiphenyl or 4-cyano-4'-n-heptylbiphenyl wherein Constituent Two is 4'-n-hexyloxyphenyl-4-n-butylbenzoate and wherein Constituent Three is 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentylbenzoyloxy) benzoate.

Claim 8

The nematic liquid crystal composition of claim 1 wherein Constituent One is the mixture of 4-cyano-4'-n-pentylbiphenyl and 4-cyano-4'-n-heptylbiphenyl, wherein Constituent Two is a 4'-n-hexyloxyphenyl-4-n-butylbenzoate, wherein Constituent Three is 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentylbenzoyloxy) benzoate, and wherein 4'-cyanophenyl-4-n-heptylbenzoate.

Claim 9

Liquid crystal electro-optical devices containing the liquid crystal of claim 5.

Claim 10

Liquid crystal electro-optical devices containg the liquid crystal composition of claim 1.

Claim 11

The liquid crystal electro-optical devices containing the liquid crystal composition of claim 7.

Claim 12

A rematic liquid crystal composition having biphenyl liquid crystal dominant electro-optical characteristics and a wide nematic phase temperature range including room temperature, actuable in a twisted nematic liquid crystal display cell by low actuation voltages comprising a component selected from one or more 4'-substituted-4-cyanobiphenyl liquid crystals having the formula ##STR18## wherein R is a 1 to 9 carbon alkyl or alkoxy group, blended with one or more 4, 4'-disubstituted phenyl benzoate liquid crystals selected from the group consisting of: compounds having the formula ##STR19## wherein either R or R' is methoxy and the other of R or R' an alkyl or an alkoxy having 1 to 7 carbon atoms; compounds having the formula ##STR20## wherein R and R' are 1 to 7 carbon alkyl groups and a and b are hydrogen or chlorine, but either a or b being hydrogen; and compounds having the formula ##STR21## wherein R is a 1 to 9 carbon atom alkyl or alkoxy group optionally further blended with one or more 4,4'-disubstituted phenyl benzoate liquid crystal compounds having the formula ##STR22## wherein R and R' are alkyl groups having 1 to 7 carbon atoms and alkoxy groups having 2 to 7 carbon atoms; and also containing optically active liquid crystal compounds having the following formulae: ##STR23## wherein R* is an alkyl or alkoxy having 4 to 9 carbon atoms among which at least one carbon atom is asymmetrically substituted, and R is an alkyl or alkoxy group having 2-7 carbon atoms.

Claim 13

A rematic liquid crystal composition having biphenyl liquid crystal dominant electro-optical characteristics and a wide nematic phase temperature range including room temperature, actuable in a twisted nematic liquid crystal display cell by low actuation voltages comprising a component selected from one or more 4'-substituted-4-cyanobiphenyl liquid crystals having the formula ##STR18## wherein R is a 1 to 9 carbon alkyl or alkoxy group, blended with one or more 4, 4'-disubstituted phenyl benzoate liquid crystals selected from the group consisting of: compounds having the formula ##STR19## wherein either R or R' is methoxy and the other of R or R' an alkyl or an alkoxy having 1 to 7 carbon atoms; compounds having the formula ##STR20## wherein R and R' are 1 to 7 carbon alkyl groups and a and b are hydrogen or chlorine, but either a or b being hydrogen; and compounds having the formula ##STR21## wherein R is a 1 to 9 carbon atom alkyl or alkoxy group optionally further blended with one or more 4,4'-disubstituted phenyl benzoate liquid crystal compounds having the formula ##STR22## wherein R and R' are alkyl groups having 1 to 7 carbon atoms and alkoxy groups having 2 to 7 carbon atoms; and also containing optically active liquid crystal compounds having the following formulae: ##STR23## wherein R* is an alkyl or alkoxy having 4 to 9 carbon atoms among which at least one carbon atom is asymmetrically substituted, and R is an alkyl or alkoxy group having 2-7 carbon atoms.

Claim 14

The rematic liquid crystal composition as defined in claim 11 consisting essentially of said 4'-substituted -4-cyanobiphenyl component, said cyano-ester component, and said optically active component, wherein said 4'-substituted-4-cyanobiphenyl component comprises from about 10 percent to about 80 mole percent of the liquid crystal composition.

Claim 15

The rematic liquid crystal composition as defined in claim 11 including from about 10 to about 80 mole percent of the positive dielectric anisotropy (PDA) constituents and from about 90 to about 20 mole percent of one or more negative dielectric anisotropy (NDA) liquid crystals selected from the group consisting of: A. said compounds having the formula ##STR24## wherein either R or R' is methoxy and the other of R and R' is an alkyl or an alkoxy having 1 to 7 carbon atoms; and B. said compounds having the formula ##STR25## wherein R and R' are 1 to 7 carbon alkyl groups and a and b may both be hydrogen and wherein either a or b, but not both, may be Cl, optionally in combination with C. one or more of said compounds having the formula ##STR26## wherein R and R' are alkyl groups having 1 to 7 carbon atoms and alkoxy groups having 2 to 7 carbon atoms.

Claim 16

The rematic liquid crystal composition as defined in claim 13 including from about 20 to about 90 mole percent of either the A. or A. in combination with optional C. type liquid crystals

Claim 17

The rematic liquid crystal composition as defined in claim 11 up to about 25 mole percent of the total liquid crystal composition and not more than 50 mole percent of the negative dielectric anisotropy constituents of a compound including selected from the group consisting of compounds of the formula ##STR27## wherein R and R' are 1 to 7 carbon alkyl groups and a and b may both be hydrogen and wherein either a or b, but not both, may be Cl.

Claim 18

The rematic liquid crystal composition as defined in claim 11 wherein the 4'-substituted-4-cyanobiphenyl component is 4-cyano-4'-n-pentylbiphenyl.

Claim 19

The rematic liquid crystal composition as defined in claim 11 wherein the 4'-substituted-4-cyanobiphenyl component is a mixture of about 40 mole percent 4-cyano-4'-n-heptylbiphenyl and about 60 mole percent 4'-n-pentylcyano-biphenyl.

Claim 20

The rematic liquid crystal composition as defined in claim 11 wherein the 4'-cyanophenyl-4-alkylbenzoate is 4'-cyanophenyl-4-n-heptylbenzoate.

Claim 21

The rematic liquid crystal composition of claim 14 wherein the amount of PDA constituent is from 40-80 mole percent, the amount of NDA constituent is 60-20 mole percent and the amount optically active additive is 0.5-5.0 mole percent.

Claim 22

The rematic liquid crystal composition as defined in claim 9 wherein said 4'-substituted-4-cyanobiphenyl component comprises from about 65 to 95 mole percent of said positive dielectric anisotropy consituents in the composition.

Claim 23

The rematic liquid crystal composition as defined in claim 19 containing a 4,4'-disubstituted phenyl benzoate ester, which is 4'-n-hexyloxyphenyl-4-butylbenzoate.

Claim 24

The rematic liquid crystal composition as defined in claim 21 containing a double ester which is 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentyl-benzoyloxy)benzoate.

Claim 25

The rematic liquid crystal composition as defined in claim 22, wherein the optically active additive is 4'-(S-2-methylbutoxy)phenyl-4-n-hexylbenzoate.

Claim 26

A rematic liquid crystal composition for use in information handling systems comprising the following liquid crystal constituents: Constituent One -- one or more positive dielectric anisotropy liquid crystals, of which at least one is a 4'-substituted-4-cyanobiphenyl liquid crystal material having the formula ##STR28## wherein R is a 1 to 9 carbon alkyl or alkoxy group Constituent Two -- one or more low molecular weight negative dielectric liquid crystals of which one is a 4,4'disubstituted phenyl benzoate liquid crystal material having the formula ##STR29## wherein either R or R' is methoxy and the other of R or R' is an alkyl or alkoxy group having 1 to 7 carbons Optional Constituent Three--one or more low molecular weight negative dielectric liquid crystals of which one is a 4,4'-disubstituted phenyl benzoate liquid crystal material having the formula ##STR30## wherein R and R' are alkyl groups having 1 to 7 carbon atoms and alkoxy groups having 2 to 7 carbon atoms; and Constituent Four -- one or more chiral additives, comprising a minor amount of the composition and having the formulae ##STR31## wherein R* is an alkyl or alkoxy having 4 to 9 carbon atoms among which at least one carbon atom is asymmetrically substituted, and R is an alkyl or alkoxy group having 2 to 7 carbon atoms.

Claim 27

A rematic liquid crystal composition for use in information handling systems comprising the following liquid crystal constituents: Constituent One -- one or more positive dielectric anisotropy liquid crystals, of which at least one is a 4'-substituted-4-cyanobiphenyl liquid crystal material having the formula ##STR28## wherein R is a 1 to 9 carbon alkyl or alkoxy group Constituent Two -- one or more low molecular weight negative dielectric liquid crystals of which one is a 4,4'disubstituted phenyl benzoate liquid crystal material having the formula ##STR29## wherein either R or R' is methoxy and the other of R or R' is an alkyl or alkoxy group having 1 to 7 carbons Optional Constituent Three--one or more low molecular weight negative dielectric liquid crystals of which one is a 4,4'-disubstituted phenyl benzoate liquid crystal material having the formula ##STR30## wherein R and R' are alkyl groups having 1 to 7 carbon atoms and alkoxy groups having 2 to 7 carbon atoms; and Constituent Four -- one or more chiral additives, comprising a minor amount of the composition and having the formulae ##STR31## wherein R* is an alkyl or alkoxy having 4 to 9 carbon atoms among which at least one carbon atom is asymmetrically substituted, and R is an alkyl or alkoxy group having 2 to 7 carbon atoms.

Claim 28

The rematic liquid crystal composition as defined in claim 24 wherein said 4'-substituted-4-cyanobiphenyl comprises from about 10 percent to about 80 mole percent of the liquid crystal composition.

Claim 29

The rematic liquid crystal composition as defined in claim 24 further including up to about 25 mole percent of the total liquid crystal composition and not more than 50 mole percent of the negative dielectric anisotropy constituents of a compound selected from the group consisting of compounds of the formula ##STR32## wherein R and R' are 1 to 7 carbon alkyl groups and a and b may be both hydrogen and wherein either a or b, but not both, may be Cl.

Claim 30

The rematic liquid crystal composition as defined in claim 24 wherein the 4'-substituted-4-cyanobiphenyl is 4-cyano-4'-n-pentylbiphenyl.

Claim 31

The rematic liquid crystal composition as defined in claim 24 wherein said 4'-substituted-4-cyanobiphenyl is a mixture of about 40 mole percent 4-cyano-4'-n-heptylbiphenyl and about 60 mole percent 4-cyano-4'-n-pentyl-biphenyl.

Claim 32

The rematic liquid crystal composition as defined in claim 24 wherein one of the positive dielectric anisotropy liquid crystals is a 4'-cyanophenyl-4-alkylbenzoate.

Claim 33

The rematic liquid crystal composition of claim 24 wherein the amount of PDA constituent is from 40-80 percent, the amount of NDA constituent is 60-20 mole percent and the amount of chiral additive is 0.5-5.0 mole percent.

Claim 34

The rematic liquid crystal composition as defined in claim 30 wherein the positive dielectric anisotropy constituent includes said 4'-substituted-4-cyanobiphenyl from about 65 to 95 mole percent of said positive dielectric anisotropy constituent.

Claim 35

The rematic liquid crystal composition as defined in claim 30 containing a optional Constituent Three, said constituent being 4'-n-hexyloxyphenyl-4-n-butylbenzoate.

Claim 36

The rematic liquid crystal compostion as defined in claim 32 further containing up to about 25 mole percent of the total liquid crystal composition and not more than 50 mole percent of the NDA constituent of 4'-n-pentylphenyl-3-chloro-4-(4'-n-pentyl-benzoyloxy)benzoate.

Claim 37

The rematic liquid crystal composition as defined in claim 33, wherein the chiral additive is 4'-(S-2-methylbutoxy) phenyl-4-n-hexylbenzoate.

Claim 38

Liquid crystal electro-optical devices containing the liquid crystal composition of claim 24.

Claim 39

Liquid crystal electro-optical devices containing the nematic liquid crystal composition of claim 34.