Achiral fluorine-containing liquid crystals

• US 5,082,587 A
• Filed: 09/23/1988
• Issued: 01/21/1992
• Est. Priority Date: 09/23/1988
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Company
• Inventors: Janulis, Eugene P.
• Primary Examiner(s): Stoll, Robert L.
• Assistant Examiner(s): KELLY, CYNTHIA HARRIS
• Application Number:
  US07/248,948
• Time in Patent Office: 1,215 Days
• Field of Search: 252/299.01, 252/299.61, 252/299.66, 252/299.63, 252/299.66, 252/299.67, 252/299.68, 252/299.62, 560/61, 560/62, 560/64, 560/65, 560/102, 560/100, 568/331, 570/129, 570/130, 544/298, 544/242, 546/286, 546/288, 546/301, 546/302, 546/342, 549/369, 549/370
• US Class Current: 252/299.01
• CPC Class Codes: C07C 255/55 containing cyano groups and esterified hydroxy groups bound to the carbon skeleton
• CPC Class Codes: C07C 327/16 having carbon atoms of thiocarboxyl groups bound to carbon atoms of six-membered aromatic rings
• CPC Class Codes: C07C 327/28 having sulfur atoms of esterified thiocarboxyl groups bound to carbon atoms of hydrocarbon radicals substituted by singly-bound oxygen atoms
• CPC Class Codes: C07C 43/225 containing halogen
• CPC Class Codes: C07C 43/23 containing hydroxy or O-metal groups
• CPC Class Codes: C07C 45/71 being hydroxy groups
• CPC Class Codes: C07C 47/575 containing ether groups, groups, groups, or groups
• CPC Class Codes: C07C 65/21 containing ether groups, groups, groups, or groups
• CPC Class Codes: C07C 69/017 Esters of hydroxy compounds having the esterified hydroxy group bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: C07C 69/75 of acids with a six-membered ring
• CPC Class Codes: C07C 69/753 of polycyclic acids
• CPC Class Codes: C07C 69/76 Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: C07C 69/82 Terephthalic acid esters
• CPC Class Codes: C07C 69/92 with etherified hydroxyl groups
• CPC Class Codes: C07D 213/80 in position 3
• CPC Class Codes: C07D 319/06 not condensed with other rings
• CPC Class Codes: C09K 19/04 characterised by the chemical structure of the liquid crystal components , e.g. by a specific unit
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 19/3068 chain containing -COO- or -OCO- groups

Abstract

Achiral fluorine-containing liquid crystal compounds are provided. The compounds comprise a fluorocarbon terminal portion and a hydrocarbon or another fluorocarbon terminal portion, the terminal portions being connected by a central core, the compounds having smectic mesophases or having latent smectic mesophases. The compounds are useful in liquid crystal display devices both along and in mixtures with other materials. Also provided is a process for preparing these compounds.

Claims

1. A chiral fluorine-containing liquid crystal compounds comprising a fluorocarbon terminal portion represented by the formula --DC_q F_2q X where X is hydrogen or fluorine, q is 1-20, and D is ##STR114## where r and r'"'"' are independently 1 to 20 and p is 0 to 4, and a hydrocarbon or another fluorocarbon terminal portion, the terminal portions being connected by a central core, the compounds having smectic mesophases or having latent smectic mesophases.

2. The compounds of claim 1 wherein said central core comprises at least two aromatic, heteroaromatic, cycloaliphatic, or substituted aromatic, heteroaromatic, or cycloaliphatic rings.

3. The compounds of claim 2 wherein rings are connected one with another by --COO--, --COS--, --HC═

N--, or --COSe--.

4. The compounds of claim 2 wherein heteroatoms within the heteroaromatic ring are N, O, or S.

5. The compounds of claim 1 wherein said compounds can be represented by the general formula I:

##STR115## where M, N, and P are each independently ##STR116## a, b, and c are independently zero or an integer of from 1 to 3 with the proviso that the sum of a+b+c be at least 2;

each A and B are non-directionally and each independently a covalent bond, ##STR117## each X, Y, and Z are independently --H, --Cl, --F, --Br, --I, --OH, --OCH₃, --CH₃, --CN, or --NO₂ ;

each l, m, and n are independently zero or an integer of 1 to 4, ##STR118## where r and r'"'"' are independently 1 to 20, and p is 0 to 4;

r is ##STR119## where R'"'"' is ##STR120## and q and q'"'"' are independently 1 to 20, and R can be straight chain or branched, and R_f is C_q F_2q -X where X is H or F, and q and q'"'"' are independently 1 to 20.

6. The compounds of claim 1 wherein said compounds exhibit birefringences in the range of 0.05-0.18.

7. The compounds of claim 1 wherein said compounds having smectic mesophases have suppressed nematic mesophases.

8. The compounds according to claim 1 wherein said compounds exhibit rise and decay times of less than 1 millisecond have been observed for an 80% change in the light intensity in smectic C Freedericksz-type liquid crystal display devices.

9. Mixtures of two or more of the compounds of claim 1, at least one of said compounds having smectic mesophases.

10. Liquid crystal mixtures comprising at least one compound according to claim 1 and at least one chiral liquid crystal compound.

11. The liquid crystal mixtures of claim 10 wherein said chiral liquid crystal compound is present in an amount sufficient to provide the mixture with ferroelectric properties.

12. The liquid crystal mixtures of claim 11 wherein said chiral liquid crystal compound is present in an amount of about 1 to 25 weight percent.

13. Liquid crystal mixtures comprising at least one compound according to claim 1 and at least one non-liquid crystal compound.

14. The liquid crystal mixtures of claim 10 wherein said non-liquid crystal compound is present in an amount sufficient to provide the mixture with ferroelectric properties.

15. A liquid crystal display device containing said compound of claim 1 wherein said compound has a smectic mesophase.

16. A liquid crystal display device containing the mixture of claim 9.

17. A liquid crystal display device containing the mixture of claim 10.

18. A liquid crystal display device containing the mixture of claim 11.