P-cyanophenyl 4-alkyl-4'-biphenylcarboxylate, method for preparing same and liquid crystal compositions using same
AssigneeChisso Corporation
InventorsTakashi Inukai, Hideo Sato, Shigeru Sugimori, Tetsuya Ishibe
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Abstract
Novel nematic liquid crystal compounds having a broad nematic temperature range and a positive dielectric anisotropy by themselves, that is, p-cyanophenyl 4-alkyl-4'-biphenylcarboxylates wherein the alkyl is a straight chain alkyl group having 4-8 carbon atoms or a branched alkyl group having 4-7 carbon atoms and having methyl group as branched group, and a method for preparing the same are provided. Further, novel nematic liquid crystal compositions having a broader nematic temper range i.e. a sufficiently lower nematic limit and a sufficiently higher upper nematic limit is provided by using said compounds.
Claims2
A liquid crystal composition comprising the following 4 groups of (A)-(D) in the proportions specified:
- A. 35-50% by mol, based upon the total amount of the composition, of two or three compounds selected from the group consisting of 4-alkylbenzoic acid-4'-cyanophenyl esters expressed by the general formula ##STR37## (wherein R is a straight chain alkyl group having 4-8 carbon atoms or a straight chain alkoxy group having 5-8 carbon atoms), said two or at least two of said three compounds each having R as a straight chain alkyl group,
- B. 20-30% by mol, based upon the total amount of the composition, of ##STR38## or a mixture thereof with ##STR39## C. 8-13% by mol, based upon the total amount of the composition, of one or two or more of compounds selected from the group consisting of 4-alkylbiphenylcarboxylic acid-4'-cyanobiphenyls expressed by the general formula ##STR40## . (wherein C.sub.n H.sub.2n.sub.+1 is a straight chain alkyl group having 4-8 carbon atoms or a methyl branched alkyl group having 5-7 carbon atoms, and
- D. 15-30% by mol, based upon the total amount of the composition, of one or more compounds selected from the group consisting of 4-n-butylbenzoic acid-4'-alkyl esters (wherein R is n-heptyl group, n-hexyloxy group or n-heptyloxy group) expressed by the general formula ##STR41## and 4-anisic acid-4'-n-pentylphenyl ester having a formula of ##STR42## alone or in admixture with said one or more compounds selected from the group consisting of the above 4-n-butylbenzoic acid-4'-alkyl esters.
Dependencies are inferred from the claim text.