The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1994
Filed:
Mar. 25, 1993
Katsuyuki Murashiro, Ichiharashi, JP;
Makoto Kikuchi, Ichiharashi, JP;
Shinichi Saito, Ichiharashi, JP;
Chisso Corporation, Osaka, JP;
Abstract
An antiferroelectric liquid crystal composition comprising a first component comprising at least one compound expressed by the formula (I) and exhibiting no antiferroelectric phase, and a second component comprising at least one compound expressed by the formula (II) and exhibiting an antiferroelectric phase, the contents of the first component and the second component being respectively 1 to 40% and 60 to 99%, based upon the total weight of the two components: ##STR1## wherein in the formula (I), R.sup.1 is 1-18C linear alkyl or alkoxy; R.sup.2 is 1-18C alkyl or alkoxy; k, l, m and n are 0 or 1; (k+l) and (m+n) are 1 or 2, (k+l)+(m+n) are 2 or 3; X is --OCH.sub.2 --, --CH.sub.2 O--, --COO--, --OCO-- or single bond; 6-membered rings A, B, C and D are 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl or pyridazine-3,6-diyl, one of the side-positioned hydrogen atoms of which may be replaced by halogen atom or CN, and in the formula (II), R.sup.3 is 1-18C linear alkyl or alkoxy; R.sup.4 is 2-18C alkyl or alkoxy; p, q, t and u are 0 or 1; (p+q) and (t+u) each are 1 or 2; (p+q)+(t+u) are 2 or 3; j is 0 or 1; Z is --COO--, --OCO--, --OCH.sub.2 --, --CH.sub.2 O--or single bond; Y is --CH.sub.3 ; 6-membered rings E, F, G and H are 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl or pyridazine-3,6-diyl; * shows asymmetric carbon atom. An antiferroelectric liquid crystal composition having the threshold voltage lowered at the time of transition from the antiferroelectric phase to ferroelectric phase accompanying the electric field impression in the antiferroelectric phase is provided, and a light-switching element which has a good contrast and can effect a tristable switching is obtained using the above composition.