LIQUID CRYSTAL DISPLAY DEVICE

摘要

1455442 Liquid crystal compositions MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 14 Nov 1973 [15 Nov 1972 16 Nov 1972 17 Nov 1972 (4) 20 Nov 1972 (12)] 52845/73 Heading C4X [Also in Division G2] Additives for a nematic liquid crystal material are selected from: (a) sorbitan esters where the hydroxy groupsα, orαand #, to the ester grouping may also be esterified; (b) sorbide monoesters (c) glycerol 1- or 1,3- or 1,2,3-esters; (d) N-acy' sarcosines or the sodium salt (e) RNHCH 2 CH 2 OH; (f) p-alkylbenzenesulphonic acids and sodium salts; (g) R 2 R1 2 N+X-; (h) EtRR1 2 N+X-; (i) BzRR1 2 N+X- (Bz = benzyl); (j) BzR1 3 N+X- (Bz = p-alkylbenzoyl); (k) (RCOOCH 2 CH 2 )R1 2 N+X-; (1) (RO) 3 P; (m) (RO) 3 PO ; (n) R 2 HPO 4 . The alkyl portion R of the acyl groups RCO- in compounds (a)-(d) and the alkyl groups (R) in (e)-(l) have 10-24 carbon atoms, R1 is methyl or ethyl and X- is a monovalent anion. In formulae (m) and (n) R is an alkyl group with 4-24 carbon atoms. More than one additive may be present. The additives are weakly orienting in that a homotropic alignment may be produced at the electrodes of a display device, but not at glass surfaces thereof without prior treatment. As particularly described the nematic material consists of equal weights of p-anisylidene-p-nheptylaniline; p - ethoxybenzylidene - p - nbutylaniline; and p - n - propoxybenzylidenep-n-pentylaniline. Other single nematic compounds are referred to. In addition a strongly orienting additive such as a gallic acid cetyl ester or lecithin (dodecyltrimethylammonium bromide is also referred to) may be present. Reference has boen directed by the Comptroller to Specification 1,253,330.