Dai Nippon Toryo Kabushiki Kaisha

Dai Nippon Toryo Co., Ltd.

Dai Nippon Toryo Kaubshiki Kaisha

Toshio Jinnai

Kazuo Totani

Kazuhito Iwasaki

Masachika Yaguchi

Kenji Nakamura

Shigetaro Furuta

Mashachika Yaguchi

Mikio Shirotsuka

Goro Matusmoto

Shirotsuka, Mikio

Goro Matsumoto

Masayoshi Nichogi

Liquid crystalline p-cyanocinnamic acid p'-n-alkoxyphenyl esters, and nematic liquid crystal compositions containing the same, useful for electro-optical devices, are described.

Liquid crystal compositions containing cyanocinnamic acid esters

When a 4,4'-substituted benzylideneaniline compound having specific substituents is compounded in a nematic liquid crystal material, a liquid crystal composition having a positive dielectric anisotropy and a broad mesomorphic range extending above and below room temperature can be obtained. An electro-optical element comprising a thin layer of this liquid crystal composition filled and supported between two substrates can be used for light modulation and display.

Nematic liquid crystal compositions

A liquid crystal electro-optical element which comprises a nematic liquid crystal composition having a positive dielectric anisotropy which is composed of p-n-alkylbenzylidene-p'-cyanoaniline and an improver selected from the group consisting of p-n-alkyl cyanobenzene, p-alkylbenzylidene-p'-alkoxyaniline, and p-alkoxybenzylidene-p'-n-alkylaniline.

Liquid crystal electro optical element

Nematic liquid crystal compositions having positive dielectric anisotropy are obtained by mixing at least one of p-n-alkylphenyl-p'-cyanobenzoates represented by the formula, ##STR1## wherein R.sub.2 is n-alkyl group of 3 to 8 carbon atoms with at least one of p-cyanophenyl-p'-n-alkylbenzoates represented by the formula, ##STR2## wherein R.sub.1 is n-alkyl group of 4 to 8 carbon atoms. Said compositions exhibit nematic liquid crystal phase over a broad temperature range and therefore, are useful for the torsion effect-type display device.

By incorporating at least one of p-n-alkylcyanobenzene, p-cyanobenzylideneaniline and p-cyanophenyl p'-n-octyloxybenzoate into a Schiff base type nematic liquid crystal composition having negative dielectric anisotropy, a nematic liquid crystal composition having positive dielectric anisotropy is obtained. The nematic liquid crystal composition of the latter exhibits a liquid crystal state in a broad temperature range including room temperature and is useful for a torsion effect type electrooptical display device which can operate at low voltages.

In an electro-optical element comprising a pair of electrode plates and a layer of nematic liquid crystal material having a positive dielectric anisotropy positioned between the two plates, at least one of the electrode plates is coated on its inner face with organic high molecular materials. Molecular axes of the liquid crystal are oriented uniformly on the electrode face by rubbing the coated electrode along one direction.

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Kamakura, Japan

Toshio Jinnai