Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Kooji Fujisaki

Shunichi Numata

Akio Mukoh

Toshikazu Narahara

Noriyuki Kinjo

Hisao Yokokura

Teruo Kitamura

Susumu Era

Kishiro Iwasaki

Yasuhiko Kando

Tadao Nakata

Yasuo Hanawa

Polyimides represented by general formula (I), (wherein Ar.sub.1 and Ar.sub.2 each represents an aromatic ring-containing group, Cf represents a fluorinated alkyl group directly bonded to Ar.sub.1, and m.gtoreq.1), and polyamide acids as their percursors. The polyimides have excellent humidity resistance and heat resistance, thus being useful as coating materials for semiconductor chips and insulating films for multi-layered wiring. ##STR1##

Fluorine-containing polyamide acid and polyamide

A liquid crystal display element comprising a pair of substrates, a pair of electrodes provided on the respective substrates, at least one of which is transparent and a liquid crystal layer disposed between said substrates, the liquid crystal layer comprising a nematic liquid crystal, which exhibits a positive dielectric constant anisotropy and contains an optically active substance, the liquid crystal moleccule orientation direction in the liquid crystal layer is twisted in the range of 200.degree. to 250.degree. from the one substrate surface toward the other substrate surface so as to form a helical structure therein. A polyimide orientation film is provided between the electrodes and the liquid crystal layer. The polyimide orientation film is one made of a polyimide prepared by reacting a diamine compound having a long-chain hydrocarbon group or a diamine compound having a trifluoromethyl group with a tetracarboxylic dianhydride and causes a pretilt angle of at least 3.degree. relative to the nematic liquid crystal molecules. The liquid crystal display element of the present invention is free from a scattering domain.

Liquid crystal polyimide alignment free of scattering domains

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Hitachi, Japan

Kooji Fujisaki