Hitachi Chemical Company, Ltd.

Osamu Hirai

Hiroshi Nishizawa

Yoshiyuki Mukoyama

Shinji Takeda

Noriyuki Taguchi

Kazumi Kokaji

Kenji Suzuki

Osamu Watanabe

Tetsuya Aoyama

Noriji Tashiro

Production of hollow carbon fibers and hollow carbon particles includes baking and carbonization of polymer particles having a specified volume after deformation. A metal-deposited carbon fiber with metal deposited inside and/or outside the hollow carbon fiber is applicable to electron discharge devices. The thickness and crystallinity of the graphite layer can be freely controlled. Since almost no by-product is generated, separation and refining using a solvent is not required. A hollow carbon particle of desired shape can be produced at a high yield rate. The hollow carbon fiber represented by a carbon nano-tube can be controlled in such a way that a low resistance and uniform shape are provided so that there is an increase in the amount of electrons discharged from the hollow carbon fiber. Use of this hollow carbon fiber as an electron discharge source provides an excellent electron discharge device characterized by stable pixels.

Hollow carbon fiber and production method

Liquid crystals purified by treating with porous particles of a compound having one or more imide groups, or a liquid crystal composition comprising one or more liquid crystals and porous particles of a compound having one or more imide groups can provide a liquid crystal cell having a high voltage retention rate and a liquid crystal display device having high display properties.

Purification of liquid crystals and liquid crystal composition

A liquid chromatographic column packing material comprising porous styrene-divinylbenzene copolymer particles having --SO.sub.3.sup.- groups and, as counterion thereof, ions represented by the formula: .sup.+ NH.sub.n X.sub.m wherein X is --CH.sub.2 OH, --CH.sub.2 CH.sub.2 O--.sub.p H or --CR'.sub.q (CH.sub.2 OH).sub.r group; R' is hydrogen or a lower alkyl group; q and r are independently zero or an integer of 1 to 3, and q+r=3; p is an integer of 1 to 10; n is zero or an integer of 1; and m is an integer of 3 or 4, but m+n=4, is suited for separating sugars or sugaralcohols by liquid chromatography.

Liquid chromatographic column packing material

Porous styrene-divinylbenzene copolymer particles having SO.sub.3.sup.- groups and counter ions for SO.sub.3.sup.- groups, said counter ions being (a) at least one of Ca.sup.++ and Sr.sup.++ and (b) at least one of Pb.sup.++ and Ba.sup.++ and the equivalent ratio of (a)/(b) being 1/2 to 2/1, are an excellent liquid chromatographic column packing material suited for separating sugars different in kind but the same in molecular weight.

Column packing material and production thereof

A particulate polymer which has imide groups and may be in gelled state can be produced by reacting a polyisocyanate with a polycarboxylic acid having at least one acid anhydride group, and if necessary together with a polycarboxylic acid other than that mentioned above in the presence of a liquid medium containing at least one non-aqueous organic liquid, and thereby obtaining the particulate polymer having imide groups dispersed in the non-aqueous organic liquid.

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Hitachi, Japan

Osamu Hirai