Teijin Limited

Director-general of the Agency of Industrial Science and Technology

Hideharu Sasaki

Toru Sawaki

Keizo Shimada

Tsutomu Nakamura

Hiroshi Mera

Jiro Sadanobu

Akihiro Aoki

Hidemasa Honda

Yuzo Aito

Yasuhiro Yamada

Yorikazu Tamura

Takeshi Imamura

Yutaka Tabe

Tsugushi Yoshida

Yoshiaki Yoshioka

A method of manufacture of pitch-based carbon fiber by infusibilization of pitch fiber followed by carbonization, comprising doping the pitch fiber with at least 0.05 percent by weight of iodine, heating under an oxidizing atmosphere for infusibilization, and then heating under an inert atmosphere for carbonization, whereby it is carbonized or graphitized.

Method of manufacturing of pitch-base carbon fiber

A process for the preparation of high-performance grade carbon fibers, which comprises attaching a fine powder of at least one member selected from oxides and carbides of silicon, aluminum, titanium, and boron to a precursor fiber bundle of as spun pitch fibers, subjecting the fiber bundle to an infusibilization treatment, and subjecting the fiber bundle to a carbonization treatment.

Process for preparation of high-performance grade carbon fibers

A pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-sectional area and having a tensile strength of at least 300 kg/mm.sup.2. The fiber is prepared by melt-spinning an optically anisotropic pitch having an optically anisotropic phase content of at least 50% through a spinneret in which at least one central line distance in a spinning hole simultaneously satisfies the following requirements I and II,

Pitch-based carbon or graphite fiber and process for preparation thereof

The invention provides carbon fibers having mechanical properties equival to or even better than those of the polyacrylonitrile-based carbon fibers from a bituminous material, e.g. coal tar pitch, as the starting material. The starting pitch is first partially hydrogenated in tetrahydroquinoline under specific conditions followed by a heat treatment to give a pitch composition suitable for spinning which can be characterized by several parameters including the proportions of the carbons and hydrogens having different chemical shifts in the NMR analysis. The pitch composition for spinning is then subjected to spinning under specific conditions including the temperature condition for controlling the viscosity behavior of the molten pitch composition determined by use of the Andrade's equation and the pitch filament is then infusibilized in an oxidative atmosphere and carbonized in an inert atmosphere into carbon fibers having a tensile strength of at least 200 kg/mm.sup.2 and a tensile modulus of at least 10 tons/mm.sup.2.

Pitch-based carbon fibers and pitch compositions and precursor fibers

High modulus shaped articles such as fibers and films, composed of a wholly aromatic copolyamide, are provided. The wholly aromatic copolyamide is comprised of recurring units of the formulae:

Wholly aromatic halogenated polyamide fiber and film

An aromatic polyamide paper-like sheet having excellent heat- and chemical- resistances and electric insulating properties, comprises an artificial pulp ingredient comprising a number of amorphous pulp particles consisting of an aromatic polyamide material, and a fiber ingredient consisting of a number of short fibers bonded to each other with the amorphous pulp particles, the ratio in weight of the artificial pulp ingredient to the fiber ingredient being in a range of from 1:9 to 9:1 and the aromatic polyamide molecules contained at least in the amorphous pulp particles being cross-linked with a cross-linking agent.

Aromatic polyamide paper-like sheet and processes for producing the same

A wholly aromatic polyamide fiber non-woven sheet having satisfactory density, impregnating property, heat resistance, and surface evenness, comprises mutually, randomly entangled fibers consisting essentially of a wholly aromatic polyamide having 85 molar % or more of at least one type of recurring units selected from those of the formulae (I) and (II): ##STR1## The non-woven sheet is characterized in that the wholly aromatic polyamide fibers have portions thereof having a flattened cross-sectional profile; the aromatic polyamide fibers are fuse-bonded to each other at least at portions thereof intersecting each other; and the sheet includes pores connected to each other, and having a size at the peak of pore size distribution, of 13 microns or less determined by means of a mercury porosimeter, and no voids isolated from each other, and has a porosity of from 5% to 40% and an air permeability rate of from 0.1 to 10,000 sec/100 ml.

Wholly aromatic polyamide fiber non-woven sheet and processes for

A papery product consisting essentially of a fibrous web, at least part of said web being made of a wholly aromatic polyamide fiber having a readily soluble skin layer and a sparingly soluble or insoluble core layer, and pressure and heat being applied to said web. Said product is excellent in its mechanical and heat-resisting properties.

Papery product

A wholly aromatic polyamide fiber material having an excellent resistance to chemicals, comprises wholly aromatic polyamide fibers each covered with a coating of a fluorine-containing polymeric resin which coating has been derived from an aqueous emulsion of the fluorine-containing polymer resin.

Growing community of inventors

Iwakuni, Japan

Hideharu Sasaki