Asahi Kasei Kogyo Kabushiki Kaisha

Eiji Satoh

Tetsuo Matsushita

Shigemitsu Muraoka

Tamio Ishitobi

Atsushi Ishida

Jun Yamaguchi

A process for the preparation of poly-p-phenylene terephthalamide fibers according to the wet spinning method comprising passing an optically anisotropic solution of a poly-p-phenylene terephthalamide type polymer through a non-coagulating fluid layer and guiding the solution to a coagulating bath, characterized in that (a) filaments are taken out together with a stream of a coagulating solution from fine tube or fine hole arranged in the lower portion of the coagulating bath and the filaments are travelled through a second fine tube or fine hole arranged below said fine tube or fine hole through a space, and (b) in the fine tube or fine hole arranged in the lower portion of the coagulating bath, the stream of the coagulating solution flowing out together with the filaments is accelerated and in the second fine tube or fine hole, the speed of the stream of coagulating solution accompanying the filaments is decreased.

Process for preparation of polyparaphenylene terephthalamide fibers

There is provided a shaping composite dope composition comprising a cellulose derivative, an acrylonitrile polymer and a solvent capable of substantially dissolving these polymeric materials simultaneously therein, and exhibiting flow birefringence or optical anisotropy. A composite fiber made from the dope has a strucute such that the cellulose derivative is present in the form of a dispersed phase of fine fibers in a matrix of the acrylonitrile polymer, the crystalline orientation angle of the acrylonitrile polymer phase is 18.degree. to 63.degree. as measured by wide angle X-ray diffractiometry, and the ratio of the crystalline orientation angle of the cellulose derivative phase to the crystalline orientation angle of the acrylonitrile polymer phase satisfies a specified requirement. The composite fiber is excellent in the thermal dimensional stability and mechanical properties, such as tensile strength and tensile elongation and loop strength and loop elongation.

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Nobeoka, Japan

Eiji Satoh