Asahi Kasei Kogyo Kabushiki Kaisha

Kabushikikaisha Kenwood

Shigemitsu Muraoka

Taichi Imanishi

Yoshio Sakamoto

Tetsuo Matsushita

Eiji Satoh

Tamio Ishitobi

Yuji Yabuki

Masami Hamada

Syuhei Ohta

Atsushi Ishida

Ion conductive film and precursor film thereof

An acoustic diaphragm is manufactured from a film of para-orientation aromatic polyamide through a molding process. In the molding process, the die for the molding process is heated to a predetermined temperature and then the molding press is conducted onto the film of para-orientation aromatic polyamide. The combination of the dies and film are cooled into about 80.degree. C. and then the clamping of dies is released to take the pressed film off.

Method of molding an acoustic diaphragm part of para aromatic polyamide

There is presented a poly-p-phenylene-terephthalamide film which is excellent in transparency, sufficiently oriented not only in the MD direction but also in the TD direction of the film having strength, elongation, modulus and dimensional stability in both longitudinal and lateral directions, and is also excellent in flatness. The film can be produced by forming an optically anisotropic dope comprising a poly-p-phenyleneterephthalamide having an .eta.inh of 2.5 dl/g or higher and an inorganic strong acid type solvent into a film-shaped dope on a support surface, converting the dope into an optically isotropic dope by water absorption, coagulating the dope, then washing the coagulated product and drying while restricting it shrinkage.

Poly-p-phenylene-terephthalamide film and process for producing the same

There is presented a poly-p-phenyleneterephthalamide film which is excellent in transparency, sufficiently oriented not only in the MD direction but also in the TD direction of the film, having high strength, elongation, modulus and dimensional stability in both longitudinal and lateral directions, and is also excellent in flatness. The film can be produced by forming an optically anisotropic dope comprising a poly-p-phenyleneterephthalamide having an .eta.inh of 2.5 dl/g or higher and an inorganic strong acid type solvent into a film-shaped dope on a support surface, converting the dope into an optically isotropic dope by water absorption, coagulating the dope, then washing the coagulated product and drying while restricting it shrinkage.

Transparent poly-p-phenylene-terephthalamide film

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.

Polymer dope composition, composite fibers made therefrom and process

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Nobeoka, Japan

Shigemitsu Muraoka