Toyo Boseki Kabushiki Kaisha

The Dow Chemical Company

Toyobo Co., Ltd.

Takeda Chemical Industries, Inc.

Kazuyuki Yabuki

Mitsuhiro Sakuda

Yoshikazu Tanaka

Hisato Kobayashi

Takaharu Ichiryu

Tadao Kuroki

Michael E Mills

Tooru Kitagawa

Yoshimitsu Sakaguchi

Yoshihiko Teramoto

Yasuo Sano

Hideaki Ishihara

Timothy L Faley

Shuzo Sawada

Yukinari Okuyama

Hiroshi Hirahata

Kiyosuke Kamiyama

Douglas E Turek

It is an object of the present invention to overcome the problem of fibrillation which is a drawback found in solvent-spun regenerated cellulosic fibers and to thereby provide high-quality regenerated cellulosic fibers. The regenerated cellulosic fibers are produced by the use of a spinning dope of cellulose dissolved in a solvent containing N-methylmorpholine N-oxide under the conditions that the average degree of polymerization of cellulose contained in the spinning dope is held to 400 or lower and 5% to 30% by weight of the cellulose is adjusted to a degree of polymerization of 500 or higher. Thus a pseudo-liquid-crystalline phenomenon can be allowed to occur in the stretched filaments during spinning, so that the resulting regenerated cellulosic fibers have improved resistance to fibrillation as well as improved dyeability and feeling.

Process for producing regenerated cellulosic fibers

Regenerated cellulosic fibers and process for producing the same

Light weight tire including polybenzazole fibers

There is provided a cord of twisted polybenzazole fibers, which has a tenacity of 35 g/d or higher and an elastic modulus of 800 g/d or higher. The cord has not only remarkably improved fatigue resistance but also excellent mechanical characteristics at a high level that has not been achieved so far. Therefore, it can attain the weight reduction of composite materials, particularly in the field of reinforced rubber materials, and can also make a great contribution to the energy saving.

Cord of twisted polybenzazole fibers

Crimped polybenzazole staple fibers which satisfy the following specifications at the same time: (1) 2.ltoreq.number of crimps (number/inch).ltoreq.40 (2) 2.ltoreq.crimp index (%).ltoreq.30 (3) 0.3.ltoreq.crimp index/number of crimps.ltoreq.3.0; methods for manufacturing crimped polybenzazole staple fibers; and the rotary cutter therefor. The crimped polybenzazole staple fibers of the present invention are superior in crimp property and are useful for manufacturing spun yarn and unwoven fabric. According to the method of the present invention, crimped polybenzazole staple fibers superior in spinnability can be manufactured with ease. In addition, the cutting blade of the present invention stands a long time use for manufacturing staple fibers from a continuous filaments tow of high tenacity fibers.

Process of making polybenzazole staple fibers

Process of making polybenzazole nonwoven fabric

In a process for preparing polybenzoxazole or polybenzothiazole filaments by extruding a polybenzoxazole or polybenzothiazole dope, drawing the dope filament across an air gap, and coagulating the dope filament; the number of filament breaks can be reduced by placing a stress isolation device after extruding but before coagulating the filament.

Method for preparing polybenzoxazole or polybenzothiazole fibers

Crimped polybenzazole staple fiber and manufacture thereof

This invention aims at improvement of heat-treatment technology for manufacture of large amounts of polybenzazole fibers. The fibers are heat treated using steam as the heat treatment gas in a device that provides for a rapid, cocurrent, countercurrent or both cocurrent and countercurrent flow of steam.

Steam heat-treatment method for polybenzazole fiber

Rubber composite

Polyester fibers having high tenacity and high modulus can be produced practically and economically by melt-spinning a copolyester at a take-up speed of 3,000 meters/min. or more. The copolyester comprises at least 60 mol % of ethylene terephthalate units, has a persistence length of 15 angstroms or more and does not show a liquid crystalline nature in the molten state.

Process for producing polyester fibers

Growing community of inventors

Ohtsu, Japan

Kazuyuki Yabuki