Toyo Boseki Kabushiki Kaisha

The Dow Chemical Company

Kabushikikaisha Kenwood

Soshin Lining Co., Ltd.

Takaharu Ichiryu

Tadao Kuroki

Chieh-Chun Chau

Kazuyuki Yabuki

Mitsuhiro Sakuda

Hiroki Murase

Ritchie A Wessling

Tooru Kitagawa

Jang-hi Im

Katsuya Tani

Hideaki Ishihara

Yukihiro Nomura

Junichi Hayakawa

Masaru Nakagawa

Yukinari Okuyama

Go Matsuoka

Kohei Kiriyama

Hiroshi Tachimori

Muneatsu Nakamura

Hironori Eguchi

Eiji Shinya

Yukihiro Abe

Yoshiki Ono

The present invention relates to polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics containing in themselves an organic pigment having heat resistance as high as a thermal decomposition temperature of 200&#xb0; C. or higher, and soluble in a mineral acid and having group(s) of &#x2014;N&#x2550; and/or NH&#x2014; in the molecule, such as any of perinones and/or perylenes, any of phthalocyanines, any of quinacridones, and any of dioxazines, wherein they have a strength retention of 50% or higher when exposed to light from a xenon lamp for 100 hours and having a tensile strength retention of 85% or higher after exposed to an atmosphere of a temperature of 80&#xb0; C. and a relative humidity of 80% for 700 hours. The polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics can be used for cords for reinforcing rubber, sheets and rods for reinforcing cement/concrete, composite materials, sail clothes, ropes, knife proof vests and bullet proof vests.

Polybenzazole fiber and use thereof

In a diaphragm for a loud-speaker of the present invention, an increase in tensile strength is averagely attained as a whole, and the over all diaphragm is uniformly colored without showing any lattice pattern. The diaphragm includes a woven fabric comprising yarns made from a blend of a plurality of fibers wherein at least one of the plurality of fibers is PBO (poly(p-phenylene benzobisoxazole)) fiber.

Cloth for loudspeaker diaphragm, loudspeaker diaphragm, and loudspeaker

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

High temperature resistant blended yarns exhibiting an ignition loss of 70% or less when heated in air at 850.degree. C. for 30 minutes are provided. The blended yarns can attain, without using asbestos, heat resistance at 500.degree. C. or higher temperatures, satisfactory resistance to flexing abrasion, high yields in the spinning step, excellent light-weight properties and soft touch.

High temperature resistant blended yarn

The invention is a process for the preparation of polybenzazole staple fibers which includes extruding a solution of polybenzazole polymer to form a dope filament, cutting the dope filament to a desired length, and washing and drying the cut filament. It has been discovered that the process of the invention provides a suitable means to prepare staple fibers which does not require the cutting of washed, rigid polybenzazole filaments.

Process for the preparation of polybenzazole staple fiber

Crimped polybenzazole staple fiber and manufacture thereof

Polybenzazole fibers can be rapidly dried without undue fiber damage by exposing them to two or more set point temperatures with the temperatures being selected relative to the residual moisture content of the fiber. The residence time required for the fiber at each progressively higher temperature can be reduced if the fiber is always in full contact with the set point temperature of the drying equipment.

Method for rapid drying of a polybenzazole fiber

A metal fiber having unidirectional dendritic texture which is an assembly of a group of dendrites wherein primary arms have grown at angle of within 20.degree. relative to the metal fiber axis, diameter of said fiber being not greater than 100 .mu.m. There is also disclosed a single crystalline metal fiber which is a single crystalline material throughout the entire length, diameter of said fiber being not greater than 100 .mu.m, length of said fiber being not less than 40 mm. These fibers can be produced by melt-spinning of metal.

Novel metal fiber and process for producing the same

Growing community of inventors

Ohtsu, Japan

Takaharu Ichiryu