Toyo Boseki Kabushiki Kaisha

Toyo Boseki Kabushiki Kaisha (Toyobo Co., Ltd.)

Hideaki Ishihara

Kazuo Kurita

Tooru Kitagawa

Yoshimitsu Sakaguchi

Kazuyuki Yabuki

Toshihiko Ohta

Takaharu Ichiryu

Fujio Okada

Mitsuhiro Sakuda

Susumu Tate

Akira Chiba

Masahiro Hayashi

Wataru Yoshikawa

Yoshiki Ono

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

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

A polyamide fiber excellent in strength, which comprises at least one of polycapramide, polyhexamethylene adipamide and polytetramethylene adipamide in an amount of not less than 60% by weight on the basis of the polyamide fiber and which is characterized by having a relative viscosity of not less than 2.3 and less than 3.5 (measured on a 96% by weight sulfuric acid solution having a polyamide concentration of 10 mg/ml at 20.degree. C.), an index of birefringence (.DELTA.n) (measured after 24 hours under the conditions of 30.degree. C. and 80% relative humidity) of not less than 55.times.10.sup.-3 and a tenacity of not less than 12.0 g/d. The method of preparing the noted polyamide fibers includes spinning of the polyamide to produce filaments, cooling the filaments, taking up the filaments to make an index of birefringence of 13.times.10.sup.-3 or less and drawing the filaments so taken up. The drawing includes transferring the filaments onto a first supply roller and then a second supply roller with the application of a pre-draft of less than 20% between the first and second supply rollers, transferring the resultant pre-drafted filaments onto a first draw roller and thereafter onto a second draw roller. Between the draw rollers a heating zone is maintained with a temperature gradient from low to high. The first draw roller is kept at a temperature of not lower than 100.degree. C. and the second draw roller is kept at a temperature of not lower than 200.degree. C. Also, super-heated steam from a jet nozzle at a temperature of not lower than 200.degree. C. is applied to the filaments transferred onto the first draw roller.

Process for preparing polyamide fibers having improved properties

Polyester fibers having both a high strength and a high modulus prepared from ethylene terephthalate polyester, and having an intrinsic viscosity of not less than 1.0 and an initial tensile modulus is not less than 130 g/d, said intrinsic viscosity being determined in a mixed solvent of p-chlorophenol and tetrachloro ethane (3:1) at 30.degree. C. Processes for producing the fibers are also disclosed.

Polyester fibers having high strength and high modulus and process for

A polyamide fiber excellent in strength, which comprises at least one of polycapramide, polyhexamethylene adipamide and polytetramethylene adipamide in an amount of not less than 60% by weight on the basis of the polyamide fiber and which is characterized by having a relative viscosity of not less than 2.3 and less than 3.5 (measured on a 96% by weight sulfuric acid solution having a polyamide concentration of 10 mg/ml at 20.degree. C.), an index of birefringence (.DELTA.n) (measured after 24 hours under the conditions of 30.degree. C. and 80% relative humidity) of not less than 55.times.10.sup.-3 and a tenacity of not less than 12.0 g/d, the index of birefringence in section satisfying the following relationship:

Polyamide fibers having improved properties, and their production

A process for the manufacture of polyamide fibers including melt spinning a polyamide having a relative viscosity of not less than 3.50 under conditions satisfying the following relationships:

Process for the manufacture of polyamide fibers

A polyamide fiber excellent in strength, which is characterized by being made of a polyamide having a relative viscosity of not less than 3.5 (measured on a 96% by weight sulfuric acid solution having a polyamide concentration of 10 mg/ml at 20.degree. C.), showing an index of birefringence (.DELTA.n) of not less than 50.times.10.sup.-3 and having the following relationship between the break strength and the break elongation:

Polyamide fibers having improved properties and their production

A polyamide fiber excellent in strength, which is characterized by having a relative viscosity of not less than 2.3 (measured on a 96% by weight sulfuric acid solution having a polyamide concentration of 10 mg/ml at 20.degree. C.), having an index of birefringence in section which satisfies the following relationship:

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Uji, Japan

Hideaki Ishihara