The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 1990
Filed:
Jul. 28, 1987
Yoshihiro Nishihara, Hiroshima, JP;
Yoshifumi Furutani, Hiroshima, JP;
Masaaki Toramaru, Otake, JP;
Toshiyuki Yasunaga, Otake, JP;
Mitsubishi Rayon Co., Ltd., Tokyo, JP;
Abstract
A process for producing an acrylic fiber comprising the steps of: (a) dissolving a polymer having a weight-average molecular weight of at least 5.times.10.sup.5 and containing at least 80 wt. % acrylonitrile in a solvent comprising dimethylformamide or dimethylacetamide at a polymer concentration of 5-15 wt. % to provide a spinning solution having a viscosity of 500-1,500 poises at 45.degree. C.; (b) extruding the solution into a gaseous medium to form filaments; (c) introducing the filaments into a coagulation bath comprising water and at least one of dimethylformamide and dimethylacetamide at 0.degree. C. or below; and (d) stretching the coagulated filaments to a draw ratio of at least 3 to provide an acrylic fiber having at least 90% X-ray orientation and an X-ray crystallinity parameter of up to 1 degree. The resulting acrylic fiber has high strength and high modulus.