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:
Apr. 16, 1985
Filed:
Aug. 16, 1983
Han S Yoon, Seoul, KR;
Tae W Son, Seoul, KR;
Abstract
High oriented poly(p-phenylenetetraphthalamide) short fibers having an inherent viscosity of at least 5.0 and a dimension of 2-12 .mu.m in diameter and 1000-5000 .mu.m in length are provided. These fibers have a physical form of irregular cross-sections and needle point-like ends similar to those of natural wood pulp fibers, and crystalline properties such as a crystallinity of more then 50%, an orientation angle of less than 25.degree. and an apparent crystallite size of more that 50 .ANG. as determined from an X-ray diffractogram scan, and a cross-section with four extinction positions through 360.degree. rotation when observed under a polarizing microscope. These fibers are prepared, without spinning steps, by subjecting the molecular chains of poly(p-phenyleneterephthalamide) to mechanical parallelization during the growth of the chains in a polymerization system therefor containing a pyridine/amide-based solvent.