Polybenzazole fibers having improved tensile strength retention

US5552221A · kind A · utility

Assignee

• THE DOW CHEMICAL COMPANY · US

Inventors

• Ying H. So · Midland, US
• Steven J. Martin · Shoreview, US
• Chieh-Chun Chau · Midland, US
• Ritchie A. Wessling · Midland, US
• Ashish Sen · Midland, US
• Katsuhiko Kato · Ebeye, US
• Daniel B. Roitman · Menlo Park, US
• Willie E. Rochefort · Corvallis, US

Key dates

• Filing date: Dec 29, 1994
• Grant date: Sep 3, 1996
• Expiry date: Dec 29, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2929
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

Described is a method for preparing a polybenzazole filament which comprises extruding a polybenzazole dope filament, drawing the filament across an air gap, coagulating and washing the filament, and drying the filament, characterized in that a solution of a compound selected from the group consisting of ferrocenes, ruthocene, iodide-, cobalt-, and copper-containing compounds, dyes, and mixtures thereof is contacted with a filament subsequent to the washing step and prior to the drying step. This method provides a means to improve the tensile strength retention of damaged polybenzazole filaments following exposure to sunlight.