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:
Sep. 03, 1996
Filed:
Dec. 29, 1994
Ying H So, Midland, MI (US);
Steven J Martin, Midland, MI (US);
Chieh-Chun Chau, Midland, MI (US);
Ritchie A Wessling, Midland, MI (US);
Ashish Sen, Midland, MI (US);
Katsuhiko Kato, Ikeda, JP;
Daniel B Roitman, Menlo Park, CA (US);
Willie E Rochefort, Corvallis, OR (US);
The Dow Chemical Company, Midland, MI (US);
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.