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:
Dec. 08, 2009
Filed:
Nov. 30, 2004
Anton Johannes Josef Hendriks, Lent, NL;
Jan Davis Cornelis Tiecken, Didam, NL;
Harrie Grotendorst, Duiven, NL;
René Journee, Duiven, NL;
Mirjam Ellen Oldenzeel, Westervoort, NL;
Anton Johannes Josef Hendriks, Lent, NL;
Jan Davis Cornelis Tiecken, Didam, NL;
Harrie Grotendorst, Duiven, NL;
René Journee, Duiven, NL;
Mirjam Ellen Oldenzeel, Westervoort, NL;
Teijin Aramid B.V., Arnhem, NL;
Abstract
Aramid fibrils having in the wet phase a Canadian Standard Freeness (CSF) value less than 100 ml, after drying a specific surface area (SSA) less than 7 m/g, and a weight weighted length for particles having a length >250 μm (WL 0.25) less than 1.2 mm, are described. A method of preparing the fibrils includes the steps (a) polymerizing an aromatic diamine and an aromatic dicarboxylic acid halide to an aramid polymer, in a mixture of N-methylpyrrolidone or dimethylacetamide and calcium chloride or lithium chloride to obtain a dope wherein the polymer is dissolved in the mixture and the polymer concentration is 2 to 6 wt. %, (b) converting the dope to fibrils by using a jet spin nozzle under a gas stream, and (c) coagulating the fibrils using a coagulation jet.