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. 19, 2005
Filed:
Nov. 15, 2002
Ulrich Presenz, Trin, CH;
Rosmarie Hartmann, Domat/Ems, CH;
Hans Rudolf Luck, Comat/Ems, CH;
EMS-Chemie AG, Domat/Ems, CH;
Abstract
A method is disclosed for producing a polyamide molding compound which includes the following method steps: addition and dissolving of m-xylylene diamine and dicarboxylic acids, which include adipic acid and aromatic dicarboxylic acids, with water and additives in a dissolving chamber and production of a mixture, the sum of the aromatic dicarboxylic acids added being 2 mol-percent to 15 mol-percent (in relation to the addition of dicarboxylic acids); transfer of the mixture into a reaction vessel and polycondensation of the mixture in this reaction vessel; granulation of the polycondensate; drying of the granulate. This method is distinguished in that the polycondensation is performed at a pressure of at most 10 bar and a temperature of 255° C. to 270° C., the pressure being built up while heating the reaction vessel to 255° C. to 270° C. and—immediately after the mixture has reached the maximum temperature—being reduced to atmospheric conditions while maintaining a temperature of 255° C. to 270° C., and the polycondensation being continued at this temperature and a pressure of less than 800 millibar; and the granulate is subjected to an underwater crystallization before drying.