Ems-chemie Ag

Hans Rudolf Luck

Ulrich Presenz

Rosmarie Hartmann

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&#xb0; C. to 270&#xb0; C., the pressure being built up while heating the reaction vessel to 255&#xb0; C. to 270&#xb0; C. and&#x2014;immediately after the mixture has reached the maximum temperature&#x2014;being reduced to atmospheric conditions while maintaining a temperature of 255&#xb0; C. to 270&#xb0; 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.

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Comat/Ems, Switzerland

Hans Rudolf Luck