Manufacturing method of the super fines end which designates the polyamide as the base, the polyamide powder and the use of the super particulates

摘要

Process for preparing ultrafine powders based on polyamides by contacting polyamides having a relative solution viscosity &eegr;rel in the range from 1.5 to 2.0, measured in 0.5% m-cresol solution at 25° C., with an alcoholic medium in the presence of inorganic particles under the action of pressure and/or temperature to generate an at least partial solution, and then precipitating the polyamide from the at least partial solution, characterized in that a suspension of the inorganic particles suspended in the alcoholic medium is used. The resulting ultrafine polyamide powders have a specific BET surface area in the range of 5-100 m2/g; a fineness d50 of less than 70 μm; an apparent density AD in the range from 250 to 1000 g/l; and a particle content of 0.1 to 80% by weight of inorganic particles based on the total weight of the polyamide powder. They are equally suitable for coatings and for moldings and components with improved mechanical properties.