Process for maintaining or improving the mechanical properties of fibers made from aromatic copolyamides in alkaline media and moldings containing such fibers

摘要

The invention relates to a process for maintaining or increasing the tensile strength of fibres of aromatic copolyamides which are built up predominantly from para-monomers and are soluble in organic aprotic and polar solvents during storage in alkaline media. The process comprises the measures: a) production of fibres from said aromatic copolyamides by dry or wet spinning processes which are customary per se, b) aftertreatment of the resulting fibres in a manner which is known per se, and c) storage of the fibres in an aqueous environment which has a pH of at least 10 for at least a period of time and at a temperature such that the tensile strength of said fibres, based on the tensile strength of the fibres employed in step c), is at least retained or increased.