Production of reinforced polytetramethyleneadipamide

Abstract

A process for producing nylon-4,6 which is filled with a reinforcing agent by mixing a reinforcing agent with nylon-4,6 in the melt comprises the steps of a) polycondensing a salt of 1,4-diaminobutane and adipic acid in the presence of excess 1,4-diaminobutane and water at polyamide-forming temperatures under superatmospheric pressure to give a precondensate having a relative viscosity .ltoreq.1.60, b) polycondensing the precondensate of a) in solid phase in the presence of steam at 220.degree.-270.degree. C. to obtain a nylon-4,6 having a relative viscosity of from 2.0 to 2.6, c) incorporating a reinforcing agent in the melt into nylon-4,6 from stage b) to obtain a nylon-4,6 filled with a reinforcing agent, d) polycondensing said filled nylon-4,6 in solid phase in the presence of steam at 220.degree.-270.degree. C. to a relative viscosity of at least 3.2.

Dependencies are inferred from the claim text.