PRODUCTION OF POLYAMIDES BY HYDROLYTIC POLYMERIZATION AND SUBSEQUENT TREATMENT IN A KNEADER

摘要

The present invention provides a process for producing polyamides, which comprises
a) providing a monomer composition comprising at least one lactam or at least one aminocarbonitrile and/or oligomers of these monomers,b) reacting the monomer composition provided in step a) in a hydrolytic polymerization at elevated temperature in the presence of water to obtain a reaction product comprising polyamide, water, unconverted monomers and oligomers,c) the reaction product obtained in step b) being fed into at least one kneader (3) and subjected to a postpolymerization,d) optionally forming the reaction product obtained in step c) to obtain polyamide particles,e) optionally treating the reaction product obtained in step c) or the polyamide particles obtained in step d) with at least one extractant.

主权项

1. A process for producing a polyamide, the process comprising:
a) reacting a monomer composition by hydrolytic polymerization at elevated temperature in the presence of water to obtain a reaction product comprising a polyamide, water, unconverted monomers and oligomers; and b) postpolymerizing the reaction product a) in at least one kneader, to obtain a reaction product b), wherein: the monomer composition comprises at least one lactam, at least one aminocarbonitrile, an oligomer of at least one lactam, an oligomer of at least one aminocarbonitrile, an oligomer of at least one lactam and at least one aminocarbonitrile, or a mixture thereof; the kneader includes at least two screws; at least one reaction zone and a discharge zone are arranged in a direction of a longitudinal axes of the at least two screws; in the at least one reaction zone there are kneading elements arranged consecutively on each of the at least two screws; and, inside the kneader a head space zone is provided above the at least two screws with a head space volume ranging from 10 to 70%, based on an overall volume of the at least one reaction zone.