Method and device for the production of polyamide 6 with low extract content

• Main Authors: Schwarz, Raimund, Koch, Maurice, Baumert, Martin, Kriesche, Gerald, Deiss, Stefan
• Format: Patent
• Language: English
• Published: 20.07.2021
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

The present invention relates to a method for the production of polyamide 6 with low extract content and a device for it. Here, a melt of non-extracted polyamide 6 is cleaned from monomer and oligomers in a degasification device in vacuum, wherein the vapor being withdrawn from the degasification device by the vacuum generation device is cleaned from monomer, oligomers and optionally water at first in a direct condenser which is operated with liquid ε-caprolactam and subsequently in a pre-separator which is cooled with a coolant, before it reaches the vacuum generation device. A particularly preferable variant of the method envisages the usage of the melt of polyamide 6 with low extract content so prepared in a direct process of spinning into textile fibers and/or filaments.