Method for producing highly viscous polyamides

US9738756B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Rüdiger Häffner · Neustadt, DE
• Rolf-Egbert Grützner · Rudolstadt, DE
• Achim Stammer · Freinsheim, DE
• Angela Ulzhöfer · Ludwigshafen, DE

Key dates

• Filing date: Apr 30, 2014
• Grant date: Aug 22, 2017
• Expiry date: Apr 30, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2377/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a method for synthesizing a polyamide, in which method an aqueous solution is sprayed onto the polyamide before and/or during a solid-state post-condensation process. The aqueous solution comprises at least a first compound, selected from the group comprising phosphoric acid, fully neutralized salts of phosphoric acid, partially neutralized salts of phosphoric acid, and mixtures thereof, and a second compound, selected from the group comprising an acid, an anhydride, a lactone, ammonia, an amine, and mixtures thereof, with the stipulation that the second compound is not phosphoric acid and is not phosphoric acid anhydride. The spraying occurs at a temperature that lies below the boiling point of water. A polyamide that can be produced by means of the method according to the invention can be used in particular to produce films, monofilaments, fibers, threads, or textile sheet materials.