Continuous production of low molecular weight polyamides

US5674973A · kind A · utility

Assignee

• BASF SE

Inventors

• Gunter Pipper · Bad Dürkheim, DE
• Andreas Kleinke · Kierspe, DE
• Peter Hildenbrand · Karlsruhe, DE

Key dates

• Filing date: Dec 28, 1995
• Grant date: Oct 7, 1997
• Expiry date: Dec 28, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G69/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the continuous production of polyamides from a mixture of at least one lactam and water and, if required, other monomer units and/or conventional additives and fillers under polyamide-forming conditions, where the mixture of the starting materials is heated in liquid phase in a first reaction zone until a conversion of at least 70% is reached, and undergoes adiabatic decompression and further polymerization in another reaction zone, wherein, in the first reaction zone, 0.5-7% by weight of water are employed, the temperature is increased to the range from 220.degree. to 310.degree. C., and polymerization is carried out until a conversion of at least 85% is reached and, in the second reaction zone, after the decompression further polymerization is carried out in the range from 215.degree. to 300.degree. C. without heat input.