Continuous preparation of nylon from aqueous salt solution in precondensation zone having baffles

US4540772A · kind A · utility

Assignee

• BASF SE

Inventors

• Gunter Pipper · Bad Dürkheim, DE
• Franz Schmidt · Mannheim, DE
• Rainer Theysohn · Bischofswerda, DE
• Siegfried Riegger · Ettenheim, DE
• Eduard Heil · Schifferstadt, DE
• Hermann Fischer · Augsburg, DE
• Richard Thoma · Battenberg, DE
• Paul Matthies · Heidelberg, DE

Key dates

• Filing date: Jun 15, 1984
• Grant date: Sep 10, 1985
• Expiry date: Jun 15, 2004

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29B7/86
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Nylons are prepared by a continuous process in which, in a precondensation zone, an aqueous solution of a salt of a dicarboxylic acid of 6 to 18 carbon atoms and a diamine of 6 to 18 carbon atoms is heated to 250.degree.-300.degree. C. under superatmospheric pressure, with simultaneous vaporization of water and formation of a prepolymer, the prepolymer and the vapor are separated, and the former is fed into a polycondensation zone and condensed under superatmospheric pressure of from 1 to 10 bar and at from 250.degree. to 300.degree. C., wherein the aqueous salt solution is condensed under superatomspheric pressure of from 1 to 10 bar in the first third of the tubular precondensation zone provided with baffles, until the degree of conversion is not less than 93%, and the prepolymer and the vapor phase are brought into intimate contact with one another in the remaining two thirds of the precondensation zone.