Method for isolating polymers from solutions

US6506281B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Clemens Casper · Krefeld, DE
• Jorgen Weinschenck · Krefeld, DE
• Klemens Kohlgrüber · Lingen (Ems), DE
• Jürgen Heuser · Krefeld, DE
• Christian Kords · Krefeld, DE
• Thomas Elsner · Düsseldorf, DE

Key dates

• Filing date: Mar 2, 2001
• Grant date: Jan 14, 2003
• Expiry date: Mar 2, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S159/10
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process of evaporating a viscous polymer solution is described. The process includes: (a) providing a viscous polymer solution including at least 30 wt. % of solvents and monomers; (b) introducing the viscous polymer solution into a heated helix (5), the heated helix having a vapor exit velocity of 200 to 300 m/s, (a film flow including a two-phase mixture of polymer melt, and solvent vapors and monomer vapors being formed within the helix); (c) forwarding the film flow from helix (5) into a heated vapor separator (6); (d) expanding the two-phase mixture of polymer melt, and solvent vapors and monomer vapors of the film flow within vapor separator (6) at an absolute pressure of 10 mbar to 800 mbar, (a bottom product including a concentrated melt of the polymer is formed within the vapor separator); and (e) withdrawing the bottom product from vapor separator (6). Each of the helix (5) and vapor separator (6) have a separate heating device, and each of heating device independently provides a temperature that is above the softening point of the polymer.