Process for recovering polyurethane from polyurethane waste pastes

US5298128A · kind A · utility

Assignee

• Firma Carl Freudenberg · DE

Inventors

• Jorg Hausdorf · Fürth, DE
• Bardo Anselm · Hemsbach, DE
• Steffen Kosack · Haßloch, DE

Key dates

• Filing date: Apr 9, 1992
• Grant date: Mar 29, 1994
• Expiry date: Apr 9, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/17
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Polyurethane can be reclaimed from solvent-containing or solvent-free polyurethane wastage by adjusting the amount of solvent, preferably with methyl ethyl ketone; adding an emulsifier, preferably, acylpolyethyleneglycolester; then adding about twelve times the wastage weight of water; mixing, preferably for about one hour at room temperature to form an emulsion; and then expelling the solvent as a two-phase distillate using steam; separating solvent from the resulting two-phase distillate; filtering off polyurethane granular material left floating in the water residue, and drying the separated granular material.