Method for the continuous production of thermoplastically-processable polyurethane elastomers

US8287788B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Guenter Scholz · Bohmte, DE
• Marian Mours · Bad Dürkheim, DE
• Sven Lawrenz · Mannheim, DE
• Horst Papenfuss · Bohmte, DE
• Christoph Bahr · Lembruch, DE
• Ruediger Krech · Diepholz, DE

Key dates

• Filing date: Jan 31, 2006
• Grant date: Oct 16, 2012
• Expiry date: Nov 14, 2028

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29K2105/0014
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The present invention relates to a process for the continuous production of thermoplastically processable polyurethane elastomers, by metering a polyisocyanate (A), a proportion of 1-80 equivalent%, based on the isocyanate group content of the polyisocyanate (A), of a compound (B) having an average of at 1.8-3.0 hydrogen atoms having Zerewitinoff activity, with an average molar mass of 450-5000 g/mol, and a proportion of 12-99 equivalent%, based on the isocyanate group content of the polyisocyanate (A), of a chain extender (C), into a self-cleaning twin-screw extruder whose diameter is 32-62 mm, which is operated at shear rates above 6000 s−1 and residence times of 1-20 seconds, and then bringing the mixture from the self-cleaning twin-screw extruder into a second apparatus in order to complete the reaction.